Types of Biomass Fuels for Steam Boilers Available in Different Parts Of India

As India has become more urbanized and industrialized, the need for electricity has increased exponentially. Electricity is generated at power plants where turbines are used to drive generators. There are three types of power plants in India, namely hydroelectric power plants, thermal power plants, and nuclear power plants. In present scenario, 62% of power plants in India use fossil fuels. However, the government of India has been encouraging the use of renewable energy for electricity generation to reduce pollution levels and dependence on fossil fuels. A great option that can be used to replace fossil fuels is ‘Biomass Fuel’. Biomass fuels are plant or animal-based materials that can be used to generate heat via combustion.

Advantages Of Biomass Fuels

  • Biomass fuels are a renewable source of energy as most biomass fuels are mainly plant-based. 
  • Biomass fuels help to reduce greenhouse gases. The emission levels from biomass fuel are lower than fossil fuels. The biggest difference in emission levels is due to carbon emissions. The combustion of biomass fuels generates CO2, which is absorbed by the plants during photosynthesis. While the carbon emissions produced during the combustion of fossil fuels increase greenhouse effects, biomass fuels are carbon neutral.
  • The world is presently grappling with gradually reducing quantities of fossil fuel. Biomass fuels reduce dependency on fossil fuels. The availability of biomass fuel outweighs the availability of fossil fuels as they are abundantly available. 
  • Biomass fuels are much cheaper than fossil fuels. Fossil fuels are often imported and have added transportation charges.
  • A lot of waste generated by the combustion of biomass is biodegradable and plant waste. Biomass fuel such as rice straw uses the waste which would otherwise be dumped or burnt. 

Types Of Biomass Fuels

The biomass fuels can be classified into:-

  • The wood residue (forestry, pulp, and paper)
  • The agricultural residue (bagasse, rice husk, cotton pods)
  • Energy crops (straw grass, bamboo, eucalyptus)
  • Processed waste ( sawdust, wood chips)

Bagasse

Bagasse is the fibrous extract that is left after the extraction of sugar juices from sugarcane. It is considered a byproduct of sugar mills (10 tons of crushed sugarcane generates 3 tons of wet bagasse). Bagasse is one of the most widely available biomass fuels in India. India produces 880 million tons of bagasse every year.

The bagasse is mainly used to produce electricity in cogeneration plants. It can potentially generate 5000 MW by cogeneration.

The sugar belt in India is concentrated in:-

  • Uttar Pradesh
  • Haryana
  • Maharashtra
  • Karnataka
  • Andhra Pradesh

Sugarcane factories have two types of biomass:- sugarcane trash and bagasse. The composition of bagasse depends on the type and maturity of sugarcane. The GCV of bagasse depends on the moisture content of the fuel. Bagasse is fibrous and is composed of cellulose, hemicelluloses, and lignin.

Ultimate analysis of Bagasse:

Carbon

23.5%

Hydrogen

3.2%

Sulfur

0%

Oxygen

22.0%

Nitrogen

0%

Moisture

50%

Ash

1.3%

GCV

2290 kcal/kg

 

Rice Husk

The rice belt in India is concentrated in North, South, and East India. Rice husk or hull is the hard protecting covering over grains of rice. Rice husk is a byproduct of the rice mill and is mainly used in energy production. The high silica content in the ash left after combustion of rice husk is used in steel and cement factories. Rice husk needs to be burnt carefully because the high silica content can cause wear and tear to the processing machine. The ash content can also cause agglomeration and fouling. The rice mills in India have concentrated around:-

  • Haryana
  • Uttar Pradesh
  • Punjab
  • West Bengal
  • Andhra Pradesh

Ultimate analysis of rice husk:

Carbon

31.24%

Hydrogen

5.24%

Sulfur

0.13%

Oxygen

36.06%

Nitrogen

0.93%

Moisture

8.89%

Ash

17.5%

GCV

3079 kcal/kg

 

Rice Straw

Rice straw is an agricultural waste after the harvest of rice and clearing the rice straw is a major problem every year. Rice straw can be used as fodder for livestock and also as a biomass fuel in boilers. Rice belt in India is in:-

  • Haryana
  • Uttar Pradesh
  • Punjab
  • West Bengal
  • Andhra Pradesh

Ultimate analysis of rice straw

Carbon

39.74%

Hydrogen

6.03%

Sulfur

0.26%

Oxygen

35.74%

Nitrogen

0.81%

Moisture

6.03%

Ash

11.39%

GCV

3148 kcal/kg

 

Mustard Husk

Mustard is used as a spice and for producing oil. The mustard husk is a byproduct of oil mills. It needs to be burnt carefully as the ash has a high silica and sulfur content. The mustard mills in India are concentrated in:-

  • Rajasthan
  • Gujarat
  • Uttar Pradesh
  • West Bengal
  • Haryana

Ultimate analysis of mustard husk:

Carbon

39.88%

Hydrogen

4.17%

Sulfur

0.6%

Oxygen

39.37%

Nitrogen

0.67%

Moisture

9.1%

Ash

6.7%

GCV

3404 kcal/kg

 

Coconut shell

India cultivates a large number of coconuts. Coconut shell is used as a fuel and also in the production of copra. You need to burn coconut shells carefully because the flue gas is corrosive. This intensifies as the boiler reaches higher temperatures. Coconut mills in India are concentrated around:-

  • Kerala
  • Karnataka
  • Tamil Nadu
  • Andhra Pradesh

Ultimate analysis of coconut shell:

Carbon

39.19%

Hydrogen

5.89%

Sulfur

0%

Oxygen

33.97%

Nitrogen

0.7%

Moisture

15%

Ash

5%

GCV

4166 kcal/kg

 

Saw Dust

Saw dust is generated in the wood industry. Popular wood types used in India include walnut, sandalwood, teak, Sheesham, deodar, ebony, redwood, rosewood, and sal. The manufacturing factories are located in:-

  • Maharashtra
  • Karnataka
  • Kerala
  • Gujarat

Ultimate analysis of saw dust:

Carbon

35.0%

Hydrogen

2.8%

Sulfur

2%

Oxygen

13.7%

Nitrogen

0.5%

Moisture

36%

Ash

10%

GCV

3324.53 kcal/kg

 

Wood Chips

Wood chips can be used as a biomass fuel. Wood chips are available in following states:-

  • Himachal Pradesh
  • Assam
  • West Bengal

Ultimate analysis of wood chips:

Carbon

25.3%

Hydrogen

2.5%

Sulfur

0%

Oxygen

21.55%

Nitrogen

0.15%

Moisture

49%

Ash

1.5%

GCV

2223.52 kcal/kg

 

Cotton Stalk

Cotton stalk is the waste that is left after cotton is removed. Cotton is widely cultivated in:-

  • Gujarat
  • Maharashtra
  • Andhra Pradesh
  • Haryana

Ultimate analysis of cotton stalk:

Carbon

43.64%

Hydrogen

5.81%

Sulfur

0%

Oxygen

42.0%

Nitrogen

1.87%

Moisture

6.68%

Ash

6.68%

GCV

4109.26 kcal/kg