amorphous carbon with abundant porosity microcrystal or amorphous carbon particles preparation method pyrolysis of the biomass at medium temperature (400−600 °C) and then functionalization with physical or chemical methods carbonization of the coal, asphalt, or biomass at high temperature (700−1000 °C) under physical or chemical activation combustion of petroleum, coal tar, or asphalt under air-poor conditions

Lignin valorization is considered as an important part of the modern biorefinery scheme. The unique structure and composition of lignin may offer many effective routes to produce several bulk chemicals and functional materials. Thermochemical conversion of the lignin to synthesize the value-added functional materials has recently attracted lots of attention. In this review, we have presented currently available approaches and strategies for the thermochemical conversion of the lignin to functional carbon materials. The transformation behavior and mechanism of lignin during the thermochemical process (e.g., pyrolysis and hydrothermal carbonization) are illuminated. The characteristics (structure and surface chemistry) of the lignin-based functional carbon materials are summarized systematically. The advances on the functionalization of lignin-based carbon materials (surface functionality tuning and porosity tailoring) and applications of the lignin-based functional carbon materials in the fields of catalysis, energy storage, and pollutant removal are reviewed. Perspectives on how lignin-based functional materials would develop and especially in which fields the use of these functionalized materials could be expanded are discussed. This review clearly shows that rational designing of the functionalized lignin-based materials will lead to a rich family of hybrid functional carbon materials with various applications toward a green and sustainable future. many persistent organic pollutants (e.g., polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (OPAHs), and dioxins) [24][25][26] and particulate matters (e.g., PM 2.5 and PM 10) 27, 28 may form if

Biomass is increasingly perceived as a renewable resource rather than as an organic solid waste today, as it can be converted to various chemicals, biofuels, and solid biochar using modern processes. In the past few years, pyrolysis has attracted growing interest as a promising versatile platform to convert biomass into valuable resources. However, an efficient and selective conversion process is still difficult to be realized due to the complex nature of biomass, which usually makes the products complicated. Furthermore, various contaminants and inorganic elements (e.g., heavy metals, nitrogen, phosphorus, sulfur, and chlorine) embodied in biomass may be transferred into pyrolysis products or released into the environment, arousing environmental pollution concerns. Understanding their behaviors in biomass pyrolysis is essential to optimizing the pyrolysis process for efficient resource recovery and less environmental pollution. However, there is no comprehensive review so far about the fates of chemical elements in biomass during its pyrolysis. Here, we provide a critical review about the fates of main chemical elements (C, H, O, N, P, Cl, S, and metals) in biomass during its pyrolysis. We overview the research advances about the emission, transformation, and distribution of elements in biomass pyrolysis, discuss the present challenges for resource-oriented conversion and pollution abatement, highlight the importance and significance of understanding the fate of elements during pyrolysis, and outlook the future development directions for process control. The review provides useful information for developing sustainable biomass pyrolysis processes with an improved efficiency and selectivity as well as minimized environmental impacts, and encourages more research efforts from the scientific communities of chemistry, the environment, and energy.