Analisis Mikro Struktur dan Elemen Biochar Berbahan Serbuk Kayu pada Teknik Retort dan Kiln

Abstract

The quality of the biochar produced is determined by the type of biomass and pyrolysis method used. Meranti wood biomass has a fairly high lignin content of around 16-33%. The results and quality of biochar can be known by microanalysis of structures and elements using microscopic techniques, namely Scanning Electron Microscope (SEM) to determine the pore morphology of the biochar surface, Brunauer Emmnet Teller (BET) to determine the surface area of biochar and Fourier Transform Infrared Spectroscopy (FTIR) to find out the functional group. The purpose of this study is to find out the best pyrolysis technique in making wood-based biochar. This analysis was conducted at the Soil Biology Laboratory, Faculty of Agriculture, University of North Sumatra, Medan, and at the National Research and Innovation Agency (BRIN). The results of this study show that there are differences in the microstructure of biochar resulting from the retort and kiln techniques. The results of pH analysis showed that biochar with the retort technique was 7.53 while the kiln technique was 7.75. The results of SEM analysis show that biochar with the kiln technique has a more porous surface structure and is better than the retort technique. The results of EDX analysis obtained nutrients in the retort technique, namely 75.39% C, 21.19% O and 3.42% Cu while biochar nutrients with the kiln method consisted of 68.77% C, 11.81% O, 1.77% Cu, 9% K and 8.66% Zn. The results of the BET analysis show that the retort technique has a smaller surface area of 0.285 m²/g while the kiln method is 34.440 m²/g. The pore volume consisting of BJH adsorption and desorption in the retort technique has a smaller value, each has a value of 0.045 cc / g and 0.036 cc / g while in the kiln technique each has a value of 0.071 cc / g and 0.059 cc / g. The pore size of biochar with the retort method is larger at 24.921 Å or 2.4921 nm (meso pore) while the kiln method has a pore size of 19.366 Å or 1.9366 nm (micro pore). The results of FTIR analysis show that biochar with the retort technique has 19 wave peaks and 11 functional groups while the kiln technique has 9 wave peaks and 7 functional groups.