Biogas Productivity as Renewable Energy and Performance of Waste Water Treatment in Tofu Small Scale Industry using an AnSBR Reactor

¹ Mechanical Engineering Department, Politeknik Negeri Semarang, Semarang Indonesia
² Doctoral Program of Environmental Science, School of Postgraduate Studies, Universitas Diponegoro, Semarang Indonesia
³ Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro, Semarang Indonesia

^* Corresponding author: suparnirahayu@yahoo.co.id

Abstract

A research that analyzed the relationship between biogas production as renewable energy and performance of waste water treatment in tofu small industry using AnSBR reactor has been conducted. This research used system operation method in batches in to get a description of how the biogas production system works as it was operated in the batch mode, which is applied in tofu industry. An instrument capable of operation in batch mode using AnSBR reactor was designed as it does not require sludge re-circulation. An AnSBR reactor includes five stages of; filling, reaction, settling, decanting, and stabilization (idling state). The research was run for 24 days using biogas collected in a tank. Biogas was measured for each HRT starting on the second day HRT to 24^th day HRT. Biogas characteristics were monitored on day 16^th for contents of CH₄, CO₂ and heat value. Results show that CH₄ content in the biogas amounts to 78.26 %, while CO₂ comprises 20.16 %. Meanwhile, the heat value, which depends on acid methane and CO₂ content, is 4,246.55 kkal/kg.