Impact of Pyrolysis Temperature On the Properties of Sitka Spruce (Picea Sitchensis) Biochar.

Biochar as a product of pyrolysis has been found to be stable, and ‘recalcitrant’ in the environment with an estimated mean residence time of 2000 years in temperate soils (Kuzyakov et al., 2009). Hence, it appears to provide a channel for the removal of carbon from the short-term bio-atmospheric carbon cycle and sequestering it into the long-term geological carbon cycle (Bird et al., 1999). Additionally, biochar has been shown to suppress release of green house gases from soils (Spokas et al., 2009).

The need to use biochar as a soil improver raises the question of safety, which regulatory bodies ask in their quest to ensure protection of the soil environment. Hence, the importance of characterization of biochar products from all types of biomass .One of the two central factors that affect the physico-chemical properties of biochar is production temperature; the other being nature of feedstock.

In this study, Sitka Spruce (Picea sitchensis) wood was pyrolised at three different temperature values and properties such as pH, water holding capacity, surface functional groups, cation exchange capacity, total organic carbon and polycyclic aromatic hydrocarbon (PAH) contents were determined.  The methods used include: Thermal Gravimetry (TG-DSC-QMS), spectrometry (FT-IR) and GC-MS.

Some of the results obtained seem to show observable shift in properties with temperature of pyrolysis since the biomass type is fixed in this case.

 

References

Bird, M.I., Moyo, C., Veenendaal, E.M., Lloyd, J. and Frost, P. (1999) 'Stability of elemental carbon in a savanna soil', Global Biogeochem. Cycles, 13(4), pp. 923-932.

Kuzyakov, Y., Subbotina, I., Chen, H.Q., Bogomolova, I. and Xu, X.L. (2009) 'Black carbon decomposition and incorporation into soil microbial biomass estimated by C-14 labeling', Soil Biology & Biochemistry, 41(2), pp. 210-219.

Spokas, K.A., Koskinen, W.C., Baker, J.M. and Reicosky, D.C. (2009) 'Impacts of woodchip biochar additions on greenhouse gas production and sorption/degradation of two herbicides in a Minnesota soil', Chemosphere, 77(4), pp. 574-581.