Reduction in environmental hazards and enhance the energy conversion from microalgae wastewater: Characteristics evaluation

The formation of algae blooms can influence uncontrolled growth, causing hazards to aquatic ecosystems. The attention of microalgae wastewater treatment is gathering significance in bio-energy conversion, resulting in environmental sustainability. Gasification technology is found to improve energy conversion with improved environmental sustainability. The novel research is to treat microalgae wastewater via hydrothermal gasification process with the assistance of a potassium hydroxide catalyst (KOH). During the gasification process, the gasification time is varied from 10, 20, and 30 min under a higher gasification temperature of 900 degrees C is maintained throughout the gasification process. Effect of gasification processing time with KOH catalyst action on the percentage of molar fractions including carbon monoxide (CO), carbon dioxide (CO2), hydrogen (H2) and methane (CH4), lower heating value (LHV), syngas H2 yield, and gasification efficiency of hydrothermal gasification process for microalgae wastewater are experimentally investigated. The results of the present investigation are exposed with higher processing time with maximum gasification temperature processed with KOH catalyst offered maximum H2 fraction of 59%, reduced CH4 and LHV of 15% and 10 MJ/Nm3, optimum H2 yield of 22 mol/kg, and attained maximum gasification efficiency of 55%, respectively. The optimum gasification process parameters, including a 30-min processing time with a higher gasification temperature of 900 degrees C gained H2, will be suggested for energy/alternative fuel applications.