Thermochemical treatment for algal fermentation

The purpose of this study was to determine the influence of the thermochemical pretreatment process of algal fermentation on the efficiency with which algal energy is converted microbiologically to the energy in methane. The variables studies were pretreatment temperature, duration, concentration, and dosage of sodium hydroxide (NaOH). In order to optimize the thermochemical pretreatment of algae, an independent variables study was selected. The results indicate that pretreatment best efficiency was attained with a temperature of 100 degrees C for 8 h at a concentration 3.7% solids and without NaOH. Compared with untreated algae, pretreatment improved the efficiency of methane fermentation a maximum at 33%. An orthogonal square design was selected to determine the mathematical model to describe the effects of algal thermochemical pretreatment and to determine the relative significance among the pretreatment parameters. (C) 1998 Elsevier Science Ltd.