Characteristics and potential values of bio-oil, syngas and biochar derived from Salsola collina Pall. in a fixed bed slow pyrolysis system

Salsola collina Pall. as a typical euhalophyte was slowly pyrolyzed at 300 °C, 500 °C and 700 °C in a fixed-bed system. The physiochemical properties of syngas, bio-oil and biochar were assayed to understand the impact of pyrolysis temperature on these parameters and then to evaluate their potential values. The results showed that syngas yield (26.07-46.37%) increased with pyrolysis temperature, while biochar yield (47.54-26.83%) decreased. Bio-oil yield (26-30%) was hardly affected by pyrolysis temperature. Both syngas and bio-oil had poor values as direct fuel. The euhalophyte-derived biochar had higher aromaticity (H/C 0.16-0.85, O/C 0.06-0.26), higher cation exchange capacity (198.82-435.74 cmol kg−1), and higher K+ (59.35-80.42 g kg−1) and Na+ (37.56-53.26 g kg−1) compared with glycophyte-derived biochars. Our findings imply that halophyte biochar may be more suitable to use as a soil conditioner, which is worthy of further study.