Synthesis of Carbon Microspheres from Inedible Crystallized Date Palm Molasses: Influence of Temperature and Reaction Time

In this work, carbon microspheres (CMs) were prepared by hydrothermal carbonization (HTC) of inedible crystallized date palm molasses. The effects of temperature and reaction time on the prepared materials were studied. Experiments were carried out at different temperatures (180, 200, 230 and 250 degrees C) with reaction times ranging from 2 to 10 h. It was found that temperature had the greatest influence on the mass yield of the CMs. No solid products were observed at a temperature of 180 degrees C and a reaction time less than 2 h. The highest yield was found to be 40.4% at 250 degrees C and a reaction time of 6 h. The results show that the CMs produced were approximately 5-9 mu m in diameter. The results also show that the largest diameter of the CMs (8.9 mu m) was obtained at a temperature of 250 degrees C and a reaction time of 6 h. Nonetheless, if the reaction time was extended beyond 6 h at 250 degrees C, the CMs fused and their shapes were deformed (non-spherical shapes). The synthesized materials were characterized using Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR), Branuer-Emmett-Teller (BET) and thermogravimetric analysis (TGA). BET surface areas for the four samples were found to be less than 1 m(2)/g. The methylene blue adsorption studies indicated that the equilibrium adsorption capacity was reached after 15 min, with a maximum adsorption capacity of 12 mg/g. The recycling of date palm molasses (a known processed waste) to generate a useable carbon microsphere represents a beneficial step in the application of sustainable processing industries in the Middle East.

Automated summary

Carbon microspheres were prepared from inedible crystallized date palm molasses using hydrothermal carbonization. The effects of temperature and reaction time on the prepared materials were investigated. The highest yield was obtained at 250 degrees C and a reaction time of 6 h, with a diameter of approximately 5-9 μm. However, extending the reaction time beyond 6 h led to fusion and deformation of the microspheres. The synthesized materials exhibited a low BET surface area and a maximum adsorption capacity of 12 mg/g for methylene blue.