第二代典型煤气化技术

介绍了Lurqi加压气化、Texaco气化、Shell气化、Prenflo气化和GSP气化五种典型的煤气化工艺及其优缺点。为我国企业选择合适的煤气化工艺提出了几点建议,展望了我国煤气化技术的发展方向。     

气流床煤气化的Aspen Plus建模：平衡模型和动力学模型

基于Aspen Plus软件建立了GE气流床煤气化的平衡模型和动力学模型,计算了气化的煤气组成和碳转化率。模型分为热解、气化和气液分离三个阶段。其中,气化阶段又分为初步气化和气化重整,从而获得气化产物在恒定温度下的分布。平衡模型的气化阶段使用了吉布斯反应器RGIBBS,基于吉布斯自由能最小化原理对体系内的气化产物进行计算;动力学模型的气化阶段使用了全混流反应器RCSTR,基于煤气化反应的动力学机理对体系内的气化产物进行计算。模拟值与GE气化炉的实际工程数据进行了对比,结果表明,平衡模型可在一定程度上反映气化结果的变化趋势,但预测结果的准确性有所欠缺,而基于气化反应机理建立的动力学模型能很好地预测GE气化炉的气化结果。对动力学模型中的全混流反应器进行反应时间设定,可以对GE气化炉生产提供一定的指导,结果表明：反应停留时间为3.5s时就可以达到很好的气化效果。温度是影响气化反应速率及产物分布的重要因素,利用煤气化的动力学模型模拟了气化温度对气体组成及碳转化率的影响,结果表明：随着气化温度的升高,CO含量逐渐增加,H₂含量基本不变,CO₂含量逐渐减小,碳转化率逐渐升高。     

滇池底泥-褐煤超临界水共气化制氢实验研究

采用间歇式超临界水反应装置,以滇池疏浚底泥和褐煤为原料,分别将褐煤、底泥单独进行超临界水气化,对比不同反应原料对气化制氢的影响。再将二者按不同混合比例（1∶9、2∶8、 3∶7、4∶6、5∶5）进行共气化,对比不同混合比例对气化制氢的影响。结果表明,相对褐煤,底泥气化具有气体组分富氢、气相收率高、产气量小的特点;褐煤气化则具有碳气化率高、产气量大的特点。褐煤单独气化的气相收率低于底泥,共气化时气相收率达到834 mL/g。褐煤和底泥在超临界水共气化过程中碳气化率和产氢率存在明显协同效应。与加权平均值相比,碳气化率和H2产率分别提高了3.12%和55 mL/g。共气化存在最优比例,超过3∶7后,碳气化率逐渐下降。以最优比例进行共气化,既可达到处置底泥的目的,又可保持相对较高的H2产率（350 mL/g）和CH4产率（113 mL/g）。     

胜利褐煤水蒸气气化制富氢合成气及其固有矿物质的催化作用

利用微型固定床反应装置,研究了内蒙古胜利褐煤水蒸气气化过程中H₂、CO₂、CO和CH₄生成规律及其固有矿物质的催化效应。原煤(SL-raw)、盐酸洗脱(SL-HCl)、氢氟酸洗脱(SL-HF)及盐酸洗脱液回添煤样(SL-HCl-Re)在水蒸气气化反应过程中,H₂、CO₂和CO生成速率存在明显差异,充分说明胜利褐煤中某些固有的矿物质对其水蒸气气化反应具有显著的催化作用,可大幅度提高其气化反应速率,并使其起始气化温度降低96℃,气化反应主体温度降低150℃以上,同时促进了合成气中H₂生成,抑制了CO的生成,使胜利褐煤水蒸气气化反应过程中一直维持着较高的H₂/CO摩尔比,SL-raw、SL-HCl-Re水蒸气气化所得合成气中H₂/CO摩尔比分别为17.3和4.3,而SL-HCl和SL-HF水蒸气气化所得合成气中H₂/CO摩尔比均只有1.22。SL-HCl和SL-HF水蒸气气化生成H₂、CO₂和CO的规律基本相同,说明起催化作用的物质是可溶解在盐酸洗脱液中的矿物质。经过分析,发现矿物质对胜利褐煤水蒸气气化反应的催化作用主要是通过提高水煤气变换反应(WGSR)速度实现的。最后结合文献报道提出了胜利褐煤水蒸气气化反应过程中矿物质的原位催化机理。     

Potassium-catalyzed steam gasification of petroleum coke for H2 production: Reactivity, selectivity and gas release

Potassium-catalyzed steam gasification of petroleum coke for H₂ production was performed using a laboratory fixed-bed reaction system with an on-line quadruple mass spectrometer. The gasification reactivity, gasification selectivity and gas release for the catalytic gasification were investigated, compared with the non-catalytic gasification. The catalytic gasification could not only effectively promote these reactions (the water-carbon reaction, the water-gas shift reaction and the methane-steam reforming reaction), but also elevate greatly the gasification selectivity towards CO₂ (a high gasification selectivity towards CO₂ meant a high H₂ production). A quantitative calculation method for the gasification selectivity towards CO and CO₂ was proposed to further understand the catalytic behaviors of catalysts. In the case of catalytic gasification, the gasification temperature had opposite effects on the gasification reactivity and the gasification selectivity towards CO₂, suggesting that there existed an optimum gasification temperature (about 750 °C) for H₂ production from the potassium-catalyzed steam gasification of petroleum coke. In addition, petroleum coke could be feasibly utilized as the feedstocks for the catalytic steam gasification to produce gases with high H₂ (55.5-60.4%) and virtually no CH₄ (below 0.1%).     

恒温下生物质与煤共气化特性研究

煤和生物质进行共气化不仅拥有煤和生物质单独气化的优点,还能够消除弥补煤与生物质分别气化时的缺点。在自行搭建的热重分析仪上进行了煤与生物质的共气化实验研究,研究了焦样粒径、CO2流量对气化反应的影响。研究了煤与生物质单独气化的特性,结果显示生物质的气化活性要高于煤;研究了煤与生物质共气化特性,发现在气化反应前期存在一定的抑制作用,气化反应后期存在协同作用。     

Catalysis of carbon-steam gasification by ash components from two lignites

Ash transfer from a reactive to a less reactive coal is an interesting possibility for improving and equalizing gasification characteristics of coals. To assess the catalytic action of coal impurities in the steam gasification of carbon, three approaches were used. In the first series, the effects of different coal ashes on the gasification kinetics of graphite were compared. A parallel study was made by adding lignite ash to a coal of low reactivity. Finally, gasification rates of chars prepared from demineralized coals were measured. While it was found that ash from reactive coals can significantly enhance the gasification rates of chars derived from coals of lesser reactivity, it was not possible to distinguish clearly between a catalytic lowering of the activation energy and an increase in the number of gasification sites. The gasification enhancement by lignite ash may open practical possibilities for blending coals of different reactivity, and warrants further study to identify the constituents associated with this effect.     

生物质气化技术的研究进展

近年来,由于世界能源与环境危机,生物质能作为一种清洁的、可再生的能源越来越受到世界的关注,其中生物质气化是利用生物质能最重要的方式之一。本文介绍了生物质气化技术的原理,生物质气化工艺及气化设备,并对影响生物质气化装置的优化设计的各种因素进行了分析与讨论,提出了生物质气化工艺过程亟待解决的问题,为生物质气化的发展提供了一定的参考。     

高硫石油焦气化研究进展和技术经济分析

分析我国高硫石油焦的生产现状和利用过程中存在的问题,对影响石油焦气化反应活性的因素、石油焦的催化气化和石油焦与煤或生物质共气化等方面的研究以及石油焦气化的工业应用进展进行了总结;探讨高硫石油焦配煤气化的可行性,对高硫石油焦配煤气化和干煤粉气化方案分别进行了模拟计算及技术经济分析,并与工业上掺烧高硫石油焦气化的运行结果进行了比较,与干煤粉气化相比,高硫石油焦配煤气化的比氧耗、比煤耗降低,有效合成气产量增加,具有较好的经济性;采用高硫石油焦配煤气化制取合成气既可以解决高硫石油焦的利用问题,又能拓宽煤气化的原料范围,是一条高效、清洁利用高硫石油焦的新途径。     

生物质两段式富氧气化-燃气轮机燃烧集成发电系统模拟研究

为实现生物质能量的高效清洁利用,本研究基于两段式富氧气化系统改进燃气品质,并将获得的洁净高热值可燃气用于燃气轮机燃烧.通过Aspen Plus模拟研究分析了氧体积分数、气化温度对气化特性、燃机运行特性的影响,研究结果证实了生物质气化燃气在燃气轮机应用的可行性,并发现氧体积分数提高对改善生物质气化燃气品质及系统发电效率具...     

A study on the direct catalytic steam gasification of coal for the bench-scale system

Various techniques have been developed to increase the efficiency of coal gasification. The use of a catalyst in the catalytic-steam gasification process lowers the activation energy required for the coal gasification reaction. Catalytic-steam gasification uses steam rather than oxygen as the oxidant and can lead to an increased H₂/CO ratio. The purpose of this study was to evaluate the composition of syngas produced under various reaction conditions and the effects of these conditions on the catalyst performance in the gasification reaction. Simultaneous evaluation of the kinetic parameters was undertaken through a lab-scale experiment using Indonesian low rank coals and a bench-scale catalytic-steam gasifier design. The composition of the syngas and the reaction characteristics obtained in the lab- and bench-scale experiments employing the catalytic gasification reactor were compared. The optimal conditions for syngas production were empirically derived using lab-scale catalytic-steam gasification. Scale-up of a bench-scale catalytic-steam gasifier was based on the lab-scale results based on the similarities between the two systems. The results indicated that when the catalytic-steam gasification reaction was optimized by applying the K₂CO₃ catalyst to low rank coal, a higher hydrogen yield could be produced compared to the conventional gasification process, even at low temperature.     

生物质气化制富氢合成气的研究进展

生物质气化制取富氢合成气因其原料的清洁可再生性、产物应用方式的多样性被认为是最具发展前景的制氢方式之一。催化剂对调控生物质气化产物组成及焦油的裂解具有重要作用。本文综述了化石能源制氢、水分解制氢和生物质制氢方法,分析了生物质气化制氢的优势和局限性,以及存在的问题;重点介绍了生物质气化制氢的影响因素(气化剂、反应温度和催化剂)和用于生物质气化的主要催化剂种类(镍基、白云石和碱及碱土金属催化剂)及其特点,分析国内外生物质气化制取富氢合成气和催化剂的研究现状,探讨了催化气化制取富氢合成气的发展前景,提出有待解决的问题和研究方向。     

钠盐对准东煤CO2吸附能力及气化特性的影响

为探究不同化学形态的钠盐对准东煤CO₂吸附能力及气化特性影响,对酸洗后的准东煤采用溶液浸渍法负载钠盐。利用热重分析仪研究了4种负载钠盐的煤样和酸洗煤样的气化反应性和CO₂吸附能力,并对5种煤样的反应动力学模型进行了分析和计算。结果表明：负载钠盐可显著降低煤样起始气化温度和气化所需活化能,提高气化反应活性指数和吸附CO₂的能力。实验选用的4种钠盐对准东煤CO₂气化反应催化作用强弱依次是：Na₂CO₃> NaHCO₃> Na₂SO₄> NaCl。煤样的CO₂强化学吸附能力可反映出煤样的CO₂气化反应活性。随机孔模型可以较好地描述酸洗煤的CO₂气化过程,而修正的随机孔模型则能更好地反映负载钠盐煤样的CO₂气化过程。     

Volatilisation and catalytic effects of alkali and alkaline earth metallic species during the pyrolysis and gasification of Victorian brown coal. Part VIII. Catalysis and changes in char structure during gasification in steam

The purpose of this study is to investigate the major factors influencing the Na-catalysed and non-catalysed gasification reactivity of a Victorian brown coal in steam. An acid-washed (H-form) sample and a Na-exchanged (Na-form) sample prepared from the same Loy Yang brown coal were gasified in 15% steam in a novel two-stage fluidised-bed/fixed-bed reactor. All C-containing species in the gasification product gas were converted into CO₂ that was monitored with a mass spectrometer continuously to determine the in situ gasification reactivity. While the volatile-char interactions were responsible for the volatilisation of Na when the coal was continuously fed into the reactor, the physical entrainment by gas of agglomerated Na-containing crystalline species (likely to be Na₂CO₃ or Na₂O) from char surface was the main mechanism for the loss of Na during char gasification. The Raman spectroscopy of char showed the preferential release of smaller aromatic ring system to be more significant during the non-catalysed char gasification than the Na-catalysed gasification. The dispersion of Na in char appeared to deteriorate with the enrichment of large aromatic ring systems in char, greatly affecting the char gasification reactivity. The char gasification reactivity showed a maximum with increasing conversion with the maximum to shift towards lower conversion with increasing temperature. Increasing temperature does not always lead to increases in the in situ char gasification reactivity.     

生物质气化与催化剂的研究进展

生物质气化是一种在高温氧化性介质作用下将生物质热分解为可燃性气体的热解技术。为了提高生物质气化过程中气化效率、调整可燃性气体组分的含量和去除焦油,通常需要采用不同气化介质、改变气化条件或添加不同的催化剂。本文重点综述了生物质气化所使用的介质和催化剂种类以及气化条件对气化气组分,主要是H₂和CO的影响规律。最后对未来生物质气化研究进行了展望,提出了几个待研究解决的问题。     

生物质气化与催化剂的研究进展

生物质气化是一种在高温氧化性介质作用下将生物质热分解为可燃性气体的热解技术。为了提高生物质气化过程中气化效率、调整可燃性气体组分的含量和去除焦油,通常需要采用不同气化介质、改变气化条件或添加不同的催化剂。本文重点综述了生物质气化所使用的介质和催化剂种类以及气化条件对气化气组分,主要是H2和CO的影响规律。最后对未来生物质气化研究进行了展望,提出了几个待研究解决的问题。     

添加剂对煤焦催化气化特性的影响

在自行搭建的热重分析仪上进行恒温下煤焦的催化气化实验。通过添加剂对催化剂进行预处理,可能使得催化剂有着更好的催化效果。研究了氨水和冰乙酸两种添加剂催焦样催化气化的影响,催化剂分别为CaO和Fe(NO_3)_3。分别在780、810、850、900℃进行了气化实验。研究结果表明:两种添加剂对原煤焦的气化过程影响很小;对于CaO的催化气化,氨水能起到促进气化过程的作用,冰乙酸使得催化气化反应性降低;对于Fe(NO_3)_3的催化气化,冰乙酸能促进催化气化过程,氨水则使得催化气化反应性降低。     

Linking laboratory data with pilot scale entrained flow coal gasification performance. Part 1: Laboratory characterisation

Pilot scale measurements play an important role in our understanding of the coal gasification process. To gain the most practical benefits from such testing it is important to have a good understanding of the fundamental processes that influence coal behaviour under industrial conditions. In this paper, a suite of Australian coals was characterised in detail at the laboratory scale and preliminary assessments made of their likely performance under practical entrained flow conditions. The same coals were then tested using a 5 MW_th pilot-scale entrained flow gasifier in Part 2. The resulting gasification dataset for a suite of coals at both laboratory and pilot scale provides a unique opportunity to quantify the links between laboratory gasification measurements and coal gasification behaviour under realistic conditions. This paper presents a characterisation of four Australian thermal coals in terms of their slag formation and flow behaviour, coal devolatilisation and reactivity properties, and their gasification conversion behaviour. This work provides the basis for a relative assessment of their potential for use in entrained flow gasification, and identifies possible performance issues which may need consideration for use in larger-scale gasification systems. The second paper discusses the pilot-scale gasification behaviour of these coals, and relates those data with those presented here.     

射流预氧化流化床气化炉中黏结性煤的反应特性

针对现有流化床气化技术难以处理黏结性、高含灰洗中煤的问题, 中国科学院过程工程研究所开发了可处理黏结性碎煤的射流预氧化流化床气化技术, 该技术利用含氧气体将煤颗粒快速喷射送入预氧化区内破除其黏结性, 形成的半焦进入气化区内发生气化反应, 进而实现对黏结性煤的利用。本工作采用小型流化床射流预氧化反应装置研究较强黏结性煤预氧化破黏后的产物分布、半焦结构与活性变化, 并考察气化操作条件(温度、当量空气系数、水煤比等)对半焦气化行为的影响。结果表明:当预氧化区温度为950℃、当量空气系数为0.13时, 黏结性煤生成半焦的孔结构和气化活性较好;当半焦气化区温度为1000℃、当量空气系数为0.17、水蒸气与煤质量比为0.09时, 生成燃气的品质较好, 而且生成焦油中的轻质组分最多, 有利于焦油被进一步脱除。研究结果可为射流预氧化气化技术的设计放大提供基础数据。     

基于等转化率法的煤焦-CO_2气化动力学研究

为获得可靠的煤焦-CO_2气化反应动力学参数,采用Flunm-Wall-Ozawa(FWO)等转化率法进行煤焦-CO_2气化动力学研究。在3个不同升温速率下进行了煤焦-CO_2气化热重试验,计算不同碳转化率下的反应活化能,用主曲线法分析了气化机理模型,并采用拟合法对等转化率法的结果进行验证。结果表明,气化主反应区不同碳转化率下(α为0.2~0.8)活化能的变化较小,为(228.25±5.22)k J/mol。煤焦-CO_2气化反应为均相模型,该模型标准曲线与试验曲线重合度较好,并符合目前常用的煤气化动力学模型。拟合法计算的活化能仅与等转化率法相差0.74 k J/mol,说明等转化率法研究煤焦-CO_2动力学可行。