If, however, they are subjected instead to pyrolysis-a process of controlled burning in a low-oxygen atmosphere-the result is charcoal, a substance that is mostly elemental carbon.
但如果经过高温分解—在低氧环境下有控制的燃烧—它将会形成木炭，其大部分是永久碳。
2
The heat breaks the biomass down into a charcoal-like solid and the bio-oil, giving off some gas in the process.
这种情况下，加热会把生物原料变成木炭似的固体物质和生物原油，同时释放某些气体。
3
In contrast, charcoal, made by partially burning wood in a controlled process, is a fuel that creates less smoke than wood does.