Bioenergy
TYPES OF STRATEGIES
International Energy Agency (IEA) has estimated that if a New Polices Scenario is considered the traditional biomass uses will decrease by 2035 and other uses as power, industry, transport, buildings and others will increase.
Examples of biomass sources are forest, agricultural and livestock residues, energy crops, short-rotation forest plantations and solid organic urban waste. These sources are used as feedstocks to produce energy in the form of solid fuels (like chips and pellets), liquid fuels (biodiesel, ethanol and renewable diesel), gaseous fuels (biomethane), heat and power. This conversion is possible thanks to the conversion routes that can be chemical, biological and thermal processes.
Bioenergy process
One feedstock can be used in most that one conversion route. For example, oil crops can be used in combustion process but also in transesterification or hydrogenation processes. As we can see in the figure above, each route gives products. One route can give more than one product and one product can be generated by means of different conversion routes.
THERMOCHEMICAL PROCESS
COMBUSTION
In this process, hydrogen and carbon react with excess oxygen to produce CO2 and water. This process releases heat. The biomass burning can be direct for cooking and it is very common in rural areas. But feedstocks as charcoal and wood are also used in industries to produce fuels.
PYROLISIS
By supplying heat to biomass it can be decomposed in an anaerobic environment producing the following products:
- Gas products
- Liquid products: pyrolysis oil also known as bio-oil
- Solid products: charcoal
BIOMASS GASIFICATION
Partial biomass oxidation occurs upon heating that produces fuel gas which is rich in CO and hydrogen. The fuel gas quality can be improved and then syngas is obtained. Coupled with electricity generators, syngas can be used as a fuel in place of diesel. Gasification is more efficient than combustion because the heating can be better controlled and higher efficiencies can be achieve in electricity production.
CHEMICAL PROCESS
TRANSESTERIFICACION
In transesterification alcohols such as methanol react with triglycerides in the presence of a catalyst. The triglycerids are inside vegetable oils or animal fats. The generated products are an alkyl ester of fatty acids and a glycerine by-product. The fatty acid alkyl esters are the biodiesel. The protein-rich residue, also known as cake, is typically sold as animal feed or fertilizer.
HYDROGENATION
This process consists on the reaction of biomass (vegetable oil or animal fats) with H2 in the presence of a catalyst. This conversion route can be considerated as a first generation route
BIOCHEMICAL PROCESS
ANAEROBIC DIGESTION (AD)
Is the process that involvesthe breakdown of organic material by specifics microorganisms in the absence of oxygen to produce biogas.
Benefits to the environment
Bioenergy has dramatic greenhouse gas mitigation potential: the use of biomass residues and wastes and advanced conversion systems are able to deliver 80 to 90% emission reductions compared to the fossil energy fuels. The carbon mitigation potential for electricity generation by using bioenergy will reach 1,220 Mt CO2 eq by year 2030 according IPPC
If the bioenergy is combined with developing carbon capture and storage could lead to long-term substantial removal of GHGs from the atmosphere. One problem of bioenergy is the land use conflict but the use of aquatic biomass (algae) can be a solution.
For this reason, coolmyplanet encourage you to take part in the Bioenergy projects!
Trends
Here is the total bioenergy production potential in 2050 in the four different scenarios:
Bioenergy production will increase in the entire world. The highest bioenergy production will be in Africa, South of America and Asia.
By 2030, a IPCC model projects that 11% of transport fuels will be provided by biofuels:
If we look at the graphic below, we can notice that one form to combat climate change by means of reducing GHG emissions from transport is by using biofuels instead of pollutant fuels:
