气流床煤气化技术分析

阐述气流床煤气化工艺中,水煤浆加压工艺和干粉煤加压气化工艺的主要特点,详细分析GEGP煤气化炉、新型对置式对喷嘴气化炉、晋华炉、Shell气化炉、航天炉HT-L气化炉等煤气化技术的运行机理和工艺特点.对GEGP工艺、晋华炉工艺、航天炉工艺进行技术对比.提出根据原料煤特性、煤气化技术可靠性、项目投资、技术成熟度及总项目规...     

气流床煤气化工艺技术分析

气流床煤气化是我国煤高效洁净利用的关键技术.简要总结了气流床煤气化技术的基本特点和主要影响因素,着重介绍了具有代表性的气流床煤气化技术:壳牌(shell)煤气化技术、德士古水煤浆加压气化技术、GSP气流床气化技术、多喷嘴对置式水煤浆气化技术以及航天炉(HT-L)粉煤加压气化技术,讨论了各种技术各自的优势及存在的问题.     

气流床煤气化技术的现状及发展分析

研究当前气流床煤气化技术的现状及发展趋势.气流床煤气化技术在实际应用时具有很高的碳转化效率,是当前运行可靠的燃气与合成气的首选技术,结合气流床煤气化技术的特点和类型对气流床煤气化技术的典型工艺进行分析,并且对气流床煤气化技术的发展作出展望,以期切实促进国内气流床煤气化技术应用水平的提升和发展.     

当前主要气流床煤气化工艺技术分析

气流床煤气化是我国煤高效洁净利用的关键技术。本文总结了气流床煤气化技术的基本特点和主要影响因素,着重介绍了具有代表性的气流宋蟮苦气化技术：德士古水煤浆加压气化技术、壳牌删耻乾化技术、GSP气流床气化技术、多喷嘴对置式水煤浆气化技术以及航天炉（HT-L）粉煤加压气化技术,并讨论了各种技术各自的优势及存在的问题。     

气流床煤气化系统的热力学分析

在使用Aspen Plus对激冷型气流床煤气化系统进行模拟和优化的基础上,采用热力学分析方法,对气化系统进行了能量衡算和量衡算。计算结果表明,系统中损失最大的过程是化学能转变为物理能的过程。洗涤冷却室是损失最大的设备,损失占了总的21.2%;其次是气化炉气化室,占到了总的13.9%,气化室的损失主要发生在水的汽化等过程中,这一部分损失占气化过程损失的70%左右,而氧气加热至反应温度所带来的损失仅占30%左右。采用分析方法可以更准确地揭示系统中损失最大的环节和过程,为改进设备、节约能源提供目标和对策。     

干法进料气流床煤气化技术的现状与发展

煤气化按煤的粒度和气化炉内的气体流速等可分为固定床、流化床、气流床3种。其中干煤粉气流床加压气化具有易大规模化、煤种适应范围广、碳转化率高等特点,近年来得到大规模的应用。详细介绍了以干煤粉为原料的Shell、Prenflo、Simens GSP和西安热工院的两段式气化技术。     

现代煤化工企业的废水处理技术及应用分析

针对煤化工企业废水“零排放”的要求和污水回用的需求,通过分析典型煤气化工艺的废水水质特征,总结现代煤化工企业的废水处理、回用和“零排放”技术,介绍煤化工企业的废水处理技术应用案例,分析当前煤化工企业废水处理技术应用中存在的主要问题,并提出相关建议。     

气流床煤气化工艺技术的分析评价

介绍了国际上先进的气流床煤气化工艺技术特点,重点评述我国具有自主知识产权的多喷嘴对置式水煤浆气化装置的运行情况.     

气流床煤气化辐射废锅内多相流动与传热

采用多相流动与传热模型耦合的数值方法,对气流床煤气化辐射废锅内多相流场与传热过程进行了数值模拟。在Euler坐标系中采用组分输运模型计算气体组分扩散过程,并通过realizable k-ε湍流模型计算炉内流场,煤渣颗粒运动轨迹在Lagrange坐标系中计算,并考虑了气固相间双向耦合。利用灰气体加权和模型与离散坐标法相结合,计算了炉内辐射传热过程,并考虑了煤渣颗粒的热辐射特性。结果表明：炉体入口存在张角约为10°的中心射流区,其流速和温度均较高,且周围存在明显回流区,回流区内部分颗粒富集;大部分颗粒直接落入渣池,且粒径越大落入渣池时温度越高;炉内温度分布除中心射流区,整体分布均匀,且随壁面灰渣厚度的增加而升高;计算结果与实验测量结果及文献值基本一致。     

国内干粉气流床煤气化技术的工程化应用现状与展望

回顾了我国引进壳牌和GSP干粉气流床煤气化技术以及自主开发HT-L、WHG等煤气化技术的历程;分析了国内各种粉煤气化技术的工业化应用现状;提出了干粉气流床气化技术发展过程中需要解决的若干问题;展望了粉煤气化技术的工程化应用的前景。     

CO2 gasification rate analysis of coal char in entrained flow coal gasifier

Coal chars of four coal types were gasified with carbon dioxide using a PDTF or TGA at high temperature and pressure. Test conditions of temperature and partial pressure of the gasifying agent were determined to simulate the conditions in air-blown or oxygen-blown entrained flow coal gasifiers. Coal chars were produced by rapid pyrolysis of pulverized bituminous coals using a DTF with a nitrogen gas flow at 1670 K. In gasification tests with the PDTF, gasification temperatures were 1670 K or below and partial pressures of carbon dioxide were 0.7 MPa or below. Carbon monoxide of 0.6 MPa or below was supplied for the gasification tests with the TGA.As a result, coal types showed a large difference in the char gasification rate with carbon dioxide, and this difference remained large without decreasing even in the high-temperature area when the gasification rate was controlled by pore diffusion the same as in entrained flow gasifiers. Inhibition of the gasification reaction by carbon monoxide was also observed. Reaction rate equations of both the nth order and Langmuir-Hinshelwood type were applied to the char gasification reaction with the random pore model and the effectiveness factor, and the applicability of these rate equations to air-blown and oxygen-blown entrained flow gasifiers evaluated. Gasification rate equations and kinetic parameters applicable to a pore diffusion zone at high temperature were obtained for each coal.     

Experimental investigation of role of steam in entrained flow coal gasification

Experimental investigations of the influence of excess oxygen coefficient, H₂O/coal mass ratio using high-temperature steam, mean mass diameter of pulverized coal and coal size fraction on basic characteristics of coal gasification were performed. Experiments were carried out on a laboratory scale (0.09 m i.d. × 1.5 m high) coal gasification apparatus with lignite type of coal. Influence of steam was realized through comparison of results obtained from experiments with (H₂O/coal = 0.287 kg kg⁻¹) and without steam addition (H₂O/coal = 0.024 kg kg⁻¹). High values of carbon conversion, obtained both for finely ground and for coarse pulverized coal points to the easiness of lignite gasification, i.e. to its high suitability for gasification.     

Numerical study on the coal gasification characteristics in an entrained flow coal gasifier

The coal gasification process of a slurry feed type, entrained-flow coal gasifier was numerically predicted in this paper. By dividing the complicated coal gasification process into several simplified stages such as slurry evaporation, coal devolatilization and two-phase reactions coupled with turbulent flow and two-phase heat transfer, a comprehensive numerical model was constructed to simulate the coal gasification process. The k– turbulence model was used for the gas phase flow while the Random-Trajectory model was applied to describe the behavior of the coal slurry particles. The unreacted-core shrinking model and modified Eddy break-up (EBU) model, were used to simulate the heterogeneous and homogeneous reactions, respectively. The simulation results obtained the detailed information about the flow field, temperature and species concentration distributions inside the gasifier. Meanwhile, the simulation results were compared with the experimental data as a function of O₂/coal ratio. It illustrated that the calculated carbon conversions agreed with the measured ones and that the measured quality of the syngas was better than the calculated one when the O₂/coal ratio increases. This result was related with the total heat loss through the gasifier and uncertain kinetics for the heterogeneous reactions.     

气流床气化用煤灰熔融性调控技术研究进展

综述了气流床气化用煤灰熔融性影响因素和煤灰熔融性调控技术研究进展及应用,分析了添加单一助剂、复合助剂和配煤对煤灰熔融性调控效果,并对煤灰熔融性调控机理、煤灰熔融性预测模型进行了分析和阐述,对煤灰熔融调控技术选择具有重要指导意义。     

煤气化废水的超临界水氧化处理实验

对煤气化废水的超临界水氧化处理效果开展了探索性实验研究,以污水、污泥处理达标为目标,对过程中的工艺条件及有害物质的去除效果进行了研究和评价,结果表明,优化条件下无需经过预处理及后续深度处理,出水主要指标即可达到国家《污水综合排放标准》(GB 8978—1996)一级排放标准,并可实现废水的无害化处理和污泥的无害化减量。在此基础上,创新性地提出了碎煤加压气化-超临界水氧化组合工艺方案。     

煤气化废水溶解性有机物水质特征研究

煤气化废水中的溶解性有机物(DOM)决定着处理药剂和微生物生长等,直接影响废水处理工程效果,DOM的光谱表征可反映各组分在氧化、降解或吸附等方面的特性。在分析某煤气化生产尿素企业的废水产生节点基础上,采集脱酚氨后废水,采用树脂分离方法对气化废水中的DOM进行6组分(HoA、HoB、HoN、HiA、HiB、HiN)分离,通过紫外-可见光谱、三维荧光光谱等分析方法对其水质特征进行分析。结果表明:废水DOM中HoA、HoN组分占比高达43.21%和33.65%,废水中含有较多非饱和结构的芳香族化合物;脱酚后废水各组分的E300/E400数值都较低,为2.88~5.00,说明废水的腐植化程度很高,主要为难生化降解的苯环结构物质;三维荧光光谱分析表明煤气化废水DOM各组分的最强荧光响应区域对应的有机物质主要包括类腐植酸、类富里酸、类酪氨酸以及类色氨酸这四大类有机物,为控制和处理煤气化废水中有机污染物提供理论依据。     

生物质气流床气化技术的研究进展

阐述了发展生物质气流床气化技术的背景和意义,分析了生物质气流床气化技术的特征,重点介绍了国内外生物质气流床气化技术的研究进展,指出了目前该技术研究的重点及难点问题。     

水汽集成式煤气化与合成气处理近零废水生成工艺研究

为解决煤气化生产过程中废水排放对环境的污染问题,提出了水汽集成式煤气化与合成气处理近零废水生成工艺,针对典型的固定床、流化床和气流床气化技术特点提出了相应的技术重点和工艺路线。将煤气化与合成气处理工艺过程中的水与蒸汽物料流有机集成,使合成气洗涤水和冷凝液循环重复利用;同时对水中多种杂质进行综合管理,主要措施包括增设含盐/含尘水的提浓和浓缩液盐分结晶装置以解决水中含盐、含尘问题,采用有机溶剂吸收大分子有机物并回收有机物,将合成气冷凝液循环以促进水中氨转化成铵盐;采用合成气洗涤水、冷凝液蒸发生产含有杂质气体的水蒸气,用于气化炉和合成气变换反应所需的过热水蒸气并替代常规锅炉蒸汽,优化生产过程水的平衡,最终实现煤气化生产系统不排出或很少排出废水的目的。     

湿法气流床气化单废锅流程与双废锅流程比较

为了高效回收湿法气流床煤气化反应室出口的高温粗煤气的大量显热,提高系统的能量利用效率,采用废热锅炉间接换热回收显热。介绍了单废锅流程及双废锅流程2种湿法气流床废锅技术,从工艺过程、技术指标、热回收效率、综合能耗、投资及运行成本、运行情况等方面对流程进行对比。结果表明:单废锅流程及双废锅流程各有优缺点,当单纯用于IGCC发电时,优先采用双废锅流程,使能量利用效率最大化,当用于化工合成联合IGCC发电时,应优先采用单废锅流程。     

Pretreatment and feeding of biomass for pressurized entrained flow gasification

In our contribution we have compared advantages and disadvantages of four different methods for biomass (wood) thermal pretreatment and grinding for feeding of the biomass-fuel to pressurized entrained flow gasifier. The four methods of pretreatment and feeding involve drying, torrefaction, flash pyrolysis and dissolution of wood in organic solvents.