Start-up of a pilot scale anaerobic reactor for the biogas production from the pineapple processing industries of Belgium

Abstract

In this study, a pilot scale continuous stirred-tank reactor (CSTR) was used to investigate the startup of an anaerobic system, followed by a bench scale test to analyze the biogas production. Wastewater from pressing and crushing leaves of the pineapple crop was used as a substrate in the CSTR. During the study period, the organic loading rate (OLR) was gradually increased and parameters such as volatile fatty acids (VFA), temperature, pH, bio-gas production and chemical oxygen demand (COD) were carefully monitored. The result of the bench scale test showed the potential of the wastewater for producing the biogas. The study indicated an OLR of 3.8 g COD/L/d, and a maximum biogas production of 3.3 L/d, with an average of 2.8 L/d. The COD removal efficiency reached its highest peak with a value of 64.8%, when the OLR was 3.43 g COD/L with the hydraulic retention time (HRT) of 20 days. Based on the measurements made throughout the test period, there were no indications of the presence of toxic elements in the wastewater, which could inhibit the anaerobic degradation process. This study is an attempt to provide a vigorous solution for the pineapple industry wastewater scenario, thereby aiming at sustainable energy production.