First generation BIOFUELS

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What is biofuel?

Biofuels are any liquid, solid or gaseous fuels

produced from organic matter. The

extensive range of organic materials used

for biofuel production includes starch and

sugary plants such as corn, wheat or sugar

cane; oily plants such as rape seed, soya

beans or jatropha; vegetable oils and

animal fats; wood and straw; algae and

organic waste and others.

First Generation Biofuels

• The two most common 1st generation biofuels are bioethanol from starch or sugar crops and biodiesel from oil-rich plants. As these fuels are primarily derived from crops which may also be used as food for animals and humans.

Vegetable Oil-Edible vegetable oil is generally not used as fuel, but lower quality oil can be used for this purpose. Used vegetable oil is increasingly being processed into biodiesel, or (more rarely) cleaned of water and particulates and used as a fuel.

Biodiesel- Biodiesel is the most common biofuel in Europe. It is produced from oils or fats using transesterification and is a liquid similar in composition to fossil/mineral diesel. Its chemical name is fatty acid methyl (or ethyl) ester (FAME).

• Bioalcohol-:Biologically produced alcohols, most commonly ethanol, and

less commonly propanol and butanol, are produced by the action of microorganisms and enzymes through the fermentation of sugars or starches (easiest), or cellulose (which is more difficult).

• Bioethers-:Bio ethers (also referred to as fuel ethers or fuel oxygenates) are

cost-effective compounds that act as octane enhancers. They also enhance engine performance, whilst significantly reducing engine wear and toxic exhaust emissions. Greatly reducing the amount of ground-level ozone, they contribute to the quality of the air we breathe.

• Syngas-: Syngas, a mixture of carbon monoxide and hydrogen, is produced by partial combustion of biomass, that is, combustion with an amount of oxygen that is not sufficient to convert the biomass completely to carbon dioxide and water. Before partial combustion the biomass is dried, and sometimes pyrolysed.

• The resulting gas mixture, syngas, is itself a fuel. Using the syngas is more efficient than direct combustion of the original biofuel; more of the energy contained in the fuel is extracted

• Solid Biofuels-:Examples include wood, sawdust, grass cuttings, domestic refuse, charcoal, agricultural waste, non-food energy crops (see picture), and dried manure.

• When raw biomass is already in a suitable form (such as firewood), it can burn directly in a stove or furnace to provide heat or raise steam.

• Biogas-:Biogas is produced by the process

of anaerobic digestion of organic material by anaerobes. It can be produced either from biodegradable waste materials or by the use of energy crops fed into anaerobic digesters to supplement gas yields.

Poplar grown for fuel in the UK.

Green diesel

• Green diesel, also known as renewable diesel, is a form of diesel fuel which is derived from renewable feedstock rather than the fossil feedstock used in most diesel fuels. Green diesel feedstock can be sourced from a variety of oils including canola, algae, jatropha and salicornia in addition to tallow. Green diesel uses traditional fractional distillation to process the oils, not to be confused with biodiesel which is chemically quite different and processed using transesterification.

• “Green Diesel” as commonly known in Ireland should not be confused with dyed green diesel sold at a lower tax rate for agriculture purposes, using the dye allows custom officers to determine if a person is using the cheaper diesel in higher taxed applications such as commercial haulage or cars.

Ethanol yield from selected sugary materials (sinha and kishore,1991)

Raw material Possible production(t/ha)

Carbohydrate content(%)

Ethanol yields (litre/t)

Beet 40-50 16 90-100

Sugarcane 50-100 13 60-80

Maize 4-8 60 360-400

Wheat 2-5 62 370-420

barley 2-4 52 310-350

The three main methods for the development of biofuels:

1. burning of dry organic wastes

2. energy forestry

3. the fermentation of wet wastes

Plant oil

Pressing and extraction

Rapseed, palm, soya, sunflower plant

esterification

separation

biodiesel

hydrogenation

Diesel fuel

glycerol

methanol

Directly from plant

Commercial production of ethanol involves

three steps-:Wheat straw(500gm)

Cellulosic pulp(400gm)

xylose(40gm)

Glucose(105gm)

ethanol

(10gm) ethanol

(42gm)

1.Preparation of substrate

2. Fermentation3. Distillation

Why Use Biofuels over Fossil Fuels?

Biofuels - Are They The Future?

What are the benefits of biofuels?

Drawbacks of first generation biofuel• contribute to higher food prices due to competition

with food crops;

• are an expensive option for energy security taking into account total production costs excluding government grants and subsidies;

• provide only limited GHG reduction benefits sugarcane ethanol, and at relatively high costs in terms of $/tonne of carbon dioxide ($/t CO2) avoided;

• do not meet their claimed environmental benefits because the biomass feedstock may not always be produced sustainably;

• are accelerating deforestation (with other potentially indirect land use effects also to be accounted for);

• potentially have a negative impact on biodiversity; and

• compete for scarce water resources in some regions.