Hong Qin

Research on Adsorption of H2S by Oil Shale Ash

The ash of Huadian oil shale is made to remove H2S in this experiment. XRD and nitrogen adsorption experiments are used to analyze the physical and chemical properties of the ash, the results show that the ash of oil shale has many metal and nonmetal oxides, and also has much microporous and mesoporous, all above is helpful to remove H2S. The sample is modified by different ways to see the change of adsorption capacity. the sample which is modified by alkali and sprinkler is the best adsorbent, but the sample which is modified by microwave does not increase the removal ability obviously.

Analysis of Temperature Field in an Oil-Shale Retorting Furnace with Gas Heat Carrier Based on CFD

Taking the physical model of a small oil-shale retorting furnace with gas heat carrier as research object, a quasi homogeneous mathematical model was established to simulate the process of heating the pebbles in the porous zone and was solved by Fluent, a commercial CFD software. We compared the calculated results of temperature with the measured data, and analyzes the cause of the deviation between them.The result showed that the calculated value is relatively close to the measured data(the relative error is 6.85%) and the model can predict accurately the actual temperature field. The research results can provide support for the process of structural design of the large oil-shale retorting furnace with gas heat carrier.

Research on Hydrogen Sulfide Adsorption by Oil Shale and its Spent Char

Huadian oil shale and its spent char were selected to explore the adsorption properties of oil shale and oil shale char. A bench-scale adsorption system was established for capturing hydrogen sulfide in this test. What’s more, the nitrogen adsorption isotherms test was made in automatic and rapid specific surface-area-analyzer of American’s Gemini2380, which found the adsorption curve and desorption loop of the modified oil shale and oil shale char. Meanwhile, the experiment calculated and analyzed the specific surface area and pore size distribution of samples with BJH theory. The result shows that the adsorption capacity of oil shale char is greater than oil shale. The rougher the pore structure of the adsorbent samples the greater the pore volume, the larger the specific surface area, the better the adsorption effect of H2S.

Study on Thermal Kinetic Mechanism of Oil Shale

Thermogravimetric experiments were performed on Pyris-1 TGA thermal analyzer, and pyrolysis curves of four oil shale samples at different heating rates were obtained. According to Maleks method, the kinetic mechanism function of sample was determined by using the standard curves and experimental curves of y(Â?)-Â?. The influences of heating rates and species of oil shale samples on the kinetic mechanism function were analyzed. The results showed that, at the different heating rates, the heat transfer rates, temperature gradient and the chemical reactions in the interior of oil shale samples are varied, and then the kinetic mechanism function of sample is changed; The kinetic mechanism functions are not unique at the special heating rate for a single sample, which depend on the conversion rate Â?: When a Â? is less than 0.5, the weight loss during pyrolysis process, has been attributed to the loss of moisture, interlayer water from clay minerals and thermal decomposition of minerals; When Â? equals to 0.5 or so, the weight loss is due to cracking of clay minerals; When Â? is greater than 0.5, the decomposition of carbonate minerals (such as calcite, dolomite, ankerite and other carbonates). When the species of samples are different, chemical structure and the physical characteristics (such as heat transfer coefficient, voidage, specific heat capacity) are various, kinetic mechanism functions are also different, the serial numbers of kinetic mechanism functions are advanced with Â? increasing for a special sample.

Kinetics and Thermodynamics of Cadmium(II) and Zinc(II) Adsorption onto Oil shale fly ash

The kinetics and thermodynamics characteristics of Cd(II) and Zn(II) adsorption onto fly ash of a oil shale-fired power plant was investigated by using batch adsorption method. The results showed that Langmuir and Freundlich adsorption isotherms were applicable to the adsorption process, while Freundlich equation is more applicable. The mechanistic steps of the adsorption process was studied through data fitting of the experimental data using the equation of Lagergren pseudo-firstorder kinetics, the pseudo-second-order kinetics, and the intraparticle diffusion model. All the three equations were found applicable in initial stage of this study, and the absorptions of Cd(II) and Zn(II) onto fly ash from oil shale-fired CFB was in accordance of the pseudo-2nd-order reaction kinetics. The absorption characteristics of metal ions on oil shale fly ash were controlled by both film diffusion and particle diffusion. Thermodynamic analysis showed that the processes of oil shale fly ash adsorption Cd(II) and Zn(II) are endothermic reaction, and it is a spontaneous process at higher temperature.

H2S Evolution during Oil Shale Pyrolysis

H2S evolution during different oil shale samples pyrolysis was studied in fixed bed in the nitrogen atmosphere. The results show the H2S evolution is influenced by pyrolysis conditions and properties of oil shale. The yield of H2S released for two samples had a marked change at 300600°C of final temperature and 5-50°C/min of heating rate. Both the H2S yields of two samples increase with grain size increasing. While the H2S yields of Huadian oil shale was far more than that of Wangqing under same pyrolysis conditions, which may be attributed to low sulfur content and high ash content of Wangqing oil shale. It is shown that the curve of H2S escaped for Wangqing has a single wave only below 550°C, while two successive waves for Huadian oil shale occur at 440°C and 590°C respectively. The reasons of such results may be attributed to different distribution of organic and pyrite sulfur between Wangqing oil shale and Huadian oil shale. At 600 , about 10% sulfur is released from Wangqing oil shale, while about 25% sulfur fixed in semi-coke; for Huadian oil shale, about 8% sulfur is distributed in gas while 37% in simi-coke. KeywordsOil shale; pyrolysis; H2S

Experiment of Sulfur Removal in 1MW Poly-Generation System with Air Gasification and Combustion Combined

An experimental research on sulfur transformation and removal during coal partial gasification and combustion was accomplished in a 1 MW poly-generation system. Air gasification was adopted in the system. The effects of rising temperature on various components are different i.e. formation of CO and H 2 S are enhanced while H 2 , CO 2 and hydrocarbons are reduced. Limestone catalysis contributes to increase all the components release mentioned above but H 2 S. At 900-950°C, promoting temperature may bring more contribution than increasing limestone in a certain extent. It is hard to study the reactions of sulfur release and transformation quantitatively in such conditions that materials experience respectively gasification and combustion in a poly-generation system.

Experiment of H2S Evolution during Coal Pyrolysis in Fluidized Bed

A bench-scale fluidized bed reactor is used to investigate H 2 S evolution and analyze various factors influencing sulfur distribution in gas and semi-coke during coal pyrolysis. The tests results show rising temperature increases the amount of H 2 S evolution and partial pressure of hydrogen enhances hydrogen sulfide release during coal decompose at 800-950°C. While apart from other researches results, effect occurs obviously on H 2 S emission at 10 percent of hydrogen concentration, and the effect begins to decrease with H 2 concentration rise even to 55 percent. The partial pressure of hydrogen not only enhances directly on formation of H 2 S, some reactions of H 2 with other gaseous sulfur probably may take effects.