Biogas purification via optimal microalgae growth: A literature review

In this review, we compare works from the current decade that address the CO₂ -removal from biogas by means of microalgae. The microalgae culture process acts as a biochemical absorption process; it is potentially competitive with respect to classical and commercial absorption methods due to its additional benefits such as availing CO₂ for the production of valuable microalgae biomass and being an environmentally friendly technique. Nevertheless, the low yield of biogas purification translates into the need to use optimal operation strategies that render the whole biogas production process economically feasible. A class of these strategies requires models capable of reproducing key traits of the dynamical behavior of microalgae growth. Thus, without overlooking the classical physico-chemical methods for biogas purification, our literature review addresses: (i) biogas purification via microalgae and different microalgae growth conditions, (ii) approaches that maximize microalgae growth, in order to increase CO₂ -consumption, and (iii) different models that describe the representative characteristics of microalgae growth. This investigation traces a pathway to future considerations on optimal biogas purification alternatives by microalgae culture processes. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:1513-1532, 2018.