Briquette characteristics of faecal sludge combined with sawdust and coconut shell charcoal (Indonesia)

Thesis text: The study aims to assess the potential of briquette combination Faecal Sludge (FS) with sawdust (SD) and coconut shell charcoal (CSC) as an alternative solid fuel. A total of seven briquette variations were analysed including sample 1/FS100%, sample 2/FS75%:SD25%, sample 3/FS50%:SD50%, sample 4/FS25%:CSC75%, sample 5/FS75%:CSC25%, sample 6/FS50%:CSC50%, sample 7/FS25%:CSC75%. Characteristic analysis was carried out through proximate, calorific value, sulfur, and density tests of briquettes as well as the effect of combinations on characteristic parameters. Rank Spearman correlation analysis was conducted to determine the relationship within the characteristics. Briquette quality was evaluated using SNI 8021:2020, and analysed for best variation using multi-criteria analysis. The results showed that increasing the composition of the sawdust or coconut shell charcoal combination gave a characteristic advantage to faecal sludge briquettes, a decrease in ash content up to 42.56%, and an increase in calorific value to 66.70%. The correlation of the characteristic is a strong correlation between ash content and fixed carbon, and fixed carbon and calorific value; a weak correlation between moisture content and calorific value; and a very weak correlation between volatile content and fixed carbon. All briquette variations met the quality standard of moisture content, volatile content, ash content, and sulphur. While only 1 variation did not qualify for the calorific value standard (sample 1/FS100%), and 2 variations did not qualify for the density standard (sample 3/FS50%:SD50% and sample 4/FS25%:SD75%). The three best briquette sample variations are sample 7/FS25%:CSC75% (score of 50), sample 6/FS50%:CSC50% (score of 47), and sample 3/FS50%:SD50% (score of 45).