the proposal for cellulose

8/8/2019 The Proposal for Cellulose

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The Ethanol Cellulosic ProcessMaking the process of ethanol from cellulosic more economically feasible

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We want to improve the process of ethanol from cellulosic materials by making it more

economically feasible.

By

Howard Kameka 0702520

Luther-King Ferguson 0600500

Troy Nephew 0503668

Research Methodology, Semester 2

Professor-Gerald Scale

A major project submitted in partial fulfillment of the requirements for the

award of Bachelor of Chemical Engineering Degree

Of

The Faculty of Engineering and Computing, University of technology,

Jamaica

April 24, 2010.

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Table of Contents

Abstract-------------------------------------------------Page 3

Introduction--------------------------------------------4 - 7

Literature Review-------------------------------------8 - 19

Methodology------------------------------------------20 - 26

References---------------------------------------------27 - 28

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Abstract

The use of ethanol as an energy source is becoming increasingly abundant. The worlds

fossil fuel sources are depleting and of such ethanol is best alternative to replace it. Ethanol

is cleaner, more air friendly and can be obtained from organic materials or cellulosic

materials. This research aims to figure out the most economical method for producing

ethanol. This research will apply the three basic steps in ethanol production which are: 1)

Breaking down cellulosic materials either by the use of acid or enzymes, to obtain a

solution of fermentable sugars. 2) The fermentation of these sugars to obtain ethanol, and 3)

Using distillation to separate and purify our ethanol yield. Raw material source included

corn and wood chips and both were tested by acid and enzymes using the Chemical

Engineering Laboratory on the University of Technology over a three week period. A

comparative analysis was made between the two which revealed that using wood-chips as

the raw material and concentrated acid as the catalyst a higher yield of fermentable sugars

and by extension ethanol is produced over a shorter period of time.

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Introduction

Problem Introduction

An investigation of ethanol achieved from corn and wood chips as raw material as

well as using concentrated acid as opposed to enzymes as the catalyst for breakdown of raw

materials.

Background to Problem

In todays world the cost of petroleum as the main source of energy is increasing

rapidly, furthermore their industrial use have and is continuing to cause severe effects on

human health and the environment. From this the need for a more environmentally friendly

and more affordable source of energy arises.

According to P.C Badger in the article entitled Ethanol from Cellulose: A general

Review Ethanol-from-cellulose (EFC) holds great potential due to the widespread

availability, abundance, and relatively low cost of cellulosic materials. However, although

several EFC processes are technically feasible, cost-effective processes have been difficult

to achieve and only recently have cost-effective EFC technologies begun to emerge.

Additionally, according to Professor Lee Lynd in the article Making ethanol from wood

chips despite cellulosic ethanols potential, cellulosic ethanol is expensive to make today

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because it requires more costly equipment and more processing steps than does making

ethanol from corn grain.

(Jacobson, 2009) points out that the use of biofuels, particularly ethanol, has expanded in

the last few years, although in South America biofuels have been popular and successful for

decades. This more recent and rapid expansion of biofuel use in transport across North

America and elsewhere is based on the notion that by replacing fossil fuels with biofuels we

may somehow ameliorate global warming and air pollution. After all, the growing plants

absorb carbon dioxide from the atmosphere; they are then converted into biofuels, which

are burned in modified vehicle internal combustion engines, which releases the carbon

dioxide into the atmosphere again, where it is used by the next generation of biofuel crop

plants to grow and so on.

Research Problem Statement

Cheaper and more affordable ethanol can be produced. The raw materials used are a factor

as well as production time. The use of equipments, the cost for operating these equipments

on a large scale must be determined.

Purpose of study

To identify a more cost effective and efficient process of converting cellulose to ethanol.

This is to better combat the need for ethanol on the world market; making its usage more

affordable for users of this product. This research will be geared towards increasing the

yield of ethanol from cellulose and simultaneously lowering the cost of production by

improving the current methods of production or by developing an alternative method.

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Aims and Objectives

To determine the percentage yield of fermentable sugars

To determine to the time taken to achieve this yield

To determine the quality of ethanol produced with this time

To determine the overall cost of production

Research Questions

1. What is the availability of cellulose in Jamaica and the world compared to fossil fuels?

2. How high is the energy storage capacity of cellulose?

3. What is the maximum yield of ethanol that can be obtained from a specific mass of

cellulose?

4. How economical is the present production of ethanol from cellulose?

5. What are the negative and positive effects of the use of ethanol on the environment?

Hypotheses

The ethanol produced from wood chips is of a higher yield than corn.

Using concentrated acids as the catalyst this improves yield.

Significance of the Study

This project is very important because cellulose is a widely available commodity and thus

the production of ethanol from cellulose will bring about a cheaper source of ethanol. Also

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a greater use of ethanol will be much better for the environment and human health than

other regular energy fuels. The ministry of energy in Jamaica along with PETROJAM will

find this research very interesting and having tremendous potential, since the need for

cheaper energy fuels have been Jamaicas cry for a very long time and since we are blessed

with a significant proportion of vegetation, our dependence on foreign fuels will surely

decrease, furthermore significant economic benefits will be achieved.

Definition of key terms

Environmentally Friendly: guidelines and policies considered to inflict minimal or

no harm on the environment.

Efficient: Performing or functioning in the best possible manner with the least waste

of time and effort; having and using requisite knowledge, skill, and industry;

competent; capable, producing something with little waste of effort.

Economical: Avoiding waste of resources.

Cost Effective: producing good results for the amount of money spent

Fermentation: The anaerobic conversion of sugar to carbon dioxide and alcohol by

yeast. Any of a group of chemical reactions induced by living or nonliving ferments

that split complex organic compounds into relatively simple substances.

Distillation: The process of heating a liquid until it boils, capturing and cooling

the resultant hot vapors, and collecting the condensed vapors.

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Literature Review

Introduction

This research is geared towards investigating the cost of producing ethanol from

cellulosic materials as well as identifying the factors that contributes to the cost of

production and its differences compared to other sources of ethanol production. In this

research information is gathered from various sources that introduces various methods and

technology in the production of ethanol from cellulose. This investigation is also to provide

to provide information on the negative and positive effects of ethanol in comparison to

conventional fossil fuel to fight air and water pollution. It contains approximately 30%

oxygen and in that-adding oxygen to fuel results in more complete fuel combustion, hence

reducing harmful emissions. Ethanol also as a non-toxic displaces the use of toxic fossil

fuel components such as benzene and carcinogen. Corn derived ethanol was first used to

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power early cars such as Henry Fords Model-T, and when the first diesel engine was

developed by Rudolf Diesel in Germany, it was powered by peanut oil.

Subtopic 1.0: What is the availability of cellulose in the world compared to fossil fuels?

Organic Matter buried under the earths crust for hundreds of years, are succumbed

to extreme heat and pressure. Physical and chemical changes occur over time, resulting in

the formation of fossil fuel, oil and natural gas. (Shepard, 2003) explains that once these

deposits are extracted, they cannot be replaced; hence these are referred to as non-

renewable energy sources. (Shepard, 2003) goes on to say that the industrial revolution of

the 18th

and 19th

century ignited the need for the consumption of fossil fuel and natural gas

to present day as need for energy an energy source directly resulting in a depletion of the

earths fossil fuel. Bio-fuels are not new; in fact (Scott, 2003) argues that they preceded

petroleum-based fuels in the late 1800s. Corn derived ethanol was first used to power

early cars such as Henry Fords Model-T, and when the first diesel engine was developed

by Rudolf Diesel in Germany, it was powered by peanut oil.

Subtopic 1.1: Worldwide Consumption of Fuel

Cellulose is found in paper, wood and fibrous material (Badge, 2002) indicates that

the worlds forests comprise 80% of the worlds biomass. Biomass refers to plant and

animal matter, cellulose falls within this category giving bio-fuel. This form of fuel as an

energy source is becoming increasingly needed in our present day society. (Riddell, 2004)

indicate a time span of 40 years left (2050) for the current supply of the earths fossil fuel to

run out to completion. It becomes evident there is a scarcity of the fuel, and with this

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scarcity comes an incredibly high priced commodity and many developing countries around

the world find it harder to purchase. Cheaper forms of alternative source of fuel are in

demand and one of these is the fuel from cellulose.

With increase in globalization the consumption of fuel on the world market also

increases. (Shepard, 2003) reveal that between the years 1975-2000 oil consumption on a

world basis rose from 2300 million tons in 1975 to 3900 million tons in 2000. He also

revealed European countries where the largest consumers while Middle East countries

where the leading suppliers in the world. In a more recent study however the Energy

Information Administration (EIA) reports that in the year 2006 Saudi Arabia, where the

leading producers of fuel producing over 358 million tons of the total produced by the

world. The United States of America led with 587 million tons or 24.8% of the total fuel

consumed by the world. Converting cellulose to fuel though it seems to be a vital solution

to the problem of fuel shortage and scarcity, this task however can prove to be somewhat of

a difficult task. The structural composition of cellulose creates a barrier in converting it to

its fuel source directly, instead many by stages has to be under taken causing loss of fuel in

the procedure. (Wiley, 2008) gives an alternative route from breaking down cellulose to its

individual sugar particles then fermenting it. He suggests combining cellulose directly with

furans (organic compounds) to give one product, then reacting with hydrogen to give

another product of furan oil (biofuel).

Subtopic 1.2: Utilizing Biofuels as an alternate energy source

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With Wileys suggestion many flaws are found as sourcing and storing the hydrogen

as well as the furan is another problem. Biofuels are not much better than fossil fuels in

terms of the impact on atmospheric pollution levels and effects on climate change, argues

(Jacobson, 2009). This is especially true when making claims about the sustainability of

biofuels in comparison with hydrogen fuel cells and battery-driven electric vehicles charged

up using solar, wind, tidal or other truly renewable energy sources.

To quote from his web page, the main goal of Jacobsons research is to

Understand physical, chemical, and dynamical processes in the atmosphere better in

order to address atmospheric problems, such as climate change and urban air

pollution, with improved scientific insight and more accurate predictive tools. He also

evaluates the atmospheric effects of proposed solutions to climate change and air

pollution, examines resource availability of renewable energies, and studies optimal

methods of combining renewable.

In order to accomplish these important goals Jacobson has developed and applied various

models to simulate gas, aerosol, cloud, radiative, and land/ocean-surface processes that

could give scientists and engineers a much more overarching perspective on the climate

than other simpler models.

Jacobson points out that the use of biofuels, particularly ethanol, has expanded in

the last few years, although in South America biofuels have been popular and successful for

decades. This more recent and rapid expansion of biofuel use in transport across North

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America and elsewhere is based on the notion that by replacing fossil fuels with biofuels we

may somehow ameliorate global warming and air pollution. After all, the growing plants

absorb carbon dioxide from the atmosphere; they are then converted into biofuels, which

are burned in modified vehicle internal combustion engines, which releases the carbon

dioxide into the atmosphere again, where it is used by the next generation of biofuel crop

plants to grow and so on.

This claim is still being hotly debated, especially given the impact on agriculture

and the environment of turning over vast tracts of land to biofuel crops rather than growing

food. However, Jacobson believes that, the real comparison should be between biofuels

and other emerging technologies. He reports that corn-E85 (85% ethanol/15% gasoline)

and cellulosic-E85 both degrade air quality and climate by up to two orders of magnitude

more than electric vehicles ultimately powered by solar photovoltaic cells, wind,

geothermal, hydroelectric, wave, or tidal power. As such, the use of cellulosic or corn

ethanol at the expense of the other options will cause certain damage to health, climate,

land, and water supply in the future, he asserts.

Moreover, the land required for cellulosic-E85 may also exceed that of corn-E85

and the land required for both will exceed that required for the footprint on the ground of

wind powering battery electric vehicles by a factor of 500,000 to 1 million, adds Jacobson.

He suggests that we should be considering very carefully the notion that replacing fossil

fuels with biofuels could save us from catastrophic climate change given that this is not

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only unlikely, but will also have a negative impact on land and water supply relative to

genuinely renewable energy sources.

Subtopic 2: Advantages of cellulosic material and the cost of production of ethanol

The article entitled Cellulose Ethanol further endorses this by stating that some grasses

store more energy in cellulose than does corn, and require far less nitrogen fertilizer, far

fewer pesticides, and less process heat .The article further states that the main drawback is

the expense; this was also endorsed by the Department of Energy (DOE) Biofuels program,

which stated that the high cost of cellulose enzymes are the key barrier to economic

production of cellulosic ethanol.

According to Andersen in the article entitled Economics Improvement for First

Commercial Cellulosic Ethanol Plant:

enzymes have been the most expensive component of making cellulosic fuels. Just

recently, enzymes accounted for more than half of the production price. This was at

a time when it cost $5 to $10 to make 1 gallon of fuel -- nowhere near cheap enough

to compete with even grain ethanol.

Now, the dropping enzyme costs mean they will only account for 25 percent of the

production price by next year.

The improvements come as the enzyme manufacturers have optimized and fine-

tuned the exact cocktail needed at each stage of the process. Genencor an enzyme

producer said it has managed a threefold improvement in the efficiency of its

enzyme, which means less needed per gallon of fuel.

The said article further went on to state that:

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Two enzyme producers, Genencor International and Novozymes Biotech, have

received research funding from DOE to engineer significant cost reductions and

efficiency improvements in cellulose enzymes. In October of 2004, Genencor

announced a 30-fold reduction in the cost of enzymes to a range of $.10-$.20 per gallon of

ethanol. To achieve the savings, Genencor developed a mixture of genetically modified

enzymes that act synergistically to convert cellulose into glucose. Novozymes Biotech

has also progressed in reducing enzyme costs from $5.00 to $.30 per gallon of ethanol. In

April of 2004, Novozymes was granted a one year extension and awarded an additional

$2.3 million to further reduce the cost of enzymes to $.10 per gallon.

With the high cost of enzyme being a significant factor, my project will focus on identifying

cheaper and at the same time efficient enzymes that can be utilized in the conversion

process.

The article went on to suggest that with the exploitation of cellulosic ethanol, it could

become cheaper than gasoline, which is also endorsed by Phillips, M.W in the book entitled

Fuel Energy. To achieve this however a more economical process for the conversion

of cellulose to ethanol must be developed.

According to the same article; Improvement for First Commercial Cellulosic Ethanol Plant

A Canadian company is trying to commercialize an enzymatic hydrolysis

technology for ethanol production. The company estimates that a plant with ethanol

capacity of 50 million gallons per year and lignin-fired CHP will cost about $300 million to

build. By comparison, a corn ethanol plant with a capacity of 50 million gallons per

year could be built for about $65 million, and the owners would not bear the risk

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associated with a new technology. According to John Sheehan of National Renewable

Energy Laboratory, biorefineries need to be able to process 5,000 to 10,000 tons of

biomass per day in order to be economically viable. "Below 2,000 tons per day, capital

costs skyrocket." This therefore indicates that the conversion process of cellulose to

ethanol is still quite expensive in spite of the reduced price of enzymes

Furthermore according to Stefan Osborne in the article Energy in 2020:

Cellulosic ethanol currently costs about $2.65 per gallon to produce, down from

more than $5 per gallon in 2001, while corn-based ethanol costs between $0.90 and

$1.65 per gallon to produce, depending on the price of corn. The DOE has set targets

for technological advances that would reduce the cost of producing cellulosic

ethanol to $1.07 per gallon by 2012, which would make cellulosic ethanol

competitive with corn-based ethanol (in 2004 corn and crude oil prices).Crucial

differences exist between the technologies used to produce ethanol from corn and

cellulose. In both technologies, feedstock sugars or starches are extracted and

fermented to make ethanol, but extracting sugars from cellulose requires expensive

chemical processes that are not necessary to extract sugars from corn.

According to a 2000 report by the National Renewable Energy Laboratory;

It costs $30 million to construct a typical corn-based ethanol plant that can produce

25 million gallons per year, adding the pretreatment equipment needed for cellulose

would increase the cost of constructing a plant with the same capacity to $136 million. In

addition to the higher capital costs.

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Subtopic 2.1: Techniques of producing ethanol from cellulose

According to the article Creating cellulosic ethanol: spinning straw into fuel;

Two processing options are currently employed to produce fermentable sugars from

cellulosic biomass. One such utilizes acid hydrolysis to break down the complex

carbohydrates into simple sugars. Another method, enzymatic hydrolysis, utilizes

pretreatment processes to first reduce the size of the material to make it more

accessible to hydrolysis. Once pretreated, enzymes are employed to convert the

cellulosic biomass to fermentable sugars. The final step involves microbial fermentation

yielding ethanol and carbon dioxide.

Subtopic 3: The negative and positive effects of the use of ethanol on the environment

Subtopic 3.1 Emissions

The environmental impact of ethanol can easily be noted by comparing ethanol on

the environment with conventional fossil fuel on the environment. It must be noted that

both ethanol and fossil fuel have their own negative impact on environment. However, it is

good to recognize these environmental conditions to lessen or diminish the harmful

consequences. A study done by (A Discussion Paper Canadian Institute for Environmental

Law and Policy, 1994) argues that: The ethanol made from cellulose does not emit as much

carbon dioxide as fossil fuel. It was investigated that-the use of ethanol can reduce carbon

dioxide emissions by up to 100% on a full life-cycle basis. Use of 10% ethanol blended

fuels results in a 6-10% reduction in net carbon dioxide released from ethanol production

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activities and inputs and its use is less than that absorbed by the plants used to produce

ethanol and the soil organic matter.

The beauty about it- is that the carbon dioxide formed during the ethanol production

and gasoline combustion is taken in by the plant for starch and sugar formation during

photosynthesis. It is assimilated by the crop in its roots, stalks and leaves, which usually

return to the soil to maintain organic matter, or to the grain, the portion currently used to

produce ethanol. Over time, the organic matter breaks down to carbon dioxide, but with the

implementation of soil conservation measures, such as reduced tillage, the soil organic

matter will build up. Therefore, by increasing its organic matter content, the soil acts as a

significant sink for carbon dioxide.

According to (University of Nebraska- Lincoln [UNL], 1999)-using ethanol in

place of gasoline helps to reduce carbon dioxide emissions by up to 29% given todays

technology. Because ethanol is made from renewable, plant-based feed stocks, the carbon

dioxide released during a vehicles fuel combustion is recycled by the plant as it grows.

Most recently, work done by (UNL, 1999) found ethanol reduces direct Greenhouse

Gas (GHG) emissions between 48-59% compared to gasoline. These findings are consistent

with other researchers who investigated the same responses for these two groups.

Even thou ethanol production does not emit as much carbon dioxide as fossil-based

production; it still produces toxic chemicals that could potentially be harmful to the

environment and human health. During the process and distillation, volatile organic

compounds (VOCs) are released. These VOCs include ethanol, methanol, acetic acid, lactic

acid, formaldehyde, and acetaldehyde. Note that, formaldehyde and acetaldehyde are

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known carcinogens (cancer causing chemicals). Increased exposure to ethanol also raises

the risk of inhalation, which has significant health consequences: developmental toxicity,

central nervous system dysfunction, birth defects, and cancer. The previously mentioned

study by (Canadian Institute for Environmental Law and Policy [CIELP], 1994) also

investigate Volatile Organic Compounds are highly reactive in the atmosphere, and are

significant sources of ground-level ozone formation. Because ethanol oxygenates the fuel,

there is approximately a 7% overall decrease in exhaust VOC's emitted from low-level

ethanol-blended fuels in relation to conventional fossil fuels. In high level blends, the

potential for exhaust VOC reduction is 30% or more. Therefore, high level ethanol blend

can reduce emission of Volatile Organic Compounds (VOCs) by 30%.

The study by ( Reyes, February 2004) focus mainly on Ethanol which reduces

tailpipe carbon monoxide emissions by 30% toxics content by 13% mass and 21%

(potency), and tailpipe fine particulate matter emissions by 50%. Ethanol also reduces

secondary Particulate Matter formation by diluting aromatic content in gasoline. Over half

of the air pollution attributable to vehicles comes from high emitting vehicles that make

up only 10% of the vehicles fleet. High emitters include older vehicles as well as newer cars

with malfunctioning pollution control systems. The use of ethanol-blended fuel is also one

of the best pollution control strategies for off-road vehicles such as cement tractors, police

tankers and motorcycles which represent a significant source of emissions.

Subtopic 3.2 Air and Water Pollution

However, the (U.S Government Accountability Office, 1997, para.11) determined

that ethanol produces is relatively more nitrous oxide than does gasoline. (Kreider &

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Curtiss, June 2007, para. 13) attempt to prove that carbon dioxide emissions from corn

ethanol are worst than conventional fossil fuel. They also concluded that carbon emissions

are approximately 50% higher for ethanol than fossil fuel in a life-cycle sense.

(Searchinger et al., February 2008) also determine the calculation of ethanol and

made comparison of corn-based ethanol versus fossil fuel. Searchinger et al., (February

2008) point out They found that instead of producing a 20% saving corn-based ethanol,

about twice greenhouse emissions for 30 years and increase greenhouse gases for 167 years;

because it increases emissions by 50%.

As one writer put it The Fate and Transport of Ethanol-Blended Gasoline in the

Environment (Methyl Tertiary Butyl Ether [MTBE], 2001, para. 4). They noted that

ethanol is a natural occurring substance which is formed by the fermentation process of

organic matter; which is expected to biodegrade in all environments. However, when

gasoline contaminates the ground and water, its the ethanol which is the first to quickly,

safely and naturally biodegrade.

(County groundwater Impact Committee, October 8, 2006) Shows that:

Ethanol production biggest waste production is wastewater. And this water come

about by the fact that each gallon of corn ethanol produced, 160 gallons of wastewater is

produced. And as (Pimentel, June 2003) went on to prove plant use chemicals such as

algaecides and rust inhibitors which are mostly found in wastewater and the fact that

wastewater contains 18000 to 37000 ppm of biological oxygen demand (BOD). Biological

Oxygen Demand is a measure of how much biodegradable organic matter is present in

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water; which is used to infer the quality of water- the higher the BOD, the worst the water

quality.

Conclusion

In concluding we came to the general conclusion that the availability of cellulose is

higher worldwide compared to fossil fuel as this is relatively untapped because it is not

ready to use like fossil fuel. Studies done by (Wiley, 2008) however have failed to consider

the fact that breaking down the cellulose into its biofuel counterpart and the many

challenges associated with that. These include sourcing and storing the raw material

available to carry out this procedure. Some other challenges include finding alternative

routes to break down the cellulose to get maximum yield from it via fermentation. We dont

know if producing fuel from cellulose is more economical or whether it is sustainable.

Another gap found in (Jacobson, 2009) research is that it failed to consider is that biodiesel

production requires the growth of mainly vegetation and to allow for sufficient and

adequate production worldwide, there would be strong competition for land space to grow

food for general consumption. This literature review has allowed the researcher to better

understand the above subtopic and of the availability of cellulose for fuel production. Also

to realize the effect of the worlds consumption rate of fuel and its projected termination

resulting in scarcity and price increase. As far as further research into this topic goes this

literature review has allowed the researcher to realize that though the biofuel seems to be

the future primary energy source for the world there are still many challenges left to

overcome. Another conclusion is that based on the research carried out it is quite

obvious that much more needs to be done to make the process of converting cellulose to

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ethanol more profitable. Based on the proposal the intention is to improve the process of

converting cellulose to ethanol mainly on the basis of making it more economical. As stated

by the research the cost of enzymes is a major contributing factor to this cost. Another

conclusion One of the conclusions that can be drawn from the submissions to this paper was

the lack of negative effects on the environment. As a part of this tender, Environment

requested a study on the negative effects on the surrounding of ethanol in comparison to

conventional fossil fuel. During the execution of the literature search it became apparent

that only limited information relating negative effects of ethanol and positive effects of

conventional fossil fuel. The majority of information available was only specific to the

positive effect of ethanol on the environment. Also there was limited and non-specific

information available for the ethanol blends impact. Ethanol is oxygenating, when blended

with fossil fuel increase the oxygen for the combustion process. As for the water

contamination, the severity of the impact depends how much biodegradable organic matter

is present in water.

Methodology

Introduction

This is a comparative study of using corn against wood-chips for ethanol

production. This study also seeks to compare using enzymes as opposed to concentrated

acid as catalysts for this method. The target group for this research is mainly for oil

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refineries as well as ethanol production plants. This will help them to make better choices as

well as to enlighten them of the available options for their production.

Research Design

Study Design

In order to make the production of ethanol from cellulose more economically

feasible, the strong acid hydrolysis process as well as the enzymatic process will be

employed. This process is a laboratory design that will investigate the use of corn grains as

opposed to wood-chips or waist compounds as the raw material source. This acid will be

mostly sulphuric acid and this process will utilize relatively low temperatures and pressure,

which will reduce the thermal stress on the equipments and initially will cause the

requirement of low cost materials, while the enzymes will be obtained from our local

chemical laboratory. This process was carried out over the course of a three week period,

from April 20, 2009 to May 14, 2009. The first week was geared towards breaking down

the raw material sources to their fermentable sugars. The following weeks was geared at

fermenting the sugar to obtain ethanol as well as distillation to purify the yield. To carry out

this experiment 50 kg of corn grains as well as wood chips were used. This general method

was chosen because it is the most carried out method worldwide and as of such it is only

beneficial for us to carry out the experiment in this manner. Concentrated sulphuric acid

was chosen as a catalyst because of its feasibility, one main advantage that it as high

conversion efficiency.

As opposed to acid enzymes are very expensive and mainly operates at relatively

high pressures and temperatures, which incepts the requirement of more expensive

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materials. Further as opposed to acid hydrolysis enzymatic conversion of cellulose to

ethanol, enzymatic conversion includes relatively expensive pre-treatment of the enzymes.

Secondly enzymatic conversion processes can take days as opposed to hours taken by the

acid hydrolysis method to produce the same quantities of ethanol. This therefore suggest in

order for the quantities of ethanol produced by the enzymatic conversion process to be

tantamount to that produced by the acid hydrolysis process, larger or greater quantities of

reactors must be used for the enzymatic process.

Procedure for Data Collection

Enzymatic Breakdown

First the cellulosic material, which is a mixture of grass, paper and wood chips, must

be crushed in order to increase its surface area and pre-treated with alkali at 90 to 120C for

1 to 2 hours in a double screw-type counter-current extractor. An Armfield continuous stir

tank reactor is then used to provide breakdown of the wood chips in with enzymes, this is

done for a total of three (3) hours. The immobilized flash method is then used to ferment the

resulting sugar solution. Distillation was then carried out using the UOP3CC- Continuous

distillation column. This method was repeated for the corn grains.

Concentrated acid breakdown

The woodchips are crushed once more. The cellulose must be decrystallized

(swollen) using Trifloroacetic acid (TFA) at 78oC and then hydrolyzed with a solution of

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30-40% for 1-5 hours. The contents should then be dried to increase the acid concentration

to about 70%, before it is again reacted in another reactor for approximately 3 hours to

produce a hydrolysate containing both sugars and acid. An ion exchanger should then be

employed to separate the acid and the sugar solution. The immobilized flash method is then

used to ferment the resulting sugar solution. Distillation was then carried out using the

UOP3CC- Continuous distillation column. This method was repeated for the corn grains.

Instruments and Materials Used

Sawdust, straw were obtained from Carpenter workplace, sugar bagasses and corns

were taken from sugar factory and local farmer. Methylene chloride and sulfuric acid were

obtained from the chemical industry.

The continuous stirred reactor -consist of six 25cm high by 25 cm stacked stages,

the first 2 stages are termed enriching where cellulose allows ethanol concentration to

increase in the stock and the other four stages include countercurrent gas to liquid stripping

trays where the overflow from the stage contacts a recycled carbon dioxides stream which

strips the ethanol from the fermentation stock.

Double Sew-type counter-current extractor it provides better liquid to solid

contact hence, more efficient than single-screw extractor. It is used to reduce the liquid to

insoluble solid ratio while achieving high sugar, which in return reducing the cost of

ethanol production. The main criteria for this device is to recover soluble sugars include

high sugar recovery, high sugar concentration in the extract (which is low liquid to

insoluble solids ratio).

Ethical Concerns

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In Comparison to using corn; the usage of food crop to produce ethanol raises major

ethical concerns. With a large percentage of the humans in the world now at present

malnourished, the need for grains and other food crops which are basic continues to be

critical. Take inconsideration-the local market associated with the use of corn for ethanol

are increasing in the price of Jamaica corn beef, cereals, bread and milk of 5-80%.

Jacques Diouf of the United Nation Food and Agriculture Organization warns that

using corn for ethanol is causing food shortage for the poor worldwide.So rising food

prices have accompanied rising the cost of living. In wholesome, growing crops for biofuels

squanders cropland, water and energy resources which are essential for food production

needed for people.

As for the chip of woods to make cellulose one has to consider deforestation. But as

Blackwell, 2008) shows: Rural economies will benefit in the form of increased incomes and

jobs. Growing energy crops and harvesting agricultural residuals are projected to increase

the value of farm crops, potentially eliminating the need for some agricultural subsidies.

Finally, cellulosic ethanol provides positive environmental benefits in the form of

reductions in greenhouse gas emissions and air pollution.

Timeline and Budget

Since its a seven days process:

Personnel

Salaries and Wages

Project Director: Troy Kameka Ferguson

$20,000 x 30% x 7 days----------------------------------------------$42,000

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Benefits

$42,000 x 35%---------------------------------------------------------$14,700

Equipment

Double screw-type counter-current extractor--------------------------------$5,000

Armfield continuous stir tank reactor-----------------------------------------$7,000

Continuous distillation column------------------------------------------------$6500

Round-bottom-Flask------------------------------------------------------------$4,000

Materials/Supplies

Wood chip, Saw dust, Sulphuric acid----------------------------------------$1,000

Project Total------------------------------------------------------------------------------$80,200

Future Funding

Despite the fact that most of the costs involve one-time purchases, it will be

necessary to plan for future funding of certain aspects of the project. These costs include

maintenance of the fitness equipment, and supplies such as wood chip, sawdust and sulfuric

acid.

The Chemgroup Team has indicated that if the project is funded, it will appropriate

maintenance. A similar commitment from the Pure and Applied staff Department will

ensure that the Department can sustain the project in the future.

Data Analysis

In other to analyze the results effectively it is necessary to generate graphs.

Enzyme Analysis

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1) Generate a graph of the percentage yield of the sugar from corn and wood-chips

after breakdown in the continuous reactor.

2) Generate a graph of the percentage yield of ethanol from corn and wood-chips after

fermentation.

3) Generate a graph of the quality of ethanol derived from corn and wood-chips after

the distillation process.

Concentrated Acid Hydrolysis Analysis

1) Generate a graph of the percentage yield of the sugar from corn and wood-chips

after leaving the ion exchange.

2) Generate a graph of the percentage yield of ethanol from corn and wood-chips after

fermentation.

3) Generate a graph of the quality of ethanol produced from corn and wood-chips after

distillation.

After generating these graphs comparisons should be made of the yields from each category

and thus come to an overall conclusion of the process, which is most feasible as well as

economical.

Limitations

Physical pretreatment of biomass before enzyme hydrolysis could not have been

undertaken, even though it would have given better results. This is because physical

methods may use high temperature and pressure, milling, radiation, or freezing all of which

require high-energy consumption. As a result the chemical method was chosen. The

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enzyme recovery process could not have been undertaken even though it would have also

contributed to the overall economics of the research. This is because to do this we would

need to have a UF membrane capable of fractionating molecular weights; this also would

have contributed to the cost dramatically. Due to the tough crystalline structure, the

enzymes currently available require several days to achieve good results. Since long process

times tie up reactor vessels for long periods, these vessels have to either be quite large or

many of them must be used. Either option is expensive.

Using the acids it was necessary to use acid-resistant equipment. Technical

difficulties relating to the recovery of acid prevented us from using an evaporator to recover

our acid, and the formation of by-products due to excessive decomposition this would have

improved our efficiency. Without acid recovery, large quantities of lime must be used to

neutralize the acid in the sugar solution. This neutralization forms large quantities of

calcium sulfate, which requires disposal and creates additional expense.

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References

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and new uses. ASHS Press, Alexandria, VA

Blackwell, W. (2008). Fuel from Cellulose, Cheaper and With Better Yields than Ever

Before. Science Daily. Retrieved March 22, 2010, from

http://www.sciencedaily.com/releases/2008/08/080808114928.htm

Jacobson, M. Z. (2009). Effects of biofuels vs. other new vehicle technologies on air

pollution, global warming, land use and water.International Journal of Biotechnology,

11 (1/2), 14- 59

Kreider, J. F & Curtiss, P.S (2007, June 27) "Comprehensive Evaluation of Impacts from

Potential, Future Automotive Fuel Replacements Long Beach, CA.

Phillips M.W (2004) FUEL Energy 2nd edition

Pimentel, D. (2003, June) Ethanol Fuels: Energy Balance, Economics, and Environmental

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Riddell, R. (2003). Sustainable Urban Planning; Tipping the Balance. Molden, Blackwell

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Scott, H. M. (2003). How Biodiesel Work. HowStuffWorks.com. Retrieved from

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Soet, P. J. V. (1994). Nutritional Ecology of the ruminant. Cornwall University Press. p-

166.

Timothy Searchinger et al., (2008, February 28) "Use of U.S. Croplands for Biofuels

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Webster County Groundwater Impact Committee. October 8, 2006. Groundwater Impact

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Cellulose Ethanol, Retrieved March 15, 2010 from;

http:\Cellulose Ethanol 3.htm

Economics Improve for First Commercial Cellulosic Ethanol Plants;

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first-commercial-cellu-93478.html

Energy in 2020, Retrieved March 15, 2010 from;

http://www.ethanolrfa.org/resource/cellulosic/documents/cellulosic2007.pdf

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Energy Information Administration. (2006). World consumers of oil per country. Retrieved

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Ethanol from Cellulose: A general Review, Retrieved March 17, 2010 from;

http://www.hort.purdue.edu/newcrop/ncnu02/v5-017.html

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the proposal for cellulose

Documents