Energy Guides

Biomass Energy

As the world looks to reduce its dependence on fossil fuels, one concept in development is Biomass Energy. Biomass energy is a process where we use this material to extract energy in the form of biofuels, heat and electricity.

This guide looks at what biomass energy is, how it’s created, and how it can be used moving forward.

What is biomass energy?

Biomass is simply organic matter that comes from plants and animals. Biomass energy is a process where we use this material to extract energy to create biofuels, heat and electricity.

The most common materials used in biomass energy are corn and soy. The energy extracted from these biomass substances can be burned to generate electricity or heat.

Example sources of Biomass

Here are some examples of biomass sources:

Agricultural: Sugarcane, switchgrass, plants, algae, general crops, soybeans, corn.
Biogenic materials: paper, cotton, wool, food, and wood waste.
Wood: Wood pellets, wood waste, lumber, firewood, wood chips, sawdust, pulp.
Waste: Animal waste and human sewage.

How does biomass energy work?

Biomass energy is the extraction of chemical energy from plant matter. Plants extract solar energy through photosynthesis and use it to grow. The energy plants absorb from the sun is stored as chemical energy within the structure. The larger a plant grows, the more chemical energy it contains.

Biomass energy extracts the chemical energy stored within biomass through one of the following processes.

Direct Combustion
Direct combustion, or more simply burning, can produce heat and electricity. It’s the most common form of converting biomass to energy.

The energy from combustion can heat buildings directly or boil water that generates electricity with a turbine.

Thermochemical conversion
Thermochemical conversion is a process of turning plant matter into biofuels used for transportation.

Thermochemical conversion of biomass includes gasification, pyrolysis and hydrotreating. Here’s a breakdown of each thermochemical conversion process:

Gasification: This is where you heat organic materials to 800-900 degrees Celsius by injecting oxygen or steam into a vessel to produce carbon monoxide and synthesis gas. Synthesis gas can power diesel engines, heating systems and turbines that generate electricity.
Pyrolysis: It’s the process of heating the materials to 400-500 degrees Celsius in the absence of free oxygen. The pyrosis will produce bio-oil, methane, hydrogen, and renewable diesel substances.
Hydrotreating: This is used to process the bio-oil by using hydrogen under pressure and elevated temperatures to produce jet fuel and petrol.

Chemical conversion
Using chemical conversion to produce liquid fuels. Chemical conversion involves a process known as “transesterification” to convert vegetable oil into biodiesel.

Biological conversion
Biological conversion is a process that converts biomass into natural gas. The biological conversion uses bacteria to undergo a process of anaerobic digestion that converts plant material into a hydrocarbon.

Some business energy suppliers use anaerobic digesters to produce renewable natural gas supplied under a green gas tariff. Find the best green gas tariffs today with our business gas comparison service.

Is biomass energy renewable?

Technically, yes. Biomass energy can be considered a renewable form of energy as long as the plant matter is harvested and managed sustainably through replanting and regrowth.

Biomass helps reduce carbon emissions by increasing the number of plants taking the carbon dioxide out of the atmosphere and storing it in soil, vegetation and trees.

How is biomass energy used today?

Biomass energy is used today for heating systems, electricity generation and transportation.

How can biomass energy be negative to the environment?

Unfortunately, there are a couple of big stumbling blocks regarding the widespread use of biomass energy. It seems a sustainable and potentially green energy source; however, it can have adverse environmental effects.

Pollution
Carbon emissions increase. Burning biomass releases carbon dioxide, carbon monoxide, and nitrogen oxides.

If the pollutants are not recycled correctly and efficiently, biomass has the potential to exceed the number of pollutants created by burning fossil fuels.

High water usage
Plants need water to grow, and the more biomass we burn, the more we need to replenish, therefore needing to use higher amounts of water.

The process of converting biomass into energy also uses a considerable amount of water. Water scarcity is becoming a bigger and bigger environmental issue for our planet.

Deforestation
If biomass becomes a widespread energy source, it may cause people to cut down existing forests as a cheap fuel source.

However, growing new forests specifically for biofuel also causes a secondary issue of stripping nutrients from the soil. The production of biomass crops relies on phosphorous fertilisers, which damage the water supply in the surrounding areas.

Biomass is not efficient
The most common use of biofuels is to produce bioethanol, which is used as a fuel in transportation. Unfortunately, engines work less efficiently on ethanol compared with fossil fuels.