Synergistic effects on cellulose and lignite co-pyrolysis and co-liquefaction

Hydrothermal Co-Liquefaction of Lignite and Lignocellulosic Biomass with the Addition of Formic Acid: Study on Product Distribution, Characteristics, and Synergistic Effects

“…The major compounds in the oil product derived from lignite were hydrocarbons (40.30%) (e.g., 1,3-cyclopentadiene, 5,5-dimethyl-2-ethyl- and 2,4-heptadiene, 2,6-dimethyl-) and phenols (20.23%) (e.g., phenol and p-cresol), as well as some alcohols, acids, esters, etc. This was consistent with the findings of Zhao et al, who reported that phenols, aromatics, and hydrocarbons were the main components in the liquid fuel generated from liquefaction of lignite in ethanol–water cosolvents. As for the liquefaction of CS, the major groups of compounds in the oil product were phenols (35.09%) (e.g., phenol, 4-ethyl- and phenol, 4-ethyl-2-methoxy-), followed by ketones (16.98%), alcohols (9.21%), acids (8.07%), aldehydes (6.58%), etc.…”

“…Moreover, according to the research by Du et al, the arenes and aliphatic hydrocarbons generated from sub-bituminous coal disappeared during co-alcoholysis with white pine sawdust, due to the fact that the phenoxy radicals from thermal depolymerization of biomass could attack the aliphatic C–C bonds and promote the decomposition of hydrocarbons to gaseous products. Zhao et al also found that the free radical fragments formed from cellulose could promote the cracking of lignite-derived hydrocarbons and aromatics in liquid fuel into smaller molecules. Nevertheless, the results from this work showed that hydrocarbons are present in significant amounts in the oil products from the co-liquefaction process, which might be attributed to the capture of excess reactive radicals or the hydrogenation reactions by in situ hydrogen generated from formic acid .…”

Progress on the Co-Pyrolysis of Coal and Biomass

“…Song et al [73] reported that co-pyrolysis was unfavorable to the formation of benzene, naphthalene, and hydrocarbons in tar, but favorable to the formation of phenols and guaiacol. Zhao et al [83] found that the co-pyrolysis of cellulose and lignite was conducive to the generation of −OH components, and cellulose could promote the thermal conversion of lignite to a certain extent, resulting in more ketones or esters in the co-pyrolysis tar, which was conducive to improving the quality of liquid products. Zhu et al [84] reported that the reactive H 2 from water-gas shift reaction and hydrogen-rich radicals such as •CH 3 , •OCH 3 from cedar can inhibit the secondary polymerization to form methylphenol and naphthalene instead of 3-ring phenanthrenes and 4-ring pyrenes during co-pyrolysis of a massive coal and cedar mixture.…”

MW‐assisted hydrothermal liquefaction of spent coffee grounds

“…[7] Many research efforts have been made to improve HTL conversion efficiency and optimize product distribution, and most of these studies applied conventional heating methods to facilitate HTL processes. [8,9] Different from conventional heating, where the subject material is heated by convective and conduction heat transfer from the reactor wall and then from the material surface to the material core, microwave (MV) heating is featured with non-contact, uniform heat distribution, faster heating, and lower energy consumption. [10] Using MW irradiation to accelerate organic chemical transformation dates back to 1986, and since then relevant studies have been well documented.…”

“…[ 7 ] Many research efforts have been made to improve HTL conversion efficiency and optimize product distribution, and most of these studies applied conventional heating methods to facilitate HTL processes. [ 8,9 ]…”