Topic
Char
About: Char is a research topic. Over the lifetime, 14457 publications have been published within this topic receiving 408727 citations.
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TL;DR: A molecular-level assessment of the physical organization and chemical complexity of biomass-derived chars and, specifically, that of aromatic carbon in char structures suggests the existence of four distinct categories of char consisting of a unique mixture of chemical phases and physical states.
Abstract: Char black carbon (BC), the solid residue of incomplete combustion, is continuously being added to soils and sediments due to natural vegetation fires, anthropogenic pollution, and new strategies for carbon sequestration (“biochar”). Here we present a molecular-level assessment of the physical organization and chemical complexity of biomass-derived chars and, specifically, that of aromatic carbon in char structures. Brunauer−Emmett−Teller (BET)−N2 surface area (SA), X-ray diffraction (XRD), synchrotron-based near-edge X-ray absorption fine structure (NEXAFS), and Fourier transform infrared (FT-IR) spectroscopy are used to show how two plant materials (wood and grass) undergo analogous but quantitatively different physical−chemical transitions as charring temperature increases from 100 to 700 °C. These changes suggest the existence of four distinct categories of char consisting of a unique mixture of chemical phases and physical states: (i) in transition chars, the crystalline character of the precursor ma...
2,283 citations
TL;DR: In this paper, X-ray photoelectron spectroscopy (XPS) was used to investigate the fate of nitrogen functional forms present in a lignite and its chars, derived from the model compounds acridine, carbazole and polyacrylonitrile (PAN).
1,792 citations
TL;DR: In this paper, the authors review the design considerations faced by the developers of fast pyrolysis, upgrading and utilisation processes in order to successfully implement the technologies and provide a case study of the application of the technology to waste wood and how this approach gives very good control of contaminants.
1,664 citations
TL;DR: The conversion technologies for utilizing biomass can be separated into four basic categories: direct combustion processes, thermochemical processes, biochemical processes and agrochemical processes as discussed by the authors, which can be subdivided into gasification, pyrolysis, supercritical fluid extraction and direct liquefaction.
1,578 citations
01 Jan 2011
TL;DR: The wet pyrolysis process, also known as hydrothermal carbonization, opens up the field of potential feedstocks for char production to a range of nontraditional renewable and plentiful wet agricultural residues and municipal wastes as discussed by the authors.
Abstract: The carbonization of biomass residuals to char has strong potential to become an environmentally sound conversion process for the production of a wide variety of products. In addition to its traditional use for the production of charcoal and other energy vectors, pyrolysis can produce products for environmental, catalytic, electronic and agricultural applications. As an alternative to dry pyrolysis, the wet pyrolysis process, also known as hydrothermal carbonization, opens up the field of potential feedstocks for char production to a range of nontraditional renewable and plentiful wet agricultural residues and municipal wastes. Its chemistry offers huge potential to influence product characteristics on demand, and produce designer carbon materials. Future uses of these hydrochars may range from innovative materials to soil amelioration, nutrient conservation via intelligent waste stream management and the increase of carbon stock in degraded soils.
1,360 citations