BIOMASA

Biomass is defined as substance of biological origin (planting in soil or in water, breeding, organic material, organic wastes). Biomass is designedly captured as a result of production activities or wastes from agricultural or food industry or from forestry, communal area and landscape maintenance are used.

Theoretic calculations of different experts show that annual worldwide production of biomass is on the level 100 milliards tons with energetical potential about 1 400 EJ. It is almost five times more than annual worldwide consumption of fossil fuels (300 EJ). Therefore biomass is used for energetical purposes and it solves one of the global problems of humanity.

Production of biomass for energetical purposes competes another way in its use (for example for food and feed purposes, like a base for industrial purposes, non-producing function of biomass).
Increasing of production of biomass call for expanding of producing area or for raising of biomass production. It brings need to raise investments to production of biomass.
In actual conditions development of power from biomass competes alongside classical energetical sources. It can be changed by new ecological legislation.
From the worldwide view the maximal use of biomass sources for energetical purposes is problematic because there are problems with locations of biomass sources and energetical appliances, problems with accumulation, transport and distribution of captured energy. On the other hand:
there are lower negative impacts on environment
this is a renewable energy source.

The ways of biomass use for energetical purposes

Biomass use for energetical purposes is predetermined by its physical and chemical properties. A very important parameter is humidity, i. e. solid content in biomass. The value 50% of solid content is the approximate limit between wet (solid content is lower than 50%) and dry (solid content is greater than 50%) processes. In principal we can discern several ways to develop power from biomass and prepare biomass for energetical use:

a) thermo chemical transformation of biomass (dry processes for energetical use of biomass)

biomass combustion
biomass gasification
biomass pyrolysis

b) biochemical transformation of biomass (wet processes for energetical use of biomass):

alcohol fermentation
alkaline fermentation

c) physical and chemical transformation of biomass:

mechanical (chipping, crushing, pressing, briquetting, pelleting, mill grinding, etc.)
chemical (esterification of raw bio-oils).

d) development of waste heat from manufacturing of biomass (for example composting, aerobic sewage treatment, anaerobic fermentation solid organic wastes, etc.).In spite of the existing ways that biomass is used for energetical purposes biomass combustion from dry processes and producing of bio-oil by anaerobic fermentation from wet processes is predominated. In other ways the producing of acid methyl ester of bio-oils is dominated. They are manufactured from oil plant seeds in raw state.

Approximately 8 tons of biomasss can be used for energetical purposes in the Czech Republic.

Sources of biomass for power use in the Czech Republic.

BIOFUEL	mil. t
waste and fuel wood	1,7
corn and a rape straw	2,7
rapidly growing woody plants and energetical plants	1,0
municipal waste	1,5
combustible waste from the industry	1,0
TOTAL	7,9