Assessment of Chlorella sp. as a potential feedstock for biological methane production

Jungsu Park; A Naresh Kumar; Roent Dune A Cayetano; Sang-Hyoun Kim

doi:10.1016/j.biortech.2020.123075

Assessment of Chlorella sp. as a potential feedstock for biological methane production

Bioresour Technol. 2020 Jun:305:123075. doi: 10.1016/j.biortech.2020.123075. Epub 2020 Feb 24.

Authors

Jungsu Park¹, A Naresh Kumar¹, Roent Dune A Cayetano¹, Sang-Hyoun Kim²

Affiliations

¹ School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea.
² School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea. Electronic address: sanghkim@yonsei.ac.kr.

PMID: 32131041
DOI: 10.1016/j.biortech.2020.123075

Abstract

Microalgal biomass sequestrates CO₂ and is regarded as a promising renewable feedstock for anaerobic digestion because of its adequate carbohydrate content and lignin-free structure. This study optimizes the dilute-acid pretreatment of Chlorella sp. and subsequent biomethane production using response surface methodology and central composite design with temperature, pretreatment time and solid-to-liquid ratio as variables. A temperature of 64.1 °C, pretreatment time of 1.2 h, and a solid to liquid ratio of 0.29 were the optimal pretreatment conditions and resulted in a methane yield of 302.22 mL CH₄/g COD and methane production rate of 110.04 mL CH₄/g VSS-d. The severity factor of 1.5-1.6 was adequate to render the Chlorella sp. bioavailable for high methane recovery. The results obtained from the experiments conformed to those predicted by the model. This study effectively utilizes algal biomass for biomethane production and enables the possibility of scaled-up studies using a closed-loop approach.

Keywords: Biogas; Biomass; CO(2); Microalgae; Pretreatment.