Sidor

Saturday, October 22, 2011

Optimal burn temperature



This is a graph[1] that got my attention. If you look closely you will discover an optimal temperature for maximum char production at about 450 degrees centigrades. This is not a high temperature and is achieveable with low-tech solutions like the one made by Peter Hirst and many others.

Sources:
[1] J. Lehmann, “A handful of carbon,” Nature, vol. 447, no. 7141, pp. 143-144, May 2007.

Metareview (first part)

The following is a review on a review[1] titled: “The pyrolysis platform”. It tries to give an overview on the current (2009) use and possible end uses of different pyrolysis products. It has some fantastic claims as well as warnings on what could go wrong if the use of pyrolysis products are produced in an unsustainable way. For example if the biomass production (needed for pyrolysis) would start to compete for land use with food crops, the price on food could potentially rise. Nevertheless, this was supposed to be a positive blog focusing on the benefits of biochar.

The tree main products of a pyrolysis plant (regardless of size) are bio-oil bio-gas and biochar. The ratio between these three is very much dependent on the pyrolysis method. This is why the pyrolysis method is so versatile. In addition the whole concept is relatively low-tech and is suitable for small scale (as well as large scale) production. Just look at the picture (taken straight from the article):
This is it for now. Next up: different pyrolysis methods and properties of different biomasses.

Sources:
[1] D. A. Laird, R. C. Brown, J. E. Amonette, and J. Lehmann, “Review of the pyrolysis platform for coproducing bio‐oil and biochar,” Biofuels, Bioproducts and Biorefining, vol. 3, no. 5, pp. 547-562, Sep. 2009.