Fingerprint Abstract This chapter focuses on liquefaction of solids, primarily coal and biomass sources such as lignin. In a twostep process the molecular structure is broken into fragments and hydrogenated, increasing the hydrogentocarbon ratio and preventing retrogressive reactions.
WhatsApp: +86 18838072829How DCL differs from XTL. The principal alternative to XTL is direct coal liquefaction (DCL), which is the conversion of coal to liquids without the intervening step of producing synthesis gas. The primary DCL technology is hydroliquefaction, the reaction of coal with hydrogen and/or a hydrogendonor solvent, usually in the presence of a catalyst.
WhatsApp: +86 18838072829Coal can also be liquefied directly into liquid fuels through direct coal liquefaction (DCL) processes at around 450500 °C under 1530 MPa H 2 in a suitable solvent with appropriate catalysts [ 2, 3, 4, 5, 6, 7, 8, 9 ].
WhatsApp: +86 18838072829The main objective of this paper is to carry out a techno‐economic evaluation for the direct coal liquefaction (DCL) process based on the two primary conversion options under consideration: (a) catalytic coal liquefaction (CCL) the use of non‐donor solvents with added hydrogen pressure and (b) thermal coal liquefaction (TCL) the use of solvents with some H‐donor properties ...
WhatsApp: +86 18838072829A mechanistic numerical model for coal liquefaction involving hydrogenolysis of strong bonds. Rationalization of interactive effects of solvent aromaticity and hydrogen pressure ... Hydrogen Transfer in the Formation and Destruction of Retrograde Products in Coal Conversion. The Journal of Physical Chemistry A 2006, 110 (21) ... (DCL) processes ...
WhatsApp: +86 18838072829The use of highcarbonbased feeds to produce alternative fuels and valueadded chemicals is discussed. Basic conversion chemistry, chemical structures of coal and lignin biomass are discussed, followed by process technologies for direct liquefaction, liquid quality, process control and modeling, advantages and limitations, and future trends.
WhatsApp: +86 18838072829The growing demand for petroleum, accompanied by the declining petroleum reserves and the concerns over energy security, has intensified the interest in direct coal liquefaction (DCL), particularly in countries such as China which is rich in coal resources, but short of petroleum. In addition to a general introduction on the mechanisms and processes of DCL, this paper overviews some recent ...
WhatsApp: +86 18838072829The environmental footprint of coal liquefaction processes can usually be reduced by coprocessing coal and biomass and applying CO 2 capture and storage (CCS) technology but at the cost of higher ...
WhatsApp: +86 18838072829The separate characterization of biomass, coal, and their respective chars aimed at identifying the effect of sodium during different stages of combustion. ... Direct coal liquefaction (DCL) is a main pathway for converting lowrank coals into energy via thermochemical transformation [713], and DCL technology refers to conversion of solid ...
WhatsApp: +86 18838072829In this process, coal with moderate amount of biomass is converted into syncrude through reaction with Hdonor solvent and gaseous hydrogen in a catalytic twostage liquefaction unit.
WhatsApp: +86 18838072829Direct coal liquefaction (DCL) is a suitable way of producing synthetic fuels from lowrank coals, especially when the wastederived materials are coprocessed during the process.
WhatsApp: +86 18838072829Other thermochemical conversion technologies are under development for coprocessing biomass and fossil fuels. During the coliquefaction of coal with biomass, lower liquefaction temperature of coal and higher liquid products yield than those predicted by mathematic models are obtained as a result of the synergetic effect.
WhatsApp: +86 18838072829Abstract: This chapter focuses on liquefaction of solids, primarily coal and biomass sources such as lignin. In a twostep process the molecular structure is broken into fragments and hydrogenated, increasing the hydrogentocarbon ratio and preventing retrogressive reactions. Solvents solubilize smaller molecular weight components and promote hydrogenation; catalyst improves hydrogenation ...
WhatsApp: +86 18838072829For the most highly developed processes, coal conversion can be as high as 90% on a mineral ash free basis, with a C 5+ distillate yield up to 75% and hydrogen consumption of 57% wt. When an external catalyst is used, it is typically some combination of cobalt, nickel, and molybdenum on a solid acid support such as silicaalumina [].In slurry hydrogenation processes, catalyst lifetime is ...
WhatsApp: +86 18838072829Coal liquefaction conversion to tetralinsoluble products was determined by changes in ash content in the partially reacted coal relative to that of the unreacted coal. ... A Novel Process of Biomass Gasification for HydrogenRich Gas with Solid Heat Carrier: Preliminary Experimental Results. ... (DCL) processes and technology for coal and ...
WhatsApp: +86 18838072829Direct liquefaction (DCL) processes and technology for coal and biomass conversion
WhatsApp: +86 18838072829The DCL process involves adding hydrogen (hydrogenation) to the coal, breaking down its organic structure into soluble products. The reaction is carried out at elevated temperature and pressure (, 750 to 850°F and 1,000 to 2,500 psia) in the presence of a solvent. The solvent is used to facilitate coal extraction and the addition of hydrogen.
WhatsApp: +86 18838072829For the most highly developed processes, coal conversion can be as high as 90% on a mineral ash free basis, with a C 5+ distillate yield up to 75% and hydrogen consumption of 57%wt. When an external catalyst is used, it is typically some combination of cobalt, nickel, and molybdenum on a solid acid support such as silicaalumina [].DCL process concepts have been based on a variety of ...
WhatsApp: +86 18838072829There are many liquefaction processes related to DCLS [26], [29], [31], [108], [109]. Several typical or highly referential liquefaction processes that have been reported are selected in this paper for introduction. As an illustration, a flow diagram of coal liquefaction process using syngas was proposed by Fu et al. [29], as shown in Fig. 14.
WhatsApp: +86 18838072829A previous paper has shown that direct coal liquefaction in the absence of a catalyst consists of two distinct stages which are readily ... A kinetic model for the liquefaction processes based on these observations is introduced. ... Direct liquefaction (DCL) processes and technology for coal and biomass conversion. 2011, 105154. https://doi ...
WhatsApp: +86 18838072829Basic conversion chemistry, chemical structures of coal and lignin biomass are discussed, followed by process technologies for direct liquefaction, liquid quality, process control and modeling, advantages and limitations, and future trends.
WhatsApp: +86 18838072829Basic conversion chemistry, chemical structures of coal and lignin biomass are discussed, followed by process technologies for direct liquefaction, liquid quality, process control and...
WhatsApp: +86 18838072829Various metal compounds have been used to catalyze the process. This type of CTL technology is called direct coal liquefaction (DCL). DCL technology involves making a partially refined synthetic crude oil directly from coal, which is then further refined into synthetic gasoline and diesel as well as liquefied petroleum gas (LPG).
WhatsApp: +86 18838072829Direct liquefaction (DCL) processes and technology for coal and biomass conversion C. B. Clifford Chunshan Song Chemistry 2011 Abstract: This chapter focuses on liquefaction of solids, primarily coal and biomass sources such as lignin. In a twostep process the molecular structure is broken into fragments and hydrogenated,. Expand 4
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