Introduction and Types of Biofuel
– Biofuel is a fuel produced from biomass, rather than fossil fuels.
– It can be derived from plants, agricultural waste, or industrial waste.
– Biofuels are mainly used for transportation but can also be used for heating and electricity.
– They are considered a renewable energy source.
– The two most common types of biofuel are bioethanol and biodiesel.
– Bioethanol is produced through fermentation of carbohydrates in crops like maize and sugarcane.
– Biodiesel is produced from oils or fats using transesterification.
– Cellulosic biomass is being developed as a feedstock for ethanol production.
Climate Impact of Biofuel
– Biofuels emit fewer greenhouse gas emissions when burned.
– They are generally considered carbon-neutral fuels.
– However, life-cycle assessments have shown emissions associated with land-use change for biofuel production.
– Estimates of climate impact vary depending on the methodology and situation examined.
– The climate change mitigation potential of biofuel varies, with some scenarios showing comparable emissions to fossil fuels and others showing negative emissions.
Conventional and Advanced Biofuels
– Conventional biofuels are made from food crops grown on arable land.
– The crops’ sugar, starch, or oil content is converted into biodiesel or ethanol.
– First-generation biofuels are readily available but low in efficiency and produce pollutants.
– They have advantages in terms of ease of use but have significant downsides.
– Second-generation biofuels are made from waste products or crops grown on marginal land.
– These biofuels aim to avoid the food vs fuel dilemma.
– However, they have downsides like expensive production costs and high water requirements.
Aviation Biofuel
– Aviation biofuel is a biofuel used to power aircraft.
– It is considered a sustainable aviation fuel (SAF) and helps reduce the carbon footprint of aviation.
– Can lower CO2 emissions by 20-98% compared to conventional jet fuel.
– First test flight using blended biofuel was in 2008.
– Blended fuels with 50% biofuels allowed in commercial flights since 2011.
– International Air Transport Association (IATA) aims for a 2% penetration by 2025.
– Produced from plant or animal sources such as Jatropha, algae, tallows, waste oils, palm oil, Babassu, and Camelina.
Environmental and Social Impacts
– Biofuels emit fewer greenhouse gas emissions when burned in an engine.
– Life-cycle assessments show large emissions associated with land-use change for biofuel production.
– Indirect land use change refers to the unintended consequences of clearing natural lands for biofuel crop production.
– The food vs fuel debate arises from the competition between biofuel production and food production.
– The European Commission has approved measures to phase out palm oil-based biofuels by 2030.
– Modifications may be necessary to run an engine on biofuel.
– Assessing the wider and interrelated factors is crucial when assessing biofuel sustainability. Source: https://en.wikipedia.org/wiki/Biofuel
Biofuel is a fuel that is produced over a short period from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels, such as oil. Biofuel can be produced from plants or agricultural, domestic, or industrial biowaste. Biofuels are mostly used for transportation but can also be used for heating and electricity. Biofuels (and bioenergy in general) are regarded as a renewable energy source. However, the use of biofuel has been controversial because of the several disadvantages associated with the use of it. These include for example (and this varies on a case-by-case basis): the "food vs fuel" debate, biofuel production methods being sustainable or not, leading to deforestation and loss of biodiversity or not.
In general, biofuels emit fewer greenhouse gas emissions when burned in an engine and are generally considered carbon-neutral fuels as the carbon emitted has been captured from the atmosphere by the crops used in production. However, life-cycle assessments of biofuels have shown large emissions associated with the potential land-use change required to produce additional biofuel feedstocks. Estimates about the climate impact from biofuels vary widely based on the methodology and exact situation examined. Therefore, the climate change mitigation potential of biofuel varies considerably: in some scenarios, emission levels are comparable to fossil fuels and in other scenarios the biofuel emissions result in negative emissions.
The two most common types of biofuel are bioethanol and biodiesel. Brazil is the largest producer of bioethanol, while the EU is the largest producer of biodiesel. The energy content in the global production of bioethanol and biodiesel is 2.2 and 1.8 EJ per year, respectively. Demand for aviation biofuel is forecast to increase.
Bioethanol is an alcohol made by fermentation, mostly from carbohydrates produced in sugar or starch crops such as maize, sugarcane, or sweet sorghum. Cellulosic biomass, derived from non-food sources, such as trees and grasses, is also being developed as a feedstock for ethanol production. Ethanol can be used as a fuel for vehicles in its pure form (E100), but it is usually used as a gasoline additive to increase octane ratings and improve vehicle emissions.
Biodiesel is produced from oils or fats using transesterification. It can be used as a fuel for vehicles in its pure form (B100), but it is usually used as a diesel additive to reduce levels of particulates, carbon monoxide, and hydrocarbons from diesel-powered vehicles.
