Hydrothermal carbonization biochar

Kumar, S., Loganathan, V.A., Gupta, R.B. Barnett, M.O. (2011) An assessment of U(VI) removal from groundwater using biochar produced from hydrothermal carbonization. Journal of Environmental Management, 92, 2504-2512. 

In general, lower temperatures (160-220°C) and pressures (less than 20 atm) result in hydrothermal carbonization which gives a solid, carbonaceous product (biochar), which can be further gasified and used for Fischer-Tropsch fuel synthesis. The concept has been demonstrated on a lab scale using Chlamydomonas reinhardtii (Heihnann et al., 2010). 

Reza, M.T., et al., 2012. Pelletization of biochar from hydrothermally carbonized wood. Enviromnental Progress Sustainable Energy 31 (2), 225—234. 

Most thermochemical conversion technologies used for production of biofuels and biochemicals yield solid residues as a byproduct. Depending on the technology, this residue contains more or less carbon, and can therefore be considered biochar in its own right, or a biochar precursor. The key relevant technologies, fast pyrolysis, gasification, and hydrothermal carbonization are discussed individually in the following sections. 

Busch, D., Stark, A., Kammann, C.I., Glaser, B., 2013. Genotoxic and phytotoxic risk assessment of fresh and treated hydrochar from hydrothermal carbonization compared to biochar from pyrolysis. Ecotoxicology and Environmental Safety 97, 59—66. http //dx.doi.org/ 10.1016/j. ecoenv.2013.07.003. 

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