Potential of Biomass Liquefaction Hydrochar for Soil Amendment

Extensive research has been done on applications of pyrolysis biochar to amend soil. However, no research has been done on hydrothermal liquefaction (HTL) hydrochar regarding its potential for soil amendment. In this study, corn stover derived hydrochar from HTL at 280 °C were characterized using suitable analytical techniques to determine the functional groups, specific surface area and morphology. The effects of HTL hydrochar on water holding capacity (WHC) and water retention ability of sandy loam soil and the resistance to biodegradation were also studied. The BET surface area of hydrochar was found to be 27.61 m2/g. The hydrochar particles are micro-sized stacking of nanometer-thick foliates. The hydrochar amended soil consistently showed better WHC ranging from 50 -55 % compared to the unamended soil of 48 %. Similar trend in results were observed for water retention over a period of four days. No notable biodegradation was observed for both the hydrochar and the heavy biocrude over up to over 115 days in soil or potting mix. Overall, these results demonstrate the potential of HTL hydrochar as a valuable soil amendment to enhance agriculture sustainability.