SAF is a liquid fuel currently used in commercial aviation which reduces CO2 emissions by up to 80%. It can be produced from several sources (feedstock/raw materials) including used cooking oil, municipal waste and forestry biomass.
HVO is produced through a hydrotreatment process that removes oxygen from vegetable oils, waste oils, and animal fats. As a result, it has significantly lower carbon emissions compared to fossil diesel. Depending on the feedstock used, HVO can reduce greenhouse gas emissions by 80-90% on a lifecycle basis.
HVO can be produced from various renewable feedstocks, including vegetable oils, used cooking oil, and waste fats (animal fat not for human consumption). These feedstocks are sustainable and help divert waste from landfills. A key advantage of HVO fuel is its compatibility with existing diesel engines, negating the need for any modifications. This aspect makes it a readily adoptable alternative in the transition towards sustainable energy.
Biodiesel, another form of biofuel, is produced through a chemical process known as transesterification. This process transforms vegetable oils or animal fats into a fuel that is more akin to conventional diesel. A variety of feedstocks, including soybean oil, canola oil, and recycled cooking oil, are used to produce biodiesel.
The resulting fuel is renewable and biodegradable, and it can be used in diesel engines with minor or no modifications. Biodiesel blends are common, where a percentage of biodiesel is mixed with conventional diesel, offering a practical approach to reducing reliance on fossil fuels.
Anaerobic digestion is a fascinating process that occurs without oxygen.
Organic Matter Breakdown: Anaerobic digestion involves the breakdown of organic matter, such as animal manure, food waste, and wastewater biosolids. Bacteria play a crucial role in this process.
Sealed Reactor: The entire process takes place in a sealed vessel called an anaerobic digester. These digesters come in various shapes and sizes, customized for specific site conditions and feedstock.
Microbial Communities: Within the digester, complex microbial communities work together. They break down the organic waste, digesting it in the absence of oxygen.
As the bacteria “work,” they generate biogas. This biogas primarily consists of methane (CH₄), which is the primary component of natural gas. Alongside methane, the biogas also contains carbon dioxide (CO₂), hydrogen sulfide (H₂S), water vapor, and trace amounts of other gases.
Heat : Biogas can be used like natural gas to provide heat.
Electricity : It can generate electricity.
Cooling Sysems : Biogas can power cooling systems.
enewable Natural Gas (RNG) : By removing low-value constituents (such as CO₂ and H₂S), biogas can be purified into RNG. This can be sold, injected into the natural gas distribution system, or used as vehicle fuel.
Digestate : After the digestion process, we’re left with digestate. It’s the residual material composed of both liquid and solid portions. These can be separated and used in various ways :
– Solid Portion : Used as animal bedding, organic-rich compost, or soil amendment (fertilizer).
– Liquid Portion : Used as nutrient-rich fertilizer or a foundation material for bio-based products.
In summary, anaerobic digestion is a sustainable process that not only breaks down waste but also produces valuable biogas and digestate. It’s a win-win for both waste management and renewable energy!
Bioethanol is chemically identical to petroleum derived ethanol. Usual feedstocks of bioethanol include corn, switchgrass, sugar cane, algae, or other biomass. The feedstocks undergo fermentation, during which certain species of yeast digest the sugar contained in the feedstocks. The process releases bioethanol and carbon dioxide.
Besides alcoholic beverage production, ethanol is also used as an alternative fuel to petrol. It can be mixed with petrol to any percentage, and all existing petrol engines on automobiles can operate with blends of up to 10% ethanol with petrol. On a life cycle analysis basis, corn-based bioethanol production and use reduces greenhouse gas emissions (GHGs) by up to 52% compared to petrol production and use. Bioethanol use could reduce GHGs by as much as 86%.
MTBE (methyl tertiary butyl ether) made from methanol and isobutylene is a high value petrol component that can be blended into gasoline at high quantities without any application issues.
Overall, bio-methanol offers significant environmental benefits compared to conventional fossil-based methanol, as it reduces carbon dioxide emissions by up to 95% and eliminates sulfur oxide and particulate matter emissions.
