Evaluation of biogas production potential from combination of food waste with Pre-treatment of Napier grass by NaOH

Abstract

This research aimed to find the amount of biogas produced by the co-fermentation of Napier grass and food waste and to compare the amount of biogas before and after pretreatment with 4% w/v sodium hydroxide solution for 0.5 and 1 hour, respectively. The 1.5-liter anaerobic reactor was used. The ferment materials were filled in the reactor for a single time. The experiment period was 45 days. The ferment materials were Napier grass mixed with food waste at the ratio of 25:75. The results showed that Napier grass without pretreatment contained cellulose content equal to 36.21%, hemicellulose content equals 6.64% and lignin content equal to 15.66%. When the grass were treated with sodium hydroxide solution at the concentration of 4% for 0.5 and 1 hour, it found out that the amount of cellulose content increased to 3.94% and 4.38%, respectively. The amount of Hemicellulose content decreased to 3.94 and 4.37% and lignin was 6.28 and 8.05%, respectively. Therefore, pretreated Napier grass with 4% w/v sodium hydroxide solution for 1 hour was selected for co-fermentation process with food waste for biogas production. This is because it demonstrated the most effective lignin and hemicellulose bond dissociation. The amount of biogas was measured at the end of the experiment and It found out that the amount of biogas in the reactor with 4% w/v sodium hydroxide pretreatment for 1 hour is higher than the amount of biogas of the reactor without pretreatment with the increased efficiency of 37.37%, indicating that the alkaline pretreatment technology is used to eliminate lignocellulose in Napier grass to enhance the potential for biogas production.