The effect of various varieties of cassava stems waste and tapioca adhesive concentrations on the quality of bio-coal briquette

This study aims to utilize the combination of cassava and coal waste as raw materials for making briquettes using several different concentrations of tapioca adhesives. This study uses a completely randomized design (RDC) with 2 factorials. The first factor is material composition, assigned by the letter P, which has 3 different varieties of different cassava, which are (P1) Kasetsart cassava and coal waste, (P2) Thai cassava and coal waste, and (P3) butter cassava and coal waste. The second factor is tapioca adhesive concentration, which consists of two different treatments: (M1) 15% and (M2) 20%. The combination of these different treatments then repeated 4 times resulted in 24 experimental units. The briquettes produced then underwent several characteristics tests, including water content, calorific value, combustion rate, density, compressive strength, shatter resistance index, and changes in the temperature of the pan base when the briquettes were burned. The acquired data then processed using Microsoft Excel 2010 and SAS v9 software. The data obtained will then be compared to SNI (Indonesia National Standard) to find out whether the briquette is fulfilling the requirement for application. The results are as follows: treatment P1M1 and P1M2 have a water content ranging from 5.36-7.09% and a calorific value between 4.427 – 5.541 cal/g, and it also fulfills the SNI Standard. Another characteristic is shown by P1M1 and P1M2 such as combustion rate around 0.37-0.4 g/min, density between 0.37-0.39 g/cm³, compressive strength between 48.67 N/cm², and shatter resistance index numbering around 99.90-99.92%, able to fulfill 95% of the SNI requirement for bio coal briquette, as well as changes in the bottom temperature of the pan which has reached the highest temperature of 303°C in the 26th minute of the P1M1 treatment combination and the lowest is 311°C at the 28th minute of the P1M2 treatment combination.