Future production of bioethanol from microalgae as a renewable source of energy

Fossil fuels that mainly supply the current increasing world’s energy demand originated from non-renewable resources. In addition to the depletion of their resources within the next short time, the combustion of fossil fuels to power industries and transportation also negatively impacts humans and the environment due to the release of various gaseous pollutants. To increase the share of renewables in the primary energy mix, the Government of Indonesia is currently struggling to meet a target of 23% by 2025. Therefore, more significant efforts to search for potential renewable energy sources are the only way to overcome this issue. Bioethanol is an eco-friendly renewable energy source since its combustion emits a low concentration of pollutants. Microalgae have gained significant interest in bioethanol production because of rapid biomass growth and relatively easy pre-treatment steps. It is renewable, carbon-neutral, sustainable and can be grown in wastewater coupling as wastewater treatment. This paper reviews bioethanol production, providing knowledge on the characteristics of microalgae potential for producing biomass to be converted into bioethanol, introducing process for bioethanol production, and presenting the potential challenges of bioethanol as a future renewable energy.