. Bioenergy:

Bioenergy is renewable energy made available from materials derived from biological sources. 

Biomass:

       Biomass is any organic material, may include wood, wood waste, straw, manure, sugar cane and many other byproducts from a variety of agricultural processes.

Biomass energy:

Biomass continues to account for an estimated 1/3rd of primary energy use, while in the poorest counties up to 90% of all energy is supplied by biomass .Biomass energy, or bio energy is the conversion of biomass (organic material originating from plants, trees, and crops and essentially the collection and storage of the sun’s energy through photosynthesis) into useful forms of energy such as heat, electricity, and liquid fuels.

 Biomass energy conversion technologies

1.Combustion

2. Gasification

3. Pyrolysis

Primary energy conversion technologies

1. Combustion - direct combustion of biomass is the most common way of converting biomass to energy - both heat and electricity. Compared to the gasification and pyrolysis it is the simplest and most developed. 

2.Gasification - gasification is a high-temperature (1200-1400 Degree Celsius) thermo chemical conversion process but the process is used for production of gas, instead of heat.

3.Pyrolysis - thermal decomposition occurring in the absence of oxygen. We use pyrolysis to produce a liquid fuel, bio-oil or pyrolysis oil.

 Biogas:

Getting energy out of biomass by burning it, turning it into a liquid or by turning it into a gas called bio gas.  It contains about 65% of methane gas as a major constituents

Biofuel

 Biofuel (also called agro fuel) is a bioorganic fuel .It is obtained by the fermentation of biomass. The process by which micro-organisms break down complex organic substances generally in the absence of oxygen to produce alcohol and carbon dioxide is Fermentation.

Examples of Biofuel

Ethanol: It is produced from sugarcane .Its CALORIFIC VALUE is less than petrol. It also less heat when compare to petrol.

Methanol: It is easily obtained from ethanol .Its CALORIFIC VALUE is too low when compared to gasoline and diesel.

Gasohol: It is a mixture of ethanol + gasoline .It is used in cars and buses.

ADVANTAGES 

1.It’s a renewable source of energy.

2.It’s a comparatively lesser pollution generating energy.

3.Biomass energy helps in cleanliness in villages and cities.

4.There is tremendous potential to generate biogas energy. 

5.Biomass energy is relatively cheaper and reliable. 

6.It can be generated from every day human and animal wastes, vegetable and agriculture left-over etc. 

7.Growing biomass crops use up carbon dioxide and produces oxygen.

Disadvantages of Biomass Energy 

1.It is dispersed and land intensive as a source 

2.It is often of low energy density 

3.It is labour intensive and the cost of collecting large quantities for commercial application is significant