ECONOMIC PRODUCTION OF BIO-ETHANOL FROM VARIOUS INDIGENOUS SOURCES IN INDIA-A REVIEW A.K.Ray*, S.P.Yadav, and Pooja Sharma Indian Institute of Technology Roorkee, Saharanpur, India ABSTRACT Ethanol is usually produced in India by fermentation of molasses (generally 5% on cane) with an yield, 250.7 liter per tons of molasses with yeast Saccharomyces cerevisiae or by strains, Zymomonas mobilis. Uses of cane juice, jaggerry, mohua flower are also used in some installations. An alternative feedstock for ethanol production is ligno-cellulosic biomass;bagasse,rice straw, cotton straw, groundnut shells, wood and forest residues, waste paper products, paper and pulp mill wastes using thermophilic anaerobic bacteria, Clostridium thermocellum. Cellulose enzyme produced by aerobic mesophilic fungus, Trichoderma reesei, also releases glucose from plant biomass and converts to ethanol by simultaneous saccharification and fermentation. Acid hydrolysate of hemicelluloses extracted from bagasse and other agriculture wastes by fermentation with the yeast Saccharomyces cerevisiae has also been a potential feedstock. Starch based natural produce like wheat, rice, millets, potatoes, corn, tapioca can also be a potential and economic source of ethanol production. In this paper potential for profitable production of alcohol by various indigenous sources are reviewed. Economics of alcohol manufacture in relation to various constraints is discussed. INTRODUCTION Presently the entire ethanol production in India is based on molasses as feedstock.the government will soon move for mandatory blending of petrol with ethanol (EBP) pegging the target at 5%, in what could be a first step towards reducing the escalating fuel import bill. The chemical ministry (1) has argued that 5% petrol-ethanol blending will require 105 crore litres of ethanol annually, even though oil companies could procure only 36 crore litres last year. The expert panel for government of India also suggested peg ethanol costs Rs. 27 per litre with a floor price of Rs. 23 and a ceiling price of Rs. 31.During the years 1989-90, and 1991-92, there had been a surplus of ethanol in the country (2) even after exporting 3 to 4 % of the domestic production during each of these 3 years. Against an installed capacity of almost 27,000 lakh litres per annum, the distillery industry had been producing alcohol to the extent of 11,000 lakh litres(assuming 220 litres of ethanol per tonne of molasses) per annum having a capacity utilization of only 41 %. Therefore enough distillation capacity is available in the country to process additional molasses which is likely to be produced till the year 2002 provided there was market for that extra quantity of ethanol. Ethanol production from molasses, consumption and economics In India there are 300 distilleries producing alcohol using molasses as raw material, out of which 115 distilleries are attached to sugar factories. The total installed capacities of all the distilleries is 2964million litres in the year 2008 with 67.5% capacity utilization [ 2 ].The growth of alcohol production in India over the years is shown in fig. 1 which is linear
4000 3500 3000 Production, Mt 2500 2000 1500 1000 500 0 1985-86 1986-87 1987-88 1988-89 1989-90 1990-91 1991-92 1992-93 1993-94 1994-95 1995-96 1996-97 1998-99 1999-00 2000-01 2001-02 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08 2008-09 2009-10 2010-11 2011-12 Year Figure 1 : Production of alcohol from molasses in India (2) India is surplus in alcohol as on today as it produces more than 28 million tons of cane sugar and 2074.5 million litres of alcohol per annum through its nearly 300 distilleries. The annual total licensed capacity is 3287.491 million litres out of which 1321.585 million litres are produced from the distilleries attached with sugar factories. On the other hand total annual installed capacity for the same are 3198.314 and 1360.627 million litres respectively. India is producing indigenously around 33 million tons of petrol whereas our annual requirement is around 120 million tons. This may go up to 365 million tons in the year 2025. Presently India imports 75% fuel and will rise to 90% by 2020. The present scenario of sugar, fossil fuel stock, and power shortage, it is imperative to go for non-conventional bio liquid fuel and power production to cope up with the present and future demand. As a World s largest producer of cane molasses, India should take initiative to use biofuels, to overcome the mounting pollution problem in the metros. With a normal av. production rate of 1,900 million litres a year, India is the World s fourth largest producer of ethanol after Brazil, The United States and China. Production and Consumption pattern of ethanol in some countries are shown in the following tables 1 and 2. Table 1. Production and consumption of Ethanol worldwide Countries Production of Ethanol,10-3 million litres 2007 2017 Brazil 18 28 USA 26 58 Europe 3.0 15 India 2.2 4.0
It is evident that the ethanol production in 2007 was around 49.2 billion litres and in 2017, it will increase up to 105 billion litres. It is also clear that US is the major contributor, Brazil followed the next and unlike others, the amount is expected to be double in US and India. It is expected that in 2017 nearly 4.0 billion litres of alcohol will be produced in India. In India 94-96% ethanol is produced from sigar cane based molasses and only 3-4% from grains. Production wise India s share is only 4%. The consumption pattern is quite different in India compared to global situation. This is shown in the following table: The following table shows the projected demand for petrol and diesel and the amount of ethanol and biodiesel required for 5, 10, and 20 per cent blending. Table 2. Projected demand for petrol,diesel and ethanol requirements in India Ethanol Biodiesel Year Petrol demand @ 5 per @ 10 per cent @ 20 per cent Diesel demand @5 per cent @10 per @20 per cent (Mt) cent (Mt) cent 2006-2007 10.07 0.50 1.01 2.01 52.32 2.62 5.23 10.46 2011-2012 12.85 0.64 1.29 2.57 66.91 3.35 6.69 13.38 2016-2017 16.40 0.82 1.64 3.28 83.58 4.18 8.36 16.72 Source: Planning Commission, Government of India. Report of the Committee on Development of BioFuel, 16 April 2003 & 2008. The above demands are based on estimated growth rates of 7.3 and 5.6 per cent for petrol and diesel, respectively, in the 10 th plan (2001-2002 to 2006-2007), 5.0 and 5.0 per cent in the 11 th plan (2006-2007 to 2011-2012) and 5.0 and 4.5 per cent in the 12 th plan (2011-2012 to 2016-2017). PRODUCTION OF ALCOHOL FROM VARIOUS INDIGENOUS SOURCES: In India, alcohol is usually produced from molasses, though some distilleries also use cane juice, deteriorated cane juice, gur,. Alcohol may however be produced from any sugary(cane or beet molasses or sugar cane juice, sorghum or starchy agricultural crops,vegetable crops, crop residues, grain,, starch, sago waste, corn, jowar, barley, wheat, rice, millets, tapioca cassava, potatoes, soybeans etc. or even from cellulose- hemicellulosic materials.large amount of lignocellulosic wastes are generated through forestry and agricultural practices, sugar industry, pulp and paper industries, timber industries and many agro-industries,bagasse, rice straw, wheat straw, cotton straw, corn stover,groundnut shells, wood, grasses, sarkanda, paper pulp and many others. The average yield from some of the sources are shown in Table 3 below.the biomass requires pretreatment, saccharification of cellulose and hemicelluloses complexes and simultaneous fermentation of reducing sugars( hexose and pentose sugars). Acid hydrolysisof lignocellulosic biomass ion addition to sugars,aliphatic acids ( acetic, formic, and levulinic acids), furan derivatives, furfural and 5-hydroxymethylfurfural (HMF) and phenolic compounds are formed. These compounds are known to affect ethanol fermentation efficiency Table 3 Yield of ethanol from various substrates, kg of ethanol/tonne of substrate
Substrate Approx. Yield,kg/tonne Mohua Flower 250 Molasses 200 Bagasse 150 Rice husk 113 Wheat Straw 57 Jute Stick 42 Rice Straw 42 RESEARCH EFFORTS TO PRODUCE ETHANOL FROM VARIOUS INDIGENOUS RESOURCES INCLUDING LIGNOCELLULOSIC WASTES Utilization and value addition of Lantana Camera and Pine needle(pinus Roxburghii) as lignocellulosic wastes for ethanol. Attempt has been made( 3.) to convert Lantana Camara and Pine needle into maximum fermentable sugars by acid hydrolysis. The method utilizes biomass, macerated with 72 %H 2 SO 4 at ambient temperature in bath ratio 1: 1.25 for 18 hrs, then diluted to 5% acid concentration, digesting it at 120oC for different time periods(20 min. to 90 min.), detoxified following standard procedures and finally fermented with yeast culture of Sachharomyces cerevisiae. The results obtained is shown in the following Table 4. Table 4 Ethanol from Lantana plant of Indian origin(3) Biomass Exp 1 Lantana Camara Pine needle Exp.2 A Lantana Camara Pine needle B Lantana Camara Pine nedle T.R.S.(g/l) 24.8 22.2 22.18 21.49 25.9 23.13 Phenolics*(%) 0.005 0.007 0.005 0.005 0.003 0.002 Ethanol(g/l) 9.35 (11.76) 7.06 (8.88%) 8.43 (7.01) 8.02 (6.67%) 10.22 (8.51%) 8.94 (7.43%) Efficiency(%) 70.56 64,.59 74.60 72.51 78.93 77.27 Utilization of bagasse pith and low grade non-recyclable waste paper Thakur et. al(4) used thermophilic ethanologen, yeast strain at 50 o C to produce alcohol from bagasse pith and found that 80% glucose (30g/l) of enzyme hydrolysate was gfermented to
ethanol (9.5 g/l) within 40 h and thereafter some oligosachharides also converted to ethanol bringing the final ethanol concentration 11.5 g/l in the broth. Bioethanol production from mixed wastes using Fungi Archana Mishra et al.( 5) employed enzymatic hydrolysis of biomass, namely rice straw and vegetable wastes by Trichoderma viride followed by fermentation with Sachharomyces cerevisiae. Detailed kinetic studies have been conducted at different temperatures ( 21± 2 o C,27± 2 o C, 33± 2 o C. during 6 days to 12 days of incubation for formation of TRS and total sugar as well as ethanol production. The yield of TRS was found to be 55.27 mg/g of biomass and ethanol of the order of 17.54 mg/ml of substrate from 3:1 ratio of rice straw and vegetable waste after 9 days of incubation at 27 o C and alcohol after 4 days of fermentation at 27 o C. Results of fermentation at different temperature are shown in figure 2. 18 17 16 Yield (mg/ml) 15 14 13 12 11 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 time(days) yield at 21±2 0 C yield at 27±2 0 C yield at 33±2 0 C Figure 2: Ethanol yield at various conditions Bioethanol from agri-residues and groundnut shells Padmaja et.al.(6) utilized various agri-residues such as bagasse, rice straw, cotton straw, groundnut shells using thermophilic anaerobic bacteria,clostridium thermocellum and found 0.20-0.12 g ethanol per g of substrate degraded( compared to the yield of ethanol on pure crystalline cellulose was 0.25 g/g of substrate degraded).the reaction has been carried out at 60 o C and ph of 7.5 under continuous sparging of nitrogen to make the system oxygen free. Mild alkali treatment given to the substrate, enhanced their utilization and ethanol yields. The extent of conversion in the treated and untreated wastes ranged between 65.95 % and 42.68 % respectively. Improved production of ethanol using Zymomonas mobilis from molasses
Using modified strains of zymomonas mobilis for hydrolysed and unhydrolysed molasses, high ethanol production has been obtained over conventional yeast fermentation at an optimum temperature of 30 o C and ph 6(7,8). Ethanol concentration of 47 g/l with 92 % fermentation efficiency was obtained from 20% molasses medium.cane molasses contains sufficient nutrients for growth of Zymomonas mobilis and no supplements were required for ethanol production.effects of temperature, initial sugar concentration and ph on ethanol production and fermentation efficiency were studied. Production of alcohol from Sago wastes Subashini et al.(9) conducted a series of experiments on sago waste( both solid as well as liquid phase) using saccharomyces cerevisiae strain Vits-MI isolated from molasses and found that this strain is betterthan the standard strain MTCC 173.. The process consists of simulataneous saccharification with acids ( 0.3 N hydrochloric as well as 0.3 N sulphuric acid) followed by fermentation.effect of temperature(10 o C-40 o C), concentration of sugars( 10%48%,glucose),pH(2.5-5.5),time (60 min-120 min) were studied for saccharification step followed by fermentation with varying time ( 5 day-20 day) with liquid phase as well as solid phase. Maximum yield of 15.8 % alcohol were obtained in 15 th day in liquid phase. Production of alcohol from muhua flowers Behera et al.(10) attempted from mahua flowers by submerged fermentation (Smf) using immobilized cells of Saccharomyces cerevisiae and Zymomonas mobilis in calcium alginate beads. Maximum ethanol concentration were 154. 5 and 134. 55 gkg -1 flowers using immobilized cells of S. cerevisiae in calcium alginate beads which were found more effective (14. 83% more yield) for ethanol production than immobilized cells of Z. mobilis.the ethanol yields were found of the order 0.483 g/g and 0.473 g/g for S. cerevisiae and z. mobilis respectively. Production of alcohol from corn and tapioca Lehri and Agarwal (11) utilized both corn and tapioca (which are rich sources of carbohydrates, viz., 77.3 and 82.1 % respectively) employing a fungal glucoamylase at 60 o C for 30 h for hydrolysis and found 85 % hydrolysis of both the raw materials.the concentrated hydrolysates containing 13-15% TRS content when subjected to fermentation with distiller yeast, S.cerevisiae NSI-113, at 30 o C for 72 h, resulted alcohol productivity 9 0.496 g/g) with fermentation efficiency of the order of 98%. The alcohol content in wash varied from 8 to 9.1 % (v/v) and the residual sugar content inwash from 0.18 to 0.25 % (w/w). The alcohol yields from corn and tapioca were 362 and 370 litres at 24 h, and 411 and 437 litres per ton, at 72 h, respectively; as compared to about 225 liters per ton of molasses normally obtained in India distilleries operating on conventional batch fermentation process. In the study it is found that when period of fermentation has been varied from 24 h to 72 h the alcohol productivity g/g FS increases at first significantly, then almost remaining constant after 30h. Results regarding yield of reducing sugar as well as productivity of alcohol from both corn and tapioca are shown in figures 3 to 5.
14 12 TRS(g%, w/v) 10 8 6 4 2 y = 0.015x 2-0.746x + 12.96 R² = 0.996 Total reducing sugars Poly. (Total reducing sugars) 0 0 20 40 60 80 Period of fermentation (hrs.) Figure 3: Total reducing sugars by fermentation of Enzymatic hydrolysate of Tapioca powder by C. Cerevisiae (11) 460 Alcohol Litres/Ton of sample 440 420 400 380 360 340 20 30 40 50 60 70 80 Period of Fermentation(Hrs.) Production by Hydrolysates of Corn powder Production by Hydrolysates of Tapioca powder Figure 4: Comparison between quantity of alcohol produced from enzymatic hydrolysates of Corn and Tapioca powders (11)
640 Produced Litres/Ton of FS 630 620 610 600 590 580 20 30 40 50 60 70 80 Period of Fermentation(Hrs.) Production by Hydrolysates of Corn powder Production by Hydrolysates of Tapioca powder Figure 5: Comparison on alcohol production from Enzymatic hydrolysate of corn & Tapioca powders (11) Bioethanol from renewable cellulosic wastes and waste newspapers Ali et al.( 12) studied on the renewable agricultural cellulosic wastes, groundnut hulls, rice husks and waste newspapers for production of bioethanol using two locally isolated microorganisms cellulase producing fungus Aspergillus niger during saccharification and ethanol producing Saccharomyces cerevisiae fofermentation. Groundnut hulls gave highest yield of ethanol in chemically defined medium around 4.5 g/100 g with 5 days of incubation in stationery fermentation process. Results of ethanol production from groundnut Huls in shaking fermentation are shown in figure 6. 5 Ethanol produced (g/100g) 4 3 2 1 0 0 1 2 3 4 5 6 7 Time (in days) ethanol produced with distilled water as varian ethanol produced with lactose as variant ethanol produced with chemically defined medium Figure 6: Ethanol production from groundnut Hulls in shaking fermentation (12)
Bioethanol from Jatropha oilseed cakes Mishra et al. (13) dealt with the bioconversion of cellulose from press cakes of Jatropha oilseeds into ethanol by using the method of dilute acid pretreatment ( sulphuric acid), hydrolysis and fermentation by Saccharomyces cerevisiae. About 80% ethanol was recovered as a result of the process. Jatropha incentives in India was a part of India's goal to achieve energy independence by the year 2012. Jatropha oil is produced from the seeds of the Jatropha curcas, a plant that can grow in wastelands across India, and the oil is considered to be an excellent source of biodiesel. India is keen on reducing its dependence on coal and petroleum to meet its increasing energy demand and encouraging Jatropha cultivation is a crucial component of its energy policy.large plots of waste land have been selected for Jatropha cultivation and will provide much needed employment to the rural poor of India. Businesses are also seeing the planting of Jatropha as a good business opportunity. The Government of India has identified 400,000 square kilometres (98 million acres) of land where Jatropha can be grown, hoping it will replace 20% of India's diesel consumption by 2011 Alcohol from sweet Sorghum( 2 ) The National Institute of agriculture research, Hyderabad has advocated the extraction of ethanol from sweet sorghum. About 800 acres is currently cultivated with sweet sorghum in Andra Pradesh, Maharastra, and Karnataka. The extraction of ethanol from sweet sorghum is cheaper than extraction of alcohol from sugar cane, since the cost of sugar cane is higher than sweet sorghum. The grain from sweet sorghum can be used for ethanol extraction or it can be used as a by-product. Ethanol from Sugar beet(2) The sugar present in sugar beet is normally between 14-16%. One can extract alcohol directly from sugar beet about 75 to 90 litres / tonnes of sugar beet as against te 60 litres alcohol per tonne of sugar cane. The yield per acre is around 40 MT and the average age of the crop is only 4 moontemplating cultivation of sugarbeet.nths as against the 11 months of sugar cane. The water consumption is less by 75 % on cane. That is the reason the Northen states and Tamil nadu are contemplating the production of bioethanol from Jatropha seeds. CONCLUSION Production of Ethanol, its demand, and supply projection from Indian perspective have been reviewed. Production of bioethanol from various sources has been discussed. Some research efforts in Indian research institutions as well as from industry are highlighted. REFERENCES 1. Amiya Kumar Ray,Pradosh Sanyal,Biorefinery based on Indian Distillery- Innovation of Forest Products, 17000, Proceedings of 11 AIChE Annual Meeting, held between Oct.16-Oct.21, at Minneapolis 2011,USA,Paper 228d,pp.206
2. The times of India,July 16, 2012, pp.9 3. Dr. Sanjay Naithani, Dr. Gyanesh Joshi and Aloke Kumar Dubey,Detoxification of acid catalyzed lignocellulosic hydrolyzate to enhance fermentation efficiency for ethanol production,inpaper, vol 14, issue 2, March-A[pril, 2011, pp.14-22 4. Dr. Vasanta V. Thakur, Diwakar Pandey, Dr. R.K.Jain, Dr. R.M.Mathur, Sevond generation biofuels: Bioethanol from lignocellulosic materials,inpaper India, vol.14, Issue 2, March-April, 2011, pp.4-12. 5. Archana Mishra, Mishra N.C., and Yogesh Sharma, Bioethanol production from mixed wastes using fungi, 6. Padmaja A., Venkateshwar S, Seenayya G and Bhagavanth Rao M,Evaluation of cellulosic substrates in the conversion of biomass to ethanol., Indian Chem. Engr., Section A, vol.37, July Sep(1995), pp.140-144. 7. Jain V.K. Present status and prospects of Bacterium Zymomonas mobilis for ethanol production, Proc. of the Eleventh National Convention of Chemical Engineers, Sept. 2829, 1995, pp.iii-1iii-5. 8. Singh Abha and V.K.Jain, Batch fermentation of cane molasses for ethanol production by Zymomonas mobilis, Indian Chemical engineer, Section A. vol.37, No.3, Jul-Sept(1995), pp.95-98 9. Subashini D.,J.Ejilane, A. Radha,M.A.Jayasri and K.Suthindhiran, Ethanol production from Sago waste using Saccharomyces cerevisiae VITS-MI, curr. Res. J. Biol.Sci,3(1):42-51,2011, pp.42-51 10. Behera Shuvashish, Ramesh C Ray, and Rama C Mohanty,Comparative study of bioethanol production from mohua ( Madhuca latifolia L.) flowers by immobilized cells of Saccharomyces cerevisiae and Zymomonas mobilis in calcium alginate beads, Journal of Scientific and Industrial Research, vol.69, June 2010, pp. 472-475 11. Lehri Madhu and P.K. Agarwal, Studies on alcohol production from corn and tapioca, Proceedings of 58 th Annual Convention of The Sugar Technologists Association of India, General & By-Product, pp.85-97, 1996 12. Ali Mir Naiman, and Mazharuddin Khan Mohd., Production of bioethanol fuel from renewable agrobased cellulosic wastes and waste newspapers, International Journal of Engineering Science and Technology(IJEST), vol.3 No.2, Feb 2011,pp. 884-892. 13. Mishra Mohit, Chandrashekhar B, Tanushree Chatterjee and Kanwal Singh, Production of bioethanol from Jatropha oilseeds cakes via dilute acid hydrolysis and fermentation by Saccharomyces cerevisiae, International J of Biotechnology Applications,vol.3, Issue 1, 2011, pp.41-47