众志成城——太原煤炭气化总公司嘉乐泉煤矿透水抢险恢复生产纪实

1996年8月9日晚12时30分,古交太原煤炭气化总公司嘉乐泉煤矿上空的广播声打破了山野的寂静,把人们从梦中惊醒:“井下黄泥水突涌,水位猛涨,漏水点在嘴头沟……”,广播喇叭的声音在电闪雷鸣中重复着。人们纷纷从矿上的四面八方不约而同地冒着大雨聚集到了调度室。不到20分钟,调度室已挤满了自愿参战抢险的矿领导、中层干部和普通工人及家属。

KOH活化法制备气化稻壳活性炭及其吸附性能

以气化稻壳炭(GRHC)为原料,KOH为活化剂制备活性炭,研究了不同活化温度和碱炭比对活性炭得率、比表面积、孔径分布以及碘值的影响。利用全自动气体吸附分析仪、X射线衍射仪、傅里叶变换红外光谱仪、扫描电镜等仪器对活性炭的理化性质进行表征,并通过吸附等温线、吸附动力学探讨其对甲基橙的吸附机制。结果表明:活化时间为1 h时,随着活化温度和碱炭比的增加,活性炭得率逐渐下降,比表面积和碘吸附值呈先增加后减少的趋势;气化稻壳炭制备活性炭的最佳工艺为碱炭比2∶1、活化温度800℃、活化时间1 h,此条件下制备的活性炭得率41.73%、比表面积1829.09 m^2/g,总孔容1.007 cm^3/g、碘吸附值1984.85 mg/g、甲基橙饱和吸附量为217.87 mg/g。气化稻壳活性炭对甲基橙的吸附过程与Langmuir和Freundlich模型相关性都良好(R2>0.99),吸附动力学更加符合准二级动力学模型。

重油气化干法回收炭黑的应用试验

我厂自七十年代初以来,对重油气化炭黑(以下简称气化炭黑)的回收利用,进行了大量的研究工作。在炭黑回收方面,取得了干法回收气化炭黑的研究成果。该项技术已转让给湖北省宜城县化肥厂,该厂自1987年底建成投产以来,系统运行正常,各项工艺指标均达到要求,过滤后的水可返回系统循环使用,滤饼含水份在85%以下,干燥后的炭黑含水份在2%左右。所以。

钙催化活化制备活性炭的研究进展

介绍了采用钙催化物理活化制备活性炭的机理,对水蒸气和二氧化碳在钙催化物理活化中所起到的作用进行了介绍并进行了比较。随后介绍了钙催化剂的热力学和分散性的研究,以及物理活化制备活性炭的应用。

一种新型粉状活性炭吸附剂

本文从孔隙结构和性能的角度介绍了开发重油气化副产炭黑作为一种新型活性炭吸附剂的概况,并将传统活性炭和新型活性炭进行了比较,值得进一步开发应用。

Microstructures and formation mechanism of headstand pyrocarbon cones developed by electromagnetic-field-assisted CVD

Novel headstand pyrocarbon cones （HPCs） with hollow structure were developed on the surfaces of pyrocarbon layers of the carbon/carbon （C/C） composites at 650-750 °C by the electromagnetic-field-assisted chemical vapor deposition in the absence of catalysts. The fine microstructures of the HPCs were characterized by high-resolution transmission electron microscopy. The results show that the textural features of the HPCs directly transfer from turbostratic structure in roots to a well-ordered high texture in stems. And the degree of high texture ordering decreases gradually from the stem to the tail of the HPCs. The formation mechanism of the HPCs was inferred as the comprehensive effect of polarization induction on electromagnetic fields and particle-filler property under disruptive discharge.

B型超声诊断胆囊内多发性胆固醇息肉1例

患者 男 42岁,于91年9月无明显诱因,出现右上腹进食后不适,伴右肩背困乏、恶心、反酸、呕吐、厌油腻食无发热、寒战、黄疸,近六个月症状明显入院。 体查:T:36℃。P:65次/分,R:20次/分,BP:16/10kpa,腹平软,右下腹压痛可疑,肝脾肋下未触及,巩膜及皮肤无黄染,全身浅表淋巴结未触及。化验:ALT:20单位,TTT:3单位,HB_SAG:阴性,总胆红素:12.3umol/L。

Groundwater Pollution from Underground Coal Gasification

In situ coal gasification poses a potential environmental risk to groundwater pollution although it depends mainly on local hydrogeological conditions. In our investigation,the possible processes of groundwater pollution origi-nating from underground coal gasification (UCG) were analyzed. Typical pollutants were identified and pollution con-trol measures are proposed. Groundwater pollution is caused by the diffusion and penetration of contaminants generated by underground gasification processes towards surrounding strata and the possible leaching of underground residue by natural groundwater flow after gasification. Typical organic pollutants include phenols,benzene,minor components such as PAHs and heterocyclics. Inorganic pollutants involve cations and anions. The natural groundwater flow after gasification through the seam is attributable to the migration of contaminants,which can be predicted by mathematical modeling. The extent and concentration of the groundwater pollution plume depend primarily on groundwater flow ve-locity,the degree of dispersion and the adsorption and reactions of the various contaminants. The adsorption function of coal and surrounding strata make a big contribution to the decrease of the contaminants over time and with the distance from the burn cavity. Possible pollution control measures regarding UCG include identifying a permanently,unsuitable zone,setting a hydraulic barrier and pumping contaminated water out for surface disposal. Mitigation measures during gasification processes and groundwater remediation after gasification are also proposed.

Investigation on the catalytic effects of AAEM during steam gasification and the resultant char reactivity in oxygen using Shengli lignite at different forms

The purpose of this study is to investigate the catalytic effects of alkali and alkaline earth metallic species （AAEM） on char conversion during the gasification in steam and the changes in ex-situ char reactivity in oxygen after the gasification in steam using different forms （i.e. H-form, Na-form） of Shengli brown coal. The surface area, AAEM concentration and carbon crystallite of chars were obtained to understand the change in char reactivity. It was found that not only Na concentration and carbon structure were the main factors governing the char reactivity in the atmosphere of steam and oxygen, but also they interacted each other. The presence of Na could facilitate the formation of disordering carbon structure in char, and the amorphous carbon structure would in turn affect the distribution of Na and thus its catalytic performance. The surface area and pore volume had very little relationship with the char＇s reactivity. Addi- tionally, the morphology of chars from different forms of coals were observed using scanning electron microscope （SEM）.

A remining technology of underground coal gasification at Zhongliangshan Coal Mine

The field trail used a mixture of steam and air with various levels of oxygen en- richment.Steady conditions were achieved in the field trail which produced high quality hydrogen-enriched syngas.To understand and optimize the UCG process,a simplified heat and mass transfer model was presented,providing a predictive tool for temperature and the major constituents of the syngas production.The model is compared with the field trail measurements for air and two levels of oxygen enrichment,showing reasonable agreement for the channel temperature and product syngas concentration profile.

An analysis of new generation coal gasification projects

The global trends of increasing oil and gas costs have compelled coal possessing countries to start long term underground coal gasification （UCG） projects. These enhance national energy security and are among the cleanest, ecologically safest coal utilization technologies. This paper delineates the major characteristics of such technologies and analyzes technical solutions. Highlighting the desire to develop large scale industrial UCG plants, pilot level projects are presented using a new UCG method developed in Russia by Joint Stock Company Gazprom Promgaz. This method is distinct for its high controllability, stability, and energy efficiency. New, efficient technical solutions have been developed over the last 10-15 years and are patented in Russia. They guarantee controllability and stability of UCG gas produc- tion. Over one hundred iniection and gas production wells have been operated simultaneously.

A contrast study on different gasifying agents of underground coal gasification at Huating Coal Mine

To optimize the technological parameter of underground coal gasification （UCG）, the experimental results of air gasification, air-steam gasification, oxygen-enrichment steam gasification, pure oxygen steam gasification and two-stage gasification were studied contrastively based on field trial at the Huating UCG project. The results indicate that the average low heat value of gas from air experiment is the lowest （4.1 MJ/Nm3） and the water gas from two-stage gasification experiment is the highest （10.72 MJ/Nm3）. The gas productivity of air gasification is the highest and the pure oxygen steam gasification is the lowest. The gasification efficiency of air gasification, air-steam gasification, oxygen-enriched steam gasification, pure oxygen steam gasification and two-stage gasification is listed in ascending order, ranging from 69.88% to 84.81%. Described a contract study on results of a field test using steam and various levels of oxygen enrichment of 21%, 32%, 42% and 100%. The results show that, with the increasing of O2 content in gasifying agents, the gas caloricity rises, and the optimal O2 concentration range to increase the gas caloricity is 30%-40%. Meanwhile, the consumption of O2 and steam increase, and the air consumption and steam decomposition efficiency fall.

Method of oxygen-enriched two-stage underground coal gasification

Two-stage underground coal gasification was studied to improve the caloric value of the syngas and to extend gas production times.A model test using the oxygen-enriched two-stage coal gasification method was carried out.The composition of the gas produced,the time ratio of the two stages,and the role of the temperature field were analysed.The results show that oxygen-enriched two-stage gasification shortens the time of the first stage and prolongs the time of the second stage.Feed oxygen concentrations of 30%, 35%,40%,45%.60%,or 80%gave time ratios（first stage to second stage） of 1：0.12,1：0.21.1：0.51,1：0.64, 1：0.90.and 1：4.0 respectively.Cooling rates of the temperature field after steam injection decreased with time from about 19.1-27.4℃/min to 2.3-6.8℃/min.But this rate increased with increasing oxygen concentrations in the first stage.The caloric value of the syngas improves with increased oxygen concentration in the first stage.Injection of 80%oxygen-enriched air gave gas with the highest caloric value and also gave the longest production time.The caloric value of the gas obtained from the oxygenenriched two-stage gasification method lies in the range from 5.31 MJ/Nm^3 to 10.54 MJ/Nm^3.

Enhanced-hydrogen gas production through underground gasification of lignite

Underground coal gasification is one of the clean technologies of in-situ coal utilization.Hydrogen production from underground gasification of lignite was investigated in this study based on simulation experiments.Pyrolysis of lignite, gasification activity, oxygen-steam gasification and the effect of groundwater influx were studied.As well, the advantages of lignite for stable underground gasification were analyzed.The results indicate that lignite has a high activity for gasification.Coal pyrolysis is an important source of hydrogen emission.Under special heating conditions, hydrogen is released from coal seams at temperatures above 350 °C and reaches its maximum value between 725 and 825 °C.Gas with a hydrogen concentration of 40% to 50% can be continuously obtained by oxygen-steam injection at an optimum ratio of steam to oxygen, while lignite properties will ensure stable gasification.Groundwater influx can be utilized for hydrogen preparation under certain geological conditions through pressure control.Therefore, enhanced-hydrogen gas production through underground gasification of lignite has experimentally been proved.

Changes in char reactivity due to char-oxygen and char-steam reactions using Victorian brown coal in a fixed-bed reactor

This study was to examine the influence of reactions of char–O2and char–steam on the char reactivity evolution.A newly-designed fixed-bed reactor was used to conduct gasification experiments using Victorian brown coal at800 °C. The chars prepared from the gasification experiments were then collected and subjected to reactivity characterisation(ex-situ reactivity) using TGA(thermogravimetric analyser) in air. The results indicate that the char reactivity from TGA was generally high when the char experienced intensive gasification reactions in 0.3%O2in the fixed-bed reactor. The addition of steam into the gasification not only enhanced the char conversion significantly but also reduced the char reactivity dramatically. The curve shapes of the char reactivity with involvement of steam were very different from that with O2 gasification, implying the importance of gasifying agents to char properties.

Effect of operating parameters on coal gasification

Coal combustion and gasification are the processes to utilize coal for production of electricity and many other applications. Global energy demand is increasing day by day. Coal is an abundant source of energy but not a reliable source as it results into high CO2 emissions. Energy industries are expected to decrease the CO2 emission to prevent global warming. Coal gasification is a process that reduces the CO2 emission and emerges as a clean coal technology. Coal gasification process is regulated by several operating parameters. A Number of investigations have been carried out in this direction. A critical review of the work done by several researchers in the field of coal gasification has been compiled in this paper. The effect of several operating parameters such as coal rank, temperature, pressure, porosity, reaction time and catalyst on gasification has been presented here.

Control of combustion area using electrical resistivity method for underground coal gasification

Underground coal gasification （UCG） is one of the clean technologies to collect heat energy and gases （hydrogen, methane, etc.） in an underground coal seam. It is necessary to further developing environ- mentally friendly UCG system construction. One of the most important UCG＇s problems is underground control of combustion area for efficient gas production, estimation of subsidence and gas leakage to the surface. For this objective, laboratory experiments were conducted according to the UCG model to iden- ti[y the process of combustion cavity development by monitoring the electrical resistivity activity on the coal samples to setup fundamental data for the technology engineering to evaluate combustion area. While burning coal specimens, that had been sampled from various coal deposits, electrical resistivity was monitored. Symmetric four electrodes system （ABMN） of direct and low-frequency current electric resistance method was used for laboratory resistivity measurement of rock samples. Made research and the results suggest that front-end of electro conductivity activity during heating and combusting of coal specimen depended on heating temperature. Combusting coal electro conductivity has compli- cated multistage type of change. Electrical resistivity method is expected to be a useful geophysical tool to for evaluation of combustion volume and its migration in the coal seam.

Characterization of Catalytic Cracking Catalysts Regenerated by Gasifying Deposited Coke

Partially or fully regenerated catalytic cracking catalysts were prepared by gasifying the coke deposited on coked catalysts with a gaseous mixture of oxygen and steam in a fixed fluidized bed （FFB）. The resultant samples were characterized by different methods such as the nitrogen adsorption-desorption analysis, the X-ray diffractometry, the infrared spectroscopy, the ammonia temperature-programmed desorption （NH3-TPD） method, the X-ray fluorescence （XRF） analysis, the transmission electron microscopy and energy dispersive X-ray spectroscopy （TEM-EDX）, the thermal-gravimetric analysis （TGA） and the differential thermal analysis （DTA）. The results showed that exposure of catalyst to steam for about 10 minutes at temperature ≥ 800 ℃ could not cause too much destruction of the catalysts, and an amount of coke equating to about 0.27 m% was enough to block approximately all acid sites in micro-pores of the zeolite catalyst. Coke didn＇t show equal reactivity during coke burning-off that could be accelerated by the catalytic action of nearby metal atoms. However, when the carbon content on the catalyst reached about 2.44 m%, the catalytic action of metals on the catalyst was not evident. The severe thermal and hydrothermal environment during exposure of the catalyst to steam at a temperature in the range of about 860--880 ℃ for 30 minutes could lead to collapse of pore structure and transformation of crystal phase and consequently decrease of the surface area and acid amount on the catalyst.

Temperature field distribution of burnt surrounding rock in UCG stope

In order to study temperature field distribution in burnt surrounding rock and to determine ranges of burnt surrounding rock, coal-wall coking cycle and heat influence in the underground coal gasification(UCG) stope, based on the Laplace transform and inversion formula, we studied the temperature analytical solution of one-dimensional unsteady heat conduction for multi-layer overlying strata under the first and the forth kinds of boundary conditions, and we also carried out a numerical simulation of twodimensional unsteady heat conduction by the COMSOL multiphysics. The results show that when the boundary temperature of surrounding rock has a linear decrease because of a directional movement of heat source in the UCG flame working face, the temperature in surrounding rock increases first and then decreases with time, the peak of temperature curve decreases gradually and its position moves inside surrounding rock from the boundary. In the surrounding rock of UCG stope, there is an envelope curve of temperature curve clusters. We analyzed the influence of thermophysical parameters on envelope curves and put forward to take envelope curve as the calculation basis for ranges of burnt surrounding rock, coal-wall coking cycle and heat influence. Finally, the concrete numerical values are given by determining those judgement standards and temperature thresholds, which basically tally with the field geophysical prospecting results.

Prediction of cavity growth rate during underground coal gasification using multiple regression analysis

During underground coal gasification （UCG）, whereby coal is converted to syngas in situ, a cavity is formed in the coal seam. The cavity growth rate （CGR） or the moving rate of the gasification face is affected by controllable （operation pressure, gasification time, geometry of UCG panel） and uncontrollable （coal seam properties） factors. The CGR is usually predicted by mathematical models and laboratory experiments, which are time consuming, cumbersome and expensive. In this paper, a new simple model for CGR is developed using non-linear regression analysis, based on data from 1 l UCG field trials. The empirical model compares satisfactorily with Perkins model and can reliably predict CGR.