Title of Invention

PRETREATMENT OF AGRICULTURAL RESIDUES AS FEEDS TO PRODUCE BIOGAS

Abstract

The present invention provides a method for pretreatment of agricultural residue. The method uses physical and mechanical means to change floating nature of the agricultural residue to a bottom settling sludge and enables to form slurry that can be pumped easily. Further, the method ensures that any scum formed on the surface is made to sink thus ensuring a continuous contact of the biological matter with the microbial consortia.

Full Text

FORM 2 THE PATENT ACT 1970 & The Patents Rules, 2003 PROVISIONAL / COMPLETE SPECIFICATION (See section 10 and rule 13) 1. TITLE OF THE INVENTION: "Pretreatment of Agricultural Residues as Feeds to Produce Biogas' 2. APPLICANT (a) NAME: (b) NATIONALITY: (c) ADDRESS: 1. Kirloskar Oil Engines Limited 2. Gangotree Eco Technologies Pvt. Ltd. Indian Companies registered under the provisions of the Companies Act/1956 1. Laxmanrao Kirloskar Path, Khadki, Pune 411003, M. S. India. 2. Flat no.l Susheeldatta Apts., Plot No. 4, Padamarekha Society Karvenagar, Pune 411052, M. S., India. 3. PREAMBLE TO THE DESCRIPTION PROVISIONAL The following specification describes the invention. COMPLETE The following specification particularly describes the invention and the manner in which it is to be performs Technical field: The present invention relates to the pretreatment of agricultural residues, which is used as feeds in the biogas plants for generating biogas. Background of the invention & the Prior art: With the supply of fossil fuels getting progressively scarce, there is an increasing trend to generate, energy from renewable sources. Several approaches have been tried for this purpose such as conversion of vegetable oils to produce bio-diesel, conversion of corn or other starch rich feeds to produce bio - ethanol, utilization of biomass by gasification technique and the like. Use of this biomass has created some side effects in the energy market. The large scale diversion of corn for ethanol production has been viewed as a major factor leading to reduced availability of foods and hence, an increase in world food prices. Generation of biogas from biomass has been mainly used as a means of waste utilization or of effluent treatment. This route has recently been found attractive as a commercial source of energy and a good deal of work is reported. A variety of grasses and agricultural residues have been tried in attempts to convert these into methane as a source of energy. One of the most popular feeds tried is maize whole plant. It has been used in European experiments in the form of silage to ensure round the year availability. As a practice, maize is fed in the form of whole plant - leaves, stems, grain and cob included. A screw type device is commonly used for introducing the biomass into the biogas plant from its bottom. Special agitators are used to break the scum and ensure a continuous contact of the bio-matter with microbial consortia that serially convert the degradable matter into biogas. After a predetermined residence time, the 2 unconverted biomass exits the digester from the bottom without disturbing the anaerobic conditions. The biomass is partially processed before feeding into the digester. Mostly, the whole plant is cut into pieces and silaged. One of the major problems is that the feed in question tends to float in water and presents difficulty in its conversion to biogas. For operating a continuous or a continuous batch-fed biogas plant, the feed needs to enter the digester from its bottom to keep the system in anaerobic condition. The floating matter needs special designs for ensuring this condition. The material tends to form a scum once entered. The present invention, in which a combination of physical and mechanical means, such as size reduction, pH and temperature adjustments and surface tension alterations have been made to overcome this problem, helps create a pumpable slurry of biomass that can enter the biogas plant from its bottom inlet and reduces or eliminates scum formation. Thus, the difficulties experienced in prior art is overcome. 1) Emerging trends in small scale biogas plants for agro residues and biomass feedstock - A case study from India. By H N Chanakya and Rene Moletta at 'Centre for Sustainable Technologies (formerly ASTRA Centre), Indian Institute of Science, Bangalore- 560 012, India, [email protected] & 'Laboratory for Environmental Biotechnology', INRA, Narbonne, 11100, France, [email protected] air Abstract: A case study is presented on emerging trends in small scale biogas plants for agri-residues and biomass. Work done at five different Indian institutions was reviewed. Data on a number of plant designs that can use biomass in place of cow dung is presented. 3 The specific reference is made to continuously floating biomass in the biogas digester. Drawback: Floating biomass has been identified as a major drawback for operating the plants in a, continuous manner. No appropriate method is suggested to settle the biomass in the digester. 2) WO/2007/059688- A METHOD AND AN APPARATUS TO PRODUCE BIOGAS A method and an apparatus to produce biogas with garbage and sewage and plant are provided, whose advantage is continuous production on a scale. The processing comprises the following steps: loading the material to be treated and basic substance into a liquid permeable container; pending the container into a sieving tank to sieve and screen; sending the container into a pretreatment tank for heating and sterilizing; sending the container into a sealed biogas generating tank for fermentation; extracting the container from the tank after finishing the fermentation and sending the new container filled with the material to be treated; opening the extracted container to separate the residue therein. Drawback: No pretreatment is done to the feed. When agricultural residues are used, it is considered to handle huge amount of biomass. Only the different methods of handling the biomass are explained in above patent application. 3) (WO/2005/061114) METHOD AND PLANT FOR PRE-TREATMENT OF SOURCE SEPARATED WET ORGANIC WASTE. .Method and plant for pre-treatment of source separated wet organic waste from house holds, institutional house holds etc., comprising shredding of the waste in a course shredder unit, allowing the shredded material to fall down to a fine dissolver unit where more heavy objects are removed, adding a process liquid until a desired content of solids of 6 to 12 % is achieved, shredding the mixture with a rapid rotating paddle mechanism, transferring the mixture to a separation 4 init for plastics, and transportation of the remainder mixture into a plant for production of biogas and decomposing remainder. Drawback: The method is used specifically for the organic waste from households and not for agricultural residues as such. The agricultural residues do not comprise plastic like waste materials.. Also, the organic material is only shredded and not pulverized. 4) WO 2006017991- STEPPED SEQUENTIAL TREATMENT METHOD FOR MUNICIPAL DOMESTIC REFUSE The present invention provides a treatment method of municipal domestic refuse. In the method the organic matter processes an anaerobic fermentation; the obtained methane can be helpful to burning to generate electricity. The biogas residue from the anaerobic fermentation can be used as a culture material for growing edible mushrooms. The residue discharged from edible mushrooms can be used to cultivate earthworm. Besides the organics, the other substance of the municipal domestic refuse will be incinerated to generate electricity. The present invention realizes a comprehensive utilization of waste resource. Abstract: The process is for waste disposal. There is no special pretreatment for the feedstock for producing biogas. The output of one stage is utilized for the next sequential stage. 5) (WO/2004/076082) PROCESS FOR TREATMENT OF AN ORGANIC WASTE MATERIAL The present invention relates to a process for treatment of an organic waste material, the process comprising the steps of subjecting said organic waste material to a heat treatment process, where the bio-availability of a resulting hydrolyzed product is increased ior later treatment, and of subjecting said hydrolyzed product to at least one anaerobic fermentation process whereby biogas is produced and an organic residue is formed, wherein said process .5 furthermore comprises a first step of providing said organic waste material in a solid form to said heat treatment process. The present invention furthermore relates to a process for treatment of an organic waste material wherein the aforementioned process furthermore comprises a fourth and a fifth step of separating said organic residue into a liquid phase and a solid phase, and combusting said solid phase of said organic residue at a maximum temperature of 900°C resulting in liberation of thermal energy and concentrated combustion residue, and the formation of flue gasses. Abstract: The method suggests only 'heating' as the part of the pre treatment. There is no mention of particle size reduction to improve on the output of biogas. Other Drawbacks in Prior art: • The processes have large retention time for feeds into the digester. It ranges from 20 to 40 days. The longer retention time increases the capital cost accordingly. • The biomass floating in the digester has to be regularly pushed down in the body of the digester to ensure a proper contact. Even after deploying specially designed agitators, the contact with the digester medium is not appropriate. • Plants designed for feeds that can be readily fed in the form of slurry cannot be used for agricultural residue as feeds. Object of the invention: The object of the present invention is to provide a method which uses physical and mechanical means to change floating nature of the agricultural residue to a bottom settling sludge and enables to form slurry that can be pumped in easily. Another object of the present invention is to ensure an appropriate contact between the biomass and the digestion microbial culture medium. 6 Yet another object of the present invention is to reduce the capital cost of the equipment. Detailed description of present invention: The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. The present invention describes a process that uses physical and mechanical methods to change floating nature of the agricultural residue to a bottom settling sludge and enables formation of slurry that can be pumped easily. The slurry thus formed can be easily introduced in the digester using a mud pump or sludge pump and the digester does not need any special design, for inlets and outlets of the slurry. Once the pretreated agricultural residue enters the biogas plant there is negligible scum formation in the digester. This ensures a good contact between the biomass and the digestion microbial culture medium. Exit of the biomass from the plant is simple as well. Advantages of the present invention: • Any conventional digester can be used for biogas generation. No specific design is required. • Once the agricultural residue is properly pretreated, the further process of microbial digestion is simplified. This result in a saving of energy required for further operations. 7 • The proper pre-treatment effectively results in reduced retention time of the feedstock and that leads to a cost-saving of capital, as the biogas plant size gets reduced. Dated this 1st October 2008 M. D. BHATE (Agent for the applicant)

Documents:

2135-MUM-2008-ABSTRACT(6-10-2009).pdf

2135-MUM-2008-ASSIGNMENT(29-9-2009).pdf

2135-MUM-2008-CLAIMS(6-10-2009).pdf

2135-MUM-2008-CLAIMS(AMENDED)-(10-12-2013).pdf

2135-MUM-2008-CLAIMS(AMENDED)-(7-3-2014).pdf

2135-MUM-2008-CLAIMS(MARKED COPY)-(10-12-2013).pdf

2135-MUM-2008-CORRESPONDENCE(23-9-2009).pdf

2135-MUM-2008-CORRESPONDENCE(5-10-2009).pdf

2135-MUM-2008-CORRESPONDENCE(6-10-2009).pdf

2135-MUM-2008-CORRESPONDENCE(6-8-2010).pdf

2135-mum-2008-correspondence.pdf

2135-MUM-2008-DESCRIPTION(COMPLETE)-(6-10-2009).pdf

2135-mum-2008-description(provisional).doc

2135-mum-2008-description(provisional).pdf

2135-MUM-2008-FORM 1(7-3-2014).pdf

2135-mum-2008-form 1.pdf

2135-MUM-2008-FORM 13(10-12-2013).pdf

2135-MUM-2008-FORM 18(16-9-2010).pdf

2135-mum-2008-form 2(6-10-2009).pdf

2135-MUM-2008-FORM 2(TITLE PAGE)-(6-10-2009).pdf

2135-MUM-2008-FORM 2(TITLE PAGE)-(7-3-2014).pdf

2135-mum-2008-form 2(title page).pdf

2135-mum-2008-form 2.doc

2135-mum-2008-form 2.pdf

2135-MUM-2008-FORM 3(6-10-2009).pdf

2135-mum-2008-form 3.pdf

2135-MUM-2008-FORM 5(6-10-2009).pdf

2135-mum-2008-form 6(29-9-2009).pdf

2135-MUM-2008-GENERAL POWER OF ATTORNEY(10-12-2013).pdf

2135-MUM-2008-MARKED COPY(7-3-2014).pdf

2135-mum-2008-power of authority.pdf

2135-MUM-2008-REPLY TO EXAMINATION REPORT(10-12-2013).pdf

2135-MUM-2008-REPLY TO HEARING(7-3-2014).pdf

2135-MUM-2008-SPECIFICATION(AMENDED)-(7-3-2014).pdf