Effect of Fe Addition on Anaerobic Digestion Process in Treating Vinasse: Experimental and Kinetic Studies

Authors

  • Iqbal Syaichurrozi
    Affiliation

    Department of Chemical Engineering, Faculty of Engineering, University of Sultan Ageng Tirtayasa, Jl. Jendral Soedirman Km 3, 42435 Cilegon, Indonesia

  • Sarto Sarto
    Affiliation

    Department of Chemical Engineering, Faculty of Engineering, Universitas Gadjah Mada, Jl. Grafika 2., 55281 Yogyakarta, Indonesia

  • Wahyudi Budi Sediawan
    Affiliation

    Department of Chemical Engineering, Faculty of Engineering, Universitas Gadjah Mada, Jl. Grafika 2., 55281 Yogyakarta, Indonesia

  • Muslikhin Hidayat
    Affiliation

    Department of Chemical Engineering, Faculty of Engineering, Universitas Gadjah Mada, Jl. Grafika 2., 55281 Yogyakarta, Indonesia

https://doi.org/10.3311/PPch.20611

Abstract

Vinasse is a continuously resulting waste by a bioethanol industry with a high chemical oxygen demand (COD) concentration and a large volume. Anaerobic digestion (AD) is the best method to treat vinasse because it converts COD to biogas, so the biogas can support the Indonesia's primary energy need. The goal of this study was to study the effect of Fe concentration on the AD process in treating the vinasse. The Fe concentration was varied to 0.06, 0.29, 0.64, 0.99 g/L. The results showed that increasing the Fe concentration from 0.06 to 0.29 g/L intensified the biogas yield by 360% (from 10.8 to 49.6 mL/g COD). However, further increasing the Fe concentration to 0.99 g/L decreased the biogas yield by 37.8% (from 10.8 to 6.7 mL/g COD). The Fe significantly affected the methane formation stage, but not the acid formation stage. A mechanistic model was built and successfully applied to predict the AD process. Based on the simulation results, Fe concentration of 0.29 g/L resulted in the highest values of YVFA/X2 (yield of volatile fatty acids (VFAs) consumption per biomass of X2 ), μm,2 (specific growth rate for X2 ),  fCH4 (composition of methane in biogas) and the lowest values of Ks,VFA (affinity coefficient in VFAs consumption), kd2 (death rate constant for X2 ), kVFA (consumption rate of VFAs for maintenance). The addition of Fe until 0.29 g/L was recommended to increase the quantity and quality (methane content reached 53.4%) of biogas production.

Keywords:

anaerobic, biogas, Fe, kinetic, vinasse

Published Online

2023-02-01

How to Cite

Syaichurrozi, I. Effect of Fe Addition on Anaerobic Digestion Process in Treating Vinasse: Experimental, Kinetic Studies, Periodica Polytechnica Chemical Engineering, 67(1), pp. 127–140, 2023. https://doi.org/10.3311/PPch.20611

Issue

Section

Articles