Methanol-to-olefins(MTO)is industrially applied to produce ethylene and propylene using methanol converted from coal,synthetic gas,and biomass.SAPO-34 zeolites,as the most efficient catalyst in MTO process,are subject...Methanol-to-olefins(MTO)is industrially applied to produce ethylene and propylene using methanol converted from coal,synthetic gas,and biomass.SAPO-34 zeolites,as the most efficient catalyst in MTO process,are subject to the rapid deactivation due to coke deposition.Recent work shows that steam regeneration can provide advantages such as low carbon dioxide emission and enhanced light olefins yield in MTO process,compared to that by air regeneration.A kinetic study on the steam regeneration of spent SAPO-34 catalyst has been carried out in this work.In doing so,we first investigated the effect of temperature on the regeneration performance by monitoring the crystal structure,acidity,residual coke properties and other structural parameters.The results show that with the increase of regeneration temperature,the compositions of residual coke on the catalyst change from pyrene and phenanthrene to naphthalene,which are normally considered as active hydrocarbon pool species in MTO reaction.However,when the regeneration temperature is too high,nitrogen oxides can be found in the residual coke.Meanwhile,as the regeneration temperature increases,the quantity of residual coke reduces and the acidity,BET surface area and pore structure of the regenerated samples can be better recovered,resulting in prolonging catalyst lifetime.We have further derived the kinetics of steam regeneration,and obtained an activation energy of about 177.8 kJ·mol^(-1).Compared that with air regeneration,the activation energy of steam regeneration is higher,indicating that the steam regeneration process is more difficult to occur.展开更多
研究按订单生产(make to order,MTO)模式下随机订单的准入策略.本文提出的准入决策方法分为两步,首先在考虑随机订单的不同属性基础上,采用TOPSIS(technique for order preference by similarity to an ideal solution)方法计算新到订...研究按订单生产(make to order,MTO)模式下随机订单的准入策略.本文提出的准入决策方法分为两步,首先在考虑随机订单的不同属性基础上,采用TOPSIS(technique for order preference by similarity to an ideal solution)方法计算新到订单与理想订单的接近程度,以此作为订单的综合收益,从而对新订单进行分层排序;其次采用MDP(Markov decision process)模型分别计算接受和拒绝订单的期望收益,从而决定是否接受该订单.研究发现,当市场需求接近或大于产能时,企业可从订单分层中获益;反之,市场需求显著小于产能时,分层不会带来额外收益.企业分层收益随需求增加或产能减少而递增,且与生产前置期呈倒U型关系.数值模拟发现,订单分层越精细,收益越大,且分层数约为需求与企业产能的比值时,订单分层收益接近最大值.展开更多
甲醇制烯烃技术(DMTO,Dimethylether/Methanol to Olefin)是中科院大连化学物理研究所与中石化洛阳工程有限公司和新兴能源科技公司合作开发的具有自主知识产权的低碳烯烃生产新技术。2010年8月采用DMTO技术的世界上首套甲醇制烯烃工业...甲醇制烯烃技术(DMTO,Dimethylether/Methanol to Olefin)是中科院大连化学物理研究所与中石化洛阳工程有限公司和新兴能源科技公司合作开发的具有自主知识产权的低碳烯烃生产新技术。2010年8月采用DMTO技术的世界上首套甲醇制烯烃工业装置在神华包头投料开车成功;2013年2月宁波禾元的DMTO工业装置也投入运行。这两套装置的甲醇进料量均为1.80 Mt/a,烯烃产量为600 kt/a。本文对DMTO工艺机理、工程设计特点和投料运行进行了介绍。DMTO工业装置运行结果表明,DMTO专用催化剂具有非常好的活性、选择性及抗磨损性能;采用大型浅层密相流化床反应器可以发挥催化剂性能,保障反应床层恒温及提高运行可靠性。为了减少开工阶段喷燃烧油可能对催化剂带来的不利影响,两套工业装置的投料开车均采用首创的利用反应热来进行再生器和反应器升温的方法。DMTO工业装置稳定运行时甲醇转化率接近100%,双烯选择性达到80%。72 h标定结果显示,生产1 t烯烃所需要的甲醇原料约为2.97 t。展开更多
基金the National Natural Science Foundation of China(91834302)。
文摘Methanol-to-olefins(MTO)is industrially applied to produce ethylene and propylene using methanol converted from coal,synthetic gas,and biomass.SAPO-34 zeolites,as the most efficient catalyst in MTO process,are subject to the rapid deactivation due to coke deposition.Recent work shows that steam regeneration can provide advantages such as low carbon dioxide emission and enhanced light olefins yield in MTO process,compared to that by air regeneration.A kinetic study on the steam regeneration of spent SAPO-34 catalyst has been carried out in this work.In doing so,we first investigated the effect of temperature on the regeneration performance by monitoring the crystal structure,acidity,residual coke properties and other structural parameters.The results show that with the increase of regeneration temperature,the compositions of residual coke on the catalyst change from pyrene and phenanthrene to naphthalene,which are normally considered as active hydrocarbon pool species in MTO reaction.However,when the regeneration temperature is too high,nitrogen oxides can be found in the residual coke.Meanwhile,as the regeneration temperature increases,the quantity of residual coke reduces and the acidity,BET surface area and pore structure of the regenerated samples can be better recovered,resulting in prolonging catalyst lifetime.We have further derived the kinetics of steam regeneration,and obtained an activation energy of about 177.8 kJ·mol^(-1).Compared that with air regeneration,the activation energy of steam regeneration is higher,indicating that the steam regeneration process is more difficult to occur.
文摘研究按订单生产(make to order,MTO)模式下随机订单的准入策略.本文提出的准入决策方法分为两步,首先在考虑随机订单的不同属性基础上,采用TOPSIS(technique for order preference by similarity to an ideal solution)方法计算新到订单与理想订单的接近程度,以此作为订单的综合收益,从而对新订单进行分层排序;其次采用MDP(Markov decision process)模型分别计算接受和拒绝订单的期望收益,从而决定是否接受该订单.研究发现,当市场需求接近或大于产能时,企业可从订单分层中获益;反之,市场需求显著小于产能时,分层不会带来额外收益.企业分层收益随需求增加或产能减少而递增,且与生产前置期呈倒U型关系.数值模拟发现,订单分层越精细,收益越大,且分层数约为需求与企业产能的比值时,订单分层收益接近最大值.
