Herein, we report on a combined process that incorporates hydrothermal liquefaction (HTL) and supercritical water gasification (SCWG) to improve energy recovered from algal biomass. Eight algal bio-masses, including four microalgae and four macroalgae with a large difference in biochemical compositions, were screened for this dual process. The algal biomass feedstocks significantly affected the carbon and energy distribution in the product fractions (crude bio-oil, solid, gas, and water-soluble products). 62.50-71.34% energy of microalgae and 6.03-41.06% energy of macroalgae could be recovered as crude bio-oil. 11.86-21.55% carbon of the microalgae and 8.01-15.82% carbon of the macroalgae was distributed in the HTL process water in form of water soluble products after the HTL process. 14.3-33.7% energy of microalgae and 30.18-36.34% energy of macroalgae was retained in the HTL process water. SCWG could convert the organics in the HTL process water into fuel gases consisting mainly of H-2 and CH4. 54-91% carbon of the HTL process water was transformed into the fuel gases, which correspond 5.53-18.30% energy of the algal biomass. Thus, this work shows that the integration of HTL and SONG could improve energy recovery from algal biomass relative to the HTL process alone. (C) 2018 Elsevier Ltd. All rights reserved.