# US 2008/0187976 A1 · Three-Step Biomethanation Process

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2008/0187976 A1
- Document ID: US20080187976A1
- Status: Published application
- Kind: A1
- Application number: 12/065,764
- Filed: 2006-08-30
- Published: 2008-08-07
- Earliest claimed: 2005-09-05
- Assignees: Gangotree Resource Developers Pvt. Ltd.
- Inventors: Santosh Gondhalekar; Arvind Joshi; Shreekant Patwardhan; Neelesh Kulkarni; Vijay Paranjpye
- Web page: https://patentgrep.com/patent/US20080187976A1

## CPC

- C12P 5/023: {Methane}
- C02F 11/04: Anaerobic treatment; Production of methane by such processes
- C02F 3/348: {characterised by the way or the form in which the microorganisms are added or dosed}
- Y02E 50/30: Fuel from waste, e.g. synthetic alcohol or diesel
- Y02W 10/20: Sludge processing
- C12P: FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE {(brewing of beer C12C; producing vinegar C12J; producing specific peptides or proteins C07K; producing enzymes C12N9/00; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; measuring or testing processes involving enzymes or microorganisms C12Q; measuring or testing processes involving nucleic acid amplification reactions C12Q1/6844; fermentation processes to form a food composition, A21 or A23; compounds in general, see the relevant compound class, e.g. C01, C07)}
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT

## Abstract

A triphasic biomethanation process, to convert starch or sugary agricultural feed stock into a methane rich gas mixture for facilitating generation of biogas to be used as kitchen fuels, electrical power or transportation from renewable biomass in a cost-effective manner. The process brings about conversion of starch-rich or sugar-rich biomass into methane through three stages, namely, hydrolysis, acidogenesis and methane formation. The present invention deploys enzymes/physical/microbial parameters to hasten the hydrolytic reaction in the first stage. It also deploys microbial consortia that have been enriched for a targeted feed in order to speed up the process of conversion. The formation of alcohol from starch is prevented, as a result of the consortia deployed, the conversion efficiency is substantially improved and the retention time is also reduced to cut the capital cost of the plant.

## Claims

### Claim 1

A triphasic biomethanation process for converting starch or sugary agricultural feed stock into a methane rich gas mixture comprising of dissolution and hydrolysis of agricultural feed rich in starch and sugar at temperatures between 40° C. to 90° C., subject to the moist heat; thereafter the agricultural feed is exposed to appropriate enzymes or to microbial populations or a combination of enzymes and is carried out in less than 24 hours; the product obtained from the hydrolysis process is led in second reactor to convert the hydrolysed submits into short chain fatty acids, subject to enriched microbial consortia that is enriched from natural biological mixtures; this acidogenesis reaction is carried out between temperatures 30° C. to 50° C. with occasional stirring of the mixture; the reactor size is optimized according to microbial population and the retention time required for conversion is usually less than 72 hours; the output is subjected to methanogenesis by methanogenic micro-organisms for converting the short chain fatty acids into a mixture of methane, carbon dioxide and traces of hydrogen sulphide; depending upon the feed material and the methane rich gas, being not less than 500 litres per kilogram of starch/sugary substance of the feed and the methane content of the gas so evolved is not less than 55%, starts evolving; the effective retention time in this stage being less than 96 hours and thereby the process gets completed in three stages, enabling the operation of each stage at its optimal condition.

### Claim 2 (depends on 1)

A triphasic biomethanation process for converting starch or sugary agricultural feed stock into a methane rich gas mixture as claimed in claim 1 wherein crude tapioca starch which is rich in starch, is converted into a methane gas mixture.

### Claim 3 (depends on 1)

A triphasic biomethanation process for converting starch or sugary agricultural feed stock into a methane rich gas mixture as claimed in claim 1 wherein maize powder which is rich in starch, is converted into a methane gas mixture.

### Claim 4 (depends on 1)

A triphasic biomethanation process for converting starch or sugary agricultural feed stock into a methane rich gas mixture as claimed in claim 1 wherein sugarcane which is rich in sugar, is converted into a methane gas mixture.

### Claim 5

(canceled)