Carbochemistry

About: Carbochemistry is a research topic. Over the lifetime, 1010 publications have been published within this topic receiving 16626 citations.

The effect of added heterogeneous catalysts on low-severity coal liquefaction

Abstract: Liquefaction data in the presence and absence of added catalysts were obtained for two coals from the Argonne premium Sample Bank (Beulah-Zap lignite and Utah Blind Canyon high volatile bituminous). Experiments were carried out in tubing bomb microautoclave batch reactors over a broad temperature range (310 to 425 °C), and THF and hexane conversion profiles were measured at residence times of 5, 10, 15, and 30 minutes in order to elucidate the effect of both time and temperature at reaction conditions ranging from low to high severity. All runs were carried out in a non-donor vehicle (l-methylnaphthalene) using powdered presulfided Shell 324 as the catalyst. The results generally reflect the expected trends for catalyst on coal conversion, in that the primary influence of catalyst was found to be in terms of promoting conversion of coal to hexane solubles. A hexane selectivity parameter was developed and utilized to provide insight into the role and effect of catalyst.

Drying and preheating coals before coking. Part 1

Abstract: A coal preheater capable of drying and preheating sufficient coal for one complete coal charge to the pilot coke oven has been designed and built in the Illinois State Geological Survey laboratories. Coking tests on high-volatile A, B, and C bituminous coals preheated to a maximum of about 450° F have indicated that preheating consistently reduces coking time and increases the potential coke making capacity of a coke oven. The strength of coke made from the individual high-volatile coals tested is consistently improved by preheating. Similar tests being made on coal blends such as those used commercially to produce metallurgical coke will be described in a subsequent publication. INTRODUCTION The demand for metallurgical coke, coupled with high operating and replacement costs of coke ovens, has been responsible for a continuing interest in development of methods to increase the daily throughput of coal in ovens producing coke for blast furnace and foundry uses. Several ways to accomplish this objective have been proposed, including the construction of tall coke ovens, holding 27 to over 3 tons of coal, as compared with 15 to 18 tons in the average present-day oven. Tall ovens have been developed and used in Europe, and several batteries are under construction or planned in this country and Canada. Also planned is an increase in the oven coking rate by use of high density silica brick and thinner oven wall shapes, allowing more rapid transfer of heat from oven flues to coal. This combination of dense silica and thinner walls has been

Variation of temperature effect with hydrogen supply in non-catalytic coal liquefaction

Abstract: A Spanish subbituminous coal was subjected to non-catalytic liquefaction with tetralin in a 250 ml stirred autoclave. The operating conditions used were: one hour reaction time, 17 MPa operating pressure and 400 r.p.m, stirring speed. The liquefaction products were fractionated into oils, asphaltenes, preasphaltenes and solid residue by a solvent extraction technique using pentane, toluene and THF as extractive solvents. It was found that the influence of temperature on coal liquefaction yields and product distributions varies with the amount of donatable hydrogen. Total coal conversion increases with temperature, when very high tetralin/coal ratios are used On the contrary, when 1/1 ratio is used, conversion does not seem to depend on temperature, and appears to be limited by the amount of liquid medium available as physical solvent. At intermediate tetralin/coal ratios,conversion generally increases with both factors: temperature and amount of solvent. However, retrogressive reactions are obser...