International Journal of Renewable Energy Development
Vol 11, No 2 (2022): May 2022

Comparative Study on the Various Hydrolysis and Fermentation Methods of Chlorella vulgaris Biomass for the Production of Bioethanol

Megawati Megawati (Department of Chemical Engineering, Faculty of Engineering, Universitas Negeri Semarang, Gunungpati, Semarang 50299)
Zuhriyan Ash Shiddieqy Bahlawan (Department of Chemical Engineering, Faculty of Engineering, Universitas Negeri Semarang, Gunungpati, Semarang 50299)
Astrilia Damayanti (Department of Chemical Engineering, Faculty of Engineering, Universitas Negeri Semarang, Gunungpati, Semarang 50299)
Radenrara Dewi Artanti Putri (Department of Chemical Engineering, Faculty of Engineering, Universitas Negeri Semarang, Gunungpati, Semarang 50299)
Bayu Triwibowo (Department of Chemical Engineering, Faculty of Engineering, Universitas Negeri Semarang, Gunungpati, Semarang 50299)
Haniif Prasetiawan (Department of Chemical Engineering, Faculty of Engineering, Universitas Negeri Semarang, Gunungpati, Semarang 50299)



Article Info

Publish Date
05 May 2022

Abstract

One of the microalgae that can be potentially used to produce bioethanol is Chlorella vulgaris, as it is rich in carbohydrates. However, the carbohydrates in C. vulgaris cannot be converted directly into ethanol. This study aimed to investigate the chemical and enzymatic hydrolysis of C. vulgaris, which is subsequently followed by fermentation. The catalysts used in the chemical hydrolysis were hydrochloric acid, sodium hydroxide, and potassium hydroxide, while the enzymes used were the mixture of alpha-amylase + glucoamylase, alpha-amylase + cellulase, and alpha-amylase + glucoamylase + cellulase. The hydrolysate obtained from chemical hydrolysis was fermented through Separate Hydrolysis Fermentation (SHF), while the one from enzymatic hydrolysis was fermented through Simultaneous Saccharification and Fermentation (SSF), in which both processes used S. cerevisiae. After undergoing five hours of enzymatic hydrolysis (using alpha-amylase + glucoamylase), the maximum glucose concentration obtained was 9.24 ± 0.240 g/L or yield of 81.39%.  At the same time and conditions of the substrate on chemical hydrolysis, glucose concentration was obtained up to 9.23 + 0.218 g/L with a yield of 73.39% using 1 M hydrochloric acid. These results indicate that chemical hydrolysis is less effective compared to enzymatic hydrolysis. Furthermore, after 48 hours of fermentation, the ethanol produced from SHF and SSF fermentation methods were 4.42 and 4.67 g/L, respectively, implying that producing bioethanol using the SSF is more effective than the SHF method.

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Journal Info

Abbrev

ijred

Publisher

Subject

Control & Systems Engineering Earth & Planetary Sciences Electrical & Electronics Engineering Energy Engineering

Description

The International Journal of Renewable Energy Development - (Int. J. Renew. Energy Dev.; p-ISSN: 2252-4940; e-ISSN:2716-4519) is an open access and peer-reviewed journal co-published by Center of Biomass and Renewable Energy (CBIORE) that aims to promote renewable energy researches and developments, ...