含氧煤层气脱氧制LNG工艺研发

设计了一种利用氮-甲烷膨胀制冷低温精馏含氧煤层气制LNG的工艺,并对其进行了模拟分析。结果表明,该工艺可较彻底除去氮气、氧气等,获得较高浓度的LNG产品。同时分析了回流比、塔板数以及入塔温度对塔底产品含氧量和甲烷含量的影响,并且对该低温精馏工艺中的各设备进行了能耗分析。结果表明,在精馏塔进料温度为-163℃、压力为0.2 MPa时,最佳工艺操作条件为回流比1.5,塔板数24,在此条件下,甲烷回收率可达99.64%,塔底甲烷产品纯度高达99.98%,氧气体积分数仅为0.016%,系统单位能耗0.573 kWh/m3。     

焦炉气转化气作为甲醇精馏热源的应用总结

0引言 我公司200kt／a焦炉气配水煤气制甲醇项目于2008年6月投产。该项目利用公司焦化厂的32650m^3／h焦炉气为主要原料,焦炉气中甲烷转化采用纯氧转化工艺,甲醇精馏采用预精馏塔、加压精馏塔、常压精馏塔、回收塔的“三加一塔”工艺流程。     

前脱丙烷预切割分离MTO粗产品工艺的模拟与优化

选择"前脱丙烷"流程对甲醇制烯烃粗产物进行分离。先利用高低塔脱丙烷工艺, 然后经过脱甲烷塔、脱乙烷塔、乙烯精馏塔、丙烯精馏塔, 最终得到聚合级的烯烃产品, 其中脱甲烷工段采用"预切割-油吸收"脱甲烷工艺, 使用耗能较小的中冷分离, 吸收剂选择产自工艺自身的丙烷产品。丙烯精馏工段采用双塔预分流程, 降低塔高。采用Aspen Plus流程模拟软件对脱甲烷工段进行模拟和优化, 选用Radfrac精馏模型和RKS-BM热力学模型进行计算, 对脱甲烷工艺段进料位置、塔板数、回流比进行灵敏度分析, 并确定出丙烷吸收剂的用量和温度, 最终得到纯度为99.98%的乙烯和99.90%的丙烯。     

甲醇双效精馏系统的优化研究

为优化焦炉气制甲醇工艺中甲醇双效精馏系统,利用流程模拟技术对系统进行模拟分析,对比分析模拟数据与实际数据,提出甲醇双效精馏系统的优化措施。结果表明:模拟数据与实际数据基本吻合,模拟状态下每天可产甲醇350.4 t,与实际产量350 t相符,说明Wilson方程可用于甲醇-水体系。甲醇双效精馏系统中所需蒸汽量为9.83 t/h,而实际工况中蒸汽使用量为12.2 t/h,实际工况中的蒸汽使用量仍偏大,应降低蒸汽使用量;加压精馏塔、常压精馏塔最佳回流比分别为1.50和0.94;加压精馏塔中第25块塔板为灵敏板,常压精馏塔中第18、38块塔板作为灵敏板,日常操作中应重点关注以上塔板温度的变化。     

变压精馏分离甲醇-丙酮的工艺模拟及优化

采用Aspen Plus软件,以塔釜能耗为目标,以甲醇、丙酮纯度为约束函数,对双效变压精馏分离甲醇-丙酮工艺过程进行模拟。分析了操作压力、理论板数、回流比、进料位置和进料温度等参数对精馏过程的影响。确定了最优工艺参数：减压塔操作压力40 kPa,理论板数37,回流比2.4,进料塔板数26,进料温度25 ℃;常压塔理论板数30,回流比4.2,进料塔板数23。减压塔所得甲醇质量分数为99.0%,常压塔所得丙酮质量分数为99.7%。对比变压精馏和萃取精馏过程,变压精馏更容易得到高纯度丙酮产品,节能约13.4%。模拟结果对工业设计和设备改造具有一定指导意义。     

乙腈法分离C5馏分模拟及实验研究

利用ProⅡ化工模拟软件对乙腈法分离碳五馏分进行模拟,尤其对第一萃取精馏塔、第二萃取精馏塔内异戊二烯的质量分数和温度进行了模拟计算,并对各分布曲线进行了系统分析,结果表明,在第一萃取精馏塔和第二萃取精馏塔中,各组分并非均匀分布,而是在特定的部分塔板分离,进而实现各组分按质量要求进行分离.通过实验验证了模拟结果,最终得到聚合级异戊二烯产品.     

流程模拟软件在甲醇精馏塔中的应用

通过对甲醇常压常规精馏塔模拟,分析了塔板数、回流比对产品纯度的影响,以及塔板数与回流比之间的相互关系。当理论板数为30块、回流比为3、侧线采出在第23块塔板时,可产出满足要求的甲醇产品,同时也给出了最小回流比及最小理论板数;利用隔壁塔对甲醇常压塔进行模拟,同工况下可得到更高纯度的精甲醇,且甲醇中乙醇的含量降低约1倍左右。     

流程模拟软件在甲醇精馏塔中的应用

通过对甲醇常压常规精馏塔模拟,分析了塔板数、回流比对产品纯度的影响,以及塔板数与回流比之间的相互关系。当理论板数为30块、回流比为3、侧线采出在第23块塔板时,可产出满足要求的甲醇产品,同时也给出了最小回流比及最小理论板数;利用隔壁塔对甲醇常压塔进行模拟,同工况下可得到更高纯度的精甲醇,且甲醇中乙醇的含量降低约1倍左右。     

半湿法熄焦与焦炉气综合利用优化组合方式探讨

分析了焦化产业湿法熄焦技术存在的问题,简述了现有焦炉综合利用技术的现状及发展瓶颈;提出了半湿法焦炉气制天然气联产甲醇的新工艺。结果表明,该工艺具有以下优势:①可提高焦炉气产量,调整焦炉气有效成分,改善湿法熄焦工况;②可省去单一焦炉气制甲醇装置的转化工序和空分设备,节省项目投资;③可省去单一焦炉气制天然气装置中的甲烷化工艺过程,剔除了甲烷化技术瓶颈的约束。     

焦炉气联产LNG、纯氢气和甲醇工艺开发

介绍了四川天一科技股份有限公司开发的焦炉气联产液化合成天然气、纯氢气和甲醇的新工艺,此工艺具有原料损耗较少、各系统技术成熟简单、产品结构多元化等优势;并介绍了一种适用于此联产工艺的合成甲烷催化剂。     

焦炉气低温精馏制LNG、补碳生产甲醇的可行性研究

本文结合生产运行实际情况,对焦炉气低温精馏制LNG、补碳生产甲醇的可行性进行了论证。     

Dry reforming of coke oven gases over activated carbon to produce syngas for methanol synthesis

The dry reforming of coke oven gases (COG) over an activated carbon used as catalyst has been studied in order to produce a syngas suitable for methanol synthesis. The primary aim of this work was to study the influence of the high amount of hydrogen present in the COG on the process of dry reforming, as well as the influence of other operation conditions, such us temperature and volumetric hourly space velocity (VHSV). It was found that the reverse water gas shift (RWGS) reaction takes place due to the hydrogen present in the COG, and that its influence on the process increases as the temperature decreases. This situation may give rise to the consumption of the hydrogen present in the COG, and the consequent formation of a syngas which is inappropriate for the synthesis of methanol. This reaction can be avoided by working at high temperatures (about 1000 °C) in order to produce a syngas that is suitable for methanol synthesis. It was also found that the RWGS reaction is favoured by an increase in the VHSV. In addition, the active carbon FY5 was proven to be an adequate catalyst for the production of syngas from COG.     

Study on a multifunctional energy system producing coking heat, methanol and electricity

A multifunctional energy system (MES) capable of consuming coke oven gas (COG) and coal, and simultaneously producing coking heat, methanol and electricity, was subject to an exergy analyses based on Energy Utilization Diagrams (EUDs). In this system a coal-fired coke oven is adopted to produce coke and COG, where non-coking coal is burned to supply thermal energy to the coking process. The COG and coal gas gasified from coal in a gasifier, were mixed to produce syngas for methanol synthesis. Since COG rich in hydrogen and coal gas rich in CO, the mixture of COG and coal gas can easily adjust the mole ratio of CO to H₂ of syngas instead of the conversional reforming and shift processes. The active component of syngas is firstly converted into methanol and then the rest is introduced to a gas turbine for power generation. As a result, the overall efficiency of the MES system is about 62.3%, and its energy savings ratio is about 15% comparing with individual systems. The paper provides a new approach to use coal more efficiently and cleanly.     

Carbon dioxide reforming of methane with a free energy minimization approach

Carbon dioxide reforming of methane to syngas is one of the primary technologies of the new poly-generation energy system on the basis of gasification gas and coke oven gas. A free energy minimization is applied to study the influence of operating parameters (temperature, pressure and methane-to-carbon dioxide ratio) on methane conversion, products distribution, and energy coupling between methane oxidation and carbon dioxide reforming methane. The results show that the methane conversion increases with temperature and decreases with pressure. When the methane-to-carbon dioxide ratio increases, the methane conversion drops but the H₂/CO ratio increases. By the introduction of oxygen, an energy balance in the process of the carbon dioxide reforming methane and oxidation can be realized, and the CO/H₂ ratio can be adjusted as well without water-gas shift reaction for Fischer-Tropsch or methanol synthesis. This work was presented at the 6 ^th Korea-China Workshop on Clean Energy Technology held at Busan, Korea, July 4–7, 2006.     

焦炉煤气-甲醇产业链延伸技术方案的经济分析

与煤制甲醇和天然气制甲醇工艺相比,焦炉煤气制甲醇不仅可以有效利用焦炉煤气中的氢,而且具有低成本的优势。在焦炉煤气制甲醇工艺基础上,文中提出了3种具有发展潜力的焦炉煤气综合利用方案：①气化煤气-焦炉煤气制甲醇生产方案;② 焦炉煤气-乙炔-甲醇下游产品方案;③ 气化煤气-焦炉煤气-乙炔-甲醇下游产品方案。以200×10⁴ t焦炭的生产规模分析了3种方案经济性,其毛利润分别为24.21亿元,18.92亿元和28.74亿元;内部收益率分别为28.29%、24.34%和27.11%。气化煤气-焦炉煤气-乙炔-甲醇下游产品方案充分发挥了规模效应和产品高附加值的特点,具有明显的经济优势;系统灵活性高,抵御市场风险能力强。     

焦炉煤气非催化部分氧化制合成气实验研究与数值模拟

在带有单孔喷嘴石英管反应器实验的基础上,对焦炉煤气非催化部分氧化工艺制合成气进行了研究,分析了O_2/GAS比对合成气各组分含量的影响,反应器中反应过程和温度分布及出口产品组成.实验结果表明CH4转化率随O_2/GAS比增大而增大,O_2/GAS比调节到0.22～0.26时,CH_4转化率达到95%～97%,此时合成气CH_4含量低于1%.利用CFD软件平台对转化反应器进行了数值模拟.模拟结果显示,流量一定时出口气体组分H_2与CH4分别随着进气氧气与焦炉煤气体积流量比值的增加而减少.CO和CO_2分别随着比值的增加而增加.出口气体有效组分摩尔分数随进气流量的变化不是非常明显.在壁面温度为1 100 K时转化效果最好.     

焦炉煤气制甲醇补碳工艺的探讨

焦炉煤气制甲醇工艺日趋成熟,为了充分利用资源,达到节能降耗的要求,采用精馏不凝气进行补碳操作,应用于实际生产当中,这样可以变废为宝,增加资源的综合利用率,真正的作到节能降耗、保护环境,可以优化工艺,提高甲醇产量。     

焦炉煤气制取甲醇合成原料气技术评述

我国每年有大量焦炉煤气放空,利用焦炉煤气制甲醇不仅可以充分利用资源,同时可以减轻焦炉煤气排放对环境造成的污染。介绍了各种焦炉煤气制甲醇合成原料气的技术,并评述了各种技术的优缺点,可供相关工程技术人员参考。     

Thermodynamic Equilibrium Calculations for the Reforming of Coke Oven Gas with Gasification Gas

Thermodynamic analyses of the reforming of coke oven gas with gasification gas for syngas were investigated as a function of coke oven gas‐to‐gasification gas ratio (1–3), oxygen‐to‐methane ratio (0–1.56), pressure (25–35 bar) and temperature (700–1100 °C). Thermodynamic equilibrium results indicate that the operating temperature should be approximately 1100 °C and the oxygen‐to‐methane ratio should be approximately 0.39, where about 80 % CH₄ and CO₂ can be converted at 30 bar. Increasing the operating pressure shifts the equilibrium toward the reactants (CH₄ and CO₂); increasing the pressure from 25 to 35 bar decreases the conversion of CO₂ from 73.7 % to 67.8 %. The conversion ratio of CO₂ is less than that in the absence of O₂. For a constant feed gas composition (7 % O₂, 31 % gasification gas, and 62 % coke oven gas), a H₂/CO ratio of about 2 occurs at temperatures of 950 °C and above. Pressure effects on the H₂/CO ratio are negligible for temperatures greater than 750 °C. The steam produced has an effect on the hydrogen selectivity, but its mole fraction decreases with temperature; trace amounts of other secondary products are observed.     

降低7.63m焦炉炉顶空间温度的方法

针对德国UHDE设计的7.63m焦炉产生的炉顶空间温度较高问题进行了分析,阐述了如何有效降低炉顶空间温度的方法。通过采取调整煤气孔板、蓄热室喷嘴板、稳步降低标准温度等措施,炉顶空间温度从950℃以上降至870℃左右,煤气使用量比投产初期减少了15%以上,并解决了炉顶结石墨的问题。