新河烟煤地下气化模型

为了探索烟煤地下气化过程的基本规律,为新河“煤炭地下气化发电示范工程”制定合理的工艺参数,测定了新河烟煤反应活性,并进行了富氧-水蒸气地下气化模型实验;研究了不同工艺条件下,出口煤气有效组分含量、热值的变化规律.实验结果表明,气化初期因煤层中含水,纯氧直接气化,可获得合格的煤气;在保持汽氧比在1.5∶1～2∶1之间时,新河烟煤采用富氧-水蒸气正向供风、辅助孔供风和反向供风连续气化可获得有效气体组分在70%、热值在10 MJ·m^-3左右的煤气;新河烟煤的产气率平均为1950 m³·t^-1,煤层气化率可达到74.6%.     

鹤壁烟煤地下气化模型试验研究

通过自行研制的煤炭地下气化模拟试验系统,采用富氧空气/水蒸气两阶段气化工艺,完成了鹤壁煤的地下气化模型试验。文章就试验不同阶段的煤气组成、热值变化和气化过程的稳定性特征进行分析,结果如下:鹤壁煤地下气化水煤气平均热值达11.85 MJ/m3,空气煤气热值为4—6 MJ/m3,水煤气中氢气最高体积分数超过80%,相应的煤气热值达到12.91 MJ/m3;适当增大鼓风量有利于高温温度场的快速建立与恢复,试验条件下,最佳鼓风量为20 m3/h,最佳蒸汽流量为0.26 m3/h。试验为煤炭地下气化制氢提供了有力依据。     

BGL煤气化动力学模型构建与验证

在目前节能减排需求下,针对BGL煤气化技术的装备研发与性能优化正越来越受重视。BGL煤气化性能分析和预测仍主要采用平衡模型和整体反应模型,但在预测准确度上仍显不足。本文针对BGL煤气化过程,改进缩核模型,将碳核细分为界面反应区和内部反应区,改善了模型适应性。煤热解气最终产率和组成预测采用装置标定数据和热解数据相结合预测,简化了迭代寻优过程。煤热解层高度预测采用通用热解动力学模型,计算值为1.22 m,较符合实际情况。本文构建的BGL煤气化一维模型计算结果表明：粗煤气组成计算值与标定校核值很接近;烧嘴邻近区气相温度2012℃,颗粒相温度1978℃,与经验估测值一致;粗煤气出口温度549℃,实测粗煤气出口温度约538℃。     

BGL煤气化动力学模型构建与验证

在目前节能减排需求下,针对BGL煤气化技术的装备研发与性能优化正越来越受重视。BGL煤气化性能分析和预测仍主要采用平衡模型和整体反应模型,但在预测准确度上仍显不足。本文针对BGL煤气化过程,改进缩核模型,将碳核细分为界面反应区和内部反应区,改善了模型适应性。煤热解气最终产率和组成预测采用装置标定数据和热解数据相结合预测,简化了迭代寻优过程。煤热解层高度预测采用通用热解动力学模型,计算值为1.22 m,较符合实际情况。本文构建的BGL煤气化一维模型计算结果表明：粗煤气组成计算值与标定校核值很接近;烧嘴邻近区气相温度2012℃,颗粒相温度1978℃,与经验估测值一致;粗煤气出口温度549℃,实测粗煤气出口温度约538℃。     

Gasification of lignite and hard coal with air and oxygen enriched air in a pilot scale ex situ reactor for underground gasification

The main goal of the study presented in the paper was an experimental comparison of the underground lignite and hard coal seams air gasification simulated in the ex situ reactor. In the study lignite and hard coal were gasified with oxygen, air and oxygen enriched air as gasification agents in the 50- and 30-h experiments, respectively, with an intrinsic coal and strata moisture content as a steam source. Application of air as a sole gasification agent was problematic for a resulting rapid decrease in temperatures, deterioration of gas quality and, finally, cessation of gasification reactions. Use of oxygen/air mixture of an optimum ratio led to valuable gas production. In lignite seam gasification with oxygen/air (of 4:2 volume ratio) the average H₂ and CO contents in product gas were 23.1 vol.% and 6.3 vol.%, respectively, and the calorific value was 4.18 MJ/m³, whereas in hard coal gasification with the oxygen/air ratio (of 2:3 volume ratio) the average H₂ and CO contents in produced gas were 18.7 vol.% and 17.3 vol.%, respectively, and product gas calorific value equaled 5.74 MJ/m³.     

Numerical simulation of underground coal gasification using the CRIP method

A three‐dimensional simulation of the Underground coal gasification (UCG) process is studied in terms of the heat and mass transport phenomena and chemical kinetics in a coal seam during coal combustion by applying the controlled retracting injection point technique. The STARS module of the Computer Modelling Group software is used in this study. The gas species flow rate, cavity shapes, and temperature profile in the coal seam during gasification are investigated. The main motivation behind this study is to provide a simulation methodology by using a comprehensive porous media flow approach to understand the critical aspects of the UCG process.     

高温煤焦气化反应的Langmuir-Hinshelwood动力学模型

应用基于吸附和脱附原理的Langmuir-Hinshelwood （L-H） 动力学模型来描述煤焦在H₂O和CO₂混合气氛下的气化反应时,存在单独活性位和相同活性位两个相互矛盾的假设。在管式炉实验装置内考察了在不同气化温度和气化剂分压的条件下,内蒙煤焦（NMJ）与H₂O和CO₂的气化反应特性,获得了NMJ-H₂O 和NMJ-CO₂反应的L-H动力学模型,同时考察了H₂、CO对煤焦气化反应的抑制作用,并探究了NMJ在H₂O和CO₂混合气氛下的气化反应机理。研究结果表明：NMJ-H₂O以及NMJ-CO₂反应的活化能分别为214.78 kJ·mol^-1和145.96 kJ·mol^-1。H₂对NMJ-H₂O以及CO对NMJ-CO₂的反应存在明显的抑制作用,且CO的抑制作用随反应温度的降低而愈加明显。基于L-H动力学模型计算得到的反应速率曲线与实验结果十分吻合。对于NMJ在H₂O和CO₂混合气氛下的气化反应,基于相同活性位假设的L-H模型的反应速率预测值与实验结果吻合,更加适用于NMJ在混合气氛下的气化反应机理。     

Large-scale laboratory study on the evolution law of temperature fields in the context of underground coal gasification

This article presents the evolution law of temperature fields in a large-scale laboratory Underground Coal Gasification reactions using Ulanqab lignite under actual conditions. The results show that in the cultivation stage of oxidation zone, the main direction of the temperature field expansion is consistent with the crack direction of the coal seam. In the gasification stabilization stage, the main direction of the temperature field expansion is along the channel. The temperature of the coal seam and the overlying rock mass at its interface with the furnace directly above the gasification channel is equivalent to that of the coal seam temperature, and this temperature is much greater than the temperatures observed near both side walls of the gasification channel at the interface. However, temperatures perpendicular to the axis of the gasification channel are similar at a vertical distance of 40 cm away from the interface. The temperature distributions indicate that the transmission of heat through the overlying rock mass is more rapid in the vertical direction than in the horizontal direction. Moreover, some degree of thermal dispersion is observed in the vertical direction near the outlet. The thermal dispersion coefficient is 0.72 and dispersion angle γ is 78.7°.     

Online temperature estimation of Shell coal gasification process based on extended Kalman filter

Obtaining the temperature inside the gasifier of a Shell coal gasification process(SCGP) in real-time is very important for safe process operation. However, this temperature cannot be measured directly due to the harsh operating condition. Estimating this temperature using the extended Kalman filter(EKF)based on a simplified mechanistic model is proposed in this paper. The gasifier is partitioned into three zones. The quench pipe and the transfer duct are seen as two additional zones. A simplifi...     

Shell干煤粉气化的模拟与分析

为研究Shell干煤粉气化特点,利用Aspen Plus模拟软件为工具,建立Shell气化炉模型。通过模拟Shell干煤粉气化的压力、氧煤比、蒸汽煤比对气化过程的影响,结果表明,增加压力能够使合成气中的甲烷含量升高,氧煤比和蒸汽煤比对气化温度和合成气组成有重要影响。气化温度随氧煤比的增加而升高,有效气体摩尔分数先增加后减少,蒸汽煤比可以调节气化反应温度。对屯留煤来说,Shell煤气化的最佳氧煤比为0.74~0.80kg/kg,反应温度为1475.6~1580.17℃,最佳蒸汽煤比为0.09~0.13kg/kg,相对应的反应温度为1630.60~1532.11℃。     

Effect of catalyst addition on gasification reactivity of HyperCoal and coal with steam at 775-700 °C

HyperCoal is a clean coal with ash content <0.05 wt%. HyperCoal was prepared from a bituminous coal by solvent extraction method with an extraction yield of 66.7%. Effect of K₂CO₃ loading and temperature on steam gasification rate of HyperCoal and parent raw coal was investigated. Experiments were carried out at 775 and 700 °C for both HyperCoal and coal with 0-25% catalyst loading. Gasification rates increased with increased catalyst loading and reached a value above which rates did not change with catalyst loading. The catalyst loadings were 6% for HyperCoal and 20% for coal. The difference is most likely due to the difference in ash content of HyperCoal and coal and not due to the effect of H₂ inhibition on the rate. In the presence of catalyst effect of temperature was only on gasification rate and total gas yield and gas composition were unaffected.     

褐煤焦中的矿物质对气化动力学的影响

利用热重分析仪研究了水蒸气气氛下霍林河褐煤焦和脱灰褐煤焦的气化动力学特性,并考察了脱灰前后褐煤焦孔结构的变化。结果表明:褐煤原焦气化反应速率在反应初始阶段(转化率30%)高于脱灰褐煤焦,但在反应后期低于脱灰焦,这是因为煤焦中灰分的脱除一方面去除了矿物质的催化作用,另一方面增大了煤焦的孔径,因而减小了气化剂的扩散阻力。灰层扩散控制的缩核模型可以描述褐煤焦水蒸气气化过程,而脱灰后褐煤焦水蒸气气化过程用均相模型可以很好地表示。     

Design of laboratory reactors for the measurement of catalytic carbon and coal gasification kinetics

A great deal of conflicting experimental kinetics results have appeared for catalytic carbon and coal gasification by water and carbon dioxide. The reason for this can in large part be attributed to inhibition of these reactions by their products and the influence of this product inhibition on the measured kinetics in different laboratory reactor systems. The measurement of differential rates and the determination of true kinetic values requires the use of feed streams with an excess of water and hydrogen for the catalytic CH₂O reaction and an excess of carbon dioxide and carbon monoxide for the catalytic CCO₂ reaction. Recommendations are put forward for the design of laboratory reactors for the measurement of catalytic carbon and coal gasification kinetics.     

The kinetic study of catalytic low-rank coal gasification under CO2 atmosphere using MVRM

In this study, we carried out a kinetic investigation and analysis of the syngas produced by low-rank coal gasification. We conducted a proximate and ultimate analysis of six types of coals in order to measure the amount of sulfur and ash. The coal was then analyzed using a thermo gravimetric analyzer (TGA) to select a suitable sample. The selected Samhwa coal sample was mixed with catalysts. Samples mixed with catalysts were used to determine the activation energy under CO₂ atmosphere using the modified volume reaction model (MVRM). An analysis of the resulting syngas was performed using gas chromatography (GC).     

煤化工多联产系统中的煤气化过程模拟

德士古水煤浆气化技术采用气流床气化炉,对煤种的兼容性较好,其清洁、高效代表着当今煤气化技术的发展潮流。采用AspenPlus软件对德士古煤气化生产过程进行模拟,包括水煤浆制备,气化反应,CO变换,低温甲醇洗等工段,详细介绍了模拟过程,并求解气化炉在工况下的出口煤气成分。     

废弃矿井地下气化大直径排气钻孔过老空区技术实践

在当今全球倡导低碳经济的环境下,利用煤炭地下气化技术对已闭坑矿井遗留的煤炭资源进行二次回采在全球多地已取得成效。煤炭地下气化施工过程中存在大直径排气钻孔经过采空区时很难施工的难题,很大程度上对工程进度和安全生产都造成影响。基于此,工程技术人员经过合理论证及施工组织,采取水泥浆堵漏,充填裂隙,多次钻进、扫孔、纠斜、规则孔径等方法措施,成功解决该项难题,取得了很好的经济效益和社会效益。     

煤地下气化低效的化学反应工程根源：滞留层及通道中的传质与反应

煤地下气化技术历经国内外一百多年的实验室研究和大量现场试验仍然存在产率低等关键问题。虽然一些文献认为该技术是未来煤炭利用技术的发展方向,但其至今仍未实现工业应用的现象说明其本身存在尚未被充分关注的关键科学（卡脖子）问题。本文从化学反应工程基本原理出发分析该技术涉及的关键传质与反应过程,并与现代大型地上煤气化技术对比,探讨其工业应用技术挑战的科学根源。     

首套GSP干煤粉气化的模拟与分析

为研究GSP干煤粉气化反应特点,以Aspen Plus模拟软件为工具,选择Gibbs自由能最小化建立气化炉模型。通过模拟GSP干煤粉气化的压力、氧煤比、蒸汽煤比及不同输送载体对气化过程的影响,结果表明:压力增加可使粗煤气中甲烷含量增加;氧煤比和蒸汽煤比影响着气化温度和有效气组成;输送载体切换为二氧化碳后可使有效气增加2%。该模拟计算对于GSP干煤粉气化工业操作有一定借鉴意义。