Capturing Carbon Dioxide (CO2) in Biogas Using Calcium Oxide and Sawdust Pellet Combination

Abstract

Biogas is one of the alternative energy and has been applied to the community, especially for farming communities. Methane (CH4) and carbon dioxide (CO2) are the main constituents. Carbon dioxide is an undesirable compound (contaminant). The presence of carbon dioxide is a major problem because generate harmful environmental emissions and causing low calorific value. This research investigated effect and affectivity of combination calcium oxide (CaO) and sawdust in the form of pellet to purify biogas and capture CO2. Biogas purification in this research based on adsorption system. This research is divided into three different treatments with combination ratio between calcium oxide and sawdust code for treatment are K35S55, K45S45 and K55S35. Effect of the use pellets combination calcium oxide and sawdust significantly can reduce CO2 content on biogas. The reduction effect was analyzed by paired t test. The results showed that there were non significant differences between variation percentage combination CaO and sawdust with CO2 reduction.

Potensi biogas sangat besar sebagai sumber energi terbarukan karena kandungan metana (CH4) yang tinggi dan nilai kalornya yang cukup tinggi yaitu berkisar antara 4.500–6.300 kkal/m3. Metana yang hanya memiliki satu karbon dalam setiap rantainya, dapat membuat pembakarannya lebih ramah lingkungan dibandingkan bahan bakar berantai karbon panjang. Kemurnian biogas yang dihasilkan dari biodigester belum optimal, kandungan CH4 sekitar 50-60% serta CO2 sekitar 40-60%. Kandungan CO2 pada biogas masih cukup besar, hal ini menyebabkan efisiensi panas yang dihasilkan masih rendah sehingga kualitas nyala api biogas masih belum optimal. Optimalisasi penggunaan biogas dilakukan dengan cara pemurnian, salah satu caranya adalah dengan menggunakan pelet dari kombinasi CaO dan serbuk gergaji kayu.