Pyrolysis and biochar
Pyrolysis
Fast pyrolysis of small biomass samples is carried out as a precursor to thermolysis viz. analysis of the products of pyrolysis using GCMS, NMR, FTIR etc to discover more about the composition of the original biomass.
Slow pyrolysis facilities are available for pyrolysing batches of biomass. Some of this work is directed at bio-char production. There is also an interest in using pyrolysis as a technique for converting biomass into a material that is more energy-dense in order to facilitate its transportation to centralised facilities for subsequent thermochemical conversion.
Biochar
The pyrolysis of biomass (viz thermal conversion in the absence of oxygen) produces 3 outlet streams: solid, liquid and gas. In slow pyrolysis processes, the reaction favours production of the solid biochar stream at the expense of the other two. Biochar has been shown to act as a soil improver which under the right conditions can improve crop yields and reduce the need for artificial fertiliser. The use of biochar as a soil improver provides a mechanism for sequestering carbon from the original biomass material on a long-term basis. Newcastle University hosted the 2nd annual international meeting of the International Biochar Initiative in September 2008, and is partner of the UK Biochar Research Centre (UKBRC). Work at Newcastle focuses on developing slow pyrolysis technology, examining the efficacy of biochar as a soil improver, and generating data to quantify the overall carbon footprint associated with converting biomass into energy when the bio-char fraction is recycled back into biomass crop production.
Schematic diagram of biochar production process.
Biochar pot trials at Moorbank Botanical Garden, Newcastle University.
The wood biochar addition can be clearly seen in this image.
There is also some activity in developing varieties of plants to convert atmospheric CO2 through photo-synthesis into carboxylic acids that are forced down into the soil via plant root systems, ultimately becoming sequestered in the form of carbonates in the soil.
Brick with calcite overgrowths recovered from trial pit in Byker, Newcastle
