Economic analysis of biomass briquettes from septic tank

The aim of this research is to utilize slack waste into charcoal briquettes as an environmentally friendly alternative energy and minimize slack waste. The process for making briquettes is by adding polyacrylamide type adhesives with a variation of the material: adhesive ratio of 5:2 and 2:1 respectively on the slack charcoal that has been crushed, then formed into a cylinder with a press tool with pressure 85 and 105 kg/cm 2 . Furthermore, drying is done in an oven with a temperature of 150°C with a variation of 1.5 and 2 hours drying time. From the results of the economic analysis it was found that the business of making stool briquettes with a capacity of 300 kg/day is feasible to run, where from the business a profit of Rp. 547,029,828/year where the Net Present Value (NPV), Internal Rate of Return (IRR), and Break Event Point (BEP) were Rp. 203,510,791; 21.59%; and 26.08% respectively which requires 24.41 tons of briquettes to be returned in capital in around 11.34 months with an income of Rp. 183,075,000.