Biogas Technology on Supporting "Sustainable" Coffee Farmers in North Sumatera Province, Indonesia

• Published in: IOP conference series. Materials Science and Engineering 2017-03, Vol.180 (1), p.12112
• Main Author: Ginting, N
• Format: Article
• Language: English
• Subjects: Biogas; Buffalo; Chemical composition; Coffee; Digesters; Feces; Methane; Productivity; Roasting; Slurries
• ISSN: 1757-8981; 1757-899X
• DOI: 10.1088/1757-899X/180/1/012112

A study has been conducted in an area of coffee plantation in Samosir District, North Sumatera Province. The study was conducted in August until September 2016. The objective of this study is to investigate the benefits of using biogas technology in supporting coffee farmers' productivity to be sustainable, i.e. methane as energy source for coffee roasting proceed instead of fired wood and slurry as organic fertilizer. Coffee cherry causes environmental problem when it is dumped openly, hence it is used to mix with buffalo feces in biodigesters to produce methane and organic fertilizer. Five biodigesters were used with 5 differents designs of composition: T1) 100% buffalo feces, T2) 75% buffalo feces + 25% coffee cherry, T3) 50% buffalo feces + 50% coffee cherry, T4) 25% buffalo feces + 75% coffee cherry, and T5) 100% coffee cherry. The key parameters measured were methane production and slurry chemical compositions including NPK, pH, and C/N. It is found that designs T1 and T2 were superior in methane production, and about 400 liters of methane were used in roasting 3 kg coffee bean as opposed to 6,6 kg fired wood. Designs T1 and T2 were also better in slurry chemical compositions than the other 3 designs. It is recommeded that local coffee farmers utilize coffee cherry based biogas technology in order for their productivity to be sustainable. It is noteworthy that this study is continued with the next one in which the resulting slurries are implemented to foster the growth of the coffee plants during the period of October until December 2016.