M1RCEN Journal, 1988, 4, 95-98
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Status of biomethanation development in India
B. P. Gupta Madhya Pradesh Urja Vikas Nigam Ltd., Bhopal, India
Introduction
India has more than 142 alcohol distilleries. The annual licensed capacity of these distilleries is about 800 million litres. Generally, alcohol production is based on molasses as raw material and generates 14 to 15 litres of stillage per litre of alcohol. Thus about 12000 million litres of stillage are produced every year. This effluent contains high percentage of organic matter and has BOD as high as 40000 ppm to 55 000 ppm. The organic matter is primarily non-sugar, almost entirely biodegradable and is a useful source for biomethanation, capable of generating 20 to 30 litres of biogas per litre of stillage under suitable anaerobic conditions. Presently this enormous quantity of stillage is not only being wasted but is also creating serious problems of water and air pollution. It also gives off a foul smell and is a nuisance to the neighbourhood. This agro-industrial effluent could be effectively utilized as an additional and cheap source of energy through the process of biomethanation which will ultimately lead to the production of very good organic manure from the distillery effluent. There are three major methods of treatment of stillage. Firstly, anaerobic digestion in closed digesters to recover methane gas, followed by further biological aeration treatment to meet the desired standards of the effluent before it is released from the distilleries. Secondly, concentration and incineration of the effluent to recover potash and steam. Thirdly, anaerobic fermentation in open lagoons followed by further biological aeration treatment without recovery of any useful by-products. Surprisingly a large number of distilleries in India do not adopt any of the methods of treatment of stillage. Only a few of them use anaerobic lagooning methods. Biomethanation in distilleries
(1) Advantages The anaerobic treatment of distillery wastes in India is particularly relevant for several reasons. Firstly, the distilleries are numerous and widespread and huge quantities of highly concentrated biodegradable organic effluents are generated. Secondly, the existing methods are inadequate and the alternative activated-sludge aerobic treatment may be comparatively much more expensive. Thirdly, the distilleries use 9 Oxford UniversityPress 1988
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coal and furnace oil for the distillation process and the methane recovered could substitute part of the fuel requirements. Lastly, the ambient temperature in India averages 30~ or more for most of the year. Since the temperature range of 30 to 35~ is optimum for anaerobic processes, the anaerobic reactor heating costs as required in cold countries may be avoided.
(2) Realizations Recently four distilleries have adopted the biomethanation techniques to treat their effluents. These distilleries are: (a) Ashok Organic Industries Ltd. (Pungam, Ankleshwar, Baruch District, Gujrat, India). This industry has adopted the 'Aqua Technos Process' which consists of a combination of anaerobic methane fermentation (monophasic, thermophilic, contact reactor), aerobic activated sludge process and chemical treatment process. Ashok Organic Industries are the sole selling agent of this technology in India and have constructed one plant at their own distillery using this technology. Their principals are Aqua Technos Co. Ltd. (Bangkok, Thailand). (b) Cellulose Products of India Ltd. (Pungam, Ankelshwar, Baruch District, Gujrat, India). This industry has recently commissioned a plant for the treatment of 300 m 3 effluent per day at their own distillery in Pungam. The process adopted is biphasic and works in the mesophilic range. The plant cost is US$525000 of which 33% is subsidized by the Department of Non-Conventional Energy Souyrces, New Delhi, 15% by the Gujrat Energy Development Agency, Baroda, and 50% from the unit's own resources. (c) Walchandnagar Industries (Walchandnagar 413114, Pune District, Maharashtra, India). This industry has been working since 1971-1972 in the field of treatment of stillage. A pilot plant of 10 m 3 digester volume was constructed in May 1984 and used the UASB (Upflow Anaerobic Sludge Blanket) process developed by Dr. Lettinga of The Netherlands. A pre-acidification stage was also added to this plant in October 1984 which gave very good results and improved the performances of the system. (d) Mohan Meakins (Kasauli, Himachal Pradesh, India). This industry secured the services of Walchandnagar Industries Ltd. and constructed a 75-m 3 effluent per day processing plant of their own design. This plant was expected to be commissioned by May 1986. The present status is not known. The expected BOD reduction was at least 90%.
(3) Technical know-how availability As already mentioned, Ashok Organic Industries are the sole selling agent of the 'Aqua Technos Process' in India. Similarly, technical know-how is available from Vam Organic Chemical Ltd. (Bhartiya gram-244223, Muradabad District, U.P., India) who entered into collaboration with Biotim N.V. of Belgium for setting up biogas plants based on stillage in India. It is reported that the biggest biogas plant of the world with a capacity to treat 4000 m 3 of stillage coming from a distillery based on sugar-cane molasses has been constructed by Biotim in Thailand. Kolhapur Sugar Mills Ltd. (Udyog Bhawan, Walchand Hira Chand Marg., Ballard Estate, Bombay400038, India) recently concluded a collaboration agreement with Soci6t6 G6n6rale
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pour les Techniques Nouvelles (SGN) of France for the treatment of distillery effluents by biomethanation techniques. This process is based on a monophasic and operates as a mesophilic, packed reactor. Finally, the National Heavy Engineering Co-operatives Ltd. (16, Mahatma Gandhi Road, Pune, Maharashtra411001, India) also offers on a completely turnkey basis effluent treatment plants for distilleries.
(4) Incentives for development In India, on one hand there is pressure from public Government, and pollution control boards for treatment of effluents before their release to land, canal or river. On the other hand, assistance and subsidies are provided by the Department of NonConventional Energy Sources (DNES), Government of India, and the Industrial Development Bank of India (IDBI) for the promotion of effluent treatment plants based on biomethanation techniques. An outright subsidy of 33% on incremental costs of biomethanation system is provided by DNES, New Delhi, and IDBI provides assistance to distilleries for treatment and disposal of stillage both under the refinance and the bill rediscounting schemes. There are various options available for the treatment of effluents through the process of biomethanation. People will adopt the process on the basis of initial investment, payback period, quality of the treated effluent, ease of operation, availability of financial assistance, grants or loans from various agencies and also after seeing the performances of the plants already installed in the country. In India raw material and alcohol prices are controlled by Government. It is reported that the profit earned by distilleries is low. This is one of the main reasons for the delay by the distilleries to adopt the process of biomethanation. They are unable to experiment with the various biomethanation techniques available in the world using their own resources. Thus there is an urgent need to identify the best technology, e.g. the one with the lowest investment, the shortest payback period and the best suitability to the climatic conditions of India. Biomethanation of stillage
India also has a few biogas plants based on sewage wastes working at Okhla (New Delhi), Dadar (Bombay) and the Bharat Heavy Electrical Ltd. (BHEL) township (Bhopal). The B H E L plant has been working satisfactorily since 1961-62. It is supplying fuel gas to a hospital and a few families in the surroundings. Okhla plant has been supplying fuel gas to more than 1000 families in the vicinity for many years. There is lot of scope for installation of sewage-based biogas plants. A garbage-based (landfill) biomethanation plant is also operating in New Delhi. The gas produced is being used for generation of electricity. Biomethanation of manure
There are about 200 community or institutional type biogas plants and more than 200000 family-type biogas plants based on animal waste functioning in India. The size of family-type biogas plants varies from i m 3 to 15 m 3. Institutional plants go from 35 m 3 to 140 m 3 and multiples of the same.
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Summary More than 142 distilleries in India produce 12000 million litres of effluent per year with a biogas potential of 22 to 30 litres per litre of effluent. Only four distilleries already produce biogas from their effluent. In these distilleries the biogas replaces coal for the production of energy. Incentives for the development of biomethanation are provided in the form of ediction of pollution control laws, subsidies on incremental costs, special refinance and discounting schemes, etc. Ashok Organics Ltd. possesses the know-how and sells the technology.
R6sum6 Etats du d(veloppement du biogaz en Inde En Inde, plus de 142 distilleries produisent 12 millions de m 3 d'effluents par an, avec un potentiel de production de biogaz de 22 ~ 30 m 3 par m 3 d'effluent. A l'heure actuelle quatre distilleries seulement produisent du biogaz ~ partir de leurs effluents. Dans ces distilleries le biogaz remplace le charbon pour la production d'6nergie. I1 existe pourtant des incitants au d6veloppement de la biom6thanisation, sous la forme de subsides, de programmes sp6ciaux de financement, de taux d'int6r6ts avantageux et de lois pour le contr61e de la pollution. De plus une firme indienne, Ashok Organics, poss6de le know how et vend la technologie.
Resumen Estado de desarrollo de la biometanci6n en la India M~is de 142 destilerias en la India producen 12000 millones le litros de efluentes al afio, con un potencial para la producci6n de biogas de 22 a 30 m 3 por litro de efluente. Unicamente 4 destilerias producen biogas a partir de sus efluentes. En estas destilerias el biogas sustituye al carb6n para la producci6n de energfa. Se esta incentivando el desarrollo de sistemas de biometanaci6n mediante la promulgaci6n de leyes para el control de la poluci6n, subsidios para los costes instrumentales y planes especiales de descuento y financiaci6n. Mesas Ashok Organics Ltd. posee y vende la tecnologia adecuada.
