PENENTUAN POTENSIAL BIOGAS DARI SAMPAH ORGANIK KOTA MELALUI PROSES ANAEROBIC DIGESTION SISTEM BATCH MENGGUNAKAN INOKULUM DARI INSTALASI BIOGAS SOBACKEN BORÅS SWEDIA SEBAGAI SALAH SATU PARAMETER DALAM PERANCANGAN REAKTOR BIOGAS SKALA MASAL

Abstract

This research is about the determination of the biogas potentials from municipal organic waste taken from Borås municipality and the designing of a large scale biogas reactor to convert cattle dung, which to be hoped for helping poor households in Temon sub district in Kulon Progo Regency. 

The method used was the Completely Randomized Design with four treatments and triplicates. By using treatments of 1%VS, 1.5% VS, 2% VS, and  3% VS Pre-treated municipal organic waste as samples were filled into the reactors which contain of 20 ml volume of inoculums then they were incubated at temperature of 55ºC (thermophilic temperature). During the time period of 30 - 50 days simultaneously measurements of biogas/methane were necessary done.  

The results showed that the volatile solid values of municipal organic waste and waste simulator were 21.04 %, and 25.89 %. Based on the accumulated biogas production curves  and the 2^nd degree of polynomial regression analysis, were obtained that the biogas potential of municipal organic waste were 832.89 ml/g VS on 2% VS and 864.5 ml/g VS on 1.66 %VS. Whereas based on the accumulated biogas/methane production curves of waste simulator were obtained of 982.89 ml/g VS dan 369.46 ml/g VS on 1.5% VS.  On the other side, by using the 3^rd degree of polynomial regression analysis, the biogas potential of waste simulator mathematically obtained of 1147.38 ml/g VS on 1.49%VS, and the potential methane of 447.30 ml/g VS on 1.47% VS.

Within the designing of a large scale biogas reactor to convert dried cattle dung to be biogas, for building the biogas plant was needed the total cost of 3,465,000 USD. The project was funded by loan with interest rate of 10% and had to be paid in 10 years. The biogas reactor was estimated 20 years in operation and would produce 1700 m³ of biogas or 952 m³ of methane daily, and to be hoped could help 1,030 poor households. The total benefit obtained would reach 4,278,758 USD for 20 years.