Renewable Bioenergy – Biomass, Biogas, and Biofuel; Waste-to-Energy

Renewable Energy Production with Biomass


types of biomassBioenergy (biomass, biofuel, and biogas) is produced by using wood, crops, and organic matter such as plants or organic waste.

Bioenergy production incorporates all sorts of organic materials including agricultural food crops and residues, farm waste, kitchen waste, other waste streams, plants specifically grown for bioenergy (energy crops), and forestry by-products.

Algae has emerged as a promising next-gen bioenergetic source.

Biomass can be used to generate power for a municipality in a biomass power plant. Biomass power plants are also sometimes used in parallel with on-site combined heat and power (CHP) plants. CHP using biomass as the feedstock is a low-carbon climate solution.

Bioenergy (biomass, biofuel, biogas) is also produced from organic material in the gasification process.

Bioenergy can also be produced through anaerobic digestion (AD) plants; from organic material such as farm waste, or waste streams from industry, businesses, and municipalities (waste-to-energy).

Waste-to-energy (W2E) is also a climate solution, as emissions from landfills are reduced (by diverting waste from landfills for use in AD plants) while simultaneously producing energy with a renewable natural resource - making productive use of waste.

First, Second, and Third-generation (and 4th-gen) Biomass and Biofuel


2 First-generation biofuels are produced from edible biomass, while... | Download Scientific Diagram

First-generation biomass sources consist of food crops. Starch-based crops like corn, wheat, and barley; sugar-based crops like sugarcane, sugar beet, and sorghum; as well as oil-based crops, are all sources for first-generation biomass/ biofuel production (just to name a few sources of 1st-gen biomass and biofuel).

Second-gen biomass consists of forestry by-products; wood and wood chips, peat, and bark, as well as agricultural waste (such as corn stover and rice hulls), other waste streams, and straw. Also included in second-gen biomass are plants grown as energy crops like switchgrass, hemp, poplar, palm, and other lignocellulosic plants.

Algae represent the third-gen biomass source for biofuel production. Algae is a very promising biofuel source. Algae are a quick-growing, energy-rich, abundant, non-food source of biofuel.

First-generation biomass/ biofuel feedstock sources are food crops, however, 2nd and 3rd-generation biomass/ biofuel are not food crops. This is a major advantage of next-generation biomass sources - as with these sources, biomass production doesn't take away from the world's food supply. 

There is also the emerging field of 4th-generation biomass. This includes transforming biomass to biochar through the process of pyrolysis, creating genetically modified organic biomass, and solar-to-fuel.

See these articles on 2nd and 3rd-generation biomass:

Cellulosic Biofuel - Fuel Solutions

Algae: The Future of Biofuel

Please also see Anaerobic Digestion - A Proven Solution to Our Waste Problem - for more on W2E, putting waste to good use in creating renewable energy.

Another category of bioenergy, biofuel, represents an energy source that is being applied substantially in modern transportation. The two main types of biofuels are ethanol and biodiesel (biofuel types are discussed below). Production of biofuels using 1st, 2nd, and 3rd-generation biomass sources is also discussed below.

What are the Two Types of Biofuels?


Biofuels are broken down into two main types: ethanol and biodiesel. 1st generation biofuel is made from corn, wheat, barley, soybean, sorghum, sugar beet, and sugarcane (among other crops) - food crops that are fermented to create ethanol.

Ethanol can also be produced from 2nd generation, cellulosic biomass, such as switchgrass, wood chips, straw, corn stover, and rice hulls. These are just some of the many cellulosic plants and organic materials that can readily be converted into sugars and then fermented into ethanol. 

A small level (10%) of ethanol can be blended with standard gas (10% ethanol and 90% gasoline, or E-10) to make effective gasoline with less environmental impact (this type of gas is used in many nations, as is E-15 - the higher the use of ethanol in the blend, the lower the emissions).

Just this relatively low level of ethanol blended in fuel for vehicles decreases air pollution compared with 100% gasoline or diesel. The higher the ethanol blend, the cheaper and less emissions of the blend (also, E-15 does get 1-2% less miles per gallon than E-10).

A fuel known as E-85 - 85% ethanol and 15% gasoline, is gaining popularity throughout the world (E-85 is for "Flex Fuel" vehicles; hybrids specially designed to run on this blend). There are many grades of ethanol-based biofuel blends, from E-10 to E-100.

Biodiesel is derived from animal fats, vegetable oil, and other lipids; which are processed with chemicals or alcohol. Kitchen oil is most the commonly used oil for processing into biodiesel.

Biodiesel can then be mixed with traditional hydrocarbon-based diesel (i.e. B-2, B-5, B-20) or used as a clean fuel replacement for diesel (B-100). Brazil, which uses biodiesel blends in city buses, uses over 10% biodiesel blended fuel for buses.

The future of biodiesel lies in using promising, emerging sources such as algae. The 3rd generation of biofuel is represented by algae. A large part of algae's weight is in the form of lipids, making it ideal for biofuel. Often, over half of algae's weight is extractable plant-based oil, to produce the oil needed for biofuel.

The Nations That Lead in Biofuel Production


Biofuel Production



The US and Brazil; followed by Germany, China, Argentina, and France, are the biggest producers of biofuels (both ethanol and biodiesel) in the world.

Which Countries Use Biofuels?


Renewable Bioenergy Biomass Biogas And Biofuel Waste To EnergyWorldwide, countries that produce biofuels also tend to be the countries that correspondingly consume biofuels to roughly a similar degree. However, Germany is an example of a country that consumes far more biofuels than it produces. On the other hand, many countries, including the United States, are net exporters of biofuels.

Both ethanol-based biofuel, and biodiesel, are put to use in transportation vehicles in most countries in the world - particularly countries throughout Europe, Asia, and North and South America.

While there's growing use of biofuels in regions throughout the world, two countries stand out (the same two countries that produce the highest shares of the world's biofuels).

Where are Biofuels Used the Most?


USA and Brazil are the #1 and #2 countries for both biofuel production and consumption.

RFS in the US -

Transportation fuel in the United States is required by law to contain a minimum volume of renewable fuels. In the United States, the renewable fuel standard (RFS) mandates that biofuel be blended in transportation fuel (at least 10% of biofuel must be present in gasoline/ biofuel blends in the US). 

Congress created the RFS federal program in 2007 and expanded it 12 years later. Congress created the RFS to make gasoline burn cleaner and more efficiently - reducing greenhouse gas emissions (GHGs) from burning gas. The RFS has also helped in expanding the nation's renewable fuels sector and lowering the country's dependence on foreign oil.

Biofuels are also spreading in use throughout Europe; for transportation, heating, and electricity. Biofuel use achieves the interim climate goal of producing carbon net neutral energy to help reduce GHGs. Biofuels are especially popular in the Nordic countries Sweden, Norway, Finland, Denmark, and Iceland.

In Sweden, the E85 biofuel blend is gaining popularity, thanks to a nationwide network of ethanol refueling stations. The country of Sweden hopes to get to net zero carbon emissions by 2045, which is five years faster than most other countries with a similar goal.

Biofuels help to lower GHGs from transportation, electricity, and heating; so using biofuels makes net zero goals easier to achieve.

Waste-to-energy (W2E)


An application of biomass energy with several benefits is waste-to-energy, such as landfill waste burned for energy in power plants. W2E puts garbage to good use and cuts down on the size of dumps.

Among the many existing sustainable technologies that can be used effectively for bioenergy production are gasification and anaerobic digester plants (AD plants). These technologies can also convert biomass material and viable landfill gasses (LFGs), such as methane, into a renewable source of energy.

A next-gen bioenergetic production method - landfill gases can be captured and then processed into bio-synthetic natural gas (bio-SNG). Bio-SNG is also produced through the gasification of cellulosic sources like forestry by-products and energy crops.

Along similar lines, biogas is produced by anaerobic digestion of organic material such as farm waste. Essentially, all organic matter found at an agricultural site; including crops, plants, farm waste, livestock waste - can be fed into an anaerobic digester to create bioenergy.

The same holds true if the AD plant processes mostly municipal waste and is located in a less rural, more urban, environment.

Biofuels for Aviation


Biofuel is used in transportation, including aviation and shipping on a substantial level; both as the primary fuel source for transportation vehicles (light/ heavy-duty trucks, ships, airlines), and/ or as part of a biofuel-traditional fuel blend with gasoline and biofuel.

Biofuel needs to be converted into bio-liquefied natural gas (bio-LNG) to be effectively used in the transportation sector.

A couple of airlines, in particular, represent present use, and potentially expanded future use, of biofuel blends.

"For years, airlines have experimented with biofuels, aiming to reduce both carbon emissions and their reliance on fossil fuels...several major carriers are planning larger-scale usage of biofuel in 2019 and 2020, including JetBlue Airways Corp.  United Continental Holdings Inc. said it would cut its carbon emissions by half [by using biofuels] compared to 2005 levels, by 2050, matching an industry target set by the International Air Transport Association." 

[FROM  -]

United Eco-skies
United Eco-skies

United Airlines uses the most biofuels in their airplanes of any airline; after Jet Blue helped to pioneer the use of aviation biofuels; as detailed in an article by Fast Company.

From this same Fast Company article- "...biofuel blended jet fuel, with a carbon footprint smaller than regular jet fuel, but a comparable cost– is one way that the airline industry can begin to tackle its climate problem. By mid-century, like other industries, airlines will have to reach net zero emissions for the world to stay on track to meet the goals of the Paris climate agreement."

Is Bioenergy a Climate Solution?


Renewable Bioenergy Biomass Biogas And Biofuel Waste To Energy
bioenergy vs. fossil fuels - lifecycle of CO2 emissions

Using bioenergy is a climate solution; in that burning bioenergy sources produces much less net greenhouse gas emissions than burning fossil fuels. To be clear, burning biomass does produce a significant amount of carbon dioxide (CO2).

The net GHGs of biomass vs. fossil fuels can be determined by comparing avoided emissions from using biomass as a green alternative with the significant GHGs of just using fossil fuels.

Fossil fuels are polluting when extracted, and even more polluting when burned for energy. Biomass is a renewable natural resource that produces CO2 when burned for energy, but the CO2 emitted is roughly equivalent to the CO2 the biomass source has previously sequestered.

Carbon Net Neutral Bioenergetic Cycle

The CO2 released from the burning of biomass is then again sequestered by another biomass source; be it a tree, plant, or other organic matter. That biomass source may itself be burned in the production of energy, releasing the CO2 that had been sequestered by the previously burned biomass source.

Therefore, when looked at in this light, a case can be made that the use of bioenergetic sources is the result of a carbon-net-neutral energy production process.

Please see: 

Algae: The Future of Biofuel


Anaerobic Digestion - A Proven Solution to Our Waste Problem

Gasification - Creating Syngas

Combined Heat and Power - Making the Most of Energy