CO_2作煤粉输送载气对GSP气化过程影响的模拟研究

基于Gibbs自由能最小化原理,将GSP气化过程分解为热解单元和气化单元建模,使用灵敏度工具进行分析,探究CO2和N2分别作为煤粉输送载气时对气化温度、CO和H2以及有效气(CO+H2)产率的影响.结果表明:采用Aspen Plus软件建立的气化模型模拟计算结果与生产数据吻合;与N2相比,以CO2为煤粉输送载气时,气化温度降低约70℃,CO摩尔分数提高约4%、而H2摩尔分数降低约1%,但有效气摩尔分数提高约3%.当CO2流量从12 000Nm3/h升至15 000Nm3/h,气化温度降低约11℃,CO摩尔分数提高约0.15%,H2摩尔分数降低约0.85%,有效气摩尔分数降低约0.7%;当N2流量从12 000Nm3/h升至15 000Nm3/h,气化温度降低约6℃,CO摩尔分数降低约0.33%,H2摩尔分数提高约0.14%,有效气摩尔分数降低约0.19%.CO2作为煤粉输送载气在可减少CO2排放量的同时能够提高气化炉的生产能力和经济效益.     

气化参数影响气流床煤气化的模型研究(Ⅱ)--模型预测及分析

为评价和优化气流床煤气化中的气化方案和气化参数,利用已建立的气流床煤气化动力学模型系统地研究了不同气化剂、气化剂质量比率、气化温度、气化压力和停留时间等参数对气化过程和煤气组分的影响,并对其影响机理及规律进行了分析.结果表明:O2/H2O和O2/CO2两种气化方案各有特点,O2/H2O气化剂方案反应速度快,煤气中H2体积分数高,而O2/CO2气化剂方案可以降低未分解的水煤气,并回收利用CO2.气化温度是影响气化进程和煤气组分的最关键因素,气化压力对气化反应进程影响较大,但对接近平衡时的煤气组分影响却较小;对给定的气化反应系统,存在最佳气化剂质量比率和停留时间.     

气化参数影响气流床煤气化的模型研究(Ⅰ)--模型建立及验证

为评价和优化气流床煤气化中的气化方案和气化参数,从化学动力学角度并结合化学平衡,依据气流床特性建立了气化动力学模型.该模型考虑了煤热解和气化所经历的各反应过程,如C-O2、C-H2O、C-CO2、C-H2等异相反应以及挥发分燃烧、水煤气平衡、甲烷蒸汽重整等均相反应.模型对三个工况的计算结果与实验实测数据吻合较好;同时对气流床煤气化整个气化过程(氧化、还原和平衡三阶段)的模拟合理、正确,表明所建模型可以用于预测气化参数对气流床煤气化的影响特性.     

HT-L航天粉煤加压气化工艺

正所属单位北京航天万源煤化工工程技术有限公司产品简介HT-L航天粉煤加压气化工艺可以高效地将几乎任何形态的固态煤高温气化成洁净的气态一氧化碳和氢气混合物。该工艺可应用于化肥企业的煤头技术改造,煤制甲醇,合成氨,合成天然气、烯烃、油、氢、IGCC(整体煤气化联合循环发电系统)等。该工艺的气化工艺单元主要组成部分包括磨煤及干燥单     

甲烷磺酸铜催化氧化苯甲醛制苯甲酸

以氧化铜和甲烷磺酸合成了水稳型路易斯酸-甲烷磺酸铜,并探讨了以此作催化剂,质量分数为30%H2O2作氧化剂,应用在以苯甲醛氧化制苯甲酸中的催化作用。合成的甲烷磺酸铜由SDT2960差热-热重联用分析仪来分析,证明其含4个结晶水,即(CH3SO3)2Cu·4H2O。考察了催化剂用量、氧化剂用量、w(H2O2)、反应时间、反应温度等因素对反应结果的影响。反应产物经抽滤烘干后,通过测熔点、红外色谱来分析。结果表明,在温度为40℃,n(催化剂)∶n(苯甲醛)=1∶100,n(氧化剂)∶n(苯甲醛)=3∶1时,回流16h收率达70%,且苯甲酸为唯一产品。     

垃圾衍生燃料流化床富氧气化实验研究

为了研究不同操作工艺参数对垃圾衍生燃料（RDF）流化床富氧气化特性的影响,在常压流化床气化炉上进行徐州RDF的富氧气化实验,研究气化温度、当量比及氧体积分数对气化特性的影响.结果表明：随着气化温度由600 ℃升至800 ℃,气体产物中H2和CO体积分数显著增加,气体热值和气化效率增加;当量比通过影响气化反应程度及燃料碳转化率间接改变气化效果,当氧体积分数为425%、气化温度为770 ℃时,气化最佳当量比约为02,过高或过低均会导致可燃组分和气化效率的降低;随着氧体积分数由21%增至425%,可燃组分体积分数不断增加,与空气气化相比,富氧气化的气化效果有显著改善.     

煤基合成丙烯全过程模拟与废水利用

对5000 t/d煤气化经甲醇制备丙烯的工艺进行了废水资源化利用的研究,对该过程进行了全流程模拟,获得准确的工艺数据,如煤气化消耗用水量、甲醇及烯烃合成中排放的废水排放量、组成及pH等性质。提出将废水代替新鲜水作为汽化剂用于煤气化炉的用水策略并进行了模拟,研究了废水用作汽化剂对合成气组成和汽化温度的影响。结果表明,在煤气化条件下,废水中甲醇等有机物污染物基本可以完全转化为CO,H2,CH4及部分CO2和H2O,在合成气中的残留量低于10 ppb,且气化温度仍保持在1 500℃左右。实施改造方案可行后,可实现节水24万t/年。     

EADC/H2O/DMF引发体系对丁基橡胶的影响

以水和二氯乙基铝(EADC)为引发体系,己烷和氯甲烷为溶剂,在-90℃的条件下,通过溶液法合成丁基橡胶.考察引发剂摩尔分数、引发剂配比、第三组分(DMF)含量等对丁基橡胶分子质量、分子质量分布、单体转化率的影响.结果表明,引发剂摩尔分数在0.085％、聚合40 min,在n(EADC)/n(H2O)/n(DMF)=8.28:1:0.75时,得到数均分子质量为29.54×104 g/mol,分子质量分布为1.58的丁基橡胶.     

4,4’-二巯基二苯硫醚的合成

以二苯硫醚为起始原料,经磺化、氯化和还原三步反应制得目的产物4,4’-二巯基二苯硫醚.分别考察了各步反应的影响因素,确定反应的最佳工艺条件为n(二苯硫醚):n(氯磺酸):n(三氯氧磷)的摩尔配比为1∶2.3∶2.2,反应温度为100~110℃,反应时间为5 h.得产品4,4’一二氯磺酰二苯硫醚(2).n(锌粉):n(2)摩尔配比为9∶1,反应温度为70~80℃,反应时间为3 h,产物总收率60.1%.产物结构经IR与1H NMR证实.     

千瓦级PEMFC甲醇水蒸气重整制氢过程热力学模拟

运用Aspen Plus软件对千瓦级质子交换膜燃料电池甲醇水蒸气重整制氢系统进行热力学模拟分析,考察不同水醇物质的量比(0.8~1.6)、反应温度(140~400℃)及压力(101.325~506.625kPa)对甲醇水蒸气重整过程的影响。结果表明,升高反应温度可以提高甲醇平衡转化率和CO摩尔分数,但会降低重整气中H2摩尔分数;增大压力会降低甲醇平衡转化率,但对H2和CO摩尔分数的影响较小;增加水醇物质的量比n(W)/n(M),甲醇平衡转化率增大,但大量水蒸气的使用会增加系统的负荷,降低热效率,所以合适的n(W)/n(M)为1.2~1.4;通过对整个氢源系统的模拟发现,经甲醇水蒸气重整、水汽变化和选择性氧化后,出口气中H2摩尔分数为64.27%,CO摩尔分数小于10-5,可为千瓦级质子交换膜燃料电池提供氢源。     

Industrialization prospects for hydrogen production by coal gasification in supercritical water and novel thermodynamic cycle power generation system with no pollution emission

Energy conversion and utilization, particularly carbon-based fuel burning in air phase, have caused great environmental pollution and serious problems to society. The reactions in water phase may have the potential to realize clean and efficient energy conversion and utilization. Coal gasification in supercritical water is a typical carbon-based fuel conversion process in water phase, and it takes the advantages of the unique chemical and physical properties of supercritical water to convert organic matter in coal to H2 and CO2. N, S, P, Hg and other elements are deposited as inorganic salts to avoid pollution emission. The State Key Laboratory of Multiphase Flow in Power Engineering has obtained extensive experimental and theoretical results based on coal gasification in supercritical water. Supercritical water fluidized bed reactor was developed for coal gasification and seven kinds of typical feedstock were selected. The hydrogen yield covers from 0.67 to 1.74 Nm3/kg and the carbon gasification efficiency is no less than 97%. This technology has a bright future in industrialization not only in electricity generation but also in hydrogen production and high value-added chemicals. Given the gas yield obtained in laboratory-scale unit, the hydrogen production cost is U.S.$ 0.111 Nm3 when the throughput capacity is 2000 t/d. A novel thermodynamic cycle power generation system based on coal gasification in supercritical water was proposed with the obvious advantages of high coal-electricity conversion efficiency and zero pollutant emission. The cost of U.S.$ 3.69 billion for desulfuration, denitration and dust removal in China in 2013 would have been saved with this technology. Five kinds of heat supply methods are analyzed and the rates of return of investment are roughly estimated. An integrated cooperative innovation center called a new type of high-efficient coal gasification technology and its large-scale utilization was founded to enhance the industrialization of the technology vigorously.     

刘庄煤气化反应动力学特征的研究

针对煤炭在气化过程中高温的碳与二氧化碳和水蒸汽发生的非均匀向反应决定了出口煤气的组分和热值这一问题,在实验的基础上,研究了刘庄煤气化过程中ＣＯ２还原反应和Ｈ２Ｏ（ｇ）分解反应的动力学特征,确定了其化学反应的速率表达式,得出其反应活化能分别为１４０．４１ｋＪ／ｍｏｌ和１７１．５３ｋＪ／ｍｏｌ。     

立体瓦斯抽采条件下煤自燃预测预报标志气体的优化选择

结合义马煤业集团耿村煤矿工作面立体瓦斯抽采的实际情况,通过低温氧化试验,参照标志气体优选原则,确定CO,C2H4作为主要标志气体指标,C2H6作为辅助指标,并定量出采空区CO体积分数的临界值,建立了耿村矿23号煤层自燃预测预报标志气体体系.同时为克服采空区气体抽样的困难,推导出高抽巷气体成分与采空区气体成分间的关系,利用高抽巷的气体成分预测采空区浮煤的自然发火.     

煤焦固定床等温CO2气化反应动力学研究

利用自建固定床实验台研究了常压下神华煤煤焦等温CO2气化反应特性,实验分析了CO2流量、煤焦质量、气化温度和CO2分压对煤焦固定碳转化率的影响.在建立的化学反应动力学控制实验条件下,根据等转化率法计算得到煤焦气化反应活化能E为155 kJ/mol、CO2分压反应级数n为0.58;通过比对常用42种反应机理函数相关系数大...     

CO_2加氢制低碳烯烃反应中引入耦合反应的影响研究

针对CO2加氢制低碳烯烃反应的特点,考虑将气化反应引入到CO2加氢制低碳烯烃反应中。对无煤粉参与反应和有煤粉参与反应两种情况下的CO2加氢反应进行了热力学分析。采用总吉布斯自由能最小法计算得到不同温度下反应体系平衡组成及反应物的平衡转化率。对比两种情况下的计算结果表明,引入气化反应,平衡组成中烯烃含量和反应物H2转化率都提高了,而产物中H2O的含量降低了,表明有更多的氢储存到烃中,但反应物CO2的转化率降低了。此外,通过实验得到两种情况下CO2加氢反应产物分布,实验结果表明有煤粉参与的反应,烯烃选择性更高,但CO2转化率降低了,这与热力学分析所得结论一致。     

生物质空气/水蒸汽气化的综合计算法模型

建立生物质气化模型的目的在于确定用某种燃料为气化原料时所生成煤气的组成、热值、煤气产率、气化剂的消耗量与热效率等,并为选用设计气化系统及设备提供依据。根据生物质气化炉实测数据对煤的综合计算法模型进行了修正。主要调整了干馏段生物质气的产率及气化段的碳氮比特征值n。其中,干馏产物中CO2的产率设定为氧含量的30%,焦油的产率设定为挥发分的10%;气化段的碳氮比特征值n对应着不同的鼓风量,风量大时n值得取值小,反之亦然,在实际气化炉中过量空气系数在0.2～0.4之间,对应的n值的取值由原来的0.6变为0.3～0.6之间;此外,根据固定碳量给定了水蒸汽的喷入量。建模结果还与其它学者的实验数据进行了对比,模拟结果符合良好,在一定程度上证明了模型的有效性和可靠性。     

Chemical looping combustion of coal in interconnected fluidized beds

Chemical looping combustion is the indirect combustion by use of oxygen carrier. It can be used for CO2 capture in power generating processes. In this paper, chemical looping combustion of coal in interconnected fluidized beds with inherent separation of CO2 is proposed. It consists of a high velocity fluidized bed as an air reactor in which oxygen carrier is oxidized, a cyclone, and a bubbling fluidized bed as a fuel reactor in which oxygen carrier is reduced by direct and indirect reactions with coal. The air reactor is connected to the fuel reactor through the cyclone. To raise the high carbon conversion efficiency and separate oxygen carrier particle from ash, coal slurry instead of coal particle is introduced into the bottom of the bubbling fluidized bed. Coal gasification and the reduction of oxygen carrier with the water gas take place simultaneously in the fuel reactor. The flue gas from the fuel reactor is CO2 and water. Almost pure CO2 could be obtained after the con- densation of water. The reduced oxygen carrier is then returned back to the air reactor, where it is oxidized with air. Thermodyanmics analysis indicates that NiO/Ni oxygen carrier is the optimal one for chemical looping combustion of coal. Simulation of the processes for chemical looping combustion of coal, including coal gasification and reduction of oxygen carrier, is carried out with Aspen Plus software. The effects of air reactor temperature, fuel reactor temperature, and ratio of water to coal on the composition of fuel gas, recirculation of oxygen carrier par- ticles, etc., are discussed. Some useful results are achieved. The suitable tem- perature of air reactor should be between 1050―1150℃and the optimal temperature of the fuel reactor be between 900―950℃.     

不同煤种地下气化特性研究

在地下气化模型试验及理论分析的基础上，研究了不同煤种的地下气化特性．比较了空气连续气化及纯氧．水蒸汽气化条件下的煤气组成，并从气化煤层升温速率、气化速率、煤气产率、气化效率等方面比较了不同煤种的地下气化特性．试验结果表明，煤种的不同组成决定了空气煤气中CO，H2，CH4含量的不同，鼓风量影响着空气煤气的组成．在适宜的汽氧比条件下，不同煤种纯氧，水蒸汽地下气化均可以获得中热值煤气。对于试验煤种，褐煤具有高的气化活性、气化速率及低的煤气产率，其纯氧-水蒸汽气化效率达87％，最适于地下气化；瘦煤地下气化，气化煤层温度上升缓慢，其气化活性较低，气化速率变化平缓，纯氧-水蒸汽气化效率为74％，但气化过程稳定，且具有高的煤气产率，可以进行地下气化；气肥煤煤层升温速率最快，煤气产率仅次于瘦煤，但在煤挥发分析出后，气化速率减小，气化稳定性变差。     

△P index with different gas compositions for instantaneous outburst prediction in coal mines

In this study we measured the △P(initial speed of gas emission)index with different gas concentrations of carbon dioxide(pure CO2,90% CO2+10% CH4,67% CO2+33% CH4,50% CO2+50% CH4,30% CO2+10% CH4 and pure CH4)of coal samples from the No.2 coal seam in the Yaojie Coal Mine,Gansu province,China.The effect of carbon dioxide concentration,gas composition,coal strength and particle size of coal samples on the △P index was investigated.The experimental results show that with gas of various compositions,the △P value of three samples were clearly different.The △P index of coal samples A,B and C(0.2～0.25 mm)were 4,6 and 7 with pure CH4 and 22,30 and 21 when pure CH4 was used.Carbon dioxide concentration affects the△P index markedly.The △P index increases with an increase in carbon dioxide concentration,especially for coal B.Hence,the△P index and K(another outburst index)values tested only with pure CH4 for prediction of the danger of outburst is not accurate.It is important to determine the initial speed of gas emission given the gas composition of the coal seam to be tested for exact outburst prediction.     

急倾斜煤层无井式地下气化的试验研究

急倾斜煤层无井式地下气化的关键技术是沿煤层施工进、排气孔、气化炉点火和气化通道的贯通．在现场试验中，研究了三种导斜钻具，提出了盲孔式电点火方案，并研究了正、反向互换燃烧贯通技术，得出其贯通速度为０．３４ｍ／ｄ，通道有效直径为０．３９ｍ．当煤气中ＣＯ，ＣＯ２，ＣＨ４的体积百分比含量之和大于１８％时，则进行反向贯通，反之则进行正向贯通．