410 optpolygen

OPTIPOLYGEN

WP2

Technical Potential for Polygeneration in the

Food Processing Industry

Contents 1 Introduction........................................................................................................... 4

1.1 Definition of Polygeneration ...................................................................4

1.2 Definition of Food Sectors ......................................................................4

2 Process Descriptions ............................................................................................. 5

3 Specific energy requirements................................................................................ 6

4 Current On-Site Energy Production in the Food and drink Industry .................... 7

5 Process Waste and By-Products............................................................................ 8

6 Potential Technologies for On-Site Energy Production........................................ 9

6.1 Combined heat and Power (CHP) ...........................................................9

6.2 CHP combined with absorption cooling (Tri-generation) .....................10

6.3 CHP using biogas from process waste as fuel .......................................10

7 Energy use in the food industry .......................................................................... 11

8 Technical potential for polygeneration in the food processing industry............. 13

8.1 Methodologies used for the estimations of the potential for polygeneration .......................................................................................14

8.2 Calculation of threshold values used for the estimations of co-, tri- and poly-generation ...............................................................................14

8.3 Results of estimated technical polygeneration potentials......................17

8.4 Implemented CHP capacity compared to the technical potential of co-generation .........................................................................................23

8.5 Result of estimated CO2 saving potential ...........................................25

9 Main results and conclusions .............................................................................. 27

APPENDIX: I Fish and meat (fresh, frozen, cooked) II Cooked food & vegetables III Oils, fats, olive oil IV Beverages, juices, brewery, wine and spirits V Flours, cereals, corn, pastry, bakery, coffee and tea VI Chocolate, sugar & confectioneries VII Dairy, milk and ice-creams

2

Abbreviations CHP Combined Heat and Power

CIP Cleaning in Place

COP Coefficient of Performance

COD Chemical Oxygen Demand

MW Megawatt

kW Kilowatt

VS Volatile Solid Substances

ORC Organic Rankine Cycle

3

1 Introduction The overall aim with WP2 of the OPTIPOLYGEN project is to investigate and perform a first estimation of the general potential for polygeneration in the food industry in the EU-15 countries of Europe. 1.1 Definition of polygeneration Polygeneration is the use of multiple primary energy inputs to create multiple energy outputs. The term primary energy includes fossil fuels, biofuels, renewable energy sources, etc. Energy output means the different forms of energy which are useful in an activity. In the case of the food industry this could mean electricity, and heat in various temperature levels i.e. steam, hot water, chilling mediums etc. Other useful products, which might come out from a polygeneration process like e.g. compost fibers will be, treated as secondary by-products of polygeneration. 1.2 Definition of food sectors In order to facilitate these estimations for the whole food industry, investigations of the general processes utilised in the food processing and the energy requirements (thermal and electrical) for these industries were undertaken. In order to make this investigation possible the food processing industry was divided into 7 main sectors covering different kinds of food products and each industry sector was investigated separately. The seven food sectors are:

I. Fish and meat (fresh, frozen, cooked) II. Cooked food & vegetables.

III. Oils, fats, olive oil IV. Beverages, juices, brewery, wine and spirits. V. Flours, cereals, corn, pastry, bakery, coffee and tea.

VI. Chocolate, sugar & confectioneries. VII. Dairy, milk and ice-creams In this report general results and findings of the whole WP2 are described and discussed. The details on the processes and in detailed results as well as estimations done for the evaluations are described in the APPENDIX I VII for each food sector respectively.

4

2 Process descriptions In general, almost all food processing requires both electric power as well as heat for some kind of thermal processing. Electric power is required for mechanical processing such as pumping, ventilating, mixing and conveying etc., but a great part is also used for cooling by mechanical compression coolers. The required thermal processing comprises both high temperatures processing such as pasteurisation, cooking and evaporation as well as low temperature processing such as freezing and cooling. In Table 1 the most common thermal processes are listed and indicated in which food sector they are predominating. The detailed descriptions of processes and products are further described and explained in the APPENDIX I VII for each food sector. Table 1: Summary of some of the most common thermal processes used in the food processing industry, indicated for each food sector

Food Sector Thermal Process

Temp I II III IV V VI VII

Cooling, chilling

4 to 8C X X X X X X

Freezing -15 to -40C X X X X Blanching 80 C X Cooking, boiling, frying

90 to 150C or 100 to 300C

X X X

Degumming 100 C X

Roasting 370 to 540C (coffee) 130 to 150 C (cacao)

X X

Pasteurisation 72C X X

Bleaching 150 C X Deodorization 180 270 C X CIP > 50C X X X Baking 300 to 400 C X Distillation, Evaporation

> 100 C X X

Proofing 40C X Defrosting 20 to 40 C X Freeze storage -18 to -40C X X X Cooled storage 4 to 8 C X X X X Air condition 10 to 20 C X

5

3 Specific energy requirements In order to be able to estimate the total potential for polygeneration, the amount and type of energy required for the food processing has to be known or qualitatively approximated. Therefore, a significant part of the work within WP2 has been to determine and identify the specific energy requirements for the most common products in each food sector. By determine the specific energy requirements i.e. thermal and electric energy required per tonne food produced or processed, the energy requirements for the whole EU-15 can be calculated from available statistical data of food produced. The specific electric power and thermal energy required for producing or processing one tonne of food product in respective food sector are listed in Table 2. The results from the collections of the data showed that even for the same food product, great variations in the specific energy requirements can be expected (see Table 2). The reason is that the energy demand of each process depends on the design, technology and also scale of the plants investigated. In some cases several products are produced in the same plant and thereby the specific energy for one product will also depend on the amount of the other products processed or produced in the plant. Therefore, to keep the number of possible variations on a reasonable level, average values were derived from these data and used for the subsequent estimations of the polygeneration potentials. The calculations and origin of the data in Table 2 are descried in detail in the APPENDIX I-VII for respective food sector.

6

Table 2: Summary of specific energy needs per tone food produced or processed in each food sector

Food Sector

Product Thermal energy /tonne product

Electricity / tonne product

MWh/ tonne food processed I Fish1 0 0.97 0 1.52 Meet1 0 - 0.80 0.60 0.97 MWh/ tonne food product II Cooked food &

vegetables 0.3 0.9 0.3 0.9

III Cotton seed 1.22 0.16 Ground nut 0.69 0.09 Rape-seed 0.64 0.09 Safflower 1.02 0.13 Sesame 0.73 0.10 Sunflower 0.71 0.11 Soyabeen 1.51 0.16 Olive oil 0.87 0.29 V Corn 0.12 0.90 Bakery 0.14 0.43 Cereal - 0.14 Coffee 0.2 - 0.87 0.5 - 1.9 VI Sugar 5.05 0.56 Chocolate and Conf. 0.26 0.41 VII Consumer milk 0.055 0.128 Cheese 0.2 0.6 1.3 - 1.2 Butter 0.14 0.2 0.98 1.9 Milk powder 0.3 0.4 2 5.7 Ice Cream 0.45 0.6 0.5 - 0.9 Cultured products 0.0552 0.1282

kWh/ hl IV Beer 53.6 13.4 Spirits 302 kWh/hl pure alcohol 2 kWh/hl pure alcohol Juice, etc 36.4 7.3

1depends on which case is considered see APENDIX I, 2estimated

4 Current on-site energy production in the food and drink industry Several factors are important the most suitable energy solution has to be chosen for a food processing plant. Not only is the nature of the processes but also the operating environment of a food factory a major factor. These local factors could be local price of fuel, energy taxes, distance to grids, possibility to sell and buy waste energy or excess electricity to the grid or neighbour industries, etc.

7

The performed investigation reveals that already several food industries have implemented combined heat and power (CHP) generation. Some of these are described in the database at the webpage of the OPTIPOLYGEN project. Commonly these CHP plants are based on natural gas combusted a in a gas turbine and the exhaust heat is used for hot water and steam production. Moreover, where the natural gas network is not available, heating needs are covered with onsite oil or solid fuel burners, and electricity is bought from the electricity grid. District heat, where available, is also used, especially in the Scandinavian countries. More details on specific energy production in each food sector are described in the Appendixs. The current installations of CHP units in the food, beverage and tobacco industry are discussed in more detail in section 8.4.

5 Process waste and by-products Many sectors of the food industry produce significant amounts of biodegradable waste or by-products that could be used for energy production. This utilisation could either be directly as a solid biomass fuel or as a raw material for biogas production. The amount of bio-waste per food sector and ton product produced or processed depends on the raw material processed and the utilised cleaning technologies at the plant. Typical values for the amounts of waste produced were estimated for each food sectors and are listed in Table 3 as either kg solid or amount of chemical oxygen demand (COD). Average values of these data was subsequent used for the estimations shown in the following sections. Table 3 : Examples on amounts of waste and by-products from respective food-industry

kg solids COD Main waste products from the process

I 100 450 kg ton carcase

40 kg / ton carcase

Residues from fish and animal carcase

II 250 kg / ton product

Waste from vegetables, fish and meet

III 1000-5000 kg/ton product

Trash-rests from oil-press

IV 23 kg /hl beer Spent grains from beer production

V 1-250 kg/ ton product

Rest products from cereal production

VI 8000 kg / tonne sugar

Diffusion waste from the sugar process

VII 80 130 mg / kg cheese

Mainly whey from cheese production, rest in water from CIP

8

6 Potential and feasible polygeneration technologies for on-site energy production

The processes of each food sector were analysed and possible co- tri- and polygeneration technologies were derived for the subsequent estimations. From this investigation three general technologies were extracted as plausible for all the food sectors and subsequently used as cases for calculating the theoretical technical potential for polygeneration in the food industry in EU-15. These chosen cases used as a comparison for all food sectors were:

1. co-generation of heat and electricity in a natural gas fired gas turbine, 2. tri-generation by using heat from the gas turbine as a source for absorption

cooling and, 3. usage of biodegradable waste streams for production of biogas which in turn is

used in the gas turbine The following sections (see section 6.1- 6.3) explain the chosen technologies and there limitations in terms of size and operation. These limitations were subsequently utilised for the estimations of potentials of the whole food industry.

6.1 Cogeneration - CHP Combined heat and power production is a standard technology in large central energy producing plants. During recent years, new smaller scale CHP technologies has been developed for use onsite, reducing electricity transmission losses and costs, and giving more reliability to the electricity supply, both onsite and in the neighbourhood. Also, environmentally harmful fuels, such as oil, have been replaced by less harmful ones, such as natural gas or even biogas. The feasibility of implementing onsite CHP, e.g. in food factories, depends on several things, but often on that a sufficient heat demand can be guaranteed from the process. Moreover, assuming that electricity can be bought from or sold to the grid with reasonable prices, the remaining question concerning the applicability of CHP is the durability of heat loads. Many food factories, even big ones, operate only in one, or at most, in two shifts which results in significant fluctuation of the loads. The same problem applies for factories using batch processing which causes short time fluctuations in the energy demand. However, strong daily fluctuation of loads does not necessarily have to be an obstacle to the application of onsite CHP. Combining heat storage of suitable size with a CHP unit makes it quite easy to cope with daily load fluctuations, even if the fluctuations are strong and the difference between minimum and maximum load high. The same principle can be applied in the production of cold i.e., storage of cold as ice baths in order to deal with the daily variations in the cooling demand. There are several CHP technologies available for onsite energy production, some of which are standard technology (gas engines, gas turbines, steam turbines), others more or less mature (Organic Rankine Cycle (ORC), Stirling engines, fuel cell technologies). In most food industries, steam is used for the heat transfer and thus

9

thermal energy at more than 100 C is needed. Because of this gas turbine technology is selected as the most feasible CHP technology in almost all the estimations performed for the different food sectors investigated in this work.

6.2 Tri-generation - CHP combined with absorption cooling Tri-generation is based on the use of absorption cycles to produce cool using the exhaust heat energy from a CHP unit. The set-up of an absorption cycle depends on the temperatures where this cycle is operating. Absorption cycles are usually based on LiBr /water or on Ammonia/water binary mixtures. Details of these processes and there function can be found elsewhere1 and is out of the scope of this report. Absorption chilling and freezing equipment is commercially available in different sizes and operational temperatures suitable for food industry applications2. Absorption coolers have typically lower coefficient of performance (COP) compared to compressor driven coolers (see Table 4 in section 8.2) requires more space and also higher investment costs. On the other hand absorption coolers need much lower maintenance and can be combined with almost any source of heat for their operation. This fact makes this technology ideal to combine with a CHP unit producing waste heat. The minimum commercial available absorption coolers are about 150 kW and their COP (Coefficient of Performance) ranges from 0.6 - 1 depending on the freezing cycle served and on the heat available. The polygeneration benefit from applying tri-generation, is that electricity consumption from the grid for freezing or chilling ceases and at the same time additional electricity is efficiently co-generated by the CHP unit. Because of this a double positive energy saving effect occurs.

6.3 Polygeneration -CHP using biogas from process waste as fuel Almost all food processing industries produces some kind of organic waste- or by- products. Instead of disposal many of these materials can be used to generate thermal energy and power at the plant by direct combustion, thermal gasification or anaerobically treated to produce biogas. Among these technologies anaerobic digestion of biodegradable waste from the food industry, is the most flexible option of utilising food industry process wastes or low value by-products. The resulting biogas, rich with methane, can be combusted in gas burners and utilised as for hot water or steam production, or it can be used to run a gas engine or turbine in a CHP applications.

1 ASHRAE handbook, absorption cooling, www.ashrae.org, 2 Colibri bv, www.colibri-bv.com, December 2005

10

7 Energy use in the food industry In order to estimate the potential for polygeneration in different food sectors, the total energy used in each food sector had to be estimated. This was mainly performed by combining the specific energy requirements defined in section 3 with best available statistical data for the production or processing of the each specific product. Typically the used data for these estimations are the amounts of food products produced in the EU-15 in combination with size and number of enterprises in each food sector. Most of the data of produced amounts of food products were extracted from the EUROSTAT database PRODCOM3, but also other sources have been used when more resent and detailed data has been available elsewhere. The different data sources and total amounts of products considered are described in detail in the APPENDIX of respective food sector. In order to calculate the total energy consumption in the food and drink industry in the OPTIPOLYGEN project a number of estimations, extrapolations and averring of data was necessary. Thus the results can only be indicative and not seen as exact figures. Currently, there is no statistic data for exactly the same industries which are covered by the OPTIPOLYGEN to compare to. However, the EUROSTAT database does contain statistic data for the energy consumption in the Food, drink and tobacco industry in each country of the EU-15. These values were thus compared with the energy consumption calculated in the OPTIPOLYGEN project and are shown in Figure 1 to Figure 3. According to the EUROSTAT, the total energy consumption for the Food, drink and tobacco industry for the EU-15 countries was 316 TWh in 2004. The calculation in the OPTIPOLYGEN project revealed a figure of 211 TWh (Figure 1) which is lower but in the same size range. Investigating the different countries, the correlation for some countries such as Denmark, Finland and Germany are quite good while e.g. Italy and the Netherlands are not so close.

3 EUROSTAT, http://epp.eurostat.ec.europa.eu

11

Figure 1: Energy consumption in food drink and tobacco compared to OPTIPOLYGEN calculations

-

50

100

150

200

250

300

350

TWh

EUROSTAT 2004 316 6 3 8 53 12 26 42 6 7 44 59 36 6

OPTIPOLYGEN 211 4 3 7 49 10 10 22 6 5 25 36 28 3

EU15 Swe Fin Den Ger Bel Neth UK Ir Aus Ita Fra Spa Por

The energy was further compared in terms of consumption of electric power (Figure 2) and energy demand in form of heat (Figure 3). The general result is that the calculation of the electricity consumption is closer and sometime slightly overestimated compare to the EURSOSTAT data. The total consumption of electricity in the food, drink and tobacco industry and the EU-15 countries is 94 TWh and according to the OPTIPOLYGEN calculations 88 TWh.

Figure 2: Consumption of electricity in the food, drink and tobacco industry compared to OPTIPOLYGEN calculations

-

10

20

30

40

50

60

70

80

90

100

TWh

elec

tric

ty

EUROSTAT 2004 94 2,52 1,55 2,34 14,97 4,08 6,54 12,36 1,67 1,54 12,70 19,57 10,64 1,69 1,90

OPTIPOLYGEN 88 1,60 1,12 3,73 18,12 4,65 4,16 7,86 3,11 2,23 11,65 15,70 11,28 1,47 1,10

EU15 Swe Fin Den Ger Bel Neth UK Ir Aus Ita Fra Spa Por Gre

While the OPTIPOLYGEN calculations of electricity consumption are close and sometimes overestimated the calculated consumption of heat is lower than the EUROSTAT data (Figure 3). This is an important fact as the calculation of the potential polygeneration potential described later on in this report is mainly limited by the amount of heat needed of each food processing plant. Thus the calculated

12

technical polygeneration potential in this report is more likely to be an underestimate than an overestimate.

Figure 3: Consumption of heat in food, drink and tobacco industry compared to OPTIPOLYGEN calculations

-

40

80

120

160

200

240

TWh

EUROSTAT 2004 222 3,1 1,4 5,6 38 8,2 19 29 4,8 5,5 31 40 26 4,3 5,6

OPTIPOLYGEN 123 2,1 1,8 3,7 31 5,4 5 14 2,7 3,0 13 20 17 1,7 1,6

EU15 Swe Fin Den Ger Bel Neth UK Ir Aus Ita Fra Spa Por Gre

Moreover, taking into account the great number of estimations necessary for being able to carry out the calculation of the energy demand within the OPTIPOLYGEN project, the correlations with the EUROSTAT database has to be seen as plausible and absolutely within the correct size range. Due to this fact the calculated values of the polygeneration potential revealed in the following sections should be within a plausible size range to.

8 Technical potential for polygeneration in the food processing industry

The technical potential for co-, tri- and poly-generation was estimated for each of the food sectors specified in section 1.2. The investigation comprises the technical potential based upon estimated energy demands of the processes. No concerns were taken to economical constrains making the implementation of polygeneration less beneficial. Economical restrictions are by far much more complex than the technical and do also vary considerably by regional and political differences which considering the resources needed not possible to take into account for in this project. Attempts were made to account for already implemented CHP and polygeneration in the food industry when calculating the potentials for new implementation. However, no statistical data was found covering this type of information from the food industry and the collection of own data would be a work far beyond the resources available for this project. The calculated potentials are thus the maximum technical potential including already implemented CHP and polygeneration in the food processing industry.

13

8.1 Methodologies used for the estimations of the technical potential for polygeneration

Due to the lack of detailed data for energy use, size and number of food processing plants in whole Europe, two basic types of methodologies were developed for the estimations. The first of the methodologies is based on the assumption that a certain production volume per employee can be estimated and thereby the number of plants (enterprises) having production capacities above a certain threshold value is used in the calculations of the total polygeneration potential. The number of employees was collected from EUROSTAT using the NACE code separation. The second methodology is based upon detailed data from at least one country where the number and production distribution between existing food processing plants is known. By using this detailed information from one country, the production distribution in other EU-15 countries is estimated. In some food sectors a hybrid methodology between the two methodologies described above had to be developed in order to get useful results. For more detailed descriptions please see APPENDIX I to VII. Based on these data, estimations of the total energy requirements (electrical and thermal) can be calculated. However, due to the fact that some of the food producing industry consist of very small units there certain technological limitation to the amount of the used that can be replaced or enhanced by polygeneration at the plants. Thus threshold values had to be determined for each food product and technology in order to get a estimations closer to the true value. The determination of these thresholds values as well as the potentials for polygeneration is explained in next section. 8.2 Calculation of threshold values used for the estimations of co-, tri- and

poly-generation Threshold estimation for co-generation: Due to the development of small turbine units (micro turbines), CHP technology has become available in smaller and smaller size class applications. Currently, the smallest commercially available micro turbine are found at about 304 to 100 kWel, which are used as the threshold values in the calculations of most of the industries. In the case of the production of sugar which is produced in very large complexes a minimum threshold of 5000 kW for the gas turbine was considered more realistic and thus used for this specific industry. Other requirement data used for the threshold calculations were a minimum peak-load hours of operation at 4000 h/year for all technologies. In addition, 50 % additional thermal load is required, due to the seasonal load variations. The ratio of thermal energy output to the electrical energy output is approximately 2.5 for micro turbines.

4 Capstone Turbine Corporation, www.capstoneturbine.com; December, 2005.

14

These values result in the minimum onsite heat load requirement of 450 MWh/year, rounded up to 500 MWh/year in the calculations. The same heat to electricity ratio (2.5) is used regardless of CHP technology or unit size. Threshold estimation for tri-generation: The smallest commercially available absorption cooler has presently 100 kW cooling capacity . This means about 125 kW thermal driving force in the deep freezing applications (COP 0.8) and about 85 kW in the refrigeration applications (around +4 C; COP 1.2). These are both higher than the thermal output of the smallest available micro turbine, which means that the minimum capacity of the absorption cooler is the technical threshold in the combination of CHP and absorption cooling. This can be used directly if the capacity of the cooling equipment, or the overall cooling load, at a site is known. In the polygeneration potential calculations it is assumed, however, that only the overall electricity load of a food factory is known and the threshold load is calculated using the following assumptions: Table 4 : Typical technical data used for the calculating cooling energy

Cooling temperature + 4 C - 30 C

Compressor cooling COP 2.5 1.2

Absorption cooling COP 1.2 0.8

Threshold estimation for biogas production (polygeneration) Two types of methodology to estimate the threshold value for the production of biogas from waste streams have been used in the different food sectors analysed. One methodology to define the threshold by assuming that the biogas reactor must produce as much biogas (methane) as is needed to feed the CHP unit. The other methodology is to define the threshold from data indicating the smallest operative biogas reactor available which was set to 5 000 tons of solid waste/year Considering the first methodology, the smallest available CHP unit sets the threshold for the biowaste utilisation. Thereby, the limiting values of a micro turbine of 30 kWel and the threshold for the biogas production can be defined as follows:

15

Table 5 : Used threshold values for the potential evaluation in the different food sectors

Sect. Food Product Co- generation

Tri- generation

Biogas production

Tonnes processed /year I Fish1 4 000 989 10 417 Meet1 1 875 1 552 35 519 Tonnes product/year III Cotton seed 1 700 n.a. Ground nut 3 000 n.a. Rape-seed 2 500 n.a. Safflower 2 500 n.a. Sesame 3 000 n.a. Sunflower 2 500 n.a. Soybean 1 100 n.a.

3 000 Solid

Biomass

17 000 Biogas

V Corn 1 640 1 640 283 843 Bakery 8 857 3 490 577 778 Cereals n.a. n.a. 19 923 Coffee 2 708 7882 n.a. VI Sugar 400 000 n.a. 6 410 Chocolate3 82 286 18 581 n.a. VII Milk 11 719 32 727 n.a. Cheese 1 250 6 000 32 581 Butter 1 531 14 619 n.a Milk powder 429 10 286 n.a. Ice Cream 1 875 3 333 n,a Cultured products 11 538 32 727 n.a. hl product / year IV Beer 22 721 27 975 217 391 Spirits 4 972

hl pure alcohol

n.a. 71 429 hl pure alcohol

Juice 15 790 n.v. 400 000 Number of employees in the factory II Cooked food &

Vegetables 17 20 96

Explanations: 1. Case 3 see APPENDIX I, 2.. freeze-dried coffee, 3.. Case 2 see APPNDIX VI, n.a. not applicable according to estimation calculations, n.v.no values available By defining biogas has an energy content of 6 kWh/Nm3 and a min energy requirement of 450 MWh/year, determined by the CHP unit, a minimum production of 75 000 Nm3 biogas is required. The next step is then to define the yield of biogas production per kg of waste material. Unfortunately, the biogas yield from different waste fractions can vary quite a lot, and depends on the anaerobic digestion process details, such as temperature, pressure, pH management, etc.

16

In this work it is therefore used an average value of 400 Nm3/ton of volatile solids (VS) or 0.35 Nm3/ton per kg COD for the calculations which in turn give threshold values of 190 ton VS/year or 215 kg COD/year respectively. The amount of solid waste or COD per kg of produced food product depends on which food product that is investigated (see also Table 3) and thereby the threshold values for biogas production for each food product. In Table 5 the threshold values used for the estimations of co- ,tri- or poly-generation (biogas production) for each food sector and food product are listed in values of produced amounts. 8.3 Results of estimated technical polygeneration potentials By using the methodologies and technologies described above the technical potentials for co- tri- and poly-generation were calculated and the results summarised in Table 6 and the figures 1 to 5. The results of the calculations are shown in total electrical energy per year, which can be generated if the existing methodologies separated by co- or tri- generation or energy production of waste streams (biogas or solid biomass waste CHP combustion) take place in the EU-15 countries, split by food sector. In the food sector III, large quantities of solid biomass residues occurs which are not suitable for biogas production but could instead be used as a solid biomass fuel in CHP unit (steam turbine). Thus for this food sector a fourth methodology is added. By summing up the calculated values for all four methodologies (co-, tri- and waste stream utilisation) the total polygeneration potentials are revealed. The main part of the total polygeneration potential is made up from co-generation (56%). The possibility for co-generation is also the basic for the other methods and technologies are more or less add-ons to this type of technology. Moreover, the results in Table 6 and Figure 5 show that the single largest technical potential for polygeneration is found in the meat industry (food sector I). About half of this potential is by co-generation and the other half from tri-generation by absorption cooling. The beer and the sugar industry do also show quite high potentials for especially co-generation. In the cereal industry a remarkable potential for utilisation of waste streams for biogas production is revealed. By instead looking at the technical potentials divided by each country in the EU-15 (Figure 6), the largest potentials for polygeneration in the food sector are found in the highly populated countries Germany, France, Spain , UK and Italy. Digging further down in detail the distribution of the technical potential for each food product per methodology (co-,tri- or waste product utilisation) are shown in Figure 7 to Figure 9. The results show that the potential for co-generation is dominated from meat and beer industry (Figure 7), the potential for tri-generation is to a large part made by the meat industry (Figure 8) and the utilisation of waste streams for biogas production by the cereal industry (Figure 9).

17

Furthermore, by further looking at Figure 5- Figure 9 the interested reader can get an idea which industry and food products has the highest potential for either co-generation, tri-generation or waste product utilisation in a specific EU-15 country. Table 6 : Technical polygeneration potential in food industry of the EU-15 Co-

generationTri-generation

Waste stream utilisation

Tot

(gas turbine)

(gas turbine + abs cooler/freezer)

Waste stream for biogas prod (gas turbine)

Waste stream as solid biomass fuel (CHP)

GWhel I Fish 744 638 207 n.a. 1 588 Meet 9 701 8 327 1 029 n.a. 19 057II Cooked food &

vegetables 974 1 635 111 n.a. 2 720

III Cotton seed 0 n.a. 0 0 0 Ground nut 7 n.a. 0 2 9 Rape-seed 620 n.a. 23 193 836 Saf & Sun

flower 354 n.a. 15 97 466

Sesame 0 n.a. 0 0 Soya been 688 n.a. 18 185 891 Olive oil 584 n.a. 0 183 766IV Beer 6 311 1 545 1 485 n.a. 9 341 Spirits 3 135 n.a. 1 064 n.a. 4 199 Juice 1 743 n.v. 41 n.a. 1 784

V Corn 2 900 0 681 n.v. 3 580 Bakery 727 1 117 0 n.v. 1 844 Cereals 0 0 9 206 n.v. 9 206 Coffee 376 95 0 n.v. 471 Tea n.a. n.a. n.a. n.v. VI Sugar 3 463 - 2 473 n.a. 5 936 Chocolate 115 47 37 n.a. 199

VII Consumers milk

1 434 514 0 n.a. 1 948

Cheese 3 047 635 11 n.a. 3 692 Butter 614 64 0 n.a. 678 Milk powder &

Cond milk 2 405 100 0 n.a. 2 505

Ice Cream 611 478 0 n.a. 1 089 Cultivated

products 230 81 0 n.a. 311

Sum EU-15 40 784 15 276 16 399 660 73 119Explanations: n.a. not applicable according to estimation calculations, n.v.no values available

18

The detailed data of all calculations and background analyses in the different food sectors are revealed in the APENDIX I-VII. It should be noticed that in some of these reports the values for tri-generation potentials also includes co-generation. However, in this summary report the values for these two technologies are reported separated.

Figure 4 : Technical polygeneration potential by food sector Total polygeneration potential in EU 15: 73,1 TWhel

-

5.000

10.000

15.000

20.000

25.000

Fish

Mea

tCoo

ked

f &

Cotton

Gro

und-

Rap

e-se

edSa

f &

sun

-Se

sam

eSo

yabe

anO

live

oil

Beer

Spir

itsJu

ice

Cor

nBa

kery

Cer

eals

Cof

fee

Tea

Suga

rCho

cola

teC

onsu

mer

sC

hees

eBu

tter

Pow

der

&Ic

eCre

amYo

ghur

t

I II III IV V VI VII

GW

hel

Solid biomass combustion

Biogas production

Tri-generation

Co-generation

Figure 5: Technical polygeneration potential by EU-15 country Total polygeneration potential in EU 15: 73,1 TWhel

-

2.000

4.000

6.000

8.000

10.000

12.000

14.000

16.000

18.000

Swe Fin Den Ger Bel Neth Lux UK Ir Aus Ita Fra Spa Por Gre

GW

hel

Solid biomass comb.

Biogas production

Trigeneration

Cogeneration

19

Figure 6: Technical potential coverage of electricity demand by polygeneration in EU-15 country

-

10

20

30

40

50

60

70

80

90

100TW

h el

ectr

icty

0%

40%

80%

120%

% c

over

age

Estimated consum. 88 1,6 1,1 3,7 18,1 4,6 4,2 0,1 7,9 3,1 2,2 11,6 15,7 11,3 1,5 1,1

Pot. Polygeneration 73 1,3 0,9 2,7 15,3 3,4 3,6 0,0 8,4 1,6 1,7 8,2 14,7 9,4 1,1 0,9

% covered by poly 83% 82% 82% 72% 84% 73% 87% 41% 106 50% 74% 70% 94% 84% 76% 79%

EU15


20

Figure 7: Detailed distribution of the technical cogeneration potential among the different food products and countries investigated

Total co-generation potential: 40.8 TWhel

Juice4%

Milk powder & Cond Milk

6%

Corn7%

Cheese 7%

Sugar8%

Spirits8%

Beer15%

Meat24%

MeatFishCooked food &vegetablesConsumer milkCheese ButterMilk powder & Cond MilkIce CreamCultured ProductsCerealsBakeryCoffeeCornBeerSpiritsJuiceCotton seedGround-nutRape-seedSaf- & Sun-flowerSesameSoyabeanVirgin olive oil and refined oilve oilSugarChokolat

0%

20%

40%

60%

80%

100%


21

Figure 8: Detailed distribution of additional tecnical tri-generation potential by absorption cooling by the different food products and countries investigated

Total pure trigeneration potential: 15.3 TWhel

Fish4%

Cheese 4%

Cooked food &vegetables

11%

Meat55%

Beer10%

Bakery7%


0%

20%

40%

60%

80%

100%


22

Figure 9: Distribution of technical biogas production potential of the different food products and countries investigated

Total biogas production potential : 16.4 TWhel

Cereals56%

Sugar15%

Spirits6%

Beer9%

Meat6%

Corn4%


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Swe Fin Den Ger Bel Neth Lux UK Ir Aus Ita Fra Spa Por Gre 8.4 Implemented CHP capacity compared to the technical potential of co-

generation According to data collected by COGEN Europe for the year 2003, there are 595 CHP units installed in the food, beverage and tobacco industry in EU-15 5. Together they have a total production capacity of 3048 MWel, when running in CHP mode. The distribution of these plants among the EU-15 countries is shown in Table 7. The countries with the currently highest implementation and utilisation of CHP within this industry are Spain, UK, Germany, France and the Netherlands. It is also 5 CHP Statistics in European Member States 2003 data, COGEN EUROPE 2005

23

noticeable that some countries such as Finland, Greece and Luxembourg are supposed to have no CHP units installed. This is probably due to incomplete data as the OPTIPOLYGEN project has identified at least one Finnish CHP unit of 4.2 MWel (see database at www.optipolygen.org).

Table 7 : Installed CHP capacity and number of installed CHP units in the food,

beverage and tobacco industry in EU-15

Installed CHP capacity

Number of installed units 2003

[Mwel] #Sweden 27 2 Finland - - Denmark 131 24 Germany 723 151 Belgium n.v. n.v.Netherlands 316 61 Lux - - UK 378 41 Irland 78 13 Austria 72 6 Italy 265 107 France 503 43 Spain 543 143 Portugal 12 5 Greece - - EU 15 3.048 596

The data collected in the COGEN statistics is collected for the Food products, beverages and tobacco industry and is thus not 100% comparable to the technical potential calculated for food and drink industry in the OPTIPOLYGEN project. However they are a good indication and thereby the total amount of produced electricity from CHP units (running in CHP mode) are used as comparison to the OPTIPOLYGEN values in Figure 10. The result reveals that in 2003, 10.76 TWhel was produced from CHP-units in the Food products, beverages and tobacco industry in EU-15. This is about of the technical potential for co-generation estimated for the food and drink industry in the OPTIPOLYGEN project.

24

Figure 10: Produced electric power by CHP units in the food, beverage and tobacco industry in EU-15 (2003) compared to technical potential for CHP in the food and

drink estimated by OPTIPOLYGEN

-

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

9,0

10,0

TWh

COGEN 2003 0,0 - 0,5 1,7 - 1,5 1,9 0,4 0,3 0,6 1,4 2,4 0,03 -

OPTIPOLYGEN 0,7 0,5 1,4 8,9 2,2 2,3 4,7 0,9 1,0 4,5 7,5 5,1 0,7 0,4

Swe Fin Den Ger Bel Neth UK Ir Aus Ita Fra Spa Por Gre

Tot (EU-15) produced by CHP in food, drink and tobacco industry 10,76 Twhel (COGEN 2003)

Tot estimated CHP potential (EU15) in food, drink industry 40,78 Twhel (OPTIPOLYGEN 2004)

8.5 Result of estimated CO2 saving potential In addition to the potential for electricity generation, the environmental impact of polygeneration can also be quantified in terms of annual CO2 savings. This is done assuming that the on site more produced electricity is produced with a higher efficiency (due to higher efficiency of combined cycles) and thereby replace electricity produced from fossil fuels in power plants and distributed on the grid. I.e. the more electricity produced and saved at the plant the more CO2 is saved. Accordingly the CO2 saving effect in the case of tri-generation is the highest. This is a result of the fact that when electricity is tri-generated a double benefit is achieved as earlier explained in section 6.2. By using the values for grid transmission losses and for CHP total cycle efficiencies, the values of CO2 savings by the different polygeneration methodologies were calculated as:

0,26 kg CO2/kWhel for co-generation; 0,436 kg CO2/kWhel for tri-generation; 0,210 kg CO2/kWhel for waste stream utilisation

By using these figures the total results for the potential CO2 savings by polygeneration in the food industry in the EU-15 amounts to 20 839 ktonnes CO2/ year. The allocation of these savings among the different polygeneration technologies methodologies is shown in Figure 6 and on the EU-15 countries in Figure 7.

25

Figure 11: Summarised technical potential of CO2-savings in the food industry by polygeneration methodologies

10.604

6.660

3.443132 Co-generation

Tri-generation

Waste stream utilisation(biogas)

Waste stream utilisation(solid combustion)

[*1000 tonnes CO2]

Figure 12: Summarised technical potential CO2-savings in the food industry by polygeneration per EU-15 country

Total potential CO2 savings by polygeneration in EU 15: 20 839 ktonnes CO2/year

-

500.000

1.000.000

1.500.000

2.000.000

2.500.000

3.000.000

3.500.000

4.000.000

4.500.000

5.000.000


kto

nn

es

CO

2/year

Solid biomass comb.

Biogas production

Trigeneration

Cogeneration

The revealed figures for saving CO2 emissions by the technical potential in the food industry are calculated without withdrawing the current installed CHP discussed in section 8.4. This due to that the data for current installed CHP also contain the tobacco industry while the estimated technical potentials in the OPTIPOLYGEN project only consider the food processing industry. However, if these values should be used, about of the technical potential from co-generation is already implemented. Applying this assumption the total actual potential should be reduced to about 18 188 ktonnes CO2/year instead.

26

9 Main results and conclusions The technical polygeneration potential for the food industry has been calculated for the EU-15 countries. The performed calculations were based on data for energy consumption, existing in the literature as well as on information collected via energy audits performed by the partners of the project. Data from EUROSTAT, PRODCOM , as well as food sector specific data bases were used as sources to gather data on the size distribution of food processing plants as well as produced amounts of food products in each EU 15 country. Despite these public available data, several assumptions and estimations have been necessary in order to get useful results. The plausibility of the data has been tested by comparing energy demands calculated in the OPTIPOLYGEN project with EUROSTAT data on the actual consumption of heat and electricity in the industry sector food, beverage and tobacco. The results revealed that the despite the insecurity in all the estimations that had to performed the OPTIPOLYGEN values for the energy demand in the food processing industry are feasible and in the correct size range. Thereby the calculated technical potentials for polygeneration based upon the calculated energy demands of each food sector should also be feasible. The calculated results reveal a total technical polygeneration potential (co- + tri-generation and full utilisation of biomass waste stream) for all EU-15 countries to amount to about 73 TWhel/year, subsequently resulting in a potential CO2 emission saving of about 20 millions tonnes CO2/ year. More than half of the technical potential for polygeneration in the food industry is identified to be co-generation. By comparing with available data of installed capacities of CHP in the food, beverage and tobacco industry it can be assumed that up to of the calculated technical potential is already installed. However due to the different bases for the data calculated in the OPTIPOLYGEN project and the available data in the literature, this comparison should only be used indicative. Though, if used as valid values for the food processing industry it would reduce the additional total technical polygeneration potential to about 63 TWhel and subsequently the additional potential CO2 emission savings by polygeneration to about 18 million tonnes CO2/year. The high potential of co-generation is followed by tri-generation and the technical potential for converting waste streams into biogas which is subsequently used in a onsite CHP application. Both these technologies revealed technical potentials of about 16 TWhel each. No data for the actual total usage of these technologies in the food industry was found in the literature, although examples of both technologies implemented can be found. The fourth technology investigated was the utilisation of solid waste used as solid biomass fuel in a CHP plant using a steam turbine cycle. This technology was however only found feasible for the food sector III and was estimated to be around 0,6 TWhel for the whole EU-15. The differences between the different food sectors in terms of applicable polygeneration technologies is further shown by that e.g. in the food sector III tri-generation is not at all technically plausible while in food sector I and II, which both

27

includes a lot of freezing and cooling, tri-generation with absorption freezing or chilling cycles are very significant. The individually totally highest technical polygeneration potential is also found in the meat processing industry (food sector I). Other industries with significant technical potentials are beer production (food sector IV) and cereal production (food sector V). In the cereal production industry, the production of biogas from biomass waste residues shows the dominating technical potential. The potential for biogas generation is otherwise limited in most of the other food sectors, mainly because of the threshold value for building a biogas plant at the food plant. In order to make biogas generation viable, significant amounts of wastes for the biogas installation are needed. Although todays food processing plants are generally getting larger and larger, there is also a trend to more efficiently use of waste- and by- products as lower value products for non-human consumption purposes in the animal by-products industry. The value of such products is typically higher than the value of the waste as a source for energy production. With respect to the distribution of the technical potential for polygeneration in the food industry among the European countries (EU-15), he potential practically follows the population distribution in the same way as the production and consumption of food does. Thereby the largest technical potentials are typically found in the order Germany, France, Spain, UK and Italy. By comparing data for the electric power produced by CHP in the food, beverage and tobacco industry with the amounts consumed, this show production that on an average cover about 12% of the demand in EU-15 (2003). By applying the total technical polygeneration potential calculated for the food industry in the OPTIPOLYGEN project this figure would be increased to about 80% (2004).

28

OPTIPOLYGEN WP2-Fish & meat industry

OPTIPOLYGEN

OPTimum Integration of POLYGENeration in the food industry

WP2 Potential for Polygeneration in the

Fish & meat Industry

ESTIA consulting & engineering S.A.

P.O. BOX 60649, GR 570 01, Thessaloniki, Macedonia-GREECE el. +30-2310-487501, 487502, fax +30-2310-489927

e-mail : [email protected], www.estiaconsulting.gr

Author: Dr Ing Athanasios Katsanevakis

ESTIA consulting & engineering S.A. 1 \\Pc09\c\Documents and Settings\Administrator\Desktop\ok wp2\APPENDIX I ESTIA-WP2-Fish and meat Industry.doc


Table of contents TABLE OF CONTENTS..................................................................................................2

1 EXECUTIVE SUMMARY ........................................................................................3

2 INTRODUCTION.....................................................................................................4 2.1 GENERAL.................................................................................................................................................... 4 2.2 TERMS AND DEFINITIONS ........................................................................................................................... 4

3 PROCESS DESCRIPTION .....................................................................................5 3.1 THE FISH INDUSTRY .................................................................................................................................... 5 3.2 THE MEAT INDUSTRY. ................................................................................................................................. 8

4 ON-SITE POWER GENERATION IN THE FISH AND MEAT PROCESSING INDUSTRY............................................................................................................11

4.1 INTRODUCTION ......................................................................................................................................... 11 4.2 CHARACTERISTICS OF ON-SITE POWER GENERATION PLANTS.................................................................... 11

5 PROCESS WASTE AND BY- PRODUCTS IN THE FISH AND MEAT PROCESSING INDUSTRY. ..................................................................................13

5.1 THE FISH INDUSTRY. ................................................................................................................................. 13 5.2 THE MEAT AND POULTRY INDUSTRY. ........................................................................................................ 13

6 POTENTIAL TECHNOLOGIES FOR ON-SITE POWER GENERATION AND POLYGENERATION IN THE FISH AND MEAT PROCESSING INDUSTRY.......14

6.1 CHP.......................................................................................................................................................... 14 6.2 TRIGENERATION ....................................................................................................................................... 14 6.3 SOLID WASTES AND BY-PRODUCTS USE. ................................................................................................... 15

7 TECHNICAL POTENTIAL OF ON SITE POWER GENERATION & EMISSION SAVINGS BY POLYGENERATION IN THE FISH AND MEAT/POULTRY INDUSTRY IN EUROPE .......................................................................................17

7.1 METHODOLOGY. ....................................................................................................................................... 17 7.2 FISH AND MEAT/POULTRY PRODUCTION IN EUROPE.................................................................................. 20 7.3 RESULTS ................................................................................................................................................... 24

8 CONCLUSIONS....................................................................................................29

9 REFERENCES......................................................................................................30



1 Executive Summary On-site power generation in conjunction with the processes involved in the food industry may form an efficient alternative and a step towards sustainability. It is however impor-tant to estimate the real potential of on-site power generation methods which are cur-rently available in the European Food industry sector. A part of this sector is the Fish and meat poultry processing industry. Polygeneration potential in the fish and meat processing industry has been calculated for the Eur-15 countries. Calculations were based on data for energy consumption, which exist in the open litera-ture and collected via energy audits performed by the authors. The data from Eurostat for fish and meat/poultry production all over Europe were also used together with esti-mations for the size of the processing plants located in every country. Results show that polygeneration potential for all Eur-15 countries for this specific industry sector reach the 25.000 GWh el /year resulting in CO2 emission savings of over 11 million tones CO2 /year. The higher potential about 19000 GWh/year- comes from combination of cogenera-tion+trigeneration using absorption freezing or chilling cycles followed by cogeneration and biogas generation using anaerobic digestion of the solid residues of the processes. The reason for this is that a significant amount of thermal energy consumed in the fish and meat-processing industry concerns freezing and chilling loads at temperatures down to 20C. These loads operate more smoothly over the day and the year creating opportunities for base load efficient use of the heat co-generated by the CHP units. Biogas generation potential is limited mainly because of the size of the food plants there is a need for significant amount of wastes for a biogas installation to be viable- and the limited generation of by-products as most of them is used as lower value prod-ucts for non-human consumption purposes in the animal by-products industry. Depend-ing on the legislation and the current industrial practice in this sector biogas potential generation can be doubled in the future i.e. the electricity, which can come from biogas, may increase by 100%.



2 Introduction

2.1 General The aim of this report is to describe the general processes in the fish and meat process-ing industry, focusing on energy usage (thermal and electrical) and the type of proc-esses using this energy, with the goal to estimate the total polygeneration potential in the fish and meat processing industry in Europe.

2.2 Terms and Definitions

2.2.1 Polygeneration. Polygeneration is the use of multiple primary energy inputs to create multiple energy outputs. The term primary energy includes fossil fuels, biofuels, renewable energy sources etc. Energy output means the different forms of energy which are useful in an activity. In the case of the Food industry this could mean electricity, and heat in various temperature levels i.e. steam, hot water, chilling mediums etc. Other useful products, which might come out from a polygeneration process like e.g. compost will be, treated as secondary by-products of polygeneration. This work aims to calculate the potential of polygeneration application in the European fish & meat processing industry and the corresponding emission savings, which may arise.

2.2.2 Fish and Meat industry. Fish and Meat industry includes all processes whose products incorporate as a main component fish or meat. For the purposes of this report fish and meat industry does not include fish or animal farming activities nor retailing of the food products. More specifi-cally fish and meat industry products are ranked under the NACE codes 15.11, 15.12, 15.13, & 15.20 and are shown in the tables A1 & A2 in the appendix.

2.2.3 Geographical coverage. This report covers fish and meat processing industry in the European Union of the 15 states forming the European Union until 2004. The methodology however is easy to be used in the rest 10 countries, which jointed EU in the summer 2004.



3 Process description

3.1 The fish industry

3.1.1 Process flow chart in the fish industry Fish industry processes can be generally represented in the following simple process chart. The raw material for the fish industry is fish or other seafood coming from open sea fish-ing or fish farming. Raw fish is either send directly to the sales or to the fish processing plants. Big fish is sometimes pre-processed and fish portions are then send to the processing plants. There raw fish is usually frozen and stored. Freezing usually takes place at around20oC and refrigeration cycles driven by compressors are mainly used. Part of this frozen fish is directly sold as frozen fish and part is being defrost and then processed. Defrosting is usually take place in water tanks at about 20oC. The defrost fish is usually processed (slicing, de-heading, de-skinning, etc) and during this processing some solid residues come out tails, heads etc-. As already mentioned this process step can take place before the initial freezing of the fish. Resulting fish is either frozen again and send to the sales or is being further processed, usually cooked and canned before send to the sales. Cooking may take place at tem-peratures varying up to 120oC while an important part of packaging or canning is the sterilisation process, which follows different heating and cooling curves up to 120oC. Part of the cooked fish is frozen and stored before sold as frozen cooked food while the rest is send to the sales. Detailed description of the processes which take place in the whole spectrum of the fish industry activities can be found in specialised reports e.g. [1, 2]. It has to be mentioned that several differences exist between plants; the main processes however remain the same. Moreover it should be mentioned that not all the processes take place in a single plant. There are plants where all the processes operate under a single roof while others where frozen raw fish is stored and only part of the described processes take place e.g. canning only.



fresh fish from open sea fishing or fish farming

sales

freezing

Defrosting/de-icing

Preprocessing (de-heading, slicing etc)

packaging -freezing -storage

cooking-canning

storage -selling

solid residues

waste water+ solids

BIO

GA

S

Fish processing industry

Figure 1. Simplified process chart of the fish industry.

3.1.2 Utilities energy use and by-products in the fish industry Utilities in the fish processing industry include mainly water and energy. The present study will focus on energy needs as these are important for calculating polygeneration potential.



Energy in the fish industry is used mainly for: -Freezing-cooling -Heating cooking- sterilising-pasteurising -Drivers and other electricity consumption. Electricity is used in all processes while heat need is limited to de-icing, canning and sterilizing/cleaning. An important part of the energy needed in the industry is used to cover the freezing- cooling loads needed for product freezing, chilling and storing in the storehouses. The energy consumed in each process varies considerably between plants depending on the equipment and the details of the process used, on the specific nature of the product and on several other parameters. It is not the purpose of this report to describe the details of the various specific processes, which can be met in the fish industry. For every process however there is some energy demand. The following table shows the ranges where these energy needs often fall. Data have been taken from several sources e.g.[1,2] and from own measurements performed in 3 fish processing plants operating in Greece, [3,4,5] Fish processing by-products consist mainly from fish bones, tails, heads and other fish parts and water. The first are the process solid residues while the waste water is treated in Waste Water Treatment Plants WWTP-.

Table 1. Energy demand and by-product ranges in the fish industry processes. In the table the potential for biogas produced via anaerobic digestion of the process solid by-products is also shown. Biogas is the main renewable energy source, which can come out from the fish processing industry. Utilisation of fish processing by-products for biogas production might be of importance for potential polygeneration schemes in the fish industry. Values used in the table come out from own data recov-ered from gasability tests [3], while the range came from oral communication with bio-gas plant manufacturers. In every case where an application is sought there is a need for analysis of the solid residues. The above-mentioned values can however be used for the planning purposes of this work.



3.2 The meat industry.

3.2.1 Process flow chart in the meat industry. A simplified process flow chart for the meat processing industry is shown in fig.2 The raw material for the meat industry is animal or poultry coming from animal farming or poultries. Living animals are first send to the slaughterhouses. There raw meat named as carcase is the output while significant amount of solid and liquid by-products are generated. These by-products were used to prepare animal food and as raw mate-rial for other industries ranging from animal food staff industry to pharmaceutical indus-try. Animal by-products use is the raw input of a whole industry sector, the animal by-products industry. During the last years however and because of the BSE Bovine Spongiform Engephalopathy-, use of animal by-products has been gradually decreased and now days several of them are treated as wastes. Nowadays the options available for these by-product wastes are incineration, anaerobic treatment to produce biogas, composting, landfilling. Incineration is used in small slaughterhouses using fossil fuels and the heat generated by the incineration process is usually released to the environ-ment. Incineration is also used in big slaughterhouses and there are incineration plants dedicated to serve slaughtering plants. Biogas generation has been reported to be problematic in some cases, successful in other cases and is being reconsidered as an option, [6]. Raw meat is, after chilling, either send to the sales or is being processed in the meat processing plants. Part of the meat can also be frozen at temperatures around 20oC and sold as frozen meat portions. Meat processing might include pre-processing i.e. portioning, slicing etc, thermal proc-essing /cooking and packaging. An important part of packaging is the sterilisation proc-ess. Cooking may take place at various temperature levels up to 150oC depending on the final product. Final cooked meat products can either be frozen and stored before send to the sales or sold directly as cooked meat products e.g. delicatessen. A significant part of the meat exiting the pre-processing stage is directly stored and sold as fresh meat portions with-out any further processing cooking etc.- Further details on the processes involved in the meat and poultry processing industry can be fount in specialised documents e.g. [2,6].

3.2.2 Utilities and energy use in the meat industry.

Utilities in the meat and poultry processing industry include mainly water and energy. The present study will focus on energy needs as these are important for calculating po-lygeneration potential. Energy in the meat and poultry industry is used mainly for: -Freezing-cooling -Heating cooking- sterilising-pasteurising -Drivers and other electricity consumption. Electricity is used in all processes while heat need is limited to canning, defrosting, ster-ilizing and cleaning. An important part of the energy needed in the industry is used to



cover the freezing/chilling/cooling loads. It has been reported that about 50% of the electricity demand is devoted to freezing /chilling needs, [6].

Living animals or poultry from animal farms or poultries

sales Slaughtering

defrosting preprocessing

packaging -freezing -storage

cooking-canning

storage -selling

solid residue

waste water+ solids

BIO

GA

S/in

cine

ratio

n

Freezing

meat processing industry

Figure 2. Simplified process chart for the meat industry.



The energy consumed in each process varies considerably depending on the equip-ment and the details of the process used, on the specific nature of the product and on several other parameters. It is not the purpose of this report to describe the details of the various specific processes which can be met in the meat and poultry industry. For every process however there is some energy demand. The following table shows the typical ranges of these energy needs.

Table 2. Typical ranges of energy demand and wastes in the meat processing industry. In the table the potential for biogas produced via anaerobic digestion of the process solid wastes and water effluent is also shown. Biogas is the main renewable energy source which can result from the meat and poultry processing industry. Because of this it is important to be incorporated into the potential polygeneration schemes. Values used in the table resulted from oral communication with biogas plant manufac-turers. In every case there is a need for analysis of the solid residues, if an application is sought. The above-mentioned values can however be used for the planning purposes of this work.



4 On-site power generation in the fish and meat processing industry

4.1 Introduction On-site power generation includes Cogeneration of Heat and Power using the now days available techniques and systems. Cogeneration of Heat and Power is the efficient use of the heat co-generated with the Power when thermal cycles are used electricity generation. Cogeneration includes steam cycles using steam turbines, open cycles using gas tur-bines and Internal Combustion Engines ICE- using various fuels. During the last dec-ades CHP technologies based on fuel cells, Stirling engines and hybrid systems have been also developed and demonstrated although they are not the standard in the indus-try. Use of sun or wind or other RES, not arising from the food processes examined to gen-erate power on site, will not be considered in this report. Efficient use of on-site power generation depends on the capability to use the co-generated heat to meet real heat demand of the site. This is a demanding task and it is easier met when co-generated heat is of high temperature level. This condition is met when a gas turbine is the CHP driver. However for many reasons including cost, opera-tional flexibility and electric efficiency ICE are favourable in certain cases. There are plants within the fish and meat processing industry, which operate on-site power generation units. It is expected that a significant number of them will be filled when database of the OPTIPOLYGEN project will be fully ready. They are typically in-stalled in large processing plants where heat needs are continuous and of considerable amount. Several of the operating CHP plants in this industry sector are based on ICEs. Fuels used for on-site power generation include natural gas & diesel oil while the major-ity of installations are gas-fired. Sometimes biogas produced on-site is also used result-ing in real polygeneration schemes. There are also cases where use of heat for cool-ing purposes is also reported trigeneration plants-. During the last years increased attention has been drawn to the capabilities arising by the development of mini and micro CHP units. These are units with a nominal electricity generating capacity of less than 1000 kW, [7]. Mini and micro CHP is usually based on turbines, ICEs, Stirling engines while research is under way for fuel cell based mi-cro CHP.

4.2 Characteristics of on-site power generation plants. Several parameters of the on-site power plants are of importance when application of such technology is under consideration. Information exists in several sources e.g. [7]. For the purposes of this work the following parameters have been used.



Table 3. Parameter ranges for on-site power units used in this report. Electric efficiency is the ratio of the electrical energy-or power- produced over the total fuel power input to the CHP unit i.e nel = Pel/Pfuel (1) Total efficiency of the CHP unit is the ratio of the summary of the electrical energy-or power- and useful thermal energy or power- produced over the total fuel power input to the CHP unit i.e. ntotal = (Pel+Ptherm)/Pfuel (2) Thermal efficiency of a CHP unit is derived from eq. (1) and (2) and is ntherm = ntotal nel (3) It is obvious that electrical efficiency depends most of the times solely on the CHP equipment characteristics while thermal efficiency depends strongly and in all cases on the way the heat generated by the CHP unit is used in the plant. From this point of view the whole plant is a part of the CHP unit and participates in the calculation of the ther-mal efficiency of the CHP unit. CHP size is usually ranged according to its electrical generation capacity. The typical applications in the fish and meat industry sector can reach several MWs of installed power capacity. Although there are now days equipment available at the mini and micro range they are hardly used in industrial applications; most of the plants where on-site power has been applied concern much bigger units at the range of MWs. This can be partially assigned to the relative size of the expected profits compared to the size of the plants and the IRR achieved by this kind of investments.



5 Process waste and by- products in the fish and meat processing industry.

5.1 The fish industry. Process waste and by-products consist mainly from solid residues and waste water. Solid residues arise mainly in the pre-processing stage where the tails, the heads and the guts of the fish are separated from the fillets. Waste water result in most of the fish processing stages and is usually polluted by fish solid residues, spillages and other con-taminants like grease from the canning process or fats and liquids from the cleaning of the plant and the machinery. Sometimes solid by-products are used to produce animal feeds or other lower value products although this trend has been reduced during the re-cent years because of the BSE. Now days an increased number of by-products are treated as solid wastes. Expected amount of solid residues arising in each process stage have been shown in table 1.

5.2 The meat and poultry industry. Process waste and by-products consist mainly from solid residues and wastewater. Solid residues arise mainly in the slaughtering stage and at a second stage during pre-processing filleting, slicing etc-. Most of the solid by-products arising in the meat processing are used to create lower value products. Wastewater comes out from most of the meat processing stages and is usually polluted by blood, spillages and other con-taminants like grease from the machinery or fats and liquids from the cleaning of the plant and the machinery. During the past decade solid by-products were used to pro-duce animal feeds or other lower value products. A whole industry sector has been developed based on the by-products arised in the slaughtering stage, the animal by-products industry ranging from animal foods, leather and fats to pharmaceuticals. This trend has been reduced during the recent years because of the BSE resulting in an in-creased number of by-products treated as solid wastes. In most cases these wastes are incinerated while other ways for healthy treatment are also in use or under consid-eration. Wastewater in most of the meat processing plants has a high COD content and is treated in WWTP. Further information on the by-products arising in the meat processing industry can be found in [2,6]. Expected amount of solid residues arising in each process stage have been shown in table 2. Data in table 2 show a big range of by-products in the slaughtering stage. This comes out from the fact that the situation on the use of the solid by-products is not presently clear. A decade ago most of the solid by-products were used to produce Bonne and Meat Meals -BMM- or other products. Thus the amount of waste was sig-nificantly reduced. After the epidemy of BSE the whole cycle of by-products use has been reconsidered and several precautions have been taken. The interested can con-sult the legislation, [8]. Current practice has not been reach equilibrium yet as it de-pends on the processing cost of the by-products according to the new regulations and to the alternative routes for by-products to be used. One of the alternative routes is their use for energy production. The high value of the amount of the solid by-products ranged in table 2 corresponds to the case that most of the slaughtering by-products would be used for energy production.



6 Potential technologies for on-site power generation and polygeneration in the fish and meat processing industry

By investigating the utilities and the by-products and effluents involved in a fish or meat processing plant the following technologies have been identified as potential partici-pants for polygeneration:

1) Cogeneration of Heat and Power CHP- 2) Trigeneration Use part or all of the heat co-generated to meet chilling/freezing

needs via absorption cycles-. 3) Use of the by-products for energy production. This can be done by incineration

or by anaerobic treatment to produce biogas. Other routes include gasification. Each technology is associated with thresholds and economical values affecting applica-bility with respect to the size and other important characteristics of the plant.

6.1 CHP As already mentioned applicability of CHP depends among other parameters on the ca-pability to use efficiently the heat cogenerated with the power. This is not a straightfor-ward task especially in cases where various temperature levels of heat are needed by the process. The optimum CHP fit to the process needs becomes more difficult when batch operation is used this being quite often in the fish and meat processing industry. For the purposes of this report the following parameters shown in table 4 have been considered to be valid for CHP to be viable in a plant. In several steps of the fish and meat processing industry significant amount of heat is needed. Heat is normally needed at temperatures ranging from 40oC up to 150oC. For simplicity CHP units generating heat at high temperatures have been considered for po-tential capacity calculations. These are turbine based CHP sets. Other important parameter affecting the applicability of CHP is the total yearly operating hours. Usually these should exceed 4000 hours/year for a CHP plant to be viable. It has been already mentioned that efficient use of the heat co generated in a CHP unit defines the applicability of CHP. If micro CHP is used then the total plant requirements should exceed 1,5 GWh /year based on the minimum yearly operating hours of the CHP unit and the minimum size of unit available in the market.

6.2 Trigeneration Trigeneration is based on the use of absorption cycles to produce cool. The set-up of an absorption cycle depends on the temperatures where this cycle is operating. Ab-sorption cycles are usually based on LiBr /water or on Ammonia/water binary mixtures. Details of these processes can be found elsewhere, e.g. [9]. At this stage it is of interest that there is available in the market absorption chilling equipment suitable for food in-dustry applications i.e. suitable to generate cool down to 40oC, e.g. [10].



The minimum size of this equipment is about 150 kW and their COP ranges from 0,6-1 depending on the freezing cycle served and on the local conditions. The important fact when trigeneration is applied efficiently is that electricity consumption virtually ceases as far as freezing or chilling concerns. Moreover additional electricity is efficiently cogen-erated by the CHP unit. Because of this a double positive effect exists: Not only grid electricity consumption produced with low efficiency (40-50%) stops, but also electricity generated with efficiencies up to 85% is produced. In contrast with a typical CHP only efficient electricity is generated and sent to the grid.

6.3 Solid wastes and by-products use. Solid wastes and by-products can be used to generate thermal energy and power. It has been reported that the LCV of carcass solid wastes is about 5000kJ/kg while it is reported that can reach 10-15000 KJ/kg, [6]. Moreover solid wastes can be anaerobic ally treated to produce biogas. Gasification of solid wastes has also been reported, [6]. All these technologies have positive impacts and drawbacks and are at the moment un-der consideration within R&D programs or via demonstration applications. More infor-mation can be found in [6]. Burning of the solid wastes generate heat which can be used to generate steam which can be used in the plants and/or for power generation. High water content of the solid wastes up to 70%- require a significant amount of heat for drying before combustion. Emissions from combustion and their dioxin and heavy metal content is also under con-sideration. The size of viable combustion units is also an important factor limiting appli-cations in large size plants. High pressure steam boilers need supervision, this being a cost parameter which makes small applications unviable. Anaerobic digestion of the solid by-products seems to be a promising way of treating these wastes. Water content of the wastes is needed for the anaerobic treatment. Based on the above characteristics the energy use of the by-products in terms of their capacity to produce biogas will be examined. Biogas generated can be used for driving CHP units or generating steam and hot water. The resulting waste output of the process can be land filled as its organic content has been reduced and has been sterilised. However not all the solid by-products are suit-able for biogas generation. In several cases it has been reported that they should be mixed with manure from farms to produce suitable for biogas generation solids mixture, [6]. Gasification is a technology much less mature for industrial applications. Very few ap-plications have been reported, [6]. Because of this, gasification of the solid wastes of the fish and meat industry will not be further examined here.



Table 4. CHP parameters used in the present report for calculation



7 Technical Potential of on site power generation & emis-sion savings by polygeneration in the fish and meat/poultry industry in Europe

7.1 Methodology.

7.1.1 General The goal of this report is to determine within accuracy needed for strategic planning the technical potential of polygeneration CHP, trigeneration, RES- in the meat and fish processing industry within the wider frame of the European food industry. Studies for the other food sectors are undertaken by the other partners of the OPTIPOLYGEN pro-ject. The results of the calculations will be the total electrical energy per year, which can be generated if fully use of the existing methodologies for cogeneration, trigeneration and polygeneration take place in the European food industry split by country. This part of the work is focused in the fish and meat food products sector i.e. the indus-trial plants whose products fall within NACE 15.11, 15.12, 15.13, 15.20 codes. The countries where the calculations are focused include the 15 member states of the EU until summer 2004. On top of the total potential for electricity generation, the environmental impact of poly-generation potential will be quantified in terms of annual CO2 savings.

7.1.2 Model development. To achieve the goal i.e. to estimate the polygeneration potential several assumptions should be made and data should be used. Then by performing suitable calculations the goal can be achieved. The whole set of assumptions; data and calculations are the parts of the calculation model. These parts are described below.

7.1.3 Assumptions The assumptions, which were used, include:

1. Electricity generation potential in the case of cogeneration or tri-generation application depends on the amount of useful heat, which can be absorbed in the process served by the CHP unit. This means that dumping or spoiling the heat co-generated is not accepted and electricity can be co-generated only as a by-product when useful heat is demanded.

ESTIA consulting & engineering S.A. 17

2. It has been assumed that as far as the total yearly operating hours of the CHP or trigeneration unit exceed 4000 hours per

\\Pc09\c\Documents and Settings\Administrator\Desktop\ok wp2\APPENDIX I ESTIA-WP2-Fish and meat Industry.doc


year application of these methodologies is possible and finan-cially attractive.

3. Financial factors have not been examined. It is known that appli-cability of cogeneration or trigeneration or polygeneration de-pends strongly on the cost of the fuels, the electricity, the equip-ment etc.

4. It has been assumed that as far as equipment of suitable size ex-ist in the market and yearly oper