Chemical characterization of biochar from lablab bean under low-temperature pyrolysis

• Main Authors: Rahmat, Ali, Nur, Muhammad, Afandi, Ahmad Yusuf, Hariadi, Hari, Sutiharni, Sutiharni, Suhendar, Usep
• Format: Conference Proceeding
• Language: English
• Subjects: Beans; Carbonization; Functional groups; Limnology; Low temperature; Magnesium; Moisture content; Phosphorus pentoxide; Potassium; Pyrolysis; Research facilities; Soil improvement; Soils; Water resources; X ray fluorescence analysis
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0173055

One of the abundant wastes in the food industry is the waste of unused lablab beans due to overproduction or expiration during storage. To solve this condition, the waste of lablab bean can be used as biochar, which will be helpful for soil improvement. This study aimed to determine the chemical characterization of biochar derived from the waste of “Lablab purpureus” bean. Producing biochar is treated by carbonization of the beans using a furnace with a temperature of 250°C and 350°C. After carbonization, the biochar will be ground and sieved with a size of 355 micrometers at the Research Center for Limnology and Water Resources. Proximate analysis was done at Research Center for Limnology and Water Resources. Chemical characterization analysis was done using FTIR analysis at Integrated Laboratory of Bioproduct and X-Ray Fluorescence Spectrometer (XRF) at Lampung Advanced Characterization Laboratory-BRIN. The yields of biochar were 40.20% and 33.22% for the carbonization of 250 and 350 °C, respectively. Based on the proximate analysis the biochar shows value of moisture content 5.83-6.08% and the ash content 9.81% and 12.85% for each of the temperatures, respectively. FTIR analysis shows that the functional groups in the biochars were C-H, C=C, and C-O. The XRF analysis showed that the dominant content of lablab bean biochar is potassium (K2O) with a concentration of 75-76%, then phosphorus (P2O5) with a concentration of 16-17%, and magnesium (MgO) with a concentration of 1.7-1.9%. Furthermore, the potassium and phosphorus concentration from biochar derived from lablab beans were higher than the compost standard, which means biochar from lablab beans has potency as a candidate for soil amendment due to high nutrient contents.