In light of the recent discussions held at Cop26 about global warming, climate change, and the increase in environmental disasters, renewable energy is being seen as a must in a changing world. Let’s look at some biomass facts to see its potential!
Six interesting facts about biomass:
- Biomass can be made with various materials,
- Biomass is renewable,
- There are various ways to convert biomass to energy,
- Biomass accounts for 4.9% of energy in the USA,
- Biomass reduces acid rain, and
- The biomass industry improves job creation.
The science, as well as the socio-economic aspects of biomass, are both varied and exciting! Let’s explore each fact in detail to uncover a holistic depiction of biomass and determine its viability to answer climate change and the energy crisis!
Seven common types of materials biomass is made from:
- Dedicated energy crops,
- Agricultural crop residue,
- Forestry residues,
- Wood processing residues,
- Sorted municipal waste, and
- Wet waste.
Dedicated Energy Crops
Dedicated energy crops are crops specifically grown to manufacture biomass. Unlike food crops, they provide usage to marginal land that would be unsuited for other types of crops.
Consequently, biomass presents a unique opportunity to harvest a net gain from an otherwise unproductive space rather than using this undesirable land for housing developments or commercial infrastructure.
The two different types of energy crops are herbaceous and woody plant materials. These crops present different planting and harvesting cycles and improve water quality, soil quality, habitats, and a diversification of income.
Agricultural Crop Residue
Agricultural crop residue is the non-food, feed, or fibrous products of an agricultural harvest but is the unused by-products of a harvest.
These include stalks, leaves, husks, and cobs, among others.
Forestry residue includes residue left after logging timber and whole-tree biomass harvested for biomass production.
Residue from logging timber includes limbs, tops, culled trees, and other unmarketable material.
Algae that feed off sunlight and nutrients present a variety of components that can be converted and upgraded into various biofuels and products.
Algae can be grown in various conditions, including but not limited to freshwater, brackish water, or second-use sources such as treated industrial, agricultural, or municipal water.
The mixed quality of the various water sources allows for the production of valuable material to biomass production, which would otherwise have proven to be an unproductive source.
Wood Processing Residue
Wood processing residue is the by-products of processing in the manufacture of timber and paper.
Examples include, among others, sawdust, bark, branches, leave, and needles.
Sorted Municipal Waste
Sorted municipal waste includes both residential and commercial garbage.
This includes, among others, paper, cardboard, garden refuse, plastics, rubber, leather, textiles, and food waste. The role of sorted municipal waste provides a unique opportunity to diversify landfills for biomass production.
This commodification of landfills and other forms of municipal waste dumping provides a unique opportunity to diversify the workforce presently operating in the biomass industry.
Namely, this presents an opportunity for a marked shift from research and development into more “blue-collar” job development (see below for an in-depth discussion on job creation and skills development).
Wet waste includes residential and commercial food waste, organic bio-solids, manure slurries, organic industrial waste, and biogas.
The transformation of these waste products creates an opportunity for economic diversification in rural areas and assists in waste disposal solutions.
Is Biomass A Renewable Source Of Energy?
Biomass is a renewable source of energy.
Unlike non-renewable resources that are finite such as fossil fuels, biomass consists of organic material that stores its energy from the sun.
As an infinite source of power, the sun’s energy is essentially trapped inside organic material, such as plant debris, wood processing by-products, etc. Whereby this material can be grown or harvested on mass, without finite restrictions.
When examining the harvesting of plant and woody materials to make biomass, it is found that the decomposition of these materials releases the same amount of carbon dioxide as if they were burned for energy production.
The logic behind the renewability and reduction of CO2 emissions through biomass is that, provided this organic material is planted at the rate it is burned, it allows for a carbon-neutral cycle of oxygen and carbon dioxide production.
Despite the capability of biomass to be carbon-neutral, this is subject to the material being used to manufacture biomass, the strategy of forest and crop management, and the optimization of the biomass being burned to create energy.
For example, because the combustion and processing strategies surrounding woody material are less optimal than coal, the initial impact of substituting biomass from wood for energy over coal results in a relative increase in CO2 emissions.
This means that had a power station that remained coal operated, it would have produced less CO2 emissions than biomass, as every megawatt-hour of electricity requires less coal than woody biomass to be produced.
Therefore, while not inherently carbon-neutral or a “one-stop-shop” solution to the energy crisis, if managed correctly in collaboration with other forms of renewable energy, then biomass can prove helpful to combating climate change.
How Does Biomass Get Converted Into Energy?
There are four common processes that can be used to convert biomass into energy, these include:
- Direct combustion,
- Thermochemical conversion,
- Chemical conversion, and
- Biological conversion.
For a visualization of the biomass conversion processes, see the video below from the Student Energy YouTube channel:
The most common method, both on a residential and industrial scale, of converting biomass into forms of energy is direct combustion.
This allows for the production of heat, either for light and warmth or electricity generation through steam turbines.
The thermochemical conversation includes pyrolysis, gasification, and hydrotreating.
These involve thermal decomposition techniques in which biomass feedstock materials are heated in sealed, pressurized containers called gasifiers.
The primary difference between these processes is the degree to which the biomass materials are heated and the resultant production of oxygen during the conversion process.
Pyrolysis involves heating organic material between 800F to 900F in the absence of oxygen. The process converts biomass materials into higher-grade fuel such as charcoal, bio-oil, renewable diesel, methane, and hydrogen.
Hydrotreating is a further process of conversion of bio-oil, produced by pyrolysis, into renewable diesel, renewable gasoline, and renewable jet fuel. This is achieved by processing bio-oil with elevated temperatures and pressure.
Gasification involves heating organic material between 1400F to 1700F with controlled amounts of oxygen and steam. This heating occurs in a vessel to produce carbon monoxide and hydrogen gas called syngas.
Syngas is used as fuel for diesel engines, heating, and generating electricity in gas turbines. Syngas can be treated to separate the hydrogen for various uses or processed further to produce liquids.
Chemical conversion, otherwise known as transesterification, is the process used to convert vegetable oils, animal fats, and greases into fatty acid methyl esters for the purpose of producing biodiesel.
This is achieved by taking approximately 100 pounds of oil or fat and adding a10 pounds of short-chain alcohol in the presence of a catalyst such as sodium hydroxide or potassium hydroxide.
The resultant material from the reaction is 100 pounds of biodiesel and 10 pounds of glycerol.
Biological conversion includes fermentation to convert biomass material into ethanol and renewable natural gas.
Ethanol is used as fuel for vehicles. In contrast, the renewable natural gas produced at sewerage treatment plants and livestock operations is used for the same purposes as fossil fuel natural gas. Natural gas can also be captured from solid waste landfills.
How Much Energy Does Biomass Produce In The USA?
The United States of America produced 4532 trillion British thermal units (TBtu) in 2020, accounting for 4.9% of the country’s total energy consumption.
The amount and type of biomass materials used are as follows:
- 2101 TBtu were from wood and wood-derived biomass,
- 2000 TBtu were from biofuels, and
- 430 TBtu were from biomass found in municipal waste.
The socio-economic sectors which consumed energy made from biomass materials are as follows:
- Industrial: 2224 TBtu (50%),
- Transportation: 1263 TBtu (28%),
- Residential: 458 TBtu (10%),
- Electrical power: 424 TBtu (9%), and
- Commercial: 141 TBtu (3%).
As the largest consumer of biomass-produced energy, the industrial sector uses it primarily for the wood and paper industry. The primary function of energy usage goes toward heating and electricity generation.
As the 2nd largest consumer of biomass-produced energy, the transport sector uses liquid biofuels, such as ethanol and renewable diesel, for powering vehicles.
The residential and commercial sectors use the biomass materials of firewood and wood pellets for heating. In contrast, the commercial sector consumes and sells renewable natural gas produced at sewage treatment facilities and waste landfills.
Biomass Consumption In Other Countries
Given their status as developing countries, it is unsurprising to find that 15 out of the top 20 consumers of biomass materials in the world are African countries (with Haiti, Nepal, Myanmar, Guatemala, and Cambodia filling the other positions).
The reason for this high consumption of biomass materials for energy usage can be attributed to the high percentage of the population of these countries living in rural areas and their limited access to infrastructure for the purpose of providing energy.
Most of the energy produced through biomass materials is used for heat through direct combustion and small-scale industries such as sugar mills, sawmills, brick production, and tobacco curing.
Consequently, biomass provides an opportunity for developing countries and developing communities to access energy to improve their lives and livelihoods.
This is of particular significance as the international market which determines the price of fossil fuels is seldom favorable to the needs of people on the lower ends of the socio-economic spectrum.
This price-fixing and lack of access results in continued cycles of poverty, as access to reliable and efficient energy, is a primary source of industrialization and subsequent job development.
Does Biomass Reduce Acid Rain?
While biomass materials do not actively reduce acid rain or its effects, it is a cleaner alternative for purposes of direct combustion over fossil fuels such as coal.
The reason being is although the burning of biomass materials is a contributor to air pollution, the organic materials which make up biomass do not contain pollutants such as the ones found in fossil fuels.
These pollutants, such as sulfur dioxide and nitrogen dioxide, are released into the atmosphere upon the burning of fossil fuels. Once in the atmosphere, these pollutants react with water, oxygen, and other chemicals to form acid rain.
Acid rain causes serious harm to plant life, soil health, water sources, and human health. Consequently, the reduction of burning fossil fuels and the increase in biomass alternatives provide a parallel reduction in the creation of acid rain.
Does The Biomass Industry Improve Job Creation?
Biomass provides numerous job opportunities in the USA and Globally. These job opportunities are available at present and are likely to improve with evolving technologies in the renewable energy sector.
The combined socio-economic pressure of ordinary citizens, international bodies, and national legislation means there is a concerted effort to reduce the harvesting, production, and use of fossil fuels in favor of renewable alternatives.
This means that the current energy sectors, which employ millions of people both in the United States of America and globally, need to evolve to comply with greener regulations while not leading to increased unemployment rates.
Fortunately, assuming a constant trajectory of industrial buy-in and consistent green legislation, a study by Global Insight Inc. in 2008 projected an increase of 750 000 green jobs in the United States of America to upwards of 4 million jobs in 2038.
The study foresees this rise as a result of a shift in skills development in green jobs in engineering and research into “blue-collar” jobs similar to the current harvesting, manufacturing, and processing of fossil fuels.
By 2038 the study estimates that biomass materials will account for 30% of electricity produced in the United States of America, while 30% of the nation’s gasoline and diesel consumption will be substituted with biofuels.
The sectors and jobs most likely to benefit from a move to energy usage through biomass will be waste management, agriculture, and construction since infrastructure will need to be renovated for purposes of biomass energy usage.