Abstract

Coffee is an excellent commodity in Indonesia that has big problem in utilizing its wastes. As the solution, the abundant coffee pulp waste from processing of coffee bean industry has been used as a substrate of biogas production. Coffee pulp waste (CPW) was approximately 48% of total weight, consisting 42% of the coffee pulp and 6% of the seed coat. CPW holds good composition as biogas substrate that is consist of cellulose (63%), hemicellulose (2.3%) and protein (11.5%). Methane production from coffee pulp waste still has much problems because of toxic chemicals content such as caffeine, tannin, and total phenol which can inhibit the biogas production. In this case, CPW was pretreated by ethanol/water (50/50, v/v) at room temperature to remove those inhibitors. This study was to compare the methane production by microbial consortium of cow dung and rumen fluid mixture coffee pulp waste as a substrate with and without pretreatment. The pretreated CPW was fermented with mixture of Cow Dung (CD) and Rumen Fluid (RF) in anaerobic co-digestion for 30 days at mesophilic temperature (30-40°C) and the pH was maintained from 6.8 to 7.2 on a reactor with working volume of 3.6 liters. There were two reactors with each containing the mixture of CPW without pretreatment, cow dung and rumen fluid (CD+RF+CPW) and then compared with the CPW with pretreatment (CD+RF+PCPW) reactor. The measured parameters included the decreasing of inhibitor compound concentration, Volatile Fatty Acids (VFAs), Chemical Oxygen Demand (COD), Total Solid (TS), Volatile Solid (VS), Methane and the Calorific value of gas (heating value) were studied as well. The result showed a decrease in inhibitor component concentration due to methanol pretreatment was 90% of caffeine; 78% of polyphenols (total phenol) and 66% of tannins. The highest methane content in biogas was produced in CD+RF+PCPW digester with concentration amounted of 44.56% with heating value of 27,770 BTU/gal.

Original languageEnglish
Title of host publicationInternational Seminar on Fundamental and Application of Chemical Engineering 2016, ISFAChE 2016
Subtitle of host publicationProceedings of the 3rd International Seminar on Fundamental and Application of Chemical Engineering 2016
Editors Widiyastuti, Fadlilatul Taufany, Siti Nurkhamidah
PublisherAmerican Institute of Physics Inc.
ISBN (Electronic)9780735415102
DOIs
Publication statusPublished - 24 May 2017
Event3rd International Seminar on Fundamental and Application of Chemical Engineering 2016, ISFAChE 2016 - East Java, Indonesia
Duration: 1 Nov 20162 Nov 2016

Publication series

NameAIP Conference Proceedings
Volume1840
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616

Conference

Conference3rd International Seminar on Fundamental and Application of Chemical Engineering 2016, ISFAChE 2016
Country/TerritoryIndonesia
CityEast Java
Period1/11/162/11/16

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