Biomass Electrical Power Plants

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Various Biomass Based on Electrical Plants

(a) Bio-chemical based (i.e. Bio-gas) power plant.

(b) Thermochemical based (Municipal waste) plant.

(c) Agro-chemical based (Bio-diesel) plant.

Bio-chemical Based (i.e. Bio-gas) Power Plant

In the large scale plant following are the output energy and products :

  1. Heat energy for drying.
  2. Electrical energy to supply local consumers or to be connected in grid system.
  3. Natural gas (NCG) to gas filling stations
  4. Fibre products
  5. Liquid fertiliżer for agricultural uses.

All these are shown in the following block diagram.

Block Diagram of Bio-chemical Based (Bio-gas) Power Plant
Figure A

Components of Bio Chemical Based Power Plant :

Organic input materials :

  1. Manure cow dung.
  2. Food remainder.
  3. Fed to mixing chamber.
  4. Goes to pasteurization unit then to fermenter unit.
  5. Biogas is generated.
  6. It goes to Gunset unit.
  7. The high pressure gas drives the turbine and turbine drives the generator to produce electric energy output. Some heat passes away from (4) to (7) from where heat is taken out for boiling/drying or such various purposes from (7). 
  8. Gas from fermenter unit also goes to gas ceaner and
  9. Cleaned gas passes to natural gas/CNC storage station. This gas can be distributed by gas- cylinders to consumers.
  10. From fermenter (5) after fermented processing.
  11. Goes to storage Lagoon to fluid fertilizer.
  12. This high quality fertilizer is useful for agricultural work. Also some fibre products are coming out.

Thus the plant can be said as multipurpose plant to produce (1) Heat, (2) Electricity, (3) Natural/CNC gas, (4) By-products such as fluid fertilizer and fiber products etc. 


Advantages of bio chemical based power plant :
  1. Employment creation in villages/small towns and rural area.
  2. By-products are useful.
  3. Low cost.
  4. Organic residues, waste material, manual, cow-dung can be used which is available in these areas at no cost or very less cost.
  5. It comes in renewable energy source.
  6. It supplies electric power, heat, gas which are the needs of human beings.
  7. Biogas manure are good fertilizers.

Thermo chemical Based (Municipal Waste) Power Plant

Thermo chemical conversion :

  • Thermo chemical reactions convert the organic biomass Into convenient form of products which are more valuable.
  • These products are gaseous and liquid fuels, residues and byproducts.
  • These are produced at different temperatures and pressures.
  • In gasification process it produces gaseous fuels like  H2, CO, CH4, N2etc. which are of low calorific values.
  • In pyrolysis, biomass is heated in closed vessel at 500°C to 900°C In the absence of O2, air or steam. It produces solid, liquid, gases.
  • Gases so produced are CO, CH4, H2, N2, CO2.
  • Liquids so produced are oil, acetic acid, methanol, oil and tar.
  • Solids-similar to pure carbon charcoal.
  • Following block diagram represents the sequential steps of thermo-chemical based plant. The output can be used for various purpose like gas, electricity generation etc.
Thermo-chemical based Power Plant
Figure B
  • By thermochemical actions, energy is produced from organic waste or by biodegradable waste. 
  • For the production of fuel gas or fuel oil, the biomass is heated in thermochemical conversion in the presence of different gases. Sold waste and gas treatment unit is provided for municipal waste to energy conversion process. 
  • Firstly municipal waste is brought to the plant centre place (2). 
  • Hazardous and recyclable materials are separated. 
  • Provision of combustion and gasification methods are ready for waste to energy conversion. 
  • In some units, the municipal waste is directly burnt for combusting to complete combustion in boiler. 
  • In the boiler water is converted into steam. 
  • Further steps of electricity generation-steam turbine-generator-electrical energy. 
  • Also heat can be used for different purposes from this plant. 

Advantages of Thermo chemical Based Power Plant

  1. Land fill usage,
  2. Reduces waste volume by 90%,  
  3. Heat produced can be used for various purposes, 
  4. Electricity generation.

Layout of Agrochemical Based (Bio-Diesel) Plant

  • In this plant, bio-diesel oil is produced. 
  • The process or producing bio-diesel oil is by transesterification of vegetable oil or animal fat or non edible raw, oil material, etc. 
Layout of Agrochemical Based Plant
Figure C

Bio diesel can be used alone or

  • Bio-diesel can be blended with petrodiesel in proportion. 
  • After the process of transesterification, crude biodiesel and crude glycerin are obtained.
  • Catalyst – Methanol is used as a catalyst. 
  • Refining process refines the crude form into pure bio-diesel, pure glycerin which are used for useful purposes and electricity production. The product bio-diesel functions same as petro-diesel but not effective in working In cold climate, cold seasons.

Advantages of Bio diesel :

  1. Reduction In pollution, reduces green house gases. 
  2. Clean, renewable substitute to petroleum diesel. 
The model of biomass gasification for electricity generation can be shown simply in one diagram.

  1. Biomass: It is an organic matter from plants, animals and micro-organism grown on land and water and their derivatives. 
  2. Gasification: Heating (firing) biomass in the presence of carefully controller amount of  oxygen and under pressure is a gasification and the unit is a gasifier. 
  3. Cleaner: This unit cleans the gas, removes dust parties, ash, moisture etc. and make the gas very clean. 
  4. Boiler: Contains water, hot gas heats it and water converted into steam. 
  5. Steam turbine: It receives high pressure steam and Its blade assembly starts rotating due to steam impinchment or curved blades and turbine shaft starts rotating. 
  6. Generator: It is a machine which converts mechanical (rotational) energy into electrical energy. Generator shaft is coupled with turbine shaft and hence turbine rotates the generator (Alternator).
  7. Gas turbine: High pressure clean gas is directly impinched on the gas turbine blades and hence gas turbine rotates, in turn it rotates the generator.  
  8. Gas engine: Clean gas at high pressure drives the gas engine. Generator coupled to gas engine is driven to produce electrical energy. 

All these three modes of electric power generation from bio-mass are shown in the following diagram.

Block Diagram of Bio-mass Electricity Generation Using Gasifier
Figure D
These method of electrical energy generation are used for small scale, medium scale and even for large scale plants.

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