Pengaruh Starter Ragi, EM4 Dan Variasi Rasio C/N Terhadap Hasil Biogas Kulit Kakao

Abstract

Cocoa is an essential ingredient for making chocolate. Still, the only part of the cocoa used to produce chocolate is the cocoa beans, while around 90% of the total weight of the cocoa is immediately discarded in the form of cocoa shells. This causes cocoa shells to become plentiful, whereas many are processed into animal feed and compost. In compost processing, a decomposition process occurs, which potentially produces biogas. Biogas production from cocoa shells can use fermentation tools such as digesters. This research method is carried out through several stages. First, cocoa shells are collected from cocoa production originating from the Lima Puluh Kota district of West Sumatra. Then, the cocoa shells are prepared and processed into raw materials for biogas production. The fermentation process is carried out using yeast starter and EM4 for 21 days of observation, which is a mixture of microorganisms. The research variation consisted of adding 150 g of yeast and increasing the volume of EM4 in each digester except the control digester. The addition of EM4 for the C/N ratio test digesters 25, 27, 29 is 0.124, 0.099, 0.083 liters. The total gas production obtained from each digester is 9.054 liters (DU29), 2.590 liters (DU27), 2.562 liters (DU25), and 1.307 liters (DK). Meanwhile, the levels of methane gas produced in each test sample are 8.77% (DK), 10.47% (DU25), 18.02% (DU27), and 21.43% (DU29). The color of the gas flame produced by the DU29 and DU27 is blue, the DU25 is red, and the DK is reddish yellow.