Biofuels as Alternative Energy Sources


Biofuelsas Alternative Energy Sources

Table of Contents






General Objectives 5

Specific Objectives 5





References 12


This projectproposal focuses on the use of alternative sources of energy such asbiofuels. The project seeks to find out if there isfuel energy in the biomass of certain bio-products. These new energyalternatives are biofuels, solar, wind energy, geothermal power,nuclear energy, and other renewable energy forms. With regards tobiofuels, there exists an option of using bioethanol or bio-diesel aseither a fuel ingredient in gasohol or as a pure non-mixed fuel. Suchbiomass that produce biofuel are:

  • Cellulose (corn, sugar cane, potato peeling waste).

  • Algal oil

  • Soy

  • Jatropha seeds

  • Paper waste

Inthis project proposal, I will mainly focus on the utilization ofCellulosic biomass.

The project proposalis broken down into several components as listed below:

  • Thesis statement

  • Summary

  • Objectives

  • Problem Statement

  • Justification

  • Literature Review

  • Plan


Thereis possible production of fuel form certain types of biomass.


Renewablealternative fuels in the form of biofuels are being actively soughtafter globally. They have shown prospects in converting massivesubstrates from cellulosic feedstock into fermentable sugars thattend to produce second generation biofuels such as bio-ethanol andbio-diesel. Fuel produced from these feedstock have a potentiallylarge market value. This fuel can then be used to alternativelyreplace or reduce the pressure on the use of petroleum fuel in theindustry and transport sectors (Keshgi &amp Prince et al., 2010).The government regulations should be implemented as with theagreement of the Kyoto protocol blending of bio-ethanol withconventional gasoline should increase to 10%, which gives rise togasohol. Consequently, this will lead to a rise in demand for theproduction of bio-ethanol. Thus, bio-ethanol use will tend toincrease (Carels, 2011).

Energy availabilityhas been a major issue worldwide. With the potential of fossil fuelsbecoming depleted, the world is moving towards the development of newsources of energy that will not only be renewable but also friendlyto the environment. Bioethanol can be produced through severalmechanisms and systems. Cellulosic feedstock such as potato peelingswaste (PPW), sugarcane molasses, and others can be broken down intoindividual monomers which can be subsequently fermented to bioethanol(Jørgensen,2012).

Currently, there isa strong movement towards the research and development of thebenefits of biofuel use. This is mainly because this energy sourcesare renewable as opposed to the non-renewable fossil fuels.

As of today, thebiggest energy reserves in the US are derived from coal, oil, andnatural gas. Unfortunately, there have been problems with the factthat these resources are not renewable (Klass, 1998). There has beena recent push to develop a renewable energy source with which to fuelenergy needs, such as for vehicles and other personal use. Ethanolproduced from corn is one such step. However, other forms of plantsare able to produce much more energy from ethanol they produce.Cellulosic ethanol sources produce more than ten times as much energyas it is required to make them. This compares favorably to cornethanol, at 1.36 times. Coal and gasoline provide slightly less thanthe energy put into them, while electricity only produces half of theenergy put in.

OBJECTIVES General Objectives

  • To establish the potential ability of Biofuels as an alternative source of energy


  • To determine the level of sugars (Glucose) in cellulosic biomass.

  • To produce second generation bio-fuels (Bio-ethanol) from glucose derived from cellulosic biomass.


The over-reliance inFossil fuels&nbspas the major source of energy in the world today,has led to over-consumption and serious environmental issues suchas&nbspair pollution. This has recently become a growing concern asit threatens the livelihood of human beings. Fossil fuels releasevarious pollutants and harmful gases into the environment (carbondioxide, sulfur dioxide, carbon monoxide) when burnt. In turn, thisbrings about the depletion of natural habitats. Carbon IV Oxide isthe major gas that is ejected into the atmosphere when fossil fuelsburn. Moreover, it’s one of the “bad gas “that is responsiblefor&nbspglobal warming. This effect has resulted in temperature riseand thus melting of polar ice and the consequent flooding of coastalregions with rise in sea levels. The planet earth faces unpredictableand unwanted consequences in the future, if fossil fuels willcontinue to be used. Furthermore, as outlined earlier, fossil fuelsface a near extinction from planet earth. They won’t be availableonce they are fully utilized and their reserves fully exhausted.Currently, fossil fuels are exploited at an alarming rate so as tomeet the expectations and reduce the gap between demand and supply.Supposedly, the reserves will be exhausted in next 30-40 years. Withthat in mind, it will be a likely occurrence that fuel expensesescalate in the future. Fossil deposits take millions of years to bereplaced back and thus, that might render the current reliance topetroleum a total waste. Other issues such as the rising costs ofFossil fuels, the impact on aquatic life by Oil Spills as well ashealth hazards caused by the fuels urgently calls for instantmeasures to be put in place. There is need to develop sources ofenergy that are renewable (that cannot be depleted) and that reducethe margin or intensity of health or environmental risks caused byfossil fuels (Pretli,2002).


Theintroduction of biofuel has caused mixed reactions from variousskeptics. The consumer market has been pushing the stakeholders toadopt this alternative energy sources by embracing new technologicaladvancements and the ever rising energy demands. Moreover,based on the rising health and environmental concerns with regards toFossil Fuels, the urge to adopt Biofuels as the main sources ofenergy is increasing day by day.Biofuelsburn safely. They release comparatively less carbon and other toxins.So, they are regarded as one of the best alternative sources ofenergy because they help in preserving the atmosphere by reducing airpollution.In addition, Biofuels are a renewable energy source in that they arecreated from plants that can be re-grown each year. Biofuel sourcessuch as crop feedstock take a shorter time to re-grow and the cyclecontinues. However, fossil fuels take a longer time to generate andthis is why this project proposal has chosen to focus on usingbiofuels as the better alternative.


Presently, thesignificant biofuels are biodiesel and bioethanol which are referredto as first-generation biofuels (Naik &amp Goud et al.,2010). These derived fuels are used as additives or pure forms offuel. The additive aspect is usually termed as blending. Pureforms of these fuel types require sophisticated and modified enginetypes. As the research says, these biofuels only utilize parts of thebiomass. Besides, the second-generation biofuels such as biomass toliquid (BtL) utilize the entire biomass (Sims &amp Mabee et al.,2010). Bioethanol is produced in the conversion process of starchinto sugar. However, the advanced procedure utilizes the hydrolysisof ligno-cellulose, followed by fermentation and distillation.

Nonetheless,hydrolyzing cellulosic biomass using enzymes has various challengesthat should be overcome in order to advance to second generationbiofuel production. Initially, cellulose is derived from plants andsubsequently detached from the lignin present in the mixture.Furthermore, fermentation is used to break down the cellulose intosimple, 5 or 6-carbon sugars (Wyman&amp Decker et al., 2005). There are three methods ofpretreatment of the biomass namely physical, chemical andbiological. At an industrial level, biological process is thepreferred since it does not produce any unnecessary bio products. Thetargeted reactions are only carried out as required for productformation so that the remaining biomass after product extractioncould be used for any other purposes like animal feeds. Since all thebiological reactions take place at optimal conditions, the productionprocess takes place at optimum conditions, the production cost isalso less when compared to other methods. Starch is made up ofamylase and amylopectin. It is made up of α 1,6 and α 1,4 linkages(Wyman &ampDecker et al., 2005). Cooking starch at hightemperature and pressure causes it to gelatinize enabling the enzymesto access and digest the polymers. If dry grind method is used forproduction of ethanol, high yields are obtained and the addedadvantage is that it’s economical.

The dry grindprocess is outlined below



Simultaneous saccharification andFermentation



Saccharification(hydrolysis) breaks down the long chain cellulose, starch, andprotein and fat molecules into reduced, fermentable molecules such asamino acids, fatty acids and simple sugars. Enzymes act as catalyststo breakdown the glycoside bonds (Naik &amp Goud et al., 2010).

Regarding thefermentation process, yeast is the mostly used organism. SimultaneousSaccharification and Fermentation (SSF) process is preferred. In asingle reactor, yeast is added along with the saccharifying enzymeswhich produce the glucose yields which are immediately converted intobioethanol. In this way, there are no chances of glucose accumulationand also, the bioethanol produced hinders microbial contamination(Zhang &amp Zhao et al., 2011).

The yield of ethanolwould be calculated using the following equation

Glucose Ethanol + Carbon Dioxide + Heat

1 Mole 2 Moles 2 Moles

180g 92 g88g

The selection of themicroorganism is one of important factors for the production ofbioethanol for it should withstand the osmotic pressure andtolerance to ethanol. Yeast has been a commonly used organism forthis purpose and will be used in this process


Cellulose andhemicellulose are the major materials that are broken down throughtrial runs. Cellulose is a long chained glucose polymer, connected byβeta 1-4 glycosidic bonds with the chemical formula (C6H10 O5) nand “n” is the degree of polymerization of the polymer. Thisvaries from starch and glycogen found in animals because thosecontain α (1-4) linkages between the individual units. The two typesare differentiated by α-linkages occurring below the plane of thesugar, while the β-linkages occur above the plane. Hemicellulose,the other major component of plant structure, is similar to cellulosein that it is a polymer of sugars. However, in addition to glucose,hemicelluloses are made up of additional sugars, including arabinose,xylose, mannose, and galactose. Hemicelluloses are also shorter thanits cellulose counterpart, with a degree of polymerization around200. This material is also branched in its polymerization, as opposedto the linear cellulose (Wyman&amp Decker et al., 2005).

Importance ofEnzymatic Hydrolysis

This process is veryimportant because it reduces the strain put on the food industry fromother forms of ethanol production. Instead of utilizing food crops toproduce fuels, other forms of organic matter containing cellulose canbe used. There are a variety of uses for the sugars produces fromthis reaction ethanol, acetic acid, amino acids, antibiotics, andother chemicals are all potential products of these sugars (Wyman&amp Decker et al., 2005).

SignificantBreakthroughs/ Developments

A notable methodemployed to produce ethanol from lignocellulose biomass is known asSimultaneous Saccharification and Fermentation (SSF). The glucose andother fermentable sugars are first produced in the Saccharificationstep and then fermented in the next step. This is very promising forproducing ethanol from lignocellulose.


Proposal writing

Lab Work

Data collection


Project compilation

Project Report


Carels, N.(2011).&nbspThechallenge of bioenergies: an overview.INTECH Open Access Publisher.

Klass, D. L.(1998).&nbspBiomassfor renewable energy, fuels, and chemicals.Academic press.

Kheshgi, H.S., Prince, R. C., &amp Marland, G. (2000). The potential of biomassfuels in the context of global climate change: focus ontransportation fuels 1.AnnualReview of Energy and the Environment,&nbsp25(1),199-244.

Jørgensen,H. (Ed.). (2012). Advanced biofuels in a biorefinery approach.&nbspandno. Forest &amp Landscape Working Papers,(70-2012), 118.

Naik, S. N.,Goud, V. V., Rout, P. K., &amp Dalai, A. K. (2010). Production offirst and second generation biofuels: a comprehensivereview.&nbspRenewableand Sustainable Energy Reviews,&nbsp14(2),578-597.

Pretli, D. G.(2002).&nbspBeyondsupply and scarcity: an examination of energy systems, externalities,and the move toward renewable resources&nbsp(Doctoraldissertation, Concordia University).

Sims, R. E.,Mabee, W., Saddler, J. N., &amp Taylor, M. (2010). An overview ofsecond generation biofuel technologies.&nbspBioresourcetechnology,&nbsp101(6),1570-1580.

Zhang, L.,Zhao, H., Gan, M., Jin, Y., Gao, X., Chen, Q., &amp Wang, Z. (2011).Application of simultaneous saccharification and fermentation (SSF)from viscosity reducing of raw sweet potato for bioethanol productionat laboratory, pilot and industrial scales.&nbspBioresourcetechnology,&nbsp102(6),4573-4579.