There are no pellet classifications based on wood type. Traditionally wood pellets are classified according to the amount of the ash produced.

木屑颗粒等级不是按木材类型划分的。传统的木屑颗粒是根据所产生的灰份含量分类。在此分类下有三个等级。

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Biochar is a type of charcoal produced by heating crop wastes, wood or other biomass in a simple kiln designed to limit the presence of oxygen.

生物炭是农作物废料、木材或其它生物质在简易窑(为限制氧存量而设计的窑)内经过加热而制成的一种炭。

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The Speaker's chair - with a lighted canopy - was originally a present from Australia and is the only wood of its type in the Houses of Parliament (d).

BBC: COMMONS' CHAMBER

You get a special type of wood (known as reaction wood) laid down in response to environmental stimuli, such as tipping or wind, which induces these special woods to be formed.

BBC: Sugar-rich willow can boost biofuels' green credentials

And even though Alan had never been in the hotel or real estate business, he had an unbelievable clarity of vision I'll never forget, in 2000, he walked me through this gutted brick structure and was describing the color of the curtains, the type of wood floor, the long bench in the entrance.

WSJ: Alan Faena's Argentine Residence