Conceptual design of an integrated micro-algal biomass-to-liquids process

Abstract

A new integrated biomass­to­liquids conceptual process was developed to produce 2.6 million litres of biodiesel per year from harvested micro­algal biomass. Three unconventional harvesting methods, a thermochemical liquefaction process to extract oils from micro­algal biomass, and a process to produce biodiesel through the acid­catalyzed transesterification of micro­algal oil, were combined into an integrated BtL process. The new process combined four renewable energy sources to produce biodiesel from micro­algal biomass. Wind power is utilized indirectly, as prevailing south­easterly winds concentrate micro­algal biomass against the dam wall of the Hartbeespoort Dam. The hydraulic head of 583 kPa of the 59.4 meter high dam is utilized for transportation of the biomass through the facility, which is located down­stream of the dam. Solar energy is used to dry the microalgae, which in turn is combusted in a furnace to release its 18,715 kW of bio­energy, which is used for heating in the energy­intensive extraction unit of the processing facility