Where Is Biomass Energy Obtained?

Biomass energy is the energy that comes from plant and animal waste materials, named biofuels. Sources of biomass include trees, crops, plants, processing waste, and animal manure. Because it comes directly from living things, biomass is considered a renewable source of energy. Unlike fossil fuels such as coal, oil and natural gas which take millions of years to form, biofuels can be replenished in a relatively short time. Biomass energy can be generated from produce used directly for fuel, processed into liquid biofuels like ethanol and biodiesel, or used as feedstock for heat, electricity, or liquid fuels.

This article will overview the major sources of biomass energy, including plant materials, animal materials, municipal solid waste, industrial waste, landfill gas, and algae. We’ll also discuss the advantages and disadvantages of using biomass for energy, as well as the future outlook for this renewable resource.

Table of Contents

Plant Materials

Plants are one of the most common sources of biomass for energy production. Energy crops like corn, soybeans, and switchgrass are grown specifically to produce biomass feedstocks for energy. According to the U.S. Energy Information Administration, corn is one of the main crops grown for use as a biomass feedstock in the United States (https://www.eia.gov/energyexplained/biomass/).

Crop residues, like corn stover left over after harvesting corn, can also be used as a biomass feedstock. The unused plant parts like stalks and leaves contain energy that can be extracted. Forestry materials like wood waste and logging residue are additional plant-based sources of biomass. Wood pellets made from compressed sawdust are commonly used for heating and electricity generation (https://www.nationalgeographic.org/encyclopedia/biomass-energy/).

Plant materials have the advantage of being renewable sources of energy that can regrow after being harvested. However, potential drawbacks include impacts on land use, water needs, and food supplies when growing dedicated energy crops.

Animal Materials

Animal materials like manure and other animal byproducts make up a significant portion of biomass energy. Manure from farm animals such as cows, pigs, horses, sheep, and chickens is a major source. The high methane content in manure makes it well-suited for generating biomass energy. Manure can be converted to biogas through anaerobic digestion. The biogas can then be used directly for heating and electricity generation.¹

Other animal byproducts like fats, grease, tallow, and waste cooking oil can also be important biomass resources. Rendering plants process these materials, producing products like meat and bone meal, poultry byproduct meal, and more. These rendering byproducts can be used as fuel feedstocks.² Overall, animal manure and rendering byproducts are versatile biomass sources that are readily available in large quantities.

Municipal Solid Waste (MSW)

Municipal solid waste (MSW) refers to everyday items that are used and then discarded, such as product packaging, grass clippings, furniture, clothing, bottles, food scraps, newspapers, and batteries. MSW is a commonly-used source of biomass energy and fuel. According to the U.S. Energy Information Administration, MSW contains three primary components that can be converted into biomass energy: paper and paperboard (28%); food (15%); and yard trimmings (13%) ¹. Other components like wood, glass, metals, and plastics can also be converted.

To obtain biomass energy from MSW, the waste is typically combusted or incinerated at high temperatures. This process generates heat that can be used to produce steam, hot water, or electricity via a turbine ². Some of the most common sources of MSW biomass energy include:

Food waste from homes, restaurants, grocery stores, and food processing plants
Paper products including newspaper, cardboard, and office paper

Plastics such as water bottles, packaging, and bags
Yard trimmings and tree branches
Wood scraps from construction and demolition sites

Overall, MSW represents a significant source of renewable biomass energy if properly sorted, processed, and converted. Around 13% of waste in the U.S. is currently used for biomass energy production.

Industrial Waste

Industrial waste such as sawdust, paper mill residues, distillery residues, and food processing waste can be used as sources of biomass energy.^[1] Sawdust is a major byproduct of the wood industry and comes from the milling of lumber, plywood, veneer and other wood products. It is often used as a biomass fuel source directly in combustion or converted to wood pellets. Paper mills generate large amounts of waste called black liquor that contains lignin and other chemicals. This can be combusted in a recovery boiler to produce steam and power. Distilleries that produce ethanol, especially from corn and grains, end up with solid residues that have high heating value. Finally, the food processing industry generates residues such as olive pits, rice husks, coconut shells, and fruit seeds that can provide thermal and power generation.^[2]

^[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738282/

^[2] https://www.bioenergyconsult.com/tag/industrial-wastes/

Landfill Gas

Landfill gas is a form of biomass energy produced from the breakdown of organic waste in landfills. As waste in landfills decomposes, it produces landfill gas which is composed of roughly 50% methane and 50% carbon dioxide, along with small amounts of other gases.¹ Methane is the primary component of landfill gas that can be captured and utilized as an energy source.

Landfills produce methane through the anaerobic digestion of organic waste like food scraps, paper, and yard trimmings by microorganisms. As these materials decompose, methane is released as a byproduct. Modern landfills will have systems in place to capture this methane gas which can then be used to generate electricity, heat buildings, or as vehicle fuel.

Capturing landfill methane gas prevents its release into the atmosphere where it acts as a potent greenhouse gas around 25 times more powerful than carbon dioxide. Converting landfill gas into energy offsets the need for non-renewable resources like coal and natural gas. In 2020, landfill gas produced about 0.4 quadrillion British thermal units (Btu) of energy in the United States, enough to power over 2 million homes.¹ The use of landfill gas represents an important source of renewable biomass energy.

Algae

Algae is emerging as a promising feedstock for biofuel production due to its high oil content and fast growth rate compared to conventional crops. According to the Department of Energy, algae have the potential to yield over 30 times more energy per acre than land-based crops used for biofuels (Biofuels: The Promise of Algae).

Cultivated algae, grown in open ponds or photobioreactors, can produce substantial amounts of biomass and lipids that can be converted into biodiesel, jet fuel, and other biofuels. Advantages of using algae include its ability to grow in non-arable land using non-potable water, its high oil yield per acre, and its ability to utilize carbon dioxide as a nutrient source (Algae for Biofuel Production).

Residues left over from algae oil extraction, such as proteins and carbohydrates, can also be used to produce ethanol or biogas. However, challenges remain in developing cost-effective algae farming and oil extraction methods.

Pros and Cons of Biomass Energy

Biomass energy has several advantages that make it a promising renewable energy source (Energysage). First, biomass is abundant and readily available, as it comes from plants and animal waste, municipal solid waste, landfill gas, industrial waste, and algae. Since biomass can be replenished quickly, it is considered a renewable energy source (Solar Reviews).

Another benefit is that biomass energy helps reduce waste and garbage in landfills by providing an alternative usage for discarded materials (Energy4Me). Biomass energy facilities can be built close to waste sources, minimizing transportation and collection costs. Additionally, biomass energy is versatile – it can be converted directly into heat, electricity, and fuel for vehicles.

However, there are some drawbacks to using biomass for energy. First, it can be expensive to transport and process biomass feedstocks. Facilities require substantial space for equipment, storage, and processing (Energysage). There are also concerns about small amounts of air pollution emissions from biomass facilities. Overall, when sustainably produced, biomass offers a renewable energy source with many benefits.

Future Outlook

The future for biomass energy looks promising, with projections for substantial growth as countries seek renewable alternatives to fossil fuels. The International Energy Agency predicts that bioenergy will account for 30% of the growth in renewable energy by 2023. However, sustainability concerns remain about large-scale biomass production and its impacts on land use, biodiversity and carbon emissions. New technologies and processes are being developed to improve efficiency and reduce emissions from biomass production and conversion. These include advanced biofuels made from non-food plant materials and agricultural residues, as well as technologies like pyrolysis and torrefaction which can improve the properties of biomass feedstocks. There is also growing interest in developing integrated biorefineries that can maximize value from biomass by coproducing biofuels, biopower, and bioproducts. If biomass energy can scale sustainably, it has the potential to play a major role in a low-carbon future as both a renewable energy source and a substitute for petroleum-based products and materials.

Conclusion

In summary, biomass energy comes from a wide variety of plant and animal materials as well as waste sources. While fossil fuels like coal, oil and natural gas are finite resources, biomass can be renewable as long as the organic materials are replanted at the same rate as they are consumed. Using biomass as an energy source helps diversify our energy portfolio and reduce reliance on any single type of fuel.

Having a diverse mix of energy sources is crucial for building sustainability and resilience. Over-dependence on fossil fuels leaves nations vulnerable to price shocks and supply disruptions. Incorporating renewable sources like biomass protects against these risks. Biomass energy has the potential to provide a clean, renewable fuel source for heat, electricity and transportation. Though it has some limitations, biomass will likely play an important role in creating a sustainable energy future with multiple complimentary technologies.