Biofuel
[9][10] The outcomes of lifecycle assessments (LCAs) for biofuels are highly situational and dependent on many factors including the type of feedstock, production routes, data variations, and methodological choices.[17] Bioethanol is an alcohol made by fermentation, mostly from carbohydrates produced in sugar or starch crops such as maize, sugarcane, or sweet sorghum.It can also be used in its pure form (B100) in diesel engines, but some maintenance and performance problems may occur during wintertime utilization, since the fuel becomes somewhat more viscous at lower temperatures, depending on the feedstock used.[35] Electronically controlled 'common rail' and 'Unit Injector' type systems from the late 1990s onwards can only use biodiesel blended with conventional diesel fuel.[40] Avril Group produces under the brand Diester, a fifth of 11 million tons of biodiesel consumed annually by the European Union.For example, hydrocracking which is a widely used hydroprocessing technique in refineries is used at elevated temperatures and pressure in the presence of a catalyst to break down larger molecules, such as those found in vegetable oils, into shorter hydrocarbon chains used in diesel engines.[26] Oils and fats reacted with 10 pounds of a short-chain alcohol (usually methanol) in the presence of a catalyst (usually sodium hydroxide [NaOH] can be hydrogenated to give a diesel substitute.[53] The resulting product is a straight-chain hydrocarbon with a high cetane number, low in aromatics and sulfur and does not contain oxygen.They have several advantages over biodiesel, including good performance at low temperatures, no storage stability problems and no susceptibility to microbial attack.Using biological methods, a study led by Professor Lee Sang-yup at the Korea Advanced Institute of Science and Technology (KAIST) and published in the international science journal Nature used modified E. coli fed with glucose found in plants or other non-food crops to produce biogasoline with the produced enzymes.The enzymes converted the sugar into fatty acids and then turned these into hydrocarbons that were chemically and structurally identical to those found in commercial gasoline fuel."[56][attribution needed] Bioethers are created from wheat or sugar beets, and also be produced from the waste glycerol that results from the production of biodiesel.[62] Although Europeans still use bioether additives, the U.S. Energy Policy Act of 2005 lifted a requirement for reformulated gasoline to include an oxygenate, leading to less MTBE being added to fuel.[63] Although bioethers are likely to replace ethers produced from petroleum in the UK, it is highly unlikely they will become a fuel in and of itself due to the low energy density.The International Air Transport Association (IATA) considers it a key element in reducing the environmental impact of aviation.Biogas is a mixture composed primarily of methane and carbon dioxide produced by the process of anaerobic digestion of organic material by micro-organisms.Other trace components of this mixture includes water vapor, hydrogen sulfide, siloxanes, hydrocarbons, ammonia, oxygen, carbon monoxide, and nitrogen.[73][74] It can be produced either from biodegradable waste materials or by the use of energy crops fed into anaerobic digesters to supplement gas yields.[85][86] However, production requires large amounts of energy and fertilizer, the produced fuel degrades faster than other biofuels, and it does not flow well in cold temperatures.Light is converted to chemical energy, typically by reducing protons to hydrogen, or carbon dioxide to organic compounds.[91] A bio-digester is a mechanized toilet that uses decomposition and sedimentation to turn human waste into a renewable fuel called biogas.Anaerobic digestion uses a chemical process to break down organic matter with the use of microorganisms in the absence of oxygen to produce biogas.Environmental concerns include deforestation, biodiversity loss and soil erosion as a result of land clearing for biofuels agriculture.[45][46] Several factors are responsible for the variation in emission numbers of biofuel, such as feedstock and its origin, fuel production technique, system boundary definitions, and energy sources.This shift in land use can lead to several problems: The expansion of biofuel production, particularly through monoculture farming (growing a single crop on a large scale), poses a significant threat to biodiversity.[104] Several studies have shown that reductions in emissions from biofuels are achieved at the expense of other impacts, such as acidification, eutrophication, water footprint and biodiversity loss.[110][111] Unsustainable palm oil agriculture has caused significant environmental and social problems, including deforestation and pollution.A solution proposed to solve this issue is to supply biofuel production facilities with excess nuclear energy, which can supplement the power provided by fossil fuels.The indirect land use change impacts of biofuels, also known as ILUC or iLUC (pronounced as i-luck), relates to the unintended consequence of releasing more carbon emissions due to land-use changes around the world induced by the expansion of croplands for ethanol or biodiesel production in response to the increased global demand for biofuels.Because natural lands, such as rainforests and grasslands, store carbon in their soil and biomass as plants grow each year, clearance of wilderness for new farms translates to a net increase in greenhouse gas emissions.
BioenergybiodieselRenewable energyBiogasBiomassCarbon-neutral fuelCrosswind kite powerGeothermal energyGeothermal heatingGeothermal powerHydroelectricityRun-of-the-riverHydropowerMicro hydroPico hydroSmall hydroMarine current powerMarine energyOcean thermalOsmotic powerSolar energySolar powerSustainable biofuelTidal powerTidal stream generatorWave powerWind powerNuclear power proposed as renewable energyTopics by country and territoryMarketing and policy trendsfossil fuelsbio wastebio energyfood vs fuelsustainabilitydeforestationbiodiversity lossgreenhouse gas emissionscarbon-neutral fuelslife-cycle assessmentsland-use changeclimate change mitigationnegative emissionsaviation biofuelalcoholfermentationcarbohydratesstarchsugarcanesweet sorghumCellulosic biomassfeedstockgasolineadditivetransesterificationdieselcarbon monoxidehydrocarbonsIPCC Sixth Assessment Reportbioethanolethanolfood versus fuelsecond-generation biofuelsadvanced biofuelssustainable biofuelsarable landEthanol fuelalcoholspropanolbutanolmicroorganismsenzymesin BrazilAlcohol fuelssugar beetssugar canemolassesalcoholic beverageswhiskeypotatoenzyme digestiondistillationnatural gasbagassewaste heatcellulosic ethanolnon-renewablebiomethanolmethanol economyhydrogen economyhydrogenABE fermentationnet energy gainsbiobutanolEscherichia coliamino acid metabolismnutrient rich mediabiogasolineBiodiesel around the worldrapeseedjatrophamustardsunflowerpalm oilfield pennycressPongamia pinnatasafflowerlubricantMontana State Universitydiesel engineviscouscommon railUnit Injectorfuel railsolventengine filterscombustion chamberoxygenatedcombustionbiodegradableflash pointAvril GroupDiesterEuropean UnionBiodiesel productionGreen diesel