Options for carbon dioxide removal from the atmosphere include afforestation and chemical approaches like direct air capture of CO2 from the atmosphere or reactions of CO2 with minerals to form carbonates. But the use of biomass for energy generation combined with carbon capture and storage is less costly than chemical options, as long as sufficient biomass feedstock is available, the scientists point out.
Directly removing CO2 from the air has the potential to alter the costs of climate change mitigation. It could allow prolonging greenhouse-gas emissions from sectors like transport that are difficult, thus expensive, to turn away from using fossil fuels. And it may help to constrain the financial burden on future generations, a study now published by the Potsdam Institute for Climate Impact Research (PIK) shows. It focuses on the use of biomass for energy generation, combined with carbon capture and storage (CCS). According to the analysis, carbon dioxide removal could be used under certain requirements to alleviate the most costly components of mitigation, but it would not replace the bulk of actual emissions reductions.
“Carbon dioxide removal from the atmosphere allows to separate emissions control from the time and location of the actual emissions. This flexibility can be important for climate protection,” says lead-author Elmar Kriegler. “You don’t have…
the benefits of wood-based bioenergy all depend on what is harvested, where it is harvested from, how it is harvested, how it is transported, how it is utilized as an energy source, the time horizon considered, and the alternative fate of the feedstock material. An energy portfolio that includes wood-based bioenergy is a better long-term strategy than other viable alternatives.
Much of our nation’s energy (both liquid transportation fuels and electric power) is derived from “fossil fuels,” which include oil, coal, and natural gas.
There are several drawbacks to these energy sources:
They are non-renewable resources. Once existing deposits are used up, they are gone. Through new technology we have gotten better at finding and accessing more of these deposits, which has kept supplies plentiful, but ultimately they are finite.
Their use converts carbon stored the earth to carbon dioxide which is released into the atmosphere. Rising concentrations of carbon dioxide in the atmosphere changes global climate, with a myriad of consequences.
Prices are unstable and usually climbing, impacting all areas of our lives and economy and our nation’s foreign policy.
Extraction (e.g. mining, offshore drilling, fracking, etc.) can harm the environment, especially if there is an accident.
The advantages of bioenergy is that it can be renewable, locally…
The term ‘Biofuel’ refers to liquid or gaseous fuels for the transport sector that are predominantly produced from biomass. A variety of fuels can be produced from biomass resources including liquid fuels, such as ethanol, methanol, biodiesel, Fischer-Tropsch diesel, and gaseous fuels, such as hydrogen and methane. The biomass resource base for biofuel production is composed of a wide variety of forestry and agricultural resources, industrial processing residues, and municipal solid and urban wood residues.
The agricultural resources include grains used for biofuels production, animal manures and residues, and crop residues derived primarily from corn and small grains (e.g., wheat straw). A variety of regionally significant crops, such as cotton, sugarcane, rice, and fruit and nut orchards can also be a source of crop residues. The forest resources include residues produced during the harvesting of forest products, fuelwood extracted from forestlands, residues generated at primary forest product processing mills, and forest resources that could become available through initiatives to reduce fire hazards and improve forest health. Municipal and urban wood residues are widely available and include a variety of materials — yard and tree trimmings, land-clearing wood residues, wooden pallets, organic wastes, packaging materials, and construction and demolition debris.
Globally, biofuels are most commonly used to power vehicles, heat homes, and for cooking. Biofuel industries are expanding in Europe, Asia and the Americas. Biofuels are generally considered as offering many priorities, including sustainability, reduction of greenhouse gas emissions, regional development, social structure and agriculture, and security of supply.
First-generation biofuels are made from sugar, starch, vegetable oil, or animal fats using conventional technology. The basic feedstocks for the production of first-generation biofuels come from agriculture and food processing. The most common first-generation biofuels are:
Biodiesel: extraction with or without esterification of vegetable oils from seeds of plants like soybean, oil palm, oilseed rape and sunflower or residues including animal fats derived from rendering applied as fuel in diesel engines
Bioethanol: fermentation of simple sugars from sugar crops like sugarcane or from starch crops like maize and wheat applied as fuel in petrol engines
Bio-oil: thermo-chemical conversion of biomass. A process still in the development phase
Biogas: anaerobic fermentation or organic waste, animal manures, crop residues an energy crops applied as fuel in engines suitable for compressed natural gas.
First-generation biofuels can be used in low-percentage blends with conventional fuels in most vehicles and can be distributed through existing infrastructure. Some diesel vehicles can run on 100 % biodiesel, and ‘flex-fuel’ vehicles are already available in many countries around the world.
Second-generation biofuels are derived from non-food feedstock including lignocellulosic biomass like crop residues or wood. Two transformative technologies are under development.
Biochemical: modification of the bio-ethanol fermentation process including a pre-treatment procedure
Thermochemical: modification of the bio-oil process to produce syngas and methanol, Fisher-Tropsch diesel or dimethyl ether (DME).
Advanced conversion technologies are needed for a second generation of biofuels. The second generation technologies use a wider range of biomass resources – agriculture, forestry and waste materials. One of the most promising second-generation biofuel technologies – ligno-cellulosic processing (e. g. from forest materials) – is already well advanced. Pilot plants have been established in the EU, in Denmark, Spain and Sweden.
Third-generation biofuels may include production of bio-based hydrogen for use in fuel cell vehicles, e.g. Algae fuel, also called oilgae. Algae are low-input, high-yield feedstocks to produce biofuels.