| Abstract from DBPedia | Biomass is plant-based material used as fuel to produce heat or electricity. Examples are wood and wood residues, energy crops, agricultural residues, and waste from industry, farms and households. Since biomass can be used as a fuel directly (e.g. wood logs), some people use the words biomass and biofuel interchangeably. Others subsume one term under the other. Government authorities in the US and the EU define biofuel as a liquid or gaseous fuel, used for transportation. The European Union's Joint Research Centre use the concept solid biofuel and define it as raw or processed organic matter of biological origin used for energy, for instance firewood, wood chips and wood pellets. In 2019, 57 EJ (exajoules) of energy were produced from biomass, compared to 190 EJ from crude oil, 168 EJ from coal, 144 EJ from natural gas, 30 EJ from nuclear, 15 EJ from hydro and 13 EJ from wind, solar and geothermal combined. Approximately 86% of modern bioenergy is used for heating applications, with 9% used for transport and 5% for electricity. Most of the global bioenergy is produced from forest resources. Power plants that use biomass as fuel can produce a stable power output, unlike the intermittent power produced by solar or wind farms. In 2017, the IEA (International Energy Agency) described bioenergy as the most important source of renewable energy. The IEA also argued that the current rate of bioenergy deployment is well below the levels required in future low carbon scenarios, and that accelerated deployment is urgently needed. In IEA's Net Zero by 2050 scenario, traditional bioenergy is phased out by 2030, and modern bioenergy's share of the total energy supply increases from 6.6% in 2020 to 13.1% in 2030 and 18.7% in 2050. In 2014, IRENA (International Renewable Energy Agency) projected a doubling of energy produced from biomass in 2030, with a small contribution from traditional bioenergy (6 EJ). The IPCC (Intergovernmental Panel on Climate Change) argue that bioenergy has a significant climate mitigation potential if done right, and most of the IPCC's mitigation pathways include substantial contributions from bioenergy in 2050 (average at 200 EJ.) Some researchers criticize the use of bioenergy with low emission savings, high initial carbon intensities and/or long waiting times before positive climate impacts materialize. The raw material feedstocks with the largest potential in the future is lignocellulosic (non-edible) biomass (for instance coppices or perennial energy crops), agricultural residues, and biological waste. These feedstocks also have the shortest delay before producing climate benefits. Heat production is normally more "climate friendly" than electricity production, since the conversion from chemical to heat energy is more efficient than the conversion from chemical to electrical energy. Heat from biomass combustion is also harder to replace with heat from alternative renewable energy sources; these are either more costly or constrained by the maximum temperature of the steam they can deliver. Solid biofuel is likely more climate friendly than liquid biofuel, since the production of solid biofuel is more energy efficient. Biogas plants can provide dispatchable electricity generation, and heat when needed. A common concept is the co-fermentation of energy crops mixed with manure in agriculture. Burning plant-derived releases CO2, but it has still been classified as a renewable energy source in the EU and UN legal frameworks because photosynthesis cycles the CO2 back into new crops. How a fuel is produced, transported and processed has a significant impact on lifecycle emissions. Transporting fuels over long distances and excessive use of nitrogen fertilisers can reduce the emissions savings made by the same fuel compared to natural gas by between 15 and 50 per cent. Renewable biofuels are starting to be used in aviation.バイオマス（英: biomass）とは、生態学で、特定の時点においてある空間に存在する生物（バイオ）の量を、物質（マス）の量として表現したものである。通常、質量あるいはエネルギー量で数値化する。日本語では生物体量や生物量の語が用いられる。植物生態学などの場合には現存量の語が使われることも多い。転じて生物由来の資源を指すこともある。バイオマスの利用法には燃料とするものがあり、その場合バイオ燃料（Biofuel）またはエコ燃料、木質燃料といった言葉が使われる。またバイオマスを燃焼させて発電することをバイオマス発電という。 (Source: http://dbpedia.org/resource/Biomass) |
