Harnessing Agricultural Waste: The Enhanced Hygrothermal Performance of Biochar-Infused Building Materials

Recent research delves into the fascinating world of biochar and its potential to refine bio-oil by selectively adsorbing aromatics. Scientists have manipulated biochar structures through nitric acid oxidation and secondary pyrolysis, uncovering that biochar’s structure profoundly influences its ability to clean bio-oil. The study reveals that biochar can absorb between 2.90 and 4.00 grams of bio-oil per gram of biochar, a capacity largely dictated by its pore structure.

The presence of oxygen-containing functional groups and the level of graphitization are also critical but secondary to the influence of pore structure. Interestingly, the adsorption effectiveness is inversely related to the concentration of light aromatic compounds in the absorbed bio-oil (ABO). Among the various aromatics, biochar shows a preference for heavier aromatics over lighter ones and is particularly effective at adsorbing dihydroxybiphenyl, likely due to its diphenyl ring structure. In contrast, compounds like eugenol and propyl phenol, which only contain a single benzene ring, are less effectively absorbed.

This study highlights that the selectivity of biochar can be significantly enhanced by developing its pore structure and increasing the presence of functional groups and graphitization. The findings suggest that tailored biochar could become a pivotal tool in bio-oil purification, offering an efficient method to reduce light aromatic concentrations while favoring the retention of heavy aromatics. This advancement in biochar technology could pave the way for more sustainable and effective bio-oil purification strategies, essential for the burgeoning biofuel industry.