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

【摘要】：甲醇制丙烯(MTP)技術是一項相對獨立的丙烯生產(chǎn)技術。MTP技術的成功開發(fā)與廣泛應用,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技術開發(fā)的首要指標與核心競爭力,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)定性的調控手段,主要基于改善催化劑的傳質擴散性能以及構建或修飾分子篩酸分布,然而現(xiàn)有的調控手段普遍是“離線”調控,即未考慮或未結合反應因素對催化劑結構的“實時”調變,故不能很好地滿足催化劑對高丙烯選擇性與反應穩(wěn)定性的雙項要求。本文圍繞MTP反應因素對HZSM-5催化劑結構的調變開展研究。通過建立孔道環(huán)境與分子擴散行為的相互聯(lián)系,分別研究了水蒸汽老化對積炭的抑制作用、預積炭以及再生對二次積炭的導向作用,揭示了反應氣氛、積炭、再生等因素對催化劑孔道及酸性的作用機制,提出了積炭調控協(xié)同水調控的技術路線。進一步地,研究了積炭與水協(xié)同調控在MTP兩步法反應中的應用,并提出了移動床MTP工藝的“炭循環(huán)”技術方案�；谒羝匣瘎�,建立了結合炭含量因子的MTP反應動力學,為MTP移動床反應器的開發(fā)與設計提供了指導。具體研究工作與結果如下：(1)通過建立孔道環(huán)境與分子擴散行為的相互聯(lián)系,研究了水蒸汽老化對結焦的延緩機制。基于重量法研究了甲醇與甲苯分子在具有不同孔結構參數(shù)的老化劑內的擴散行為,提出了有利于改善傳質擴散性能的介孔形態(tài)。通過對比考察以提高空速為手段與以延長時間為手段,兩種蒸汽處理條件下催化劑的介孔網(wǎng)絡分布與積炭速率,提出了構建“外向型”介孔網(wǎng)絡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結構及其催化MTP反應性能的影響,并研究了水在分子篩酸性位的“化學吸附”隨時間的作用規(guī)律,發(fā)現(xiàn)水促使分子篩脫鋁主要發(fā)生在反應初期,且作用對象為不穩(wěn)定的非骨架鋁�；谒倪@種作用機制,將新鮮催化劑進行短時間的蒸汽老化,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,以此提高催化劑對丙烯選擇性與反應穩(wěn)定性。針對催化劑的水熱脫鋁問題,研究了在線補酸與在線補磷技術對催化劑酸性的調控�？疾炝藱幟仕釢舛�、處理溫度、以及時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@種作用機制,提出了結合在線補酸的水蒸汽老化技術�？疾炝肆缀俊⑶膀屢簼舛�、溫度、處理時間對磷、鋁形態(tài)及其分布的影響,發(fā)現(xiàn)在線補磷的高溫環(huán)境是實現(xiàn)磷與骨架鋁配位的直接誘導因素。通過進一步考察補磷催化劑的水熱穩(wěn)定性,驗證了在線補磷對穩(wěn)定骨架鋁的作用及效果。(3)研究并建立了以積炭作為調控手段的催化劑改性方法。考察了低溫炭形態(tài)與高溫炭形態(tài)隨溫度與時間的變化,揭示了低溫炭向高溫炭的演變過程。設計了在不同溫度、原料、時間下制備的積炭劑,研究了積炭對催化劑結構的修飾作用及其對二次積炭的導向作用,提出了以積炭調控輔助水調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,提出了移動床MTP兩步法工藝的“炭循環(huán)”技術。(4)研究了不同反應-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積炭而失活,顯示出不同的失活機理。通過跟蹤甲醇、甲苯、異戊烷分子在不同程度積炭劑內的擴散行為,提出了積炭“由內而外”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,在等溫固定床反應器中考察了甲醇單獨反應、甲醇分別與C2-C6烯烴耦合反應的產(chǎn)物分布隨甲醇空速(3-40(gmethanol/ gcat·h)和反應溫度(420～500℃)的變化規(guī)律,研究了甲醇平行反應、烯烴甲基化反應、以及烯烴疊合與裂化反應的競爭關系。在低甲醇空速(0.5～5 gmethanol/ gcat·h)下,通入丙烯作為烯烴氫轉移與芳構化反應的促進劑,研究了MTP反應中芳烴與丙烷的生成路徑。建立了可準確描述甲醇、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反應動力學模型,并在模型中引入了炭含量因子以考慮催化劑的積炭失活。模型適用于預測MTP反應或醇烴共煉MTP反應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.

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

【參考文獻】

相關期刊論文 前10條

1 劉金香,蔡光宇,楊立新,高秀英,季平,陳國權;熱重法研究甲醇在沸石催化劑上轉化為低級烯烴過程中的積炭行為[J];催化學報;1985年03期

2 汪樹軍,梁娟,郭文s，

本文編號：1864963