cardanol bio fuel

7/25/2019 Cardanol Bio Fuel

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DEPT OF MECHANICAL ENGINEERINGPage 1

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CHAPTER 1

INTRODUCTION

The internal combustion engines have already become an indispensable and integral

part of our present day life style, particularly in the transportation and agricultural sectors which

collectively form not only one of the main consumers of fossil fuels but also one of the major

contributors to environmental pollution. Thus, automotive, truck and non-road engines/vehicles

constitute an important field, where the use of alternative fuels emerges as a very promising, long-

term, alternative solution in order to achieve the desired diversification from petroleum products

.The world is presently facing with the twin crises of fossil fuel depletion and environmental

degradation. The increasing industrialization and motorization of the world has led to a steep rise for

the demand of petroleum-based fuels. Petroleum-based fuels are obtained from limited reserves.

These finite reserves are highly concentrated in certain regions of the world. Therefore, those

countries not having these resources are facing energy/foreign exchange crisis, mainly due to the

import of crude petroleum. Also the world reserves of primary energy and raw materials are

obviously limited. According to an estimate the reserves will last for 218 years for coal, 41 years for

oil, and 63 years for natural gas , Hence the prices of crude oil keep rising andfluctuating on a daily

basis. So it is necessary to look for alternative fuels which can be produced from resources available

locally within the country and renewable, such as alcohol, biodiesel, vegetable oils etc. which

promise a very good relation with sustainable development, energy conservation, efficiency and

environmental preservation. The fuels of bio-origin can provide a feasible solution to this worldwide

petroleum crisis. Various bio fuel energy resources explored include biomass, biogas, primary

alcohols, vegetable oils, biodiesel etc.

The name bio-diesel was introduced in the United States during 1992 by the National

Soy Diesel Development Board (presently National Bio-diesel Board) which has pioneered the

commercialization of bio diesel in the US. Bio-fuels are fuels produced by a number of chemical /

biological processes from biological materials like plants, agricultural wastes etc, Bio fuel is a source

of renewable energy. Bio diesel can be used as a pure fuel or blended with petroleum diesel

depending on the economics and emissions without any engine modifications.


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There are many tree species which bear seeds which is rich in oil and having properties

of an excellent fuel and which can be processed as a diesel substitute. One of the most promising fuel

alternatives is the vegetable oils and their derivatives. Plenty of scientific articles and research

activities from around the world were printed and recorded. Oils from coconut, soy bean, sunflower,

safflower, peanut, linseed and palm were used depending on what country they grow abundantly. It

has been reported that in diesel engines vegetable oils can be used as fuel, straight as well as in

blends with the diesel. It is evident that there are various problems associated with vegetable oils

being used as fuel in compression ignition engines, mainly caused by their high viscosity. The high

viscosity is due to the molecular mass and chemical structure of vegetable oils, which in turn leads

the problems in pumping, combustion and atomization in the injector system of diesel engine. Due to

the high viscosity, vegetable oils normally introduce the development of gumming, the formation of

injector deposits, ring sticking as well as incompatibility with conventional lubricating oils in long-

term operations.

The use of edible oil for production of bio-fuel will create scarcity in food production.

So it is recommended to use non-edible oils in bio-fuel production. Of these some important varieties

are Jatropha, Neem, Mahua etc. And the performance of Jatropha and other oils as blends with

diesel as well their esters, have been well established and documented as Internal Combustion (IC)

Engine fuels. This paper is based on a new variety of bio-fuel extracted from Cashew Nut Shell

Liquid (CSNL) called Cardanol.

1.1 LITERATURE SURVEY

Mallikappa D.N Rana pratap Reddy and Ch.S.N.Murthy (2011) found the effects cardanol oil

and its diesel blends . For 20% blends emission levels were nominal .and suggested that there is a

potential for the use upto 20% and hence 20% saving in fuel cost

Experimental investigation of CNSL as alternative fuel, was undertaken by V. Palvannan and K.

Balagurunathan(2012).And the first trial run with a maximum of 20% CNSL-diesel blend, was successfully

conducted on single cylinder CI engine. Engine power output and smoke emissions were found to be

satisfactory.Then it was decided to proceed with further testing using CNSL as alternative fuel.

A study by A.S . Ramdhas, S.jayaraj and C . Muraleedharan demonstrate the production and

characterization Of vegetable oil as well as the experimental work carried out in various countries

in this field. In addition, the scope and challenges being faced in this area of research are

clearly described.

CHAPTER 2


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CASHEW NUT SHELL LIQUID(CNSL)

2.1 Introduction to cashew tree

Cashew is important as a tree to counterbalance deforestation. These trees are wild and

therefore once established will look after themselves. Cashew is an immigrant tree from Eastern

Brazil and now among the top three commercial crops of India [2]. The Cashew Nut Shell contains

25-34% oil which was not much used earlier. Commercial and industrial applications are being

developed in the recent decade. This research work investigates Cashew Nut Shell Liquid (CNSL) as

an alternative fuel for Internal Combustion Engine, which was not experimented earlier. CNSL can

power the engines at cashew processing industries and surrounding places and has the cost savingadvantage due to its much lesser price compared to diesel.

Cashew trees are boon to the country, in the sense that they not only yield cashew but also

can produce gasoline supplement ethanol from the fruit (cashew apple), yet another valuable product

- CNSL. India is the largest producer of Cashew in the world. In India Cashew nut cultivation

presently covers a total area of 0.70 million hectares of land, producing over 0.40 million tons of raw

cashew nuts .So the potential for cashew derived fuels to supplant the increasing energy gap is

promising. Over the past 25 years, the area under the Cashew crop has increased with an average

productivity of about 635 kg per hectare. The productivity in Kerala is 1178 kg per hectare which is

nearer to Maharashtra state, is the highest with 1300 kg per hectare .

2.2 CNSL and its extraction:-

The cashew nut shell is about 0.3 cm thick, having a soft feathery outer skin and a thin

hard inner skin. Between these skins is the honeycomb structure containing the phenolic material

known as CNSL. Inside the shell is the kernel wrapped in a thin skin known as the testa[4]. CNSL is

a reddish brown viscous liquid, having 4 major components viz. Anacardic acid, Cardanol, Cardol,

Methyl Cardol which are naturally occurring unsaturated phenols. CNSL is traditionally obtained as

a byproduct during the process of removing the cashew kernel from the nut. The processes used are

mainly hot-oil and roasting in which the CNSL oozes out from the shell .

Technical CNSL, (i.e. heat extracted) the heating process leads to decarboxylation of the

anacardic acid to form cardanol. Typically, the composition of technical CNSL is approximately

52% cardanol, 10% cardol, 30% polymeric material, with the remainder being made up of other

substances. The technical CNSL is often further processed by distillation at reduced pressure to


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remove the polymeric material. The composition of distilled technical CNSL is approximately 78%

cardanol, 8% cardol, 2% polymeric material, 1% 2-methyl cardol, 2.3% heptadecyl homologue

triene, 3.8% heptadecyl homologue diene and the remainder other homologous phenols. Cardanol is

a naturally occurring monohydroxyl phenol having a long hydrocarbon chain in the Meta position.

Fig no1.Chemical Structures of Anacardic acid, Cardanol and Cardol

Methods of extraction of CSNL from cashew nut

Fig no.8 Methods for extraction of CNSL from cashew nut shell

2.2.1 Thermal extraction

There are mainly two methods for thermal exctraction, they are Roasting method and hot oil in

bath method. in India we are using the first method

Roasting method

In East Africa, the traditional method of removing CNSL involves roasting the nut in drums

or baths. The roasting process not only removes the corrosive CNSL but also makes the shell brittle,

thereby aiding the cracking process. This method causes the loss of most of CNSL. In order to


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extract the retained CNSL, the nuts are roasted in baths at a temperature of 180 185C. Vents in the

equipment dispel the unpleasant fumes. This method recovers 85 90% of the liquid (Acland, 1977).

In India, method of extracting CNSL involves roasting the nuts in a shallow pan over open

charcoal fires and uses constant agitation to prevent the nuts from becoming scorched. This methodis extremely unpleasant as the shells burst releasing CNSL and fumes with resulting losses

(Woodroof, 1967).

According to an Italian patent, the shells are scraped in a rotary apparatus with sand and steel

wool, heated at 100300C for 1 h and then roasted at 400 700C in an inert atmosphere, when the

oil again oozes out (Gedamet al., 1986).

Hot oil bath method

By and large, this is the most common method of commercial extraction of CNSL in practice

nowadays. The technique can be different depending upon the raw material, which is either raw

cashew nut or cashew nut shell. For the first, cashew nut shell are collected in the cylinder, where

steam heating is applied at temperatures around 200-250C for 2-3 minutes. CNSL is then released

from the shells and the process is repeated. This method yields CNSL of around 7-12% by weigh.

For the latter, the raw nuts are passed through a bath of hot CNSL itself, when the outer part of the

shell bursts open and releases CNSL. This method produces CNSL around 6-12 % by weight of

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2.2.2 Screw pressing method

The raw cashew nut shells are put in the hydraulic press or screw pressing and then exert high

pressure in order to release CNSL from the shells. This method is rather straightforward and quick

among others. However, the residue from this method still retains significant proportion of CNSL

around 10-15%.

2.2.3 Solvent extraction method

This method gives off most of CNSL compared to other methods. The oil remains in the

residue is less than 1% by weight. In the preparation step, the contamination is removed by the use of

magnetic device. Cashew nut shell is then reduced to small sizes to facilitate drying and extraction.

The organic solvent is added to the cashew nut shell. CNSL is then extracted in the solution. The

solution is separated from the solid particles and brought to boil off the solvent, which is

subsequently condensed for reuse in the process. The boiling solution will be distilled further until all

solvent is separated.


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The percentage yield of CNSL varies with the extraction process. Indian native method of roasting

nuts and collecting the expelled liquid is reported to yield about 50% of total oil content. Extraction

with hot oil bath method gives about 8590% of total CNSL in India. Superheated steam treatment

and collection of condensate method improves the yield further by 2%

Higher the processing methods and refinement, higher will be the cost of CNSL which is

further augmented due to increased handling, transportation, chemicals and energy input for

processing, Due to bulk availability, low price and ease of production for experimentation in IC

engine expeller cold extracted CNSL is chosen. If the performance is proven then it will be the

cheapest renewable fuel will benefit the cashew processing countries.

Fig 2. Expeller machine

2.3 Cardanol production

According to the invention , CNSL is subjected to fractional distillation at 200 to 240C

under reduced pressure not exceeding 666 Pa in the shortest possible time, which gives a distillate

containing cardol and the residual tarry matter.

This first distillate is then subjected to a second distillation under the same identical

conditions of temperature and pressure when the anacardol distils over at a temperature of 205C to

210C and the cardol distils over at a temperature of 230C to 235C. The first step of the process is

to get the decarboxylated oil by heating the oil to a temperature of 170C to 175C under reduced

pressure of 3999-5330 Pa. The next two steps are the same as above for the production of both cardol

or cordanol and anacardol.


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2.3.1 Transesterification

Cardanol oil sample, unhydrous methyl alcohol 99% grade laboratory reagent type and

sodium hydroxide was selected as the catalyst. About 4 grams of catalyst was dissolved in 200 ml

methanol to prepare alkoxide, which is required to activate the alcohol. The solution was stirred

vigorously for 20 minutes in a covered container until the alkali was dissolved completely. Mixture

was protected from atmosphere carbon dioxide and moisture as both destroy the catalyst. The alcohol

catalyst (NaOH) mixture was then transferred to the reactor containing 700 ml moisture free crude

CNSL oil. Stirring of the mixture was continued for 90 minutes at a temperature between 60-65

degrees. The round bottom flask was connected to a refractor condenser and the mixture was heated

for approximately three hours.

2.3.2 Inference and observationThe mixture was distilling and condensing within the reactor condenser. Viscosity was

reduced to half its normal value mainly due to dilution with methanol. No glycerin, because CNSL

was extracted from honeycomb structure of the cashew nut shell.

2.4. Testing of Cardanol Bio-fuel Blend (CBF)

Vegetable oil can be directly mixed with diesel fuel and may be used for running an

engine. Much of the world uses a system known as the "B" factor to state the amount of biodiesel in

any fuel mix:-

100% biodiesel is referred to as B100, while

20% biodiesel, 80% petrodiesel is labeled B20

5% biodiesel, 95% petrodiesel is labeled B5

2.4.1 Properties of the CBF blends

Table no.1 Properties of CBF blend.


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CHAPTER 3

PERFORMANCE TEST ON DOUBLE CYLINDER CI

ENGINE

In this investigation the various performance and emission tests were conducted on four strokes

twin cylinder engine manufactured by M/s Kirloskar Company limited (as shown in Fig.). The tests

were conducted up to 25% blends, because the viscosity of above 25% blends exceeds more than 5

Cs.

Fig no.4 Engine test rig.

3.1 Engine specifications:-

Table no.2 Engine specification


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3.2 Emission Equipment:-

A DELTA 1600-L of MRU make Exhaust gas analyzer is used to find the NOx (ppm),

UBHC (ppm), and CO (%) emissions in the exhaust.

3.3 Operating And Recording Procedure:-

1. Calculated volume of 10%, 20%, 30% and 40% CNSL were taken in measuring jar and mixed

with 90%, 80%, 70%, 60% neat diesel respectively. After stirring using a magnetic stirrer for 15

minutes, blends were ready on volume basis.

2. Engine was allowed to run for 15 minutes to enable warming up of components to reach stable

condition for testing.

3. Loading was done for neat diesel in 5 steps starting from no load, 25% load, 50%load, 75% load

and full load (10Hp) condition. Once the stable running was achieved, time taken for 10cc was noted

down by a stopwatch.. Engine speed was also recorded for complete range of loading.

4. Flexible hose from the flue gas tapping was taken out and connected to the exhaust gas analyzer.

5. Five sets of readings were recorded for each fuel composition and average value was calculated

and used for calculation in order to reduce the experimental errors.

6. Readings observed for standard diesel fuel are taken as the base.

7. Subsequently four CNSL blends ranging from 10 to 25% by volume and diesel 90 to 75%

respectively, were tested one after the other by filling the blend in the biodiesel tank. The 3way valve

were opened and closed suitably to changeover from one blend to another.

8. Sufficient time was allowed to empty the previous blend in the filter, pipeline and injector lines.

Warming up time of 10 minutes for each blend is necessary to obtain accurate reading in order to

assess the correct behavior of each blend.

9. All the readings are recorded in the same way as described from steps 1 to8.. For each blend and

each loading average value of 5 measurements of each parameter is recorded in the tabular format.

10. After completing all the testing of the blends, once again the neat diesel was used to purge the

lines containing the Bio fuel so that accumulation, settling and gumming could be avoided.

11. The required characteristics curves are plotted.


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DEPT OF MECHANICAL ENGINEERING Page10

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CHAPTER 4

RESULTS AND DISCUSSIONS

The performance test on Double cylinder CI engine is conducted and various characteristic

curves are plotted . The performance of the engine was evaluated in terms of Brake Power (BP),

Brake Thermal Efficiency (BTE), brake Specific Fuel Consumption (SFC) and also the emission of

various gases like NOx, UBHC, and CO are analyzed.

4.1. Brake thermal efficiency v/s Brake power

The variation of brake thermal efficiency with brake power for different volumetric

blends is presented in below figure. In all cases, it increased with increase in brake power. This was

due to reduction in heat losses and increase in brake power with increase in load. The brake thermal

efficiency obtained for CBF blends was less than that of diesel. This lower brake thermal efficiency

obtained could be due to lower calorific value and increase in fuel consumption as compared to

diesel.

Fig no.5 Brake power V/S Brake Thermal Efficiensy


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4.2 Brake specific energy consumption v/s Brake power

Brake specific energy consumption decreases by 25-30% approximately with increases

in brake power. This reverse trend was observed due to lower calorific value with increase in bio fuel

percentage in the blends.

Fig no.6 Brake Power V/S Brake Specific Energy Consumption

4.3 NOx Emission v/s Brake power

It has been observed that NOx emissions (ppm) increases with increased proportion of blends and

also with higher EGT (This increasing trend of EGT is mainly because of generating more power and

consumptions of more fuel at higher loads). This trend mainly because of presence oxygen in bio

fuel, this leads to more oxidation at higher temperature and responsible for more Nox emissions.

Fig no.7 Brake Power V/S NOxEmissions

4.4 HC emission v/s brake power

It has been observed that HC emissions are nominal up to B20, and more at B25, thereason for this is the incomplete combustion.


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Fig no.8 Brake Power V/s HC Emissions

4.5. CO emission v/s brake power

It is observed that the carbon monoxide emissions increases with higher blends, andincreases slightly more after 20% blends. The minimum and maximum CO produced was

0.03e0.08%. At higher loads Co emissions slightly decreased. At elevated temperature, performance

of the engine improved with relatively better burning of the fuel resulting in decreased CO.

Fig 9.Brake Power V/S Co Emissions


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CHAPTER 5

CONCLUSION

Based on the results of the study the following conclusions were obtained.

The significant factor of cardanol bio fuel is its low cost, its abundance and it is a byproduct

of cashew nut industries so it helps to reduce costly petroleum imports.

The price of Cashew Nut Shell Oil is in the range of US $ 0.34 to 0.51 per litre (2011 prices)

in India depending upon the location and grade. Thus the idea of blending CNSL up to 35%

with diesel (US $ 0.9/ litre) direct fuel cost savings of 20 to 25% is possible. At present, all

the biodiesel products cost 3 to 5 times the diesel price[3],

The properties like density, viscosity, flash and fire points of cardanol bio fuel volumetric

blends under test are higher, and calorific values are lower and are in the range of 94-96%that

of diesel.

The brake specific energy consumption decreases by 30-40% approximately with increases in

brake power. This reverse trend was observed due to lower calorific value with increase in

bio fuel percentage in the blends.

The brake thermal efficiency obtained for Cardanol bio fuel volumetric blends was less than

that of diesel. This lower brake thermal efficiency obtained could be due to lower calorific

value and increase in fuel consumption as compared to diesel.

The NOx emissions (ppm) increases with increased proportion of blends and also with higher

EGT. This trend mainly because of presence oxygen in bio fuel, this leads to more oxidation

at higher temperature and responsible for more NOx emissions.

The HC emissions are nominal up to B20, and more at B25, the reason for this is theincomplete combustion.

The Carbon monoxide emissions increases with higher blends, and increases slightly more

after 20% blends. At higher loads CO emissions slightly decreased may be due to at higher

temperatures the performance of the engine improved with relatively better burning of the

fuel resulting in decreased CO.

Low sulphur content and hence environment friendly.

Personal safety is improved (flash point is higher than that of diesel).


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It is biodegradable.

It contains low aromatics compared to diesel.

The ozone (smog) forming potential of CNSL constituents are less than diesel fuel.

Generally, the ozone forming potential of the biofuel hydrocarbon emission, is 50% of diesel.

From the above study it is observed that up to 20% blends of cardanol bio fuels may be used as

diesel fuel substitute in CI Engines without any modifications.


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REFERENCES

.

[1] A.S. Ramadhas , S. Jayaraj, C. Muraleedharan,Use ofvegetable oils as I.C. engine fuels.

journal of Renewable Energy 29 (2004) 727742.

[2] Mallikappa D.N., RanaPratap Reddy, Ch.S.N. Murthy.Performance and emission

characteristics of double cylinder CI engine operated with cardanol bio fuel blends, journal of

Renewable Energy 38 (2012) 150-154

[3] V. Palvannan K. Balagurunathan.Technical Sustainability of Cashew Nut Shell Liquid as a

Renewable Fuel in Compression Ignition Engine.European Journal of Scientific Research ISSN

1450-216X Vol.76 No.4 (2012)614-627

cardanol bio fuel

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