Biomass Energy: Types, Processes, Advantages & Disadvantages

Posted on Jan 13, 2025 in Geology

Biomass

  • Introduction

Biomass is a type of renewable energy obtained from organic matter of vegetal or animal origin, or by the transformation of organic matter into fuel. The energy is obtained by burning the organic matter or transforming it into fuel. Types of biomass:

  • Natural biomass: produced in nature without human intervention.
  • Residual biomass: wastes produced by human activity.
  • Energetic crops: crops specifically grown to be used as plant biomass for energy generation.

  • Theoretical Bases

To obtain energy from biomass, there are two main types of processes:

Thermochemical: These processes use heat to convert biomass into energy:

  • Combustion: Biomass is burned to obtain heat and gas, which can be used in stoves.
  • Pyrolysis: Incomplete combustion that produces charcoal, bio-gas, and fuel. The gas produced can be used in engines.
  • Gasification: Incomplete combustion of biomass at high temperatures (700-1200 °C). A gas is obtained and used to move a turbine that generates electricity.

Biochemical:

  • Alcoholic fermentation: Microorganisms convert sugars into bio-fuel.
  • Methane fermentation: Wet biomass is transformed into a bio-gas by bacteria.

  • Advantages

Biomass does not produce polluting wastes, it is a renewable resource due to dedicated energy crops, and the processes are simple and do not require a lot of energy. The CO2 released into the atmosphere is absorbed by plants, making it a carbon-neutral process.

  • Disadvantages

Biomass produces less energy compared to other sources. It can also cause deforestation. The energy distribution infrastructure is not as developed as other energy sources.

  • Environmental Impact

The main environmental impact of biomass is on forests, as large quantities of biomass are needed for energy production. However, biomass is not solely derived from forest wood.

It has a positive impact on the atmosphere and plants. It does not pollute the atmosphere, and it provides CO2 for plants to perform photosynthesis. Biomass plants can also eliminate polluting wastes, offering an alternative to nuclear power plants.

  • Cost

A 2 MW (2,000,000 W) biomass plant costs between 4 and 6 million €. A plant that consumes 1,500 kg/h of biomass, operating for 8,000 hours per year, requires 12,000 tonnes of biomass. The cost of 1 tonne of biomass is between 44 and 55 €. This plant can generate 2.8 million € annually, but this revenue must cover the cost of biomass, maintenance, and salaries.