Advancing biomass utilization: conversion of solid residues from pretreatment and enzymatic hydrolysis into porous carbon materials

Abstract

This study advances biomass utilization by focusing on Camellia oleifera seed oil residues, specifically the shell (COS) and cake (COC). Three routes were designed to optimize resource usage: (1) raw biomass directly produced 217 g kg⁻¹ biochar from COS; (2) green acidic pretreatment and pyrolysis resulted in 252.6–269.2 g kg⁻¹ sugar and 175.6–208 g kg⁻¹ biochar, respectively; and (3) combining pretreatment, enzymatic hydrolysis, and pyrolysis generated 355.6–422.2 g kg⁻¹ sugar and 138.6–148 g kg⁻¹ biochar. This process not only enhances biomass economics through high sugar production, but also creates excellent porous carbon materials, attained without supplementary treatments. Through systematic characterization, analysis, and interpretation, the study delved into the unique properties of the biochar materials. These in-depth investigations revealed critical insights into their structure and functionality. Consequently, the study envisions a wide range of potential applications for these biochars, including energy production, agricultural enhancement, wastewater purification, and carbon sequestration. The designed process exemplifies its adherence to green chemistry principles, stemming from its straightforward methodology and high resource efficiency, resulting in substantial waste reduction and minimized reagent consumption.