Editing Straw (section)

===Fuel source===

The use of straw as a carbon-neutral energy source is increasing rapidly, especially for [[biobutanol]]. Straw or hay briquettes are a [[biofuel]] substitute to coal.

Straw, processed first as [[briquette]]s, has been fed into a [[Anaerobic digestion|biogas plant]] in [[Aarhus University]], Denmark, in a test to see if higher [[gas]] yields could be attained.<ref>{{Cite web|url=http://dca.au.dk/en/current-news/news/show/artikel/vejen-fra-toert-halm-til-brugbar-energi-forkortes-markant/|title=show|last=252507@au.dk|date=2017-06-30|website=dca.au.dk|language=en|access-date=2017-07-02|archive-date=2016-04-15|archive-url=https://web.archive.org/web/20160415174332/http://dca.au.dk/en/current-news/news/show/artikel/vejen-fra-toert-halm-til-brugbar-energi-forkortes-markant/|url-status=dead}}</ref>

The use of straw in large-scale [[Energy crop|biomass power plants]] is becoming mainstream in the EU, with several facilities already online. The straw is either used directly in the form of bales, or densified into pellets which allows for the feedstock to be transported over longer distances. Finally, [[torrefaction]] of straw with pelletisation is gaining attention, because it increases the energy density of the resource, making it possible to transport it still further. This processing step also makes storage much easier, because torrefied straw pellets are hydrophobic. Torrefied straw in the form of pellets can be directly co-fired with coal or natural gas at very high rates and make use of the processing infrastructures at existing coal and gas plants. Because the torrefied straw pellets have superior structural, chemical and combustion properties to coal, they can replace all coal and turn a coal plant into an entirely biomass-fed power station. First generation pellets are limited to a [[co-firing]] rate of 15% in modern [[Integrated gasification combined cycle|IGCC]] plants.