About biomass

This folowing article come from the very good website Practical answer

What is biomass?

Biomass is the term used to describe all the organic matter, produced by photosynthesis that exists on the earth’s surface. The source of all energy in biomass is the sun, the biomass acting as a kind of energy store. To make use of biomass for our own energy needs we can simply burn it in an open fire to provide heat for cooking, warming water or warming the air in our home. More sophisticated technologies have been developed for extracting this energy and converting it into useful power and heat in more efficient and convenient ways.
Until relatively recently it was the only form of energy which was used by humans and is still the main source of energy for more than half the world’s population for their domestic energy needs. The extraction of energy from biomass is split into 3 distinct categories:

1. Solid biomass
The use of trees, crop residues, animal and human waste (although not strictly a solid biomass source, it is often included in this category), household or industrial residues for direct combustion to provide heat. Often the solid biomass will undergo physical processing such as cutting, chipping, briquetting, etc. but retains its solid form.

2. Biogas
Organic material to produce a combustible gas known as methane. Animal waste and municipal waste are two common feedstocks for anaerobic digestion

3. Liquid Biofuels
These are obtained by subjecting organic materials to one of various chemical or physical processes to produce a usable, combustible, liquid fuel. Biofuels such as vegetable oils or ethanol are often processed from industrial or commercial residues such as bagasse (sugarcane residue remaining after the sugar is extracted) or from energy crops grown specifically for this purpose. Biofuels are often used in place of petroleum derived liquid fuels.

Biomass use:

Solid biomass is widely used in developing countries, mainly for cooking, heating water and domestic space heating. Biomass is available in varying quantities throughout the developing world - from densely forested areas in the temperate and tropical regions of the world, to sparsely vegetated arid regions where collecting wood fuel for household needs is a time consuming and arduous task.

Biomass Practical Action

In past decades the threat of global deforestation, provided a focus for the efficient use of biomass (as well as introducing alternative fuels) in areas where woodfuel was in particular shortage. Although domestic fuelwood users can suffer greatly from the effects of deforestation, it often arises because of land clearing for agricultural use or for commercial timber. There have been many programmes aimed at developing and disseminating improved stove technologies to reduce the burden, primarily borne by women, of fuelwood collection as well as reducing health risks associated with smoke from burning fuelwood. Technologies have also been introduced to help with the processing of biomass to improve efficiency, allow for easy transportation or to make it more useable. Crop and industrial biomass residues are now widely used in many countries to provide centralised, medium and large-scale production of process heat for electricity production or other commercial end uses. There are several examples in Indonesia of timber processing plants using wood waste-fired boilers to provide heat and electricity for their own needs, and occasionally for sale to other consumers. There are also small scale options to utilising crop residues.