Recycling of Trees Planted for Phytostabilization to Solid Fuel: Parametric Optimization Using the Response Surface Methodology and Genetic Algorithm

Biomass resources are gaining attention to address environmental issues, ensure energy efficiency, and ensure long-term fuel sustainability. The use of biomass in its raw form is known to present a number of issues, including high shipping, storage, and handling costs. Hydrothermal carbonization (HTC), for example, can increase the physiochemical properties of biomass by converting it into a more carbonaceous solid hydrochar with enhanced physicochemical properties. This study investigated the optimum process conditions for the HTC of woody biomass (Searsia lancea). HTC was carried out at varying reaction temperatures (200-280 degrees C) and hold times (30-90 min). The response surface methodology (RSM) and genetic algorithm (GA) were used to optimize the process conditions. RSM proposed an optimum mass yield (MY) and calorific value (CV) of 56.5% and 25.8 MJ/kg at a 220 degrees C reaction temperature and 90 min of hold time. The GA proposed an MY and a CV of 47% and 26.7 MJ/kg, respectively, at 238 degrees C and 80 min. This study revealed a decrease in the hydrogen/carbon (28.6 and 35.1%) and oxygen/carbon (20 and 21.7%) ratios, indicating the coalification of the RSM-and GA-optimized hydrochars, respectively. By blending the optimized hydrochars with coal discard, the CV of the coal was increased by about 15.42 and 23.12% for RSM-and GA-optimized hydrochar blends, respectively, making them viable as an energy alternative.

Automated summary

Biomass resources are being increasingly recognized for their potential in addressing environmental concerns, ensuring energy efficiency, and promoting long-term fuel sustainability. This study focused on the hydrothermal carbonization (HTC) of woody biomass, aiming to optimize the process conditions using response surface methodology (RSM) and genetic algorithm (GA). The optimized hydrochar blends, when mixed with coal discard, demonstrated an increased calorific value, making them a viable alternative energy source.