Utilization Perspectives of Lignin Biochar from Industrial Biomass Residue

The present study aimed at utilizing technically hydrolyzed lignin (THL), industrial biomass residue, derived in high-temperature diluted sulfuric acid hydrolysis of softwood and hardwood chips to sugars. The THL was carbonized in a horizontal tube furnace at atmospheric pressure, in inert atmosphere and at three different temperatures (500, 600, and 700 & DEG;C). Biochar chemical composition was investigated along with its HHV, thermal stability (thermogravimetric analysis), and textural properties. Surface area and pore volume were measured with nitrogen physisorption analysis often named upon Brunauer-Emmett-Teller (BET). Increasing the carbonization temperature reduced volatile organic compounds (40 & DIVIDE; 96 wt. %), increased fixed carbon (2.11 to 3.68 times the wt. % of fixed carbon in THL), ash, and C-content. Moreover, H and O were reduced, while N- and S-content were below the detection limit. This suggested biochar application as solid biofuel. The biochar Fourier-transform infrared (FTIR) spectra revealed that the functional groups were gradually lost, thus forming materials having merely polycyclic aromatic structures and high condensation rate. The biochar obtained at 600 and 700 & DEG;C proved having properties typical for microporous adsorbents, suitable for selective adsorption purposes. Based on the latest observations, another biochar application was proposed-as a catalyst.

Automated summary

The aim of this study was to convert technically hydrolyzed lignin (THL) into sugars using high-temperature diluted sulfuric acid hydrolysis of softwood and hardwood chips. The THL was carbonized at different temperatures (500, 600, and 700°C) to produce biochar. The properties of the biochar, including chemical composition, thermal stability, and textural properties, were investigated. The results showed that increasing the carbonization temperature resulted in a reduction in volatile organic compounds and an increase in fixed carbon, ash, and C-content. The biochar obtained at 600 and 700°C had properties suitable for selective adsorption and catalytic purposes.