Botryococcus braunii, a green colonial microalga, is an unusually rich renewable source of hydrocarbons. In this study, wet microalgae harvest was thermally pretreated to enhance hydrocarbon recovery using a solvent extraction process. Samples containing a mixture of B. braunii and water were kept below 100 degrees C for 10 min. The observed hydrocarbon recovery was 97.8% at 90 degrees C. The extraction results suggest that the energy-intensive concentration and drying processes of the harvest could be eliminated. The proposed thermal pretreatment would revolutionize the conventional downstream processes. (C) 2009 Elsevier Ltd. All rights reserved.