Thermo-chemical conversion of Chlorella pyrenoidosa to liquid biofuels

► Solvent polarity significantly affected the liquefaction behavior of microalgae. ► Higher conversion rate and bio-oil yield were achieved in strong polarity solvent. ► Ethanol was proven to be the most suitable solvent. ► Temperature showed the largest effect on the products yield and properties of bio-oil. ► The HHVs of the bio-oils were within the range of 27.68-36.45 MJ/kg.