Biological Fuel Generation Syed Abdullah Gilani

Fossil fuels are the stored energy or ancient sunlight Fossil fuels are the stored energy or ancient sunlight. Mankind is burning fossil fuels (oil, gas reserves) for energy, causing global warming by releasing carbon dioxide into the environment that was locked in earth. Alternative fuel resources must be used such as biological fuel (biofuel). Biofuels: plant materials are burned the carbon locked in the biomass for a relatively short period of time is released back into the atmosphere thus recycling the carbon dioxide.

Biofuel is the generation of combustible/ usable energy from biological source. This can be liquid fuels such as bioethanol, biodiesel gaseous fuels e.g., methane or direct solid heat energy, e.g., wood

Main biological energy sources or crops Sugar crops Sugar cane, sugar beet: sugars is extracted and fermented to bioethanol. Starch crops Maize, barley, wheat, oats, cassava: starch is enzymatically hydrolyzed to sugars and fermented to bioethanol. Cellulose crops, waste Straw, bagasse, woody waste, cropped trees: the hemicellulose can be enzymatically hydrolyzed to sugars and fermented to bioethanol. Oil crops Rapeseed, linseed, sunflower, castor oil, groundnut: Oil extracted and trans-esterified to biodiesel. Organic wastes / manures Complex microbial fermentations to methane or methanol. Solid energy crops Coppiced trees, sorghum, reeds, grasses: Direct burning alone or with other conventional sources e.g., coal.

Bioethanol from biomass Traditional method of alcohol production is by fermentation of sugars and starch – the first microbial process used by human. Industrial alcohol is produced synthetically i.e., non-microbial, deriving from petrochemical processes. Petrochemical ethanol is made by the hydration of ethene.

Flow diagram for the production of ethanol Feedstock Molasses, Cane juice, Starch, cellulose Preparation Hydrolysis, Clarification, Filtration, Pasteurization Fermentation CO2: Yeast Distillation 96% ethanol Dehydration Absolute ethanol Denaturation Fertilizer Feed Fuel Methane Stillage Concentration

Biodiesel Conventional diesel is a by-product of the crude oil distillation process which also results in the formation petroleum and has a high aromatic and sulphur content. Biodiesel is produced from vegetable oils (e.g., rapeseed oil) and is available as alternative to conventional diesel. Successful method of biodiesel production is by trans-esterification of plant oil with methanol (or ethanol) in the presence of the catalyst, sodium hydroxide, at 50°C resulting in the formation of fatty acid methyl ester and glycerol. The glycerol is settled and biodiesel is purified and used directly.

Advantages of biodiesel Reduces the dependence on fossil fuel use/imports. Has a lower flashpoint and does not ignite. Free of toxic aromatic and sulphur compounds. Biodegradable – reducing environmental damage due to spillage. Biodiesel is renewable.

Methane Methane gas can be used for the generation of mechanical, electrical and heat energy, It is now extensively used as a fuel source for domestic and industrial purposes through national gas pipelines. Or it can be converted to methanol and used as fuel in internal combustion engines. Methane can be used produced from sewage, agricultural and urban wastes, and in biogas reactor

This purified hydrogen gas is pushed into the generator. Four African girls created Urine-powered generator that produces electricity for six hours from a single liter of urine Urine is put into an electrolytic cell, which separates out the hydrogen. The hydrogen goes into a water filter for purification, which then gets pushed into the gas cylinder. The gas cylinder pushes hydrogen into a cylinder of liquid borax, which is used to remove the moisture from the hydrogen gas. This purified hydrogen gas is pushed into the generator. http://news.yahoo.com/blogs/sideshow/urine-powered-generator-unveiled-international-exhibition-234718329.html News on 13th November 2012