Biomass as Renewable Energy Resource

Biomass is a key renewable energy resource that includes plant and animal material, such as wood from forests, material left over from agricultural and forestry processes, and organic industrial, human and animal wastes. The energy contained in biomass originally came from the sun. Through photosynthesis carbon dioxide in the air is transformed into other carbon containing molecules (e.g. sugars, starches and cellulose) in plants. The chemical energy that is stored in plants and animals (animals eat plants or other animals) or in their waste is called biomass energy or bioenergy.


A quick glance at popular biomass resources

What is Biomass

Biomass comes from a variety of sources which include:

  • Wood from natural forests and woodlands
  • Forestry plantations
  • Forestry residues
  • Agricultural residues such as straw, stover, cane trash and green agricultural wastes
  • Agro-industrial wastes, such as sugarcane bagasse and rice husk
  • Animal wastes (cow manure, poultry litter etc)
  • Industrial wastes, such as black liquor from paper manufacturing
  • Sewage
  • Municipal solid wastes (MSW)
  • Food processing wastes

Biomass energy projects provide major business opportunities, environmental benefits, and rural development.  Feedstocks for biomass energy project can be obtained from a wide array of sources without jeopardizing the food and feed supply, forests, and biodiversity in the world.

1. Agricultural Residues

Crop residues encompasses all agricultural wastes such as bagasse, straw, stem, stalk, leaves, husk, shell, peel, pulp, stubble, etc. Large quantities of crop residues are produced annually worldwide, and are vastly underutilised. Rice produces both straw and rice husks at the processing plant which can be conveniently and easily converted into energy.

Biomass from Agriculture

McLeod Harvester fractionates the harvested crop into straw and graff

Significant quantities of biomass remain in the fields in the form of cob when maize is harvested which can be converted into energy. Sugar cane harvesting leads to harvest residues in the fields while processing produces fibrous bagasse, both of which are good sources of energy. Harvesting and processing of coconuts produces quantities of shell and fibre that can be utilized.

Current farming practice is usually to plough these residues back into the soil, or they are burnt, left to decompose, or grazed by cattle. These residues could be processed into liquid fuels or thermochemically processed to produce electricity and heat. Agricultural residues are characterized by seasonal availability and have characteristics that differ from other solid fuels such as wood, charcoal, char briquette. The main differences are the high content of volatile matter and lower density and burning time.

2. Animal Waste

There are a wide range of animal wastes that can be used as sources of biomass energy. The most common sources are animal and poultry manure. In the past this waste was recovered and sold as a fertilizer or simply spread onto agricultural land, but the introduction of tighter environmental controls on odour and water pollution means that some form of waste management is now required, which provides further incentives for waste-to-energy conversion.

animal waste

The most attractive method of converting these organic waste materials to useful form is anaerobic digestion which gives biogas that can be used as a fuel for internal combustion engines, to generate electricity from small gas turbines, burnt directly for cooking, or for space and water heating.

3. Forestry Residues

Forestry residues are generated by operations such as thinning of plantations, clearing for logging roads, extracting stem-wood for pulp and timber, and natural attrition. Harvesting may occur as thinning in young stands, or cutting in older stands for timber or pulp that also yields tops and branches usable for biomass energy. Harvesting operations usually remove only 25 to 50 percent of the volume, leaving the residues available as biomass for energy.

sustainable forestry


Stands damaged by insects, disease or fire are additional sources of biomass. Forest residues normally have low density and fuel values that keep transport costs high, and so it is economical to reduce the biomass density in the forest itself.

4. Wood Wastes

Wood processing industries primarily include sawmilling, plywood, wood panel, furniture, building component, flooring, particle board, moulding, jointing and craft industries. Wood wastes generally are concentrated at the processing factories, e.g. plywood mills and sawmills. The amount of waste generated from wood processing industries varies from one type industry to another depending on the form of raw material and finished product.

Generally, the waste from wood industries such as saw millings and plywood, veneer and others are sawdust, off-cuts, trims and shavings. Sawdust arise from cutting, sizing, re-sawing, edging, while trims and shaving are the consequence of trimming and smoothing of wood. In general, processing of 1,000 kg of wood in the furniture industries will lead to waste generation of almost half (45 %), i.e. 450 kg of wood. Similarly, when processing 1,000 kg of wood in sawmill, the waste will amount to more than half (52 %), i.e. 520 kg wood.

5. Industrial Wastes

The food industry produces a large number of residues and by-products that can be used as biomass energy sources. These waste materials are generated from all sectors of the food industry with everything from meat production to confectionery producing waste that can be utilised as an energy source.

Solid wastes include peelings and scraps from fruit and vegetables, food that does not meet quality control standards, pulp and fibre from sugar and starch extraction, filter sludges and coffee grounds. These wastes are usually disposed of in landfill dumps.

Liquid wastes are generated by washing meat, fruit and vegetables, blanching fruit and vegetables, pre-cooking meats, poultry and fish, cleaning and processing operations as well as wine making.

These waste waters contain sugars, starches and other dissolved and solid organic matter. The potential exists for these industrial wastes to be anaerobically digested to produce biogas, or fermented to produce ethanol, and several commercial examples of waste-to-energy conversion already exist.

Pulp and paper industry is considered to be one of the highly polluting industries and consumes large amount of energy and water in various unit operations. The wastewater discharged by this industry is highly heterogeneous as it contains compounds from wood or other raw materials, processed chemicals as well as compound formed during processing.  Black liquor can be judiciously utilized for production of biogas using anaerobic UASB technology.

6. Municipal Solid Wastes and Sewage

Millions of tonnes of household waste are collected each year with the vast majority disposed of in open fields. The biomass resource in MSW comprises the putrescibles, paper and plastic and averages 80% of the total MSW collected. Municipal solid waste can be converted into energy by direct combustion, or by natural anaerobic digestion in the engineered landfill.

sewage sludge biomass

At the landfill sites, the gas produced, known as landfill gas or LFG, by the natural decomposition of MSW (approximately 50% methane and 50% carbon dioxide) is collected from the stored material and scrubbed and cleaned before feeding into internal combustion engines or gas turbines to generate heat and power. The organic fraction of MSW can be anaerobically stabilized in a high-rate digester to obtain biogas for electricity or steam generation.

Sewage is a source of biomass energy that is very similar to the other animal wastes. Energy can be extracted from sewage using anaerobic digestion to produce biogas. The sewage sludge that remains can be incinerated or undergo pyrolysis to produce more biogas.

How Green is Biomass?

As we strive to shrink our global carbon footprint, society must alter its energy sources. Solar panels and wind turbines are two familiar types of green power that contribute to protecting the planet. Investing in renewables can improve the environment and lower the cost of electricity.

As scientists look for efficient and sustainable solutions to non-renewable energy use, they turn back to basics. People used to rely on fire for fuel. Today, we can utilize these age-old practices to limit our reliance on environmentally polluting fuel sources.

The Importance of Renewable Energy

Nearly 80% of our current energy comes from coal, oil and gas. The use of fossil fuels in power production harms human health and the planet.

About 2.6 million Americans experience health issues from oil and gas exposure from fossil fuel transportation and processing facilities. Benzene and formaldehyde are two toxins associated with nonrenewable energy production that contribute to leukemia and blood disorders. The workers who mine oil and gas also risk exposure to airborne pollutants that cause lung cancer and breathing difficulties.

The production of fossil fuel energy affects the environment by emitting greenhouse gases into the atmosphere. The greenhouse effect is a natural process that the Earth uses to maintain life on its surface. It keeps the global temperature consistent to protect the ecosystem’s functionality.

Adding pollutants into the atmosphere changes its composition. These greenhouse gases absorb the sun’s energy, convert it into heat and release it back to space. Excess contaminants make it difficult to allow heat to escape. This increases the global temperature over time.

Renewable energy sources act as an alternative to greenhouse gas-emitting power. Various companies are working on producing a chemical-free solution known as biomass energy.

What is Biomass?

Biomass is a form of renewable energy derived from organic materials. Wood was the original source used by the first humans for survival. Now, we can rely on wood pellets, sawdust, black liquor and more to create commercial and residential fuel options.


We can also utilize agricultural matter to produce biomass. Soybeans, corn, algae, sugar cane and other plants can create fuel to power our homes, electric cars and devices. Scientists are also using refuse for energy production. Municipal solid waste, like cotton, paper, yarn and food, can transform into biomass power. A less appealing way to produce this renewable energy derives from animal manure and human waste.

Companies take these materials and create energy through a direct combustion process. It forms a refined liquid or gas to burn for power. Because plants grow naturally and indefinitely on Earth, biomass is a renewable source.

Environmental Effect of Biomass

Although biomass production and use emit no direct carbon into the environment, it may be less sustainable than other renewable power sources. When burned, these fuels release toxins like nitrogen oxide, sulfur dioxide and particulate matter into the atmosphere.


Biomass production also contributes to deforestation. Many companies use soybeans to create the renewable fuel, which affects forests in Argentina. The country produces 15% of the global soy source, using 16 million hectares of forest land for production.

As Argentina increases production to meet international demands, it must cut down trees and vegetation to make space for agricultural growth. The monoculture of soy also leads to soil depletion. To reverse these environmental impacts, farms use synthetic fertilizers and pesticides on their land.

Because biomass crops are water-intensive, they contribute to runoff pollution. When farmers water their plants, the synthetic fertilizers and pesticides drain into the ocean, contributing to oxygen depletion and dead zones. The significant amount of water used to produce these crops leads to resource exploitation. It takes nearly 4,000 gallons of water to grow a bushel of corn for biomass energy.

Is Biomass Worth the Destruction?

Biomass can effectively reduce the carbon footprint. The renewable energy source also limits the adverse health effects associated with conventional energy production. However, it emits air pollutants into the atmosphere, causing deforestation and water exploitation, which decreases its sustainability.

The answer is complicated. Every renewable energy source has its downfalls. When you use a bit of energy from each green resource, you can limit your environmental impact and still power the planet.

An Introduction to Biomass Energy

Biomass is the material derived from plants that use sunlight to grow which include plant and animal material such as wood from forests, material left over from agricultural and forestry processes, and organic industrial, human and animal wastes. Biomass energy is a type of renewable energy generated from biological (such as, anaerobic digestion) or thermal conversion (for example, combustion) of biomass resources.

Biomass comes from a variety of sources which include:

  • Wood from natural forests and woodlands
  • Forestry plantations
  • Forestry residues
  • Agricultural residues such as straw, stover, cane trash and green agricultural wastes
  • Agro-industrial wastes, such as sugarcane bagasse and rice husk
  • Animal wastes
  • Industrial wastes, such as black liquor from paper manufacturing
  • Sewage
  • Municipal solid wastes (MSW)
  • Food processing wastes

In nature, if biomass is left lying around on the ground it will break down over a long period of time, releasing carbon dioxide and its store of energy slowly. By burning biomass its store of energy is released quickly and often in a useful way. So converting biomass into useful energy imitates the natural processes but at a faster rate.

Biomass can be transformed into clean energy and/or fuels by a variety of technologies, ranging from conventional combustion process to advanced biofuels technology. Besides recovery of substantial energy, these technologies can lead to a substantial reduction in the overall biomass waste quantities requiring final disposal, which can be better managed for safe disposal in a controlled manner while meeting the pollution control standards.

Biomass conversion systems reduces greenhouse gas emissions in two ways.  Heat and electrical energy is generated which reduces the dependence on power plants based on fossil fuels.  The greenhouse gas emissions are significantly reduced by preventing methane emissions from decaying biomass. Moreover, biomass energy plants are highly efficient in harnessing the untapped sources of energy from biomass resources and helpful in development of rural areas.

Towards Sustainable Biomass Energy

Biomass is one of the oldest and simplest ways of getting heat and energy, and it’s starting to make a comeback due to its status as renewable resource. Some, however, aren’t so sure that using more of it would be good for our environment. So, how sustainable is biomass energy really?


What is Biomass?

Biomass is organic material from plants and animals. It naturally contains energy because plants absorb it from the sun through photosynthesis. When you burn biomass, it releases that energy. It’s also sometimes converted into a liquid or gas form before it is burned.

Biomass includes a wide variety of materials but includes:

About five percent of the United States’ energy comes from biomass. Biomass fuel products such as ethanol make up about 48 percent of that five percent while wood makes up about 41 percent and municipal waste accounts for around 11 percent.

The Benefits of Biomass

Biomass is a renewable resource because the plants that store the energy released when it is burned can be regrown continuously. In theory, if you planted the same amount of vegetation that you burned, it would be carbon neutral because the plants would absorb all of the carbon released. Doing this is, however, much easier said than done.

Another potential is that it serves as a use for waste materials that have are already been created. It adds value to what otherwise would be purely waste.

Additionally, many forms of biomass are also relatively low-tech energy sources, so they may be useful, or even required for older buildings that need an electrical renovation.

Drawbacks of Biomass

A major drawback of using biomass fuel is that it is not an efficient process. In fact, burning it can release even more carbon dioxide than burning the same amount of a fossil fuel.

While you can replenish the organic matter you burn, doing so requires complex crop or forest management and the use of a large amount of land.  Also, some biomass, such as wood, takes a long time to grow back. This amounts to a delay in carbon absorption. Additionally, the harvesting of biomass will likely involve some sort of emissions.

 Is it Sustainable?

So, is biomass energy sustainable? Measuring the environmental impacts of biomass fuel use has proven to be complex due to the high number of variables, which has led to a lot of disagreement about this question.

Some assert that biomass use cannot be carbon neutral, because even if you burned and planted the same amount of organic matter, harvesting it would still result in some emissions. This could perhaps be avoided if you used renewable energy to harvest it. A continuous supply of biomass would likely require it to be transported long distances, worsening the challenge of going carbon neutral.

With careful planning, responsible land management and environmentally friendly harvesting and distribution, biomass could be close to, if not entirely, carbon neutral and sustainable. Given our reliance on fossil fuels, high energy consumption levels and the limited availability of land and other resources, this would be an immense challenge to undertake and require a complete overhaul of our energy use.

How to Improve the Biomass Industry

Biomass could emerge as a major solution to our energy and sustainability issues, but it isn’t likely to be a comprehensive solution. There are some things we can do, though, to make biomass use more sustainable when we do use it.

  • Source locally: Using biomass that comes from the local area reduces the impact of distributing it.
  • Clean distribution: If you do transport biofuel long distances, using an electric or hybrid vehicles powered largely by clean energy would be the most eco-friendly way to do it. This also applies to transporting it short distances.

Measuring the environmental impacts of biomass fuel use is complex due to high number of variables

  • Clean harvesting: Using environmentally friendly, non-emitting means of harvesting can greatly reduce the impact of using biomass. This might also involve electric vehicles.
  • Manage land sustainably: For biomass to be healthy for the ecosystem, you must manage land used to grow it with responsible farming practices.
  • Focus on waste: Waste is likely the most environmentally friendly form of biomass because it uses materials that would otherwise simply decompose and doesn’t require you to grow any new resources for your fuel or energy needs.

Is biomass energy sustainable? It has the potential to be, but doing so would be quite complex and require quite a bit of resources. Any easier way to address the problem is to look at small areas of land and portions of energy use first. First, make that sustainable and then we may be able to expand that model on to a broader scale.