Biogas potential from spent tea waste: A laboratory scale investigation of co-digestion with cow manure

Spent tea waste (STW) is an organic waste that is disposed in open land after preparation of tea. Generally, it is disposed in an open land which increases anthropogenic gases. Converting it into useful energy or value added product may reduce disposal problem and anthropogenic activity. In this study, STW was co-digested with cow manure (CM) for obtaining biogas by anaerobic digestion. For this purpose, STW was mixed with CM at different proportions, namely 50:50, 40:60, 30:70, 20:80, and 0:100 percentages on a mass basis, the samples were used in five different anaerobic digesters. The samples were kept in different anaerobic digesters for the study. The effect of important input parameters like pH, Carbon to Nitrogen (C/N) ratio, and digestion time on the biogas production were studied. Further, the collected biogas from the digesters were characterised to ensure the suitability for use as a renewable fuel. Furthermore, the digested slurry was also analysed for its use in agriculture sector. The results are presented in this paper.