Goosegrass for Cellulosic Ethanol

Cellulosic ethanol production from Eleusine indica (goosegrass)

WALA PA KO KABALO KUNG ANO IBUTANG DI ! 

Arrabis, Lyra Cuizon, Jessica Delfin, Nelson Jann Pango, Kyrin Pango Polanco, Aimee

I. INTRODUCTION A. Background of the Study

Industrial growth over the past century has seen an ever-increasing demand on the earth’s fossil fuel resources such as coal and oil. These fuels have been favored due to their ease of extraction and cost-effective conversion into usable energy. However, it is a well-established fact that combustion of fossil fuels such as coal, oil and natural gas for power generation is a significant contributor to global warming. “The spiraling cost of petroleum and the need for environment-friendly or less greenhouse gas emitting energy due to global warming/global climate change have jointly made the country's political leaders, industrialists and technologists engage in a frenzied search for alternative and renewable energy, such as biofuels. One recognized biofuel source for locomotive transport is ethanol” (Mendoza, 2005). Ethanol is blended with gasoline in fixed proportion and used as alternative to fuel like diesel and petrol. Maximum of 10 % bioethanol can be blended with gasoline to be used as alternative fuel source in the Philippines. According to Michael Wang (2005) of Argonne National Laboratory, one of the benefits of bioethanol is it reduces greenhouse gas emissions (GHG) by 85% over reformulated gasoline. Moreover, ethanol-blended fuel substantially reduces carbon monoxide and volatile organic compound emissions, which are precursors to ozone. Based on Renewable Fuels Association, adding ethanol to gasoline reduces harmful emissions and lowers the cost of transportation fuels – and reduces the reliance on foreign oil imports. It also provides high quality, high octane for exceptional engine performance and reduced emissions. It keeps the fuel system clean for optimal performance because it does not leave gummy deposits (2005-2014).

Nowadays research is going on all over world for production of bioethanol from biomass. Main sources of biomass which is converted into ethanol are sugarcane, corn, wheat bran, cassava, sweet potato etc. These are used for ethanol production but they are mainly used for food source and if these sources will be used for the ethanol production, the whole world is going to face food crisis as world population is increasing rapidly. To prevent the world from fuel crisis and food crisis, research has been focused on production of biofuel from waste biomass and plant sources which are not for food purpose like waste generated in sugar mill, chemical pulp generated in paper industry, grasses and weed plants etc. (Kumar, N., et al, 2013). In line with this, the researchers come up with a study that utilizes feedstock from Eleusine indica (goosegrass) - a problematic annual grassy weed which reduces yields for it competes with the main crop for water, nutrient, and sunlight uptake. It is an alternate host for tungro, ragged stunt, and rice yellow mottle diseases and for numerous insect pests like; aphids, armyworm, cutworm, hairy caterpillar, leaf folders, leafhoppers, mealybugs, plant hoppers, rice bugs, among others. Once established, this weed is difficult to eradicate (Rice IPM, 2001). A single plant can produce up to 50,000 seeds. As a result, failure to control goosegrass can increase the quantity of goosegrass seed in the soil seedbank.

B. Statement of the Problem Is Goosegrass (Eleusine indica) a potential source for cellulosic ethanol production? 1. What is the percent lignocellulose content in Eleusine indica (goosegrass) 2. What is the suitable pretreatment method that would yield the highest lignocellulose content? 3. What is the ratio of cellulose used to ethanol produced? C. Purpose and Objectives of the Study The overall objective of this study is to ascertain that Eleusine indica (goosegrass) is a potential source for cellulosic ethanol production. *To determine the lignocellulose content – cellulose, lignin, hemicelluloses in Eleusine indica (goosegrass). *To identify the suitable pretreatment methods to be used - acid hydrolysis, ammonia fiber expansion, and sulfite pretreatment. *To determine the economic efficiency and advantage of using Eleusine indica (goosegrass) from other cellulose-containing sources (switch grass, cogon grass and corn stover) in cellulosic ethanol production. D. Significance of the Study The need of fuel has tremendously increased these past few decades. There had been a vast amount of cars produced every year. In connection with this, emission of carbon dioxide and carbon monoxide has also been in great amount. This study is conducted to lessen the emission of carbon monoxide in the fuel combustion on cars. As population increase, so as products of

technology also increase. And we cannot just stop the production of cars in order to minimize emission of carbon monoxide and carbon dioxide especially that this already had been a necessity in the life of other people. But on the other hand, we can still organize processes and/or create new inventions to minimize emission of these hazardous chemicals while making use of lignocellulosic biomass than conventional agricultural feedstock which minimize the conflict between land use for food production and energy feedstock production. And that is the very reason why this study is conducted. E. Scope and Limitation This study is conducted to prove the potential of weed plant Eleusine indica (goosegrass) in the production of cellulosic ethanol. One important factor that affects the yield of ethanol is the lignocellulose content of plant. A pretreatment is needed in order to separate cellulose from lignin. There are a lot of methods in obtaining this. However, choosing the method which will yield the highest cellulose content is desired. In this case, only three pretreatment methods will be tested namely, acid hydrolysis, ammonia fiber expansion, and sulfite pretreatment. In order to know if this study is economical, it is necessary to compare whether Eleusine indica (goosegrass) is a better source of cellulose than any other cellulose-containing plants and plant materials. In effect, the researchers will focus on comparing Eleusine indica’s (goosegrass) cellulose content with switch grass, cogon grass and corn stover. (PLEASE CHECK! PATAKA LANG NI DAAN)

F. Definition of Terms 1. Cellulose - a substance that is the main part of the cell walls of plants and that is used in making various products (Cellulose. (n.d.). Retrieved August 25, 2014, from http://www.merriam-webster.com/dictionary/cellulose). In this study, the term cellulose is used to mean a primary component of Eleusine indica (goosegrass) for ethanol production. 2. Lignocellulose - any of several closely related substances constituting the essential part of woody cell walls of plants. (Lignocellulose. (n.d.). Retrieved August 30, 2014, from http://www.merriam-webster.com/dictionary/lignocellulose). In this study, lignocellulose refers to plant dry matter which is composed of carbohydrate polymers (cellulose, hemicellulose), and an aromatic polymer (lignin) wherein it will be subjected to various pretreatment methods to separate the three components. 3. Cellulosic ethanol - a renewable, domestically produced alcohol usually blended with gasoline and diesel. In this study, it is referred to as a biofuel produced from wood, grasses, or the inedible parts of plants - Eleusine indica (goosegrass) in particular. 4. Pretreatment - to treat in advance or as part of a preliminary treatment (pretreatment. (n.d.). Dictionary.com

Unabridged.

Retrieved

August

25,

2014,

from

http://dictionary.reference.com/browse/pretreatment). In this paper, pretreatment signifies a combination of many processes. It consists of a size reduction step followed by chemical, biological, or physical treatments to extract lignocellulose content from Eleusine indica (goosegrass).

5. Acid hydrolysis - breaking down of a chemical compound into two or more simpler compounds

by

reacting

with

water

(The

Free

Dictonary,

2014.

http://www.thefreedictionary.com/ Acid+Hydrolysis). In this study, acid hydrolysis is one of the pretreatments to be conducted in order to convert cellulose to glucose. 6. Ammonia fiber expansion – is a promising method for pretreating agricultural material for bioenergy production. In this study, this process decrystallises the cellulose, hydrolyses hemicellulose, removes and depolymerises lignin, and increases the size and number of micropores in the cell wall, thereby significantly increasing the rate of enzymatic hydrolysis for better production of ethanol (Bals, B., 2009). 7. Sulfite pretreatment - This process separates hemicelluloses from the

lignocellulose

and partially separates lignin (Retrieved from http://www.nararenewables.org/docs/onepager/sulfite_pretreatment.pdf). In this study, sulfite pretreatment will be used to overcome recalcitrance of lignocellulose for robust bioconversion.

ANNOTATED BIBLIOGRAPHY Boopathy, R., & Dawson, L. (2008).Cellulosic ethanol production from sugar cane bagasse without enzymatic saccharification.Bio Resources 3(2), 452 – 460. Thibodaux, LA 70310, USA. The authors present that cane processed bagasse could be used to produce fuel grade ethanol without saccharification. A chemical pretreatment process using alkaline peroxide and acid hydrolysis was applied to remove lignin, which acts as a physical barrier to cellulolytic enzymes. The results indicate that ethanol can be made from sugarcane bagasse. Lee, D., Owens, V., Boe, A.&Jeranyama, P. (2007). Composition of Herbaceous Biomass Feedstocks.Biomass. Retrieved from http://agbiopubs.sdstate.edu/articles/SGINC1-07.pdf This report summarizes published information about the chemical composition of potential herbaceous biomass feedstocks for biorefineries in the north-central United States. The specific usefulness of this report varies according to conversion process; thus, values are intended only for exploratory calculations and preliminary estimates about the feasibility and economics of a particular feedstock. More detailed feedstock compositional information will become available as further research is completed at various locations throughout the country.

Samuel, R., Pu,Y., Foston, M. &Ragauskas, A. (2010). Solid-state NMR characterization of switchgrass cellulose after dilute acid pretreatment.Biofuels 1(1), 85–90. Georgia Institute of Technology: Atlanta, GA, USA. This study shows the results of dilute acid pretreatment of swithgrass, most of the hemicellulose in it was removed. The amorphous cellulose regions in switchgrass were degraded preferably during dilute acid pretreatment and the cellulose crystallinity index of pretreated switchgrass increased. Pretreated switchgrass had an increase in relative proportion of crystalline and paracrystalline cellulose in comparison to the starting material. Li, X. (2004).Physical, Chemical, and Mechanical Properties of Bamboo and its Utilization Potential

for

Fiberboard

Manufacturing.Renewable

Natural

Resources.Forestry

University: Beijing, China. This study investigated the chemical, physical, and mechanical properties of the bamboo species Phyllostachyspubescens and its utilization potential to manufacture medium density fiberboard. The highlight of the author’s study which is related to this study is the determination of lignocellulose content of bamboo. It is considered a composite material because it consists of cellulose fibers imbedded in a lignin matrix. Cellulose fibers are aligned along the length of the bamboo providing maximum tensile flexural strength and rigidity in that direction. Thus, making it a favorable potential for fiberboard manufacturing.

Kumar, P., Barrett, M., Delwiche, M., & Stroeve, P. (2009). Methods for Pretreatment of Lignocellulosic Biomass for Efficient Hydrolysis and Biofuel Production. Ind. Eng. Chem. Res., 2009, 48 (8), pp 3713–3729 DOI: 10.1021/ie801542g Biofuels produced from various lignocellulosic materials, such as wood, agricultural, or forest residues, have the potential to be a valuable substitute for, or complement to, gasoline. Many physicochemical structural and compositional factors hinder the hydrolysis of cellulose present in biomass to sugars and other organic compounds that can later be converted to fuels. The goal of pretreatment is to make the cellulose accessible to hydrolysis for conversion to fuels. Various pretreatment techniques change the physical and chemical structure of the lignocellulosic biomass and improve hydrolysis rates.

Kumar, N. et al. (2013). Bioethanol production from weed plant (Cyperus rotundus) by enzymatic hydrolysis. Advances in Applied Science Research. Adv. Appl. Sci. Res., 2013, 4(4):299-302. Retrieved from www.pelagiaresearchlibrary.com In this study, Cyperus rotundus was used for ethanol production. During this study it was found that sufficient amount of ethanol can be produced from this weeds plant. There are many other weeds plants are available which has high carbohydrate content so it may serve as good alternative resource for ethanol production. Since research in this area is very rudimentary so further investigation is required to optimize condition for efficient production of ethanol from weed plants and waste biomass.