【正文】 5=C6H6+C2H4 12 C6H5C2H5+H2=C6H5CH3+CH4 其他反應(yīng)生成少量的α — 甲基苯乙烯（ AMS）和其他高沸物。反應(yīng)方程式如下： C6H5C2H5 → C6H5CHCH2 + H2↑ 同時還有副反應(yīng)發(fā)生，如裂解反應(yīng)和加氫裂解反應(yīng) ： 11 C6H5C2H5 + H2↑ → C6H5CH3+ CH4 C6H5C2H5 + H2↑ → C6H6 + CH3CH3 C6H5C2H5 → C6H6 + CH2CH2 高溫裂解生碳： C6H5C2H5 → 8C + 5H2↑ 在水蒸汽存在下，發(fā)生水蒸汽的轉(zhuǎn)化反應(yīng)： C6H5C2H5 + 2H2O → C6H5CH3 + CO2 + 3H2 此外還有高分子化合物的聚合反應(yīng)，如聚苯乙 烯、對稱二苯乙烯的衍生物等。 乙苯催化脫氫法 這是目前生產(chǎn)苯乙烯的主要方法，目前世界上大約 90%的苯乙烯采用該方法生產(chǎn)。研究的催化劑種類較多，如氧化鎘，氧化鍺，鎢、鉻、鈮、鉀、鋰等混合氧化物，鉬酸銨、硫化鉬及載在氧化鎂上的鈷、鉬等。 乙苯氧化脫氫法 乙苯氧化脫氫法是目前尚處于研究階段生產(chǎn)苯乙烯的方法。 乙苯和丙烯共氧化法 本法首先在堿性催化劑作用下，使乙苯液相氧化成過氧化氫乙苯，然后與丙烯進(jìn)行環(huán)氧化反應(yīng)生成環(huán)氧丙烷，乙苯過氧化物則變?yōu)椋揭掖?，再?jīng)脫水得到苯乙烯，即： C6H5C2H5 + O2↑ → C6H5CHOOHCH3 C6H5CHOOHCH3 + CH3CHCH2 → C6H5CHOHCH3+ C3H6O C6H5CHOHCH3 → C6H5CHCH2 + H2O 本過程以乙苯計的苯乙烯產(chǎn)率約為 65%，低于乙苯脫氫法的產(chǎn)率。 苯乙酮法 較早采用苯乙酮法生產(chǎn)苯乙烯，其步驟主要分為氧化、還原和脫水三步，方程式如下： C6H5C2H5 + O2 → C6H5COCH3 + H2O 10 C6H5COCH3 + H2 → C6H5CHOHCH3 C6H5CHOHCH3 → C6H5CHCH2 + H2O 該法苯乙烯產(chǎn)率 為 75～ 80%，略低于乙苯脫氫法的產(chǎn)率，但中間副產(chǎn)物苯乙酮產(chǎn)值較高，苯乙烯的精制分離較容易。世界苯乙烯生產(chǎn)能力在 1996年已達(dá) 1900 萬噸，目前全世界苯乙烯產(chǎn)能約為 2150～ 2250 萬噸。由苯乙烯共聚的塑料可加工成為各種日常生活用品和工程塑料，用途極為廣泛。因此，苯乙烯單體在貯存和運(yùn)輸中都必須加入阻聚劑，并注意用惰性氣體密封，不使其與空氣接觸。苯乙烯從結(jié)構(gòu)上看是不對稱取代物，乙烯基因帶有極性而易于聚合。苯乙烯蒸汽與空氣混合能形成爆炸性混合物，其爆炸范圍為 ～ %（體積分?jǐn)?shù)）。濃度過高、接觸時間過長則對人體有一定的危害。苯乙烯溶于甲醇、乙醇、乙醚等溶劑中。苯乙烯為 無色透明液體，常溫下具有辛辣香味，易燃。 dehydrogenase。 distillation。s activity has been significantly improved, can lower water ratios apply, K2O content too high potassium loss exists.. in order to solve the catalyst in the use process problems, the author takes a fixed bed reactor to selfmade iron and low potassium oxide as a catalyst, visit reaction temperature, feed ratio and catalyst activity on Ethylbenzene conversion rate, the selectivity of polystyrene and styrene yield, determine the best process conditions. This design is 10 million tons/year of ethyl benzene dehydrogenation processes, process with low activity, high selectivity of iron oxide catalysts, reference rhuems (Lummus) pany production of styrene technology, to production of styrene Ethylbenzene dehydrogenation. Designs include: process design, process calculation, equipment design, etc. This design is mainly posed of dehydrogenation and distillation two operation systems. Ethylbenzene dehydrogenation in adiabatic fixed bed reactor, reactants to the distillation process. First Ethylbenzenestyrene Tower isolation of Ethylbenzene (benzene, toluene) and styrene (with reanization and tar). Ethyl benzene fractions to benzenetoluene Tower intobenzene, toluene, Ethylbenzene distillate and recycle recycling Ethylbenzene returns dehydrogenation processes. Crude distillation into fine styrene sent to styrene and tar. Process calculation includes the main reactor and distillation column material balance and thermal balance. Equipment design mainly on Ethylbenzene/styrene separation column for design, calculation of the actual number of trays, feeding in 26 block 13 block plate, diameter , Tower high 20m. Qilu 200kt/2 styrene plant pleted, Ethylbenzene/styrene separation column operation indicators a direct access to the design requirements, the Tower of styrene content up to 8%, much higher than the design value of 1%, while the Tower Kettle Ethylbenzene content in %, higher than the design value of % and feed load does not meet the design production capacity, higher feed load, to lower the effect. Programme through the development of technology operations, search and inspect a variety of different conditions on the operation status, and through cold model experiments, modeling software, through the operation of data parison and analysis, identify the problems of this tower, the analysis of the causes of the problem. On this basis, the proposed separation of Ethylbenzene/styrene Tower renovation 8 programme. On separation column for the success of technology transformation, replaced Ethylbenzene/styrene separation column rectification period portion filler and some internals, solves the puzzle without doubt the normal operation of the main contradictions, making the transformation of separation column running effect markedly. Top quality score styrene from 8% to 3%. In further analysis on the basis of the study, this tower undergone a series of actions, by adjusting the pressure distillation operations and reflux ratio and so on technology, this tower of coefficient of separation effect up to ultimately achieve even exceeded the design criteria, the unit production capacity is significantly improved. The tower is less than 1% of styrene content, the content is smaller than the caldron of Ethylbenzene, styrene % purity achieved %, achieved a better economic efficiency. Keywords: Ethylbenzene。塔頂苯乙烯含量小于 1%，塔釜乙苯含量小于 %,苯乙烯產(chǎn)品純度達(dá)到 %以上，取得了較好的經(jīng)濟(jì)效益。塔頂苯乙烯質(zhì)量分?jǐn)?shù)由原來的 8%降至 3%。在此基礎(chǔ)上，提出了乙苯 /苯乙烯分離塔 6 的改造方案 。 齊魯 200kt/2 苯乙烯裝置改造完成后，乙苯 /苯乙烯分離塔操作指標(biāo)一直達(dá)不到設(shè)計要求，塔頂苯乙烯含量高達(dá) 8%左右，遠(yuǎn)高于設(shè)計值 1%的要求，而塔釜乙苯含量在 %左右，也高于 %的設(shè)計值，而且進(jìn)料負(fù)荷也沒有達(dá)到設(shè)計的生產(chǎn)能力，進(jìn)料負(fù)荷越高，奮力效果越差。 工藝計算包括主反應(yīng)器和精餾塔的物料衡算以及熱量衡算。乙苯餾分送苯 甲苯塔分成苯、甲苯餾分和回收乙苯，回收乙苯返回脫氫工序。乙苯脫氫反應(yīng)在絕熱固定床反應(yīng)器中進(jìn)行，反應(yīng)物送至精餾工序。 設(shè)計內(nèi)容主要包括：工藝流程設(shè)計、工藝計算、設(shè)備設(shè)計等。 .為了解決催化劑在使用過程中存在的問題，作者采用固定床反應(yīng)器，以自制的高鐵低鉀氧化鐵為催化劑，考察反應(yīng)溫度、進(jìn)料比和催化劑活性對乙苯轉(zhuǎn)化率、苯乙烯選擇性和苯乙烯收率的影響，確定了最佳的工藝條件。乙苯催化脫氫法是目前國內(nèi)外生產(chǎn)苯乙烯的主要方法，采用的 催化劑主要是 FeK系催化劑，其中 Fe2O3。本人完全意識到本聲明的法律結(jié)果由本人承擔(dān)。 3 畢業(yè)設(shè)計誠信聲明 本人鄭重聲明：所呈交的畢業(yè)設(shè)計，是本人在指導(dǎo)老師的指導(dǎo)下，獨(dú)立進(jìn)行研究工作所取得的成果，成果不存在知識產(chǎn)權(quán)爭議，除文中已經(jīng)注明引用的內(nèi)容外，本設(shè)計不含任何其他個人或集體已經(jīng)發(fā)表或撰寫過的作品成果。對本文的研究做出重要貢獻(xiàn)的個人和集體均