Coal liquefaction systems

Mueller, J. J., et al., Application of advanced materials and fabrication technology to let down valves for coal liquefaction systems, Electrical Power Research Institute Report, AF-305, January 1977. 

In this way, we know that the coal liquefaction system constitutes a structure of multi-target system. In addition to these subtargets, the coal liquefaction system attaches an accomodate system which includes oxygen prdduction, hydrogen production, power production, and utilities. 

The specific reaction ( activation ) conditions for the conversion of catalyst precursors to unsupported catalysts have a direct effect on the catalytic activity and dispersion. The importance of reaction intermediates in decomposition of ammonium heptamolybdate and ammonium tetrathiomolybdate, and the sensitivity of these intermediates to reaction conditions, were studied in coal liquefaction systems. Recent results indicate that optimization of activation conditions facilitates the formation of a highly dispersed and active form of molybdenum disulfide for coal liquefaction. The use of the catalyst precursors ammonium heptamolybdate, ammonium tetrathiomolybdate, and molybdenum trisulflde for the conversion of coal to soluble products will be discussed. 

Coal liquefaction system Valve to throttle the flow of product stream 7... 

Costs based on plant processing 26,105 Mg/d (28,776 US ton/d) of Ilbnois No. 6 coal. Source Direct Coal Liquefaction Baseline Design and Systems Analysis, prepared by Bechtel and Amoco under DOE contract no. DE-AC22-90PC89857, March 1993. 

These reactors contain suspended solid particles. A discontinuous gas phase is sparged into the reactor. Coal liquefaction is an example where the solid is consumed by the reaction. The three phases are hydrogen, a hydrocarbon-solvent/ product mixture, and solid coal. Microbial cells immobilized on a particulate substrate are an example of a three-phase system where the slurried phase is catalytic. The liquid phase is water that contains the organic substrate. The gas phase supplies oxygen and removes carbon dioxide. The solid phase consists of microbial cells grown on the surface of a nonconsumable solid such as activated carbon. 

Effect of Reaction Conditions on Solubility. Earlier results ( ) suggested investigation of the ZnCl -methanol system as a coal-liquefaction medium based on high product solubility, low... 

Isomerization and Adduction of Hydroaromatic Systems at Conditions of Coal Liquefaction... 

Catalytic coal liquefaction processes do not specifically use hydrogen donor solvents although coal is introduced into the liquefaction reactor as a slurry in a recycle liquid stream. Catalyst is used as a powder or as granules such as pellets or extrudates. If powdered catalyst is used, it is mixed with the coal/liquid stream entering the reactor. Pelleted catalyst can be used in fixed bed reactors if precautions are taken to avoid plugging with solids or in fluidized bed reactors. In the latter case, the reacting system is actually a three phase fluidized bed, that is, catalyst particles and coal solids, as well as liquid, are fluidized by gas. 

We believe that the PFGC equation of state approach will be the most fruitful new route to predicting phase behavior of the diverse systems encountered in the natural gas/petroleum/coal liquefaction gasification process industry. We commend it to your attention. 

McKee RH, Kapp RW Jr, Ward DP. 1985. Evaluation of the systemic toxicity of coal liquefaction-derived materials following repeated dermal exposure in the rabbit. J Appl Toxicol 5(6) 345-351. 

Aspects of coal liquefaction have been much researched, particularly with the re-emeigence of interest caused by the oil crisis in the 1970 s. The type of reactors used in the studies has been various, ranging from small bomb type microautoclaves through larger autoclaves and bench-scale reactors to larger scale pilot or demonstration plants. The use of differently sized and designed high pressure equipment for liquefaction studies further complicates an already complex system and allows only limited comparison of results. 

This term is restricted here to equipment in which finely divided solids in suspension interact with gases. Solids fluidized by liquids are called slurries. Three phase fluidized mixtures occur in some coal liquefaction and petroleum treating processes. In dense phase gas-solid fluidization, a fairly definite bed level is maintained in dilute phase systems the solid is entrained continuously through the reaction zone and is separated out in a subsequent zone. 

The so-called cobalt molybdate catalyst has been used much in the petroleum industry for hydrotreating and hydrodesulfurization. More recently, these catalysts have been employed in coal liquefaction and synthoil upgrading. The latter probably accounts for the recent rash of publications on this very interesting catalyst system. Indeed, of the papers surveyed for this review, the majority have been published in the past 5 years with no letup in sight. 

Gas-liquid bubble columns and gas-liquid-solid slurry bubble columns are widely used in the chemical and petrochemical industries for processes such as methanol synthesis, coal liquefaction, Fischer-Tropsch synthesis and separation methods such as solvent extraction and particle/gas flotation. The hydrodynamic behavior of gas-liquid bubble columns and gas-liquid-solid slurry bubble columns are of great importance for the design and scale-up of reactors. Although the hydrodynamics of the bubble and slurry bubble columns has been a subject of intensive research through experiments and computations, the flow structure quantification of complex multi-phase flows are still not well understood, especially in the three-dimensional region. In bubble and slurry bubble columns, the presence of gas bubbles plays an important role to induce appreciable liquid/solids mixing as well as mass transfer. The flows within these systems are divided into two... 

Coal liquefaction studies with Illinois No. 6 coal in supercritical water/CO systems have demonstrated that a suitable model for liquefaction includes a branch point. Thus coal is partitioned between reducing (i.e. liquefying) steps, and steps where strictly thermal reactions consume convertible sites and yield unconvertible char. 

Forsberg, C. (2006), Assessment of Nuclear-hydrogen Synergies with Renewable Energy Systems and Coal Liquefaction Processes, ORNL/TM-2006/114, August. 

This reactor allows easy data collection for high-temperature, high-pressure reaction systems that have difficult flow properties. This includes reactants that are solid at room temperature or mixtures of solids and liquids. Typical reactions performed in autoclaves are coal liquefaction, petroleum residuals and coal liquids upgrading, and high molecular weight hydrogenation experiments. 

To develop appropriate systems and equipment for controlling any environmental, health, and safety factors that may be unique to large scale coal liquefaction plants and their products. 

The software system, to meet the needs of the 1980 s, has wide flexibility and capabilities. For processes such as coal gasification or coal liquefaction, it can be used to perform steady state material and energy balances, calculate sizes of equipment, and carry out economic evaluations. Its flexibility can allow for the handling of coal or other solids in streams and equipment, and its capabilities allow for the simulation of many different types of process equipment and the calculations of physical properties under widely different conditions. Included in this is the ability to analyze conventional chemical and petroleum processes. Another valuable feature 1s a good preliminary cost estimation capability that permits the comparison of alternative processes on an economically consistent basis at an early stage of development. 

Calculations were carried out for unit mole of carbon in feed coal (MAF basis). Since the empirical formula of feed coal is denoted by CHo.8390o.o96N0.018s0.019 its molecular weight per unit mole of carbon is 15.236. In the present exergy analysis, the exergy input to the liquefaction system is 528.71 kj, which corresponds to the exergy value of 1 mol-C of feed coal, as shown in Table V. 

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