A novel salt separator for the supercritical water gasification of biomass

The production of synthetic natural gas (SNG) via supercritical water (or hydrothermal) gasification (SCWG or HTG) offers the possibility to exploit the energetic content of biomass with a high water content. Separation and recovery of inorganic constituents present in the feed stream is crucial, as these constituents can lead to blocking of the plant, and to fouling and poisoning of the gasification catalyst. In addition, the recovery of salts offers the potential of producing a fertilizer as a valuable by-product.

A new salt separator design for the SCWG process was tested with two different setups using model solutions with water/2-propanol/Na2SO4/K2SO4. The separation and recovery efficiency proved to be superior compared to the previously used salt separator. The sulfur recovery increased by a factor of 3.5–7 and the sulfur accumulation decreased by a factor of 2–10 using the novel design.

Reimer, J., Peng, G., Viereck, S., De Boni, E., Breinl, J., & Vogel, F. (2016). A novel salt separator for the supercritical water gasification of biomass. The Journal of Supercritical Fluids, 117, 113-121. doi:10.1016/j.supflu.2016.06.009