【正文】 環(huán)氧乙烷反應(yīng)，可以得到較高的 選擇性和轉(zhuǎn)化率。因此，在實用的反應(yīng)條件下得到超過 80 %選擇性的時候，沒有進一步期望今后還能大幅改善性能。今后，乙二醇仍將是環(huán)氧乙烷的最大消費領(lǐng)域 ， 預(yù)計未來幾年里，環(huán)氧乙烷和乙二醇的需求仍將高速增長， 20xx 年我國環(huán)氧乙烷年生產(chǎn)能力將達到 390 萬噸 [4]。例如在催化劑方面，盡管載體、物理性能和制備方法略有差異，但水平比較接近，選擇性均在 80 %以上；在工藝技術(shù)方面都有反應(yīng)部分、一氧化碳脫除、環(huán)氧乙烷回收組成，但抑制劑選擇、工藝流程上有所差異。 近年來環(huán)氧乙烷的生產(chǎn)發(fā)展趨勢 近年來，全球環(huán)氧乙 烷生產(chǎn)主要呈現(xiàn)以下幾大趨勢：一是生產(chǎn)裝置逐漸趨于大型化，而且建 廠 地點逐漸趨向于原材料來源豐富、價格低廉地區(qū)；二是生產(chǎn)裝置的擴建仍然以與乙二醇配套為主；三是先進的核心生產(chǎn)技術(shù)仍然控制在少數(shù)西方發(fā)達國家和地區(qū)的跨國公司。 環(huán)氧乙烷生產(chǎn)工藝的發(fā)展 氯乙醇法存在三廢污染 等 問題，因此在上世紀 70 年代中期，經(jīng)典的氯乙醇法工藝幾乎全部被淘汰，乙烯直接氧化法成為實際工業(yè)應(yīng)用的環(huán)氧乙烷生 產(chǎn)技術(shù)。 環(huán)氧乙烷的生產(chǎn)發(fā)展概況 早期環(huán)氧乙烷的生產(chǎn) 早期環(huán)氧乙烷生產(chǎn)采用氯乙醇法工藝。本論文 還 對催化劑的制備條件進行了優(yōu)化，初步探討了助劑對催化劑催化性能的影響，考察了反應(yīng)條件如空速、反應(yīng)氣原料比等因素對催化劑催化性能的影響 。乙烷高溫裂解制乙烯的溫度通常在 900 ℃ 以上， 而 乙烯直接氧化制環(huán)氧乙烷的反應(yīng)溫度一般在 200 ℃ ~300 ℃ 之間，由于兩者溫差很大，使得在目前條件下不可能由乙烷一步氧化直接制環(huán)氧乙烷。結(jié)果表明，優(yōu)化條件下制備的催化劑在 350 ℃ 下具有 較 好的催化性能，在實驗條件下乙烯的 收 率可達 25 %。 摘 要 II 關(guān)鍵詞 ： 乙烷 ； 環(huán)氧化 ； 環(huán)氧乙烷；催化劑 ABSTRACT III THE STUDY ON THE CATALYST OF DIRECT OXIDATION ETHANE TO ETHYLENE OXIDE ABSTRACT Ethylene oxide as derivatives of ethylene industury is an important anic chemical products and wildely used as anic synthetic intermediate. In the industrial process ethylene oxide is obtained through epoxidation of ethylene which is obtained through steam cracking of ethane or naphtha. Generally, the preparation temperature of ethylene by high temperature cracking of ethane is above 900 ℃ , but the preparation temperature of ethylene oxide by direct oxidation of ethylene is between 200 ℃ and 300 ℃ . The great temperature difference makes it impossible to synthesize ethylene oxide by direct oxidation of ethane. Nanoscaled nickel oxide can greatly reduce the reaction temperature of oxidation dehydrogenation of ethane. In this paper we firstly investigate lowtemperature oxidation of ethane to ethylene using nanosized nickel oxide as catalyst in order to reduce the reaction temperature. The result indicated that under 350 ℃ the catalyst prepared in optimum conditions showed better catalystic performance and the yield of ethylene can reach 25 %. On this basis we studied the “one step with two stage” on nanosized nickel oxide and Ag with ethane flowing through them orderly under the same temprature. It’s found that ethylene oxide can be directly prepared by ethane. The catalyst was prepared by different method and AgNiO catalyst prepared by homogeneous precipitation method shows better behavior with ethane conversion of % and ethylene oxide selectivity of %. We also optimized the preparation condition of catalyst, disscussed the effect of promoter on catalytic performance, investigated the effects of reaction conditions such as space velocity, the ratio of reaction gas. This paper also discussed the mechanism of the onestep reaction over AgNiO ABSTRACT IV catalyst. The results of TPR and XPS indicated that there is an interaction between Ni and Ag in the catalyst, and it is the surface species of Ni that activate ethane. Since the surface active species were reduced and separated by the doping of Ag, the activity of AgNiO catalyst reduced pared with pure NiO. The product of ethylene oxide was obtained by the oxygen intercalation reaction between the intermediate and electrophilic oxygen species on the surface of Ag. KEY WORDS： ethane； epoxidation； ethylene oxide； catalyst 目 錄 V 目 錄 摘 要 ................................................................................................................................. I ABSTRACT ......................................................................................................................III 目 錄 ................................................................................................................................V 第 1 章 緒 論 .................................................................................................................. 1 環(huán)氧乙烷的用途 ............................................................................................. 1 環(huán)氧乙烷的生產(chǎn)發(fā)展概況 ............................................................................. 1 早期環(huán)氧乙烷的生產(chǎn) ............................................................................ 1 環(huán)氧乙烷生產(chǎn)工藝的 發(fā)展 .................................................................... 2 環(huán)氧乙烷生產(chǎn)工藝的改進 .................................................................... 4 乙烯的用途 ..................................................................................................... 7 乙烯的生產(chǎn)技術(shù)現(xiàn)狀 ..................................................................................... 7 石化原料裂解制乙烯 ............................................................................ 8 乙烷催化裂解制乙烯 ............................................................................ 8 乙烷氧化脫氫制乙烯 ............................................................................ 9 乙烯工業(yè)生產(chǎn)的技術(shù)進展 .................................................................. 13 選題意義 ....................................................................................................... 13 研究內(nèi)容 ....................................................................................................... 14 第 2 章 實驗部分 .......................................................................................................... 16 實驗 試劑及規(guī)格 ........................................................................................... 16 實驗儀器及型號 ........................................................................................... 17 催化劑性的性能評價和計算方法 ............................................................... 18 催化劑的性能評價 .............................................................................. 18 催化劑性能的計算方法 ...................................................................... 18 表征實驗 .............