Impact of reaction conditions on the simultaneous production of polysaccharides and bio-oil from heterotrophically grown Chlorella sorokiniana by a unique sequential hydrothermal liquefaction process

► Polysaccharides and bio-oil are extracted concomitantly by a novel sequential hydrothermal liquefaction (SEQHTL). ► By SEQHTL, optimal bio-oil production is achieved at much lower temperature than direct hydrothermal liquefaction (DHTL). ► SEQHTL produces 50% less bio-char than DHTL. ► SEQHTL requires less energy and has higher thermal efficiency than DHTL.