Scaleable Hydrotreating of HTL Biocrude to Produce Fuel Blendstocks

Hydrothermal liquefaction (HTL) offers an attractive route to produce fuel blendstocks from wet wastes. Scaleable hydrotreating data for the conversion of HTL biocrude to fuels is critical to the commercialization of HTL. Herein, we simulate the pore diffusion of hydrogen into the catalyst pores for the hydrotreating of HTL biocrudes and conclude that standard hydrotreating catalysts will be pore diffusion limited regarding hydrogen diffusion for HTL biocrude upgrading. By changing the catalyst size (crushed vs extrudate catalysts), we confirm an impact of pore diffusion on the overall hydrogenation rate of HTL biocrudes. When using whole pill extrudates, likely with pore diffusion limitations, we provide scale-able hydrotreating data for the stand-alone hydrotreating of a HTL biocrude (derived from sewage sludge). By running the reactor at two different hydrotreater scales (25x scale-up), we confirm the data quality.

Automated summary

This study simulated the pore diffusion of hydrogen into the catalyst pores for the hydrotreating of HTL biocrudes and found that standard hydrotreating catalysts are pore diffusion limited for hydrogen diffusion in HTL biocrude upgrading. By running the reactor at different hydrotreater scales, the data quality was confirmed for scalable hydrotreating of HTL biocrudes.