Distribution and alcohol-based index analysis of diverse forest and grass biomass resources in China

Forest and grass raw materials are abundant resources in China. The proper utilization of these resources can greatly contribute to environmental issues arising from forest and grass wastes. Therefore, this study aims to classify the representative forest and grass raw materials across mainland China. The forest and grass crops were determined in each region, according to geographical coordinates. A systematic analysis was implemented to explore the distribution and composition of diverse forest and grass raw materials. Specific indicators were measured, such as the contents of moisture, cellulose, hemicellulose, carbon, oxygen, volatile matter, and calorific value. A framework of database retrieval was established for the composition and structural analysis of diverse forest and grass raw materials. The results indicated that the sugar beet in the East China region exhibited a moisture content ranging from 80% to 90%, with a relatively lower carbon content, compared with the rest energy grasses. Nevertheless, sugar beet was unsuitable for biomass ethanol use, with a higher oxygen content of 46%, compared with the forest and grass raw materials. Soybeans shared the 40% cellulose content significantly lower than the rest. Furthermore, maize and rice crop straws showed relatively lower contents of moisture and ash, with lower oxygen and similar carbon content. Additionally, maize straws in the Southwest exhibited the highest cellulose content among various forest and grass raw materials. Consequently, maize and rice straws were suitable for biomass ethanol utilization. Ryegrass in the Northwest and sugarcane in the East and South presented a higher specific heat capacity ranging from 3.2 to 4.8 J/(kg·K), whereas other energy grasses generally ranged from 0.8 to 2.4 J/(kg·K). There were some correlations among the physical properties, chemical compositions, industrial compositions, elemental compositions, and ethanol utilization potential of typical forest and grass raw materials. This finding can provide essential support and data references for the ethanol utilization of diverse forest and grass resources.