MICROWAVE PYROLYSIS LIMBAH SEKAM PADI DENGAN VARIASI HOLDING TIME DAN PARTICLE SIZE UNTUK MENGHASILKAN BAHAN BAKAR TERBARUKAN

This study aims to examine the pyrolysis of rice husk waste mixed with silicon carbide (SiC) as an absorber using a primary microwave reactor, as well as the role of natural zeolite catalysts heated in a secondary reactor. Microwave pyrolysis converts rice husks into products with more value, in the form of biochar, bio-oil, and gas. Pyrolysis is carried out in a primary reactor, by mixing rice husks and SiC absorber. SiC is used to maximize microwave absorption to produce fast and efficient heating, and increase pyrolysis results. Meanwhile, the natural zeolite catalyst in the secondary reactor is heated conventionally with an oven maintained at a temperature of 400 °C. Then the variations in the holding time of the test are 5, 10, 15, and 20 minutes, while the particle size of rice husk waste is 18-35 and 35-60 mesh. The pyrolysis results show that the particle size of 18-35 mesh with a holding time of 5 minutes gives the highest biochar yield (72.20%). In addition, the larger particle size of rice husk waste (18-35 mesh) with a holding time of 20 minutes gave the highest bio-oil yield of 18.80%, due to the slower pyrolysis reaction compared to the size of 35-60 mesh. Then the highest gas product (21.60%) was obtained at a particle size of 35-60 mesh with a holding time of 20 minutes. In addition, the particle size of 35-60 mesh was 37 seconds faster to reach a temperature of 450 ˚C compared to the particle size of 18-35 mesh.