Integrated biogas-ethanol plant using sweet potatoes in Guyana - €110 million investment
An overall investment of some €110 million (US$140m) which would see the creation of a biomass plant to make ethanol and a range of by-products (including electricity from biogas), is planned for the tropical country of Guyana. The plant, when operational, would produce 150 million litres of ethanol per year (2600 barrels per day) and 200 gigawatt-hours of green electricity. According to David Sukhoo, president of the Canada-based Guyanese company Anand Marketing [no website], the ethanol section would cost US$67 million.
The Lands and Surveys Department of Guyana is now working to earmark some 20,000 hectares (50,000 acres) of land for the planting of sweet potatoes, the main feedstock. The land that is being considered consists of intermediate savannahs. The Guyanese National Agricultural Re-search Institute (NARI) is also "fully supporting" the project.
The proposed plant does much more than merely producing liquid biofuels. It will provide:
ethanol :: biodiesel :: biobutanol :: biomass :: bioenergy :: biofuels :: energy :: sustainability :: Africa ::
The company has two similar plants in Ontario and British Colombia, Canada, Sukhoo said. He said these were set up in tobacco growing areas. He said that with the tobacco business not doing very well the plants were set up to bring industry back to the areas. Sukhoo noted the benefits the project could bring about in Guyana pointing to the electricity it would make available and employment.
In the process the sweet potatoes are mashed and jet cooked. They are then treated with enzymes in an enzyme tank to bring about fermentation from which ethanol and the carbon dioxide gas are produced. The fermentation process, "is not for long because of the method we will use," Sukhoo said. The CO2 gas is trapped as a by-product.
Next in the process is distillation to boil off the ethanol as a vapour which would condense back into almost pure ethanol into a storage tank. The ethanol is then denatured, Sukhoo said. This is to make the spirit unfit as a beverage or for internal human medical use.
The remains from the distillation columns are passed to the anaerobic digester. Methane is given off here as a result of the reaction taking place in the digester on the organic matter by anaerobic organisms. This is in an environment lacking oxygen. The particles are also stripped of any liquids by spinning them in a centrifuge. The ammonia is secured from this process.
Water used in the process is made potable by reverse osmosis, Sukhoo said. Reverse osmosis is the process where a solution is forced through a filter which traps any dissolved substances but allowing the solvent, or the medium in which the substances where dissolved, to pass.
Source: Stabroek News, Guyana.
The Lands and Surveys Department of Guyana is now working to earmark some 20,000 hectares (50,000 acres) of land for the planting of sweet potatoes, the main feedstock. The land that is being considered consists of intermediate savannahs. The Guyanese National Agricultural Re-search Institute (NARI) is also "fully supporting" the project.
The proposed plant does much more than merely producing liquid biofuels. It will provide:
- 120 million cubic metres of methane (bio-gas) per year because of the inclusion of an anaerobic digester fed by field and processing based biomass residues. This energy source will be used to generate steam to power a generator to produce electricity.
- 150,000 metric tonnes of organic fertilizer per year
- 150,000 metric tonnes of carbon dioxide gas (CO2) which will be used in the manufacturing of soft drink beverages
- excess steam will also be available which will be used for sterilising purposes (such as the sterilisation of containers and fresh agricultural products)
- several tens of thousands of liters of pure drinking water, from a reverse-osmosis plant driven by the steam, would also be released as a byproduct
- finally, the biomass plant provides 20,000 metric tonnes of ammonia, that can be converted into bio-fertilizer (namely N-fertilizer, which is normally derived from natural gas)
- sweet potato (Ipomoea batatas - not related to the potatoes known in the West, see picture) [Handbook of Energy Crops infosheet], an excellent sugar and starch rich bioenergy crop that thrives well in harsh conditions and requires almost no fertilizer inputs; sweet potatoes produce about 3 to 4 times more ethanol per hectare (between 8000-10000 liters per hectare) than corn (2500-3500 litres per hectare)
- cassava and rice residues, of which Guyana produces a lot - market prices for these feedstocks have steadily declined, and the biomass plant could boost them
ethanol :: biodiesel :: biobutanol :: biomass :: bioenergy :: biofuels :: energy :: sustainability :: Africa ::
The company has two similar plants in Ontario and British Colombia, Canada, Sukhoo said. He said these were set up in tobacco growing areas. He said that with the tobacco business not doing very well the plants were set up to bring industry back to the areas. Sukhoo noted the benefits the project could bring about in Guyana pointing to the electricity it would make available and employment.
In the process the sweet potatoes are mashed and jet cooked. They are then treated with enzymes in an enzyme tank to bring about fermentation from which ethanol and the carbon dioxide gas are produced. The fermentation process, "is not for long because of the method we will use," Sukhoo said. The CO2 gas is trapped as a by-product.
Next in the process is distillation to boil off the ethanol as a vapour which would condense back into almost pure ethanol into a storage tank. The ethanol is then denatured, Sukhoo said. This is to make the spirit unfit as a beverage or for internal human medical use.
The remains from the distillation columns are passed to the anaerobic digester. Methane is given off here as a result of the reaction taking place in the digester on the organic matter by anaerobic organisms. This is in an environment lacking oxygen. The particles are also stripped of any liquids by spinning them in a centrifuge. The ammonia is secured from this process.
Water used in the process is made potable by reverse osmosis, Sukhoo said. Reverse osmosis is the process where a solution is forced through a filter which traps any dissolved substances but allowing the solvent, or the medium in which the substances where dissolved, to pass.
Source: Stabroek News, Guyana.
0 Comments:
Post a Comment
Links to this post:
Create a Link
<< Home