哈密煤温和液化固体产物的理化性质及热解特性

为了合理利用哈密煤温和液化固体产物(MLS),对MLS的理化性质进行了考察,并利用热重分析技术研究了MLS及其萃取组分的热解特性和各萃取组分在热解过程中的相互作用。结果表明,相比于神华煤直接液化残渣,MLS中重质油含量较高(HS,36%),沥青烯(A,13%)、前沥青烯(PA,9%)含量较低。GC-MS结果表明,HS中烷烃含量较高(41.8%)。红外结果表明,HS中含较多烷烃侧链和取代官能团,A、PA次之,而四氢呋喃不溶物(THFIS)中基本不存在,表明其芳香性较高。MLS中的矿物质主要有液化过程生成的CaCO_3、原煤中的惰性组分SiO_2、NaCl、Al_2O_3·2SiO_2·2H_2O和残留的催化剂转化产物Fe_(1-x)S。热重结果表明,MLS起始热解温度和最大失重峰温均偏低,950℃失重率较高(54%),说明其热解活性较高。MLS各萃取组分在热解过程中存在正负两种相互作用,且与MLS中HS含量有关:当HS含量较高时,HS为MLS热解过程提供小分子自由基以促进挥发分逸出;当脱除部分HS或将HS全部脱除后,MLS各萃取组分中大分子自由基之间相互结合而抑制挥发分逸出。

哈密煤温和液化固体产物热解过程中硫的变迁规律

利用固定床反应器研究了哈密煤温和液化固体产物(MLS)在热解过程中含硫气体的释放规律以及不同形态硫的变迁规律,并分析了矿物质对硫变迁规律的影响。结果表明,在实验考察的条件范围内,MLS热解过程中大部分的硫残留在半焦中,仅有不到10%的硫迁移到焦油中或转化为含硫气体逸出。热解生成的含硫气体以H 2S为主,当热解温度为400℃时H 2S的逸出速率达到最大。通过改进方法测定了MLS及其热解半焦中各种形态硫的含量,发现MLS热解过程中以硫化物硫和有机硫的分解和转化为主。随着热解温度的升高,MLS中有机硫逐渐分解并以含硫气体的形式逸出;当热解温度低于600℃时,MLS中硫化物硫逐渐转化为含硫气体、有机硫和少量的黄铁矿硫;当热解温度高于600℃时,MLS中碱性矿物质吸收气相中的H 2S转化为硫化物硫,硫化物硫缓慢增加。醋酸酸洗可以保留MLS中大部分的硫化物硫,且酸洗后MLS热解生成的H 2S逸出速率增大,峰温向低温方向移动;当热解温度高于600℃时,有机硫和硫化物硫的脱硫反应速率降低,并且MLS中的碱性矿物质与H 2S反应生成金属硫化物,导致H 2S逸出速率明显降低。

中国煤层气分布特征及高产富集因素

本文预测了中国煤层气远景资源量约25-35万亿m^3。，分布于39个含煤盆地或68个聚煤单元的八套含煤层系中；又探讨了煤层气不同于常规石油天然气或固体煤的勘探特性；划分了压力封闭气藏、承压水封堵气藏、顶板水网络状微渗滤封堵气藏和构造圈闭气藏四大类煤层气气藏类型；分析了煤层气高产富集的基本条件，特别是从煤的区域热变质、区域压实变质和构造应力变质上，论述了对煤层气高产富集的控制作用，进一步指出了热变质压力封闭及承压水封堵区、应力一热变质承压水封堵区和轻压实变质、后期抬升的承压水封堵区是煤层气高产富集最有利的地区。

道路基层材料制备中工业固体废物的应用

在道路基层施工中,对工业固体废物进行资源化再利用对于构建我国绿色循环经济体系意义重大。文章重点研究了能源固体废物、冶金固体废物、采矿固体废物、化工固体废物在道路基层材料制备中的应用。研究表明,通过调整煤类固体废物(如煤矸石和粉煤灰)原料比例或添加特定材料,可以改善道路基层材料的力学性能、抗裂性和耐久性能;添加冶金渣(如赤泥和钢渣)的路基材料展现出了良好的强度和稳定性,且具有更优的抗冻性能;尾矿可替代砂石骨料应用于路基材料中,起到骨架和支撑的作用,也可与其他材料混合反应,提高材料的力学性能和环境友好性。此外,工业副产石膏(如磷石膏和钛石膏)也可以替代传统材料,与粉煤灰和石灰等组合制备道路基层材料,且表现出较好的稳定性和力学性能。

浅议煤变油

介绍了把固体煤转化成液体油的历史与现状,以及煤变油的基本工艺。并对这项技术研发成功的重大意义,经济和社会效益,发展前景进行了简要评述。

煤热解-化学链气化耦合工艺流程模拟

为实现煤的清洁高效利用,提出一种煤固体热载体热解-化学链气化耦合工艺。利用流程模拟软件Aspen Plus建立了该耦合系统的工艺流程模型,主要包括煤干燥单元,煤热解单元,空气反应器和燃料反应器。模拟结果表明:通过将煤热解单元产生的酚废水作为燃料反应器的气化剂,可有效减少载氧体循环量和废水排放量。在热解温度500℃、半焦气化温度800℃和载氧体氧化温度1000℃条件下,载氧体的循环比为1.32,焦油分析基收率为6.6%,耦合系统的能量利用效率为43.12%,其中煤干燥单元能耗和煤热解单元能耗分别占总能耗的32.68%和33.81%,是导致系统辅助能耗大的主要原因。当进料量(100kg/h)和工艺条件相同的情况下,与单独的煤热解和煤基化学链气化技术相比,该耦合工艺在热力学效率和对环境的友好方面都有一定优势。

测定煤的气体扩散特性的新技术

本文描述了采用瞬时流动机理测定煤-甲烷系统的扩散系数(D)的一项新技术,并且检验了这项技术对那些随着流量-压力和气体浓度连续变化而变化的系数的依赖性。尽管该技术的开发主要是针对煤层气储层和采空区中的煤,由于利用了逆扩散原理,它也可应用于在煤中注入了第二种气体的情况。结果表明,D值随着煤中甲烷平均浓度的降低而连续减小。D值的对数与压力大小成正比。D值的减小可能是由两个效应引起的。第一是流动机理有可能随着煤中甲烷浓度不断下降而变,甲烷浓度下降是由于煤中孔径变化造成的。另一个效应是由气体解吸引起的固体煤基质的体积应变,即所谓“收缩效应”。这种基质收缩可能导致孔径缩小,因而,D值减小。

煤炭液化技术还有待提升

黑色的固体煤能转化成清亮的液体汽油、柴油，外行人看了很神奇，产业界对些表示出浓厚的兴趣。

Subsidence prediction method based on equivalent mining height theory for solid backfilling mining

Based on the characteristics of strata movement of solid backfilling mining technology, the surface subsidence prediction method based on the equivalent mining height theory was proposed, and the parameters selection guideline of this method was also described. While comparing the parameters of caving mining with equivalent height, the subsidence efficient can be calculated according to the mining height and bulk factor of sagging zone and fracture zone, the tangent of main influence angle of solid backfilling mining is reduced by 0.2-0.5（while it cannot be less than 1.0）. For sake of safety, offset of the inflection point is set to zero, and other parameters, such as horizontal movement coefficient and main propagation angle are equal to the corresponding parameters of caving mining with equivalent height. In the last part, a case study of solid backfilling mining subsidence prediction was described. The results show the applicability of this method and the difference of the maximum subsidence point between the prediction and the observation is less than 5%.

Low Density Dry Coal Beneficiation Using an Air Dense Medium Fluidized Bed

For the production of low ash content clean coal, separation at low density is required for some raw coals.Based on analyzing the fluidizing characteristics of magnetic-pearls with a specific size clistribution and formation mechanism of a microbubble fluidized bed, optimal technological and operating parameters suitable for low density coal separation were determined. The experimental results show that an air dense medium fluidized bed with low den-sity can be formed using magnetic pearls as medium solids, which can efficiently beneficiate coal of 6-50 mm size with a probable error Ep value of 0.05 at a separating density of 1.44 g/cm^3.

Vertical transportation system of solid material for backfilling coal mining technology

For transportation of solid backfill material such as waste and fly ash from the surface to the bottom of the shaft in a fully mechanized backfilling coal backfilling coal mining technology, we developed a new vertical transportation system to transport this type of solid backfill material. Given the demands imposed on safely in feeding this material, we also investigated the structure and basic parameter of this system. For a mine in the Xingtai mining area the results show that: (1) a vertical transportation system should include three main parts, i.e., a feeding borehole, a maintenance chamber and a storage silo; (2) we determined that 486 mm is a suitable diameter for bore holes, the diameter of the storage silo is 6 m and its height 30 m in this vertical transportation system; (3) a conical buffer was developed to absorb the impact during the feeding process. To ensure normal implementation of fully mechanized backfilling coal mining technology and the safety of underground personnel, we propose a series of security technologies for anti-blockage, storage silo cleaning, high pressure air release and aspiration. This vertical transporting system has been applied in one this particular mine, which has fed about 4 million tons solid material with a feeding depth of 350 m and safely exploited 3 million tons of coal.

Comparison between the new mechanistic and the chaos scale-up methods for gas-solid fluidized beds

The chaotic scale-up approach by matching the Kolmogorov entropy(E_K) proposed by Schouten et al.(1996) was assessed in two geometrically similar gas–solid fluidized bed columns of 0.14 and 0.44 m diameter.We used four conditions of our validated new mechanistic scale-up method based on matching the radial profiles of gas holdup where the local dimensionless hydrodynamic parameters were similar as measured by advanced measurement techniques.These experimental conditions were used to evaluate the validity of the chaotic scale-up method,which were selected based on our new mechanistic scale-up methodology.Pressure gauge transducer measurements at the wall and inside the bed at various local radial locations and at three axial heights were used to estimate KE.It was found that the experimental conditions with similar or close radial profiles of the Kolmogorov entropy and with similar or close radial profiles of the gas holdup achieve the similarity in local dimensionless hydrodynamic parameters,and vice versa.

Preparation of solid medium for use in separation with gas-solid fluidized beds

The highly-efficient dry separation technique using a gas-solid fluidized bed is very beneficial for increasing coal grade and optimizing the utilization of coal resources.The size distribution of the solid medium(e.g.,magnetite powder) used in this technique is one of key factors that influences fluidization and separation performance.It is,therefore,urgent to prepare medium in a way that operates at low cost and high efficiency.Grinding experiments were performed using a planetary ball mill equipped with a frequency converter.The effect of fed mass,rotation frequency of the mill,grinding time and the ball-size ratio on grinding performance was investigated.The grinding parameters were optimized by numerical calculations using Artificial Neural Network(ANN) in Matlab.A regression equation for predicting the yield of the desired product(i.e.,0.3～0.15 mm magnetite powder) is proposed.The maximum yield of 0.3～0.15 mm particles was 47.24%.This lays a foundation for the industrial-scale production of the solid medium required for separation with a magnetite-powder fluidized bed.

Physical properties of solid fuel briquettes from bituminous coal waste and biomass

Biomass and bituminous coal fines from four different coalfields were used to produce fuel briquettes. Two physical properties of briquettes, water resistance index and compressive strength were analyzed. The influence of type and quantity of biomass on physical properties was also studied. The results reveal that depending on the mineral content of the coal, the physical properties of the briquettes differ noticeably. The comparison of briquettes with and without biomass showed that the presence of the beet pulp increased CS in all types of coal samples. Samples containing beet pulp had better physical properties than sawdust. Mezino II coal briquettes had highest CS and WRI than the other ones. Calorific value of biomass/Mezino lI coal briquettes was lessened in comparison with raw coal, but it remained in an acceptable range.

Oxygen Gasification of Municipal Solid Waste in a Fixed-bed Gasifier

Four waste materials, paper, wood, textile and kitchen garbage, in municipal solid waste were gasified separately with oxygen in a fixed bed reactor. The yields of products char. tar and gas, the composition of gas components H2, CO, CO2 and CH4, and the lower heating value （LHV） were examined at temperatures between 700 and 900 ℃ and equivalence ratio （ER） between 0.14 and 0.32. Characteristics of gas evolution during gasification were inves- tigated. Results show that a higher temperature improves the formation of H2 and CO while lowers the yield of CO2 and CH4. The LHV of syngas increases with temperature and varies in the range of 6-10 MJ. m-3 reaching the maximum at 800 ℃ or above. As ER increases, both combustible gas component and LHV of syngas decrease while the yield of CO2 rises linearly. The appropriate ER for obtaining high quality gas is in the range of 0.18-0.23. Temperature and ER have significant effects on the product distribution. Higher temperature and ER are favorable for higher gas yield and lower yield of char and tar in the gasification of textile and kitchen garbage. At 800 ℃, the gas evolution may be divided into two regions. In the first region, the flow rate of gas increases and then de- creases ranidlv, while in the second reuion the flow rate decreases monotonically to lower level.

Influence of Negative Pressure Gradient on Pressure Distribution and Gas-Solid Flow Pattern of Solid Feed Systems

A series of experiments on a solid feed system was performed to investigate the effect of negative pressure gradient on the gas-solid flow pattern and hydrodynamic characteristics.Based on the non-fluidized gas-solid two phase flow and particulate mechanics in the standpipe,a method for predicting the pressure of the air passing through the recycle chamber and the pressure drop through the loop seal slit in these systems is also presented.The predicted pressure profile along the negative pressure gradient from the proposed model exhibits a good agreement with the experimental data.The experimental data show that the gas flow in the standpipe is always upward in the negative pressure gradients,while the direction ofthe superficial gas velocity through the recycle chamber of the loop seal does not affect the pressure drop in standpipe.It increases with an increasing negative pressure gradient.

Critical impeller speeds for a gas-inducing stirring tank loaded with solid particles

The influence of solid particles size,density and loading on the critical gas-inducing impeller speed was investigated in a gas–liquid–solid stirring tank equipped with a hollow Rushton impeller.Three types of solid particles,hollow glass beads with diameters of 300 μm,200 μm,100 μm,and 60 μm,silica gel and desalting resin,were used.It was found that the adding solid particles would change the critical impeller speed.For hollow glass beads and silica gel,whose relative densities were less than or equal to 1.5,the critical impeller speeds increased with the solid loading before reaching the maximum values,and then decreased to a value even lower than that without added solids.The size of the solids also had apparent influence on the critical impeller speed,and larger solid particles correspond to a smaller critical impeller speed.The experimental data also showed that the gasinducing was beneficial to the suspension of the solid particles.

Strata movement controlling effect of waste and fly ash backfillings in fully mechanized coal mining with backfilling face

A fully mechanized coal mining with backfilling (FMCMB) provides advantages of safety and efficiency for coal mining under buildings, railways, and water bodies. According to the field geological conditions, we analyzed the controlling effect of strata movement by the waste and fly ash backfilling in FMCMB face. Based on the key strata theory, we established the equivalent mining thickness model, and analyzed the action of the bulk factor of backfilling body to the equivalent mining thickness. In addition, we numerically simulated the controlling function of the strata movement by backfilling bodies with differ- ent strength. And the numerical simulation result show that the deformation of stratum and the subsi- dence of surface can be controlled by FMCMB. The result provides references to the effective execution of fully mechanized coal mining with solid waste backfilling in goaf.

System Validation Tests for an SOFC Power System at INER

This research presents the results of system validation tests for an SOFC power system. In the study, the system was heated up without electric device, i.e., the fuel providing the required thermal energy through an integrated BOP （balance of plant）. The ex-situ experiments, without an SOFC stack installed in the system, were fast conducted to investigate the operability of a BOP apparatus. It was found that the BOP possessed high conversion rates for both steam reforming and water gas shift reactions. The total fuel concentration of hydrogen and carbon monoxide from the reformer was around 91.2%. The system validation tests showed that, with the natural gas as fuel, the output power from the stack reached to 1,060 W, while the fuel utilization efficiency and electrical efficiency were 67.16% and 45.0%, respectively. A steady 600-hour system operation test was carried out at an average system temperature of 694℃. Of which, a 36-cell stack was employed for the test. Meanwhile, the current, voltage and output power were 26 A, 32.3 V and 840 W, respectively, and its electrical efficiency was around 33.4%.