Oil-coal slurry prepared in coal direct liquefaction is a dispersed solid-liquid suspension system. In this paper, some factors such as solvent properties, solid concentrations and temperatures, which affect viscosity...Oil-coal slurry prepared in coal direct liquefaction is a dispersed solid-liquid suspension system. In this paper, some factors such as solvent properties, solid concentrations and temperatures, which affect viscosity change of oil-coal slurry, were studied. The viscosity of coal slurry was measured using rotary viscometer, and the rheological properties have been investigated. The viscosity and rheological curves were plotted and regressed, respectively. The results show that the coal slurry behaves a pseudoplastic and thixotropic property. The rheological type of coal slurry was ascertained and its rheological equations were educed. The oil-coal slurry changes to non-Newtonian fluid from Newtonian fluid with the increasing of solid concentration.展开更多
The catalytic effects of single and mixed catalysts, i.e. single 3%Ca and 5%Na-BL（black liquor） catalysts and mixed 3%Ca＋5%Na-BL catalyst, on carbon conversion, gasification reaction rate constant and activation en...The catalytic effects of single and mixed catalysts, i.e. single 3%Ca and 5%Na-BL（black liquor） catalysts and mixed 3%Ca＋5%Na-BL catalyst, on carbon conversion, gasification reaction rate constant and activation energy, relative amount of harmful pollutant like sulphur containing gases have been investigated by thermogravimetry in steam gasification under temperature 750℃ to 950℃ at ambient pressure for three high-metarnorphous anthracites （Longyan, Fenghai and Youxia coals in Fujian Province）. The mixed catalyst of 3%Ca＋5%Na-BL increases greatly the carbon conversion and gasification rate constant by accelerating the gasification reaction C＋H2O→CO＋H2 due to presence of alkali surfacecompounds [COM], [CO2M] and exchanged calcium phenolate and calcium carboxylate （-COO）2. By adding CaCO3 into BL catalyst in gasification, in addition to improving the catalyst function and enhancing the carbon conversion, the effective desulphurization is also achieved, but the better operating temperature should be below 900℃. The homogenous and shrinking core models can be successfully employed to correlate the relations between the conversion and the gasification .time .and to estimate the reaction rate constant, The reaction acUvaUon energy and pre-exponential factor are estimated and the activation energy for mixed catalyst is in a range of 98.72-166.92 kJ·mol^-1, much less than 177.50-196.46 kJ·mol^-1 for non-catalytic steam gasification for three experimental coals.展开更多
Calcined ginger nuts admixed by fly ash and quartz sand (CGN-(F+S)) has been validated to be basically compatible to earthen sites as an anchor grout. Accelerated ageing tests including water stability test, temperatu...Calcined ginger nuts admixed by fly ash and quartz sand (CGN-(F+S)) has been validated to be basically compatible to earthen sites as an anchor grout. Accelerated ageing tests including water stability test, temperature and humidity cycling test, soundness test and alkali resistance test are conducted with the objective to further research the property changes of CGN-(F+S) grout. Density, surface hardness, water penetration capacity, water permeability capacity, soluble salt, scanning electron microscopy (SEM) images and energy dispersive spectrometry (EDS) spectrum of these samples have been tested after accelerated ageing tests. The results show that densities of samples decrease, surface hardness, water penetration capacity and water permeability capacity of samples increase generally. Besides, soluble salt analysis, SEM and EDS results well corroborate the changes. Based on the results it can be concluded that property changes are most serious after temperature and humidity cycling test, followed by water stability, soundness and alkali resistance test in sequence. But in general, CGN-(F+S) still has good durability.展开更多
基金Project 2004CB217601 supported by the National Key Basic Research Development Plan (973) of China
文摘Oil-coal slurry prepared in coal direct liquefaction is a dispersed solid-liquid suspension system. In this paper, some factors such as solvent properties, solid concentrations and temperatures, which affect viscosity change of oil-coal slurry, were studied. The viscosity of coal slurry was measured using rotary viscometer, and the rheological properties have been investigated. The viscosity and rheological curves were plotted and regressed, respectively. The results show that the coal slurry behaves a pseudoplastic and thixotropic property. The rheological type of coal slurry was ascertained and its rheological equations were educed. The oil-coal slurry changes to non-Newtonian fluid from Newtonian fluid with the increasing of solid concentration.
基金Supported by the National Natural Science Foundation of China （20376014） and Fujian Science and Technology Council Grant （HG99-01 ）.
文摘The catalytic effects of single and mixed catalysts, i.e. single 3%Ca and 5%Na-BL（black liquor） catalysts and mixed 3%Ca＋5%Na-BL catalyst, on carbon conversion, gasification reaction rate constant and activation energy, relative amount of harmful pollutant like sulphur containing gases have been investigated by thermogravimetry in steam gasification under temperature 750℃ to 950℃ at ambient pressure for three high-metarnorphous anthracites （Longyan, Fenghai and Youxia coals in Fujian Province）. The mixed catalyst of 3%Ca＋5%Na-BL increases greatly the carbon conversion and gasification rate constant by accelerating the gasification reaction C＋H2O→CO＋H2 due to presence of alkali surfacecompounds [COM], [CO2M] and exchanged calcium phenolate and calcium carboxylate （-COO）2. By adding CaCO3 into BL catalyst in gasification, in addition to improving the catalyst function and enhancing the carbon conversion, the effective desulphurization is also achieved, but the better operating temperature should be below 900℃. The homogenous and shrinking core models can be successfully employed to correlate the relations between the conversion and the gasification .time .and to estimate the reaction rate constant, The reaction acUvaUon energy and pre-exponential factor are estimated and the activation energy for mixed catalyst is in a range of 98.72-166.92 kJ·mol^-1, much less than 177.50-196.46 kJ·mol^-1 for non-catalytic steam gasification for three experimental coals.
基金Project(51578272)supported by the National Natural Science Foundation of China
文摘Calcined ginger nuts admixed by fly ash and quartz sand (CGN-(F+S)) has been validated to be basically compatible to earthen sites as an anchor grout. Accelerated ageing tests including water stability test, temperature and humidity cycling test, soundness test and alkali resistance test are conducted with the objective to further research the property changes of CGN-(F+S) grout. Density, surface hardness, water penetration capacity, water permeability capacity, soluble salt, scanning electron microscopy (SEM) images and energy dispersive spectrometry (EDS) spectrum of these samples have been tested after accelerated ageing tests. The results show that densities of samples decrease, surface hardness, water penetration capacity and water permeability capacity of samples increase generally. Besides, soluble salt analysis, SEM and EDS results well corroborate the changes. Based on the results it can be concluded that property changes are most serious after temperature and humidity cycling test, followed by water stability, soundness and alkali resistance test in sequence. But in general, CGN-(F+S) still has good durability.
