發(fā)布時(shí)間：2018-05-09 06:34

  本文選題：甲醇制丙烯 + HZSM-5��； 參考：《浙江大學(xué)》2015年博士論文

【摘要】：甲醇制丙烯(MTP)技術(shù)是一項(xiàng)相對獨(dú)立的丙烯生產(chǎn)技術(shù)。MTP技術(shù)的成功開發(fā)與廣泛應(yīng)用,代表著非傳統(tǒng)“煤基路線”或“天然氣/頁巖氣路線”增產(chǎn)丙烯技術(shù)的日趨成熟與完善,對保障我國的能源安全以及奠定未來的化工產(chǎn)業(yè)格局具有十分重要的意義。MTP技術(shù)開發(fā)的首要指標(biāo)與核心競爭力,是催化劑的高丙烯選擇性以及穩(wěn)定性。提高催化劑的丙烯選擇性和穩(wěn)定性的調(diào)控手段,主要基于改善催化劑的傳質(zhì)擴(kuò)散性能以及構(gòu)建或修飾分子篩酸分布,然而現(xiàn)有的調(diào)控手段普遍是“離線”調(diào)控,即未考慮或未結(jié)合反應(yīng)因素對催化劑結(jié)構(gòu)的“實(shí)時(shí)”調(diào)變,故不能很好地滿足催化劑對高丙烯選擇性與反應(yīng)穩(wěn)定性的雙項(xiàng)要求。本文圍繞MTP反應(yīng)因素對HZSM-5催化劑結(jié)構(gòu)的調(diào)變開展研究。通過建立孔道環(huán)境與分子擴(kuò)散行為的相互聯(lián)系,分別研究了水蒸汽老化對積炭的抑制作用、預(yù)積炭以及再生對二次積炭的導(dǎo)向作用,揭示了反應(yīng)氣氛、積炭、再生等因素對催化劑孔道及酸性的作用機(jī)制,提出了積炭調(diào)控協(xié)同水調(diào)控的技術(shù)路線。進(jìn)一步地,研究了積炭與水協(xié)同調(diào)控在MTP兩步法反應(yīng)中的應(yīng)用,并提出了移動(dòng)床MTP工藝的“炭循環(huán)”技術(shù)方案�；谒羝匣瘎�,建立了結(jié)合炭含量因子的MTP反應(yīng)動(dòng)力學(xué),為MTP移動(dòng)床反應(yīng)器的開發(fā)與設(shè)計(jì)提供了指導(dǎo)。具體研究工作與結(jié)果如下：(1)通過建立孔道環(huán)境與分子擴(kuò)散行為的相互聯(lián)系,研究了水蒸汽老化對結(jié)焦的延緩機(jī)制。基于重量法研究了甲醇與甲苯分子在具有不同孔結(jié)構(gòu)參數(shù)的老化劑內(nèi)的擴(kuò)散行為,提出了有利于改善傳質(zhì)擴(kuò)散性能的介孔形態(tài)。通過對比考察以提高空速為手段與以延長時(shí)間為手段,兩種蒸汽處理?xiàng)l件下催化劑的介孔網(wǎng)絡(luò)分布與積炭速率,提出了構(gòu)建“外向型”介孔網(wǎng)絡(luò)以延緩催化劑積炭的方法。(2)考察了N2與H20作為稀釋氣對HZSM-5結(jié)構(gòu)及其催化MTP反應(yīng)性能的影響,并研究了水在分子篩酸性位的“化學(xué)吸附”隨時(shí)間的作用規(guī)律,發(fā)現(xiàn)水促使分子篩脫鋁主要發(fā)生在反應(yīng)初期,且作用對象為不穩(wěn)定的非骨架鋁�；谒倪@種作用機(jī)制,將新鮮催化劑進(jìn)行短時(shí)間的蒸汽老化,通過水的快速脫鋁作用降低催化劑的酸密度并減少水的吸附位點(diǎn),以此提高催化劑對丙烯選擇性與反應(yīng)穩(wěn)定性。針對催化劑的水熱脫鋁問題,研究了在線補(bǔ)酸與在線補(bǔ)磷技術(shù)對催化劑酸性的調(diào)控�？疾炝藱幟仕釢舛�、處理溫度、以及時(shí)間對催化劑酸分布的影響,發(fā)現(xiàn)檸檬酸通過將部分非骨架鋁轉(zhuǎn)變?yōu)楣羌茕X從而增加了分子篩的酸性位�；跈幟仕岬倪@種作用機(jī)制,提出了結(jié)合在線補(bǔ)酸的水蒸汽老化技術(shù)。考察了磷含量、前驅(qū)液濃度、溫度、處理時(shí)間對磷、鋁形態(tài)及其分布的影響,發(fā)現(xiàn)在線補(bǔ)磷的高溫環(huán)境是實(shí)現(xiàn)磷與骨架鋁配位的直接誘導(dǎo)因素。通過進(jìn)一步考察補(bǔ)磷催化劑的水熱穩(wěn)定性,驗(yàn)證了在線補(bǔ)磷對穩(wěn)定骨架鋁的作用及效果。(3)研究并建立了以積炭作為調(diào)控手段的催化劑改性方法�？疾炝说蜏靥啃螒B(tài)與高溫炭形態(tài)隨溫度與時(shí)間的變化,揭示了低溫炭向高溫炭的演變過程。設(shè)計(jì)了在不同溫度、原料、時(shí)間下制備的積炭劑,研究了積炭對催化劑結(jié)構(gòu)的修飾作用及其對二次積炭的導(dǎo)向作用,提出了以積炭調(diào)控輔助水調(diào)控的催化劑改性方法。通過研究高溫積炭在低溫下的二次積炭行為,與低溫積炭在高溫下的二次積炭行為,提出了移動(dòng)床MTP兩步法工藝的“炭循環(huán)”技術(shù)。(4)研究了不同反應(yīng)-再生周期中焦的生長規(guī)律及催化劑失活規(guī)律。通過研究催化劑在高、低空速下反應(yīng)的積炭分布,發(fā)現(xiàn)高甲醇空速致使其殼層積炭而失活,而低甲醇空速則致使其晶內(nèi)積炭而失活,顯示出不同的失活機(jī)理。通過跟蹤甲醇、甲苯、異戊烷分子在不同程度積炭劑內(nèi)的擴(kuò)散行為,提出了積炭“由內(nèi)而外”地生長過程。通過對比研究新鮮催化劑與再生催化劑的積炭行為與反應(yīng)性能,揭示了第一周期水與第二周期積炭對催化劑失活的競爭作用。(5)采用水蒸汽老化劑為研究對象,在等溫固定床反應(yīng)器中考察了甲醇單獨(dú)反應(yīng)、甲醇分別與C2-C6烯烴耦合反應(yīng)的產(chǎn)物分布隨甲醇空速(3-40(gmethanol/ gcat·h)和反應(yīng)溫度(420～500℃)的變化規(guī)律,研究了甲醇平行反應(yīng)、烯烴甲基化反應(yīng)、以及烯烴疊合與裂化反應(yīng)的競爭關(guān)系。在低甲醇空速(0.5～5 gmethanol/ gcat·h)下,通入丙烯作為烯烴氫轉(zhuǎn)移與芳構(gòu)化反應(yīng)的促進(jìn)劑,研究了MTP反應(yīng)中芳烴與丙烷的生成路徑。建立了可準(zhǔn)確描述甲醇、乙烯、丙烯、丙烷、C4、C5、C6、C7+及芳烴等9種組分或集總組分生成與消耗速率的MTP反應(yīng)動(dòng)力學(xué)模型,并在模型中引入了炭含量因子以考慮催化劑的積炭失活。模型適用于預(yù)測MTP反應(yīng)或醇烴共煉MTP反應(yīng)在初始階段以及不同積炭階段的產(chǎn)物組成。
[Abstract]:The technology of methanol propylene (MTP) is a successful development and wide application of a relatively independent propylene production technology.MTP technology. It represents the increasing maturity and perfection of the non traditional "coal based route" or "natural gas / shale gas route" to increase the production of propylene. It will guarantee the energy security of our country and establish the future industrial pattern of chemical industry. The primary index and core competitiveness of.MTP technology development are very important. It is the high propene selectivity and stability of the catalyst. To improve the selectivity and stability of the catalyst, it is mainly based on the improvement of the mass transfer performance of the catalyst and the construction or modification of the distribution of molecular sieve acid. However, the existing regulation means It is "off-line" regulation, that is, the "real time" modulation of the catalyst structure is not considered or uncombined, so it can not meet the dual requirements of the catalyst for selectivity and stability of the catalyst. This paper studies the modulation of the structure of the HZSM-5 catalyst by the MTP reaction factors. The effects of water vapor aging on carbon accumulation, pre carbon deposition and the guiding effect of regeneration on two carbon deposits were studied, and the mechanism of reaction atmosphere, carbon accumulation, regeneration and other factors on the catalyst pore and acidity were revealed, and a technical route for regulating carbon accumulation and regulating water was proposed. The application of CO regulation with water in the MTP two step process and the "carbon cycle" technology of the mobile bed MTP process is proposed. Based on the water vapor aging agent, the MTP reaction kinetics with the carbon content factor is established, which provides guidance for the development and design of the MTP mobile bed reactor. The specific research work and results are as follows: (1) through establishment The interaction between the pore environment and the molecular diffusion behavior is studied. The diffusion behavior of methanol and toluene in the aging agent with different pore structure parameters is studied based on the gravimetric method, and the mesoporous morphology is proposed to improve the mass transfer diffusion properties. The air velocity is improved by comparison and investigation. Methods and the distribution of mesoporous network and carbon deposition rate of the catalyst under two steam treatment conditions, the method of constructing "export-oriented" mesoporous network to delay the catalytic carbon deposition was proposed. (2) the effects of N2 and H20 as diluent on the structure of HZSM-5 and the catalytic performance of MTP were investigated, and water was studied in molecular sieve. The effect of "chemical adsorption" of acid sites on time has been found. It is found that water promotes molecular sieve dealuminum mainly at the beginning of the reaction, and the action object is unstable non skeleton aluminum. Based on this mechanism of water, fresh catalyst is used for a short time steam aging, and the acid density of the catalyst is reduced by the rapid dealuminum action of water. In order to improve the selectivity and stability of propylene with less water, in order to improve the selectivity and stability of propylene, the influence of the concentration of citric acid, treatment temperature and time on the acid distribution of the catalyst was investigated. Non skeleton aluminum is transformed into skeleton aluminum to increase the acid site of molecular sieve. Based on this mechanism of citric acid, a water vapor aging technology combined with on-line acid supplementation is proposed. The effects of phosphorus content, precursor concentration, temperature, treatment time on phosphorus, aluminum morphology and distribution are investigated. The high temperature environment of on-line phosphorus supplement is found to be the realization of phosphorus and bone. The effect and effect of on-line phosphorus supplementation on the stability of skeleton aluminum were verified by further investigation of the thermal stability of the phosphorus supplementing catalyst. (3) the modification method of catalyst with carbon accumulation as a control method was studied and established. The changes of the morphology of the carbon and the morphology of the high temperature carbon with the temperature and time were investigated. The evolution process of low temperature carbon to high temperature carbon was designed. The charcoal agent prepared at different temperatures, raw materials and time was designed. The modification of carbon deposit on the structure of catalyst and its guiding effect on the two carbon deposition were studied. The modified method of catalyst was put forward with the control of auxiliary water by carbon deposition. By studying the two carbon deposits of high temperature carbon deposited at low temperature. Behavior, and the two Coking Behavior of low temperature charcoal at high temperature, a "carbon cycle" technique of MTP two step process in moving bed was put forward. (4) the growth law of coke and the deactivation law of catalyst in different reaction and regeneration period were studied. By studying the distribution of coke deposited at high and low velocity, it was found that the velocity of high methanol resulted in the shell of the catalyst. The cocharcoal is deactivated, and the low methanol airspeed leads to the inactivation of the inner carbon deposit, showing different inactivation mechanisms. By tracking the diffusion behavior of methanol, toluene, and isopentane in different degrees of carbon accumulation, the carbon accumulation "from inside to outside" growth process is proposed. The carbon accumulation behavior of fresh catalyst and regeneration catalyst is studied by comparison. The competitive effect of the first periodic water and second periodic carbon deposition on the deactivation of the catalyst was revealed. (5) using the water vapor aging agent as the research object, the methanol reaction was investigated in an isothermal fixed bed reactor. The distribution of methanol to the C2-C6 olefin coupling reaction was followed by the methanol air velocity (3-40 (gmethanol/ gcat. H) and reaction. The parallel reaction of methanol, the methylation of olefin methylation, and the competitive relationship between olefin superposition and cracking reaction were studied at temperature (420~500 degrees C). Under low methanol velocity (0.5 ~ 5 gmethanol/ gcat h), propene was used as a promoter for hydrogen transfer and aromatization of olefin, and the formation path of aromatics and propane in MTP reaction was studied. A kinetic model of MTP reaction, which can accurately describe the 9 components of methanol, ethylene, propylene, propane, propane, C4, C5, C6, C7+ and aromatics, is established and the carbon content factor is introduced in the model to consider the deactivation of the catalyst. The model is suitable for predicting MTP reaction or alcohol hydrocarbon co refining MTP reaction at the initial stage. And the composition of the products in different carbon deposition stages.

【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TQ221.212;O643.36

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相關(guān)期刊論文 前10條

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本文編號：1864963