Effect of Different Operating Conditions on Tobacco Stem Pyrolysis and Impregnation for Further Controlled Release Fertiliser Application

The development of controlled release fertilizer (CRF) was motivated by the necessity to mitigate the loss of nutrients resulting from expeditious release rates in fertilizers, which can lead to significant nutrient loss, including 40-70% N, 80- 90% P, and 50-70% K. To address this issue, the transformation of tobacco stem biomass into biochar as CRF signifies a significant advancement in the effective management of sustainable crop remnants. Nevertheless, given the comparatively limited nutrient content in biochar, its impregnation with nutrient solution is imperative. The objective of this study is to ascertain the optimal operating conditions to produce tobacco stem-based biochar (TSB) from temperature and pyrolysis holding time. Additionally, the study seeks to determine the most effective operating conditions for TSB impregnation, considering parameters such as nutrient solution concentration and stirring speed, to produce TSB impregnated (TSBI). The materials resulting from this process will undergo analysis to determine their proximate, bulk density, porosity, pH value, and NPK nutrient content. The results demonstrated that TSB-3, produced at 600°C for 1 hour, exhibited the highest fixed carbon content of 73.09%, accompanied by a porosity of 77.47% and a pH value of 9.51. Furthermore, the findings demonstrated that TSBI-6, when utilized in conjunction with a 15% nutrient solution concentration and a speed of 300 rpm, led to a 23.91% (31.78%) increase in N nutrition, a 73.18% (7.83%) increase in P nutrition, and a 87.88% (14.85%) increase in K nutrition. Consequently, TSBI emerges as a promising constituent component of CRF, demonstrating potential for widespread application in sustainable agriculture due to its capacity to enhance nutrient utilization efficiency.