第59卷第6期化工學(xué)報(bào)Vol. 59 No 62008年6月Journal of Chemical Industry and Engineering (China)June 2008研究論文催化加氫法提高乙二醇質(zhì)量曹玉霞,陳群',周繼東2,張益峰(江蘇工業(yè)學(xué)院精細(xì)石油化工重點(diǎn)實(shí)驗(yàn)室,江蘇常州213164;4北京化工研究院,北京100013)摘要:對(duì)催化加氫法提高乙二醇質(zhì)量進(jìn)行了研究,考察了反應(yīng)溫度、壓力和乙二醇空速對(duì)乙二醇紫外透過(guò)率和雜質(zhì)去除率的影響。結(jié)果表明,在反應(yīng)溫度353K、乙二醇液時(shí)空速30h1、壓力0.25MPa、氫氣質(zhì)量空速0.02g·ml-·h-1條件下,催化劑連續(xù)運(yùn)行90d,乙二醇含水料在220、275、350nm的UV值由原來(lái)的49.6%、88.2%、97.7%平均提高到738%、93.2%、99.7%,精餾后乙二醇成品的紫外透過(guò)率平均提高到84.2%、95.1%99.9%,雜質(zhì)去除率提高到75.5%、60%、95.8%,成品的醛含量由原來(lái)的11.5gg·g1下降到3.7Ag·g-1關(guān)鍵詞:紫外透過(guò)率;乙二醇;骨架鎳催化劑;催化加氫中圖分類(lèi)號(hào):TQ223.16+2文獻(xiàn)標(biāo)識(shí)碼:A文章編號(hào):0438-1157(2008)06-1600-06Catalytic hydrogenation to improve ethylene glycol qualityCAO Yuxia, CHEN Qun', ZHOU Jidong,, ZHANG Yifeng( Jiangsu Key Laboratory of Fine Chemicals, Jiangsu Polytechnic University, Changzhou 213164Jiangsu, China: Beijing Research institute of Chemical Industry, Beijing 100013Abstract: The method of catalytic hydrogenation was used to improve production of ethylene glycol (EG)over Raney nickel catalyst. Under the reaction condition of temperature 353 K, EG liquid hourly spacevelocity 30 h-, H2 pressure 0. 25 MPa, H2 mass space velocity 0. 02 g.ml-.h and hydrogenationtime 90 d, ultraviolet light transmittance of Eg with water content at 220 nm, 275 nm and 350 nm wereproved averagely from 49.., 97. 7% to 73. 8%,93 2%,99 7% respectively, and further to84.2%,95.1%,99.9% after rectification. The removal efficiency of impurities was up to 75., 60%and 95.8%. The amount of aldehyde was reduced from 11. 5 Hg.g-l to 3. 7 ug. gKey words: ultraviolet light transmittance; ethylene glycol: Raney Ni catalyst; catalytic hydrogenation引言量,因此國(guó)際上普遍釆用UV值來(lái)控制乙二醇的質(zhì)量,我國(guó)的國(guó)家標(biāo)準(zhǔn)(GB4649-93)也規(guī)定了乙二醇是生產(chǎn)聚酯纖維的重要有機(jī)化工原料,成品乙二醇在220、275、350m波長(zhǎng)處的UⅤ值其質(zhì)量的優(yōu)劣將對(duì)下游產(chǎn)品產(chǎn)生很大的影響。由于應(yīng)分別大于70%、90%、98%。隨著乙二醇需求紫外透過(guò)率(UV值)能靈敏地反映乙二醇產(chǎn)品中不斷加劇,近年來(lái)我國(guó)乙二醇生產(chǎn)裝置負(fù)荷不影響下游聚酯纖維的著色、強(qiáng)度和顏色等指標(biāo)的不斷提高,乙烯氧化催化劑使用周期不斷延長(zhǎng),致穩(wěn)定雜質(zhì)的含量狀況,間接表達(dá)乙二醇產(chǎn)品的質(zhì)使乙二醇產(chǎn)品在220mm和275nm處的UV值低2007-10-21收到初稿,2008-01-14收到修改稿Received date: 2007-10-21.聯(lián)系人:陳群。第一作者:曹玉(1983-),女,頓士研orresponding author: Prof. CHEN Qun. E-mail究生13906123032G126.com6期曹玉霞等:催化加氫法提高乙二醇質(zhì)量·1601ethylene巴小山中·[m-西ethylene glycol圖1改進(jìn)后的乙二醇生產(chǎn)工藝Fig. 1 Manufacturing technique of ethylene glycol after amelioration于國(guó)外同類(lèi)產(chǎn)品并低于國(guó)家標(biāo)準(zhǔn)值。并且隨裝置運(yùn)試樣中的脂肪醛化合物在氯化鐵存在下,與3-甲行工況的變化,UV值與醛含量不斷波動(dòng),成為乙基2-苯并噻唑酮腙(MBTH)反應(yīng),生成藍(lán)-綠色二醇生產(chǎn)行業(yè)普遍關(guān)注的難題。因此如何在不改變稠合陽(yáng)離子,在波長(zhǎng)620m處有吸收,且在一定現(xiàn)有生產(chǎn)工藝的前提下開(kāi)展提高乙二醇紫外透過(guò)率范圍內(nèi)醛含量與吸光度呈線性關(guān)系,據(jù)此可測(cè)得樣與降低醛含量的技術(shù)開(kāi)發(fā)與研究,并使乙二醇產(chǎn)品品中的脂肪醛含UV值在220、275、350nm處分別達(dá)到80%、采用離子色譜法測(cè)定加氫前后乙二醇中有機(jī)酸95%、99%以上的國(guó)際標(biāo)準(zhǔn),將具有重要的意義。含量。樣品在青島普仁PIC8型離子色譜儀上測(cè)使乙二醇U值下降的主要原因是裝置工藝定。色譜條件:淋洗流速1.5ml·min-1,輔抑制參數(shù)發(fā)生變化,并直接導(dǎo)致物料中醛、酮和羧酸類(lèi)器水流速1.5ml·min-1,主抑制器電流120mA,化合物濃度增加,這些微量有機(jī)物因含有軸抑制器電流100mAC=C”雙鍵、“C=O”雙鍵及其共軛結(jié)構(gòu)基團(tuán),采用UV1201型紫外分光光度計(jì),測(cè)定加氫極微量雜質(zhì)含量即可使乙二醇在200~400m紫前后乙二醇紫外透過(guò)率。參比水為高錳酸鉀處理的外區(qū)有較大的吸收,從而表現(xiàn)出UV值的顯去離子水。該方法符合GB4649-93中有關(guān)乙二醇著下降。UV值的分析要求。除改變催化劑工藝及裝置參數(shù)外,目前國(guó)內(nèi)外在原料乙二醇中,烯酸類(lèi)化合物如丙烯酸等在報(bào)道的提高乙二醇UV值的方法主要是吸附劑吸220mm處有較強(qiáng)的吸收峰,加氫后將轉(zhuǎn)化為對(duì)應(yīng)附1和化學(xué)還原的方法,但均存在效率低、的飽和羧酸。羰基類(lèi)化合物如甲醛、3乙基1,2-環(huán)成本高、操作復(fù)雜、對(duì)主流程影響大等問(wèn)題。查閱戊二酮等主要在275m處有強(qiáng)吸收,加氫后變?yōu)榻鼛啄暧嘘P(guān)方面的文獻(xiàn),未見(jiàn)采用固定床催化加氫相應(yīng)的醇類(lèi)化合物,其275nm處吸收消失。為此還原不飽和雜質(zhì)以提高UV值的方法的報(bào)道,催化劑活性用乙二醇的UV值變化和雜質(zhì)去除率本文將該方法應(yīng)用于乙二醇生產(chǎn)工藝改進(jìn)中,其過(guò)表示。根據(jù)朗伯比爾定律,其吸光度A與溶液液程如圖1所示。即在乙二醇多效蒸發(fā)器的末效出口層厚度b和濃度c的乘積呈正比與乙二醇精餾單元之間增加一固定床催化加氡單元,并取消原樹(shù)脂縮醛化催化降醛單元,將含有15%水的乙二醇粗產(chǎn)品(簡(jiǎn)稱含水料)經(jīng)催化加氫在同一波長(zhǎng)下物質(zhì)的吸光系數(shù)不變。另外由紫外光處理后,其中的不飽和雜質(zhì)化合物被部分轉(zhuǎn)化為飽譜原理可知,純乙二醇在波長(zhǎng)200mm以上無(wú)吸和化合物,從而提高了乙二醇的UV值,醛類(lèi)等收,所以濃度c可近似為此類(lèi)雜質(zhì)的總濃度,由不穩(wěn)定化合物的含量大大下降。lgT與雜質(zhì)總濃度c呈線性關(guān)系可得雜質(zhì)去除1實(shí)驗(yàn)部分率為X=(co-cr/c= Ig(To/T)/lg To1.I原料和產(chǎn)品的分析式中c。為原料的雜質(zhì)濃度;c1為加氫后的雜質(zhì)1.1.1原料取自揚(yáng)子石化烯烴廠乙二醇裝置末濃度;T。為原料UV值;T1為加氫后的U值效蒸發(fā)器出口取樣點(diǎn)質(zhì)量分?jǐn)?shù)為85%的乙二醇含220nm處的X變化代表了烯酸類(lèi)化合物的轉(zhuǎn)化效水料,此時(shí)的物料處于乙烯氧化銀催化劑活性與選率;275mm處的X變化代表了羰基類(lèi)化合物的轉(zhuǎn)擇性的末期,物料中的雜質(zhì)含量較高,其UV值化效率。在220、275、350m分別為49.6%、1.2催化劑的制備88.2%、97.7%。稱取一定量的AlNi合金于四口燒瓶中,升溫1.1.2分析方法用MBTH法(GB/T至358K,按1 g Al-Ni合金需6.3m去離子水和14571.3-93)測(cè)定加氫前后乙二醇物料的醛含量。2.7g固體NaOH配比配制NaOH溶液,在低速·1602化工第59攪拌下將NaOH溶液緩慢滴加到合金中,放出的表1乙二醇加氫前后醛含量的變化氫氣經(jīng)導(dǎo)氣管導(dǎo)出室外,控制溫度不高于368K,Table 1 Change of aldehyde content/ug.g攪拌1h,再在(368±2)K保溫靜置3h,用去MaterialAfterAfter離子水清洗至中性,得骨架鎳催化劑。水封保存hydrogenation rectificationGB4649--93 company備用?！?01.3催化劑活性評(píng)價(jià)drogenation condition: EG liquid hourly space velocity 30實(shí)驗(yàn)在如圖2所示的微型固定床加氫裝置中進(jìn),H: mass space velocit0.02g·m-,b1行。取2.0ml催化劑填至反應(yīng)器中部,上下均以MPa, catalyst particle size ranging from 0.5mmto.8maa石英砂填充。乙二醇原料經(jīng)恒流泵輸送到預(yù)熱爐,結(jié)果表明,采用催化加氫法大大降低了乙二醇并與減壓后的氫氣混合從催化劑床層上部加入,加中醛含量,含水料加氫后醛含量由原來(lái)的11.5氫后的物料經(jīng)冷卻后進(jìn)人儲(chǔ)液罐,未反應(yīng)的氫氣經(jīng)gg·g降至4.5g·g-1,再經(jīng)脫水精餾后的乙背壓調(diào)節(jié)閥進(jìn)入濕式氣體流量計(jì)計(jì)量后排空。取樣二醇成品中醛含量減少到3.7g·g1測(cè)定反應(yīng)后的乙二醇UV值及醛含量,計(jì)算雜質(zhì)2.2反應(yīng)溫度對(duì)乙二醇UV值和雜質(zhì)去除率的影響去除率。實(shí)驗(yàn)裝置流程如圖2所示。反應(yīng)溫度對(duì)乙二醇的UV值和雜質(zhì)去除率影響較大,溫度過(guò)低分子不能越過(guò)反應(yīng)能壘,溫度過(guò)高使反應(yīng)趨于劇烈,副反應(yīng)加劇。圖3顯示了反應(yīng)溫度對(duì)乙二醇UV值和雜質(zhì)去除率的影響。4350mm275mm70圖2乙二醇加氫流程圖63103203034030360370380Fig. 2 Flow chart of ethylene glycol hydrogenationtemperature/K3-Hz mass flow controller; 4-constant current pump:5- prehcating furnace: 6--catalyst case7-condenser: 8-stop valve: 9-wet gas flow meter1.4乙二醇含水料精餾取加氫后的含水乙二醇在精餾柱上減壓蒸餾,收集371~374K餾分。測(cè)定Uv值及醛含量△350mmX 275 nmD 220 nm2結(jié)果與討論3931032030340350360303802.1加氫前后醛含量的變化乙二醇產(chǎn)品中醛含量是一項(xiàng)獨(dú)立的質(zhì)量指標(biāo),含量必須小于10μg·g1,因?yàn)槿┑拇嬖谕瑯訒?huì)圖3溫度對(duì)乙二醇UV值和雜質(zhì)去除率的影響影響到聚酯纖維的質(zhì)最。醛含量的升高與系統(tǒng)中的Fig. 3 Effect of hydrogenation temperatureUV transmittance of ethylene glycol and鐵銹產(chǎn)生有關(guān),裝置的不定期除銹會(huì)導(dǎo)致生產(chǎn)成本removal efficiency of impurities增加。末效蒸發(fā)器出口的乙二醇含水料加氫前后以(hydrogenation condition: EG liquid hourly space velocity及加氫液脫水精餾獲得的乙二醇成品的醛含量與羧30b1,H2 mass space velocity 0.02g·ml-1,hb1,.25MPa酸含量測(cè)定結(jié)果列于表1。catalyst particle size ranging from 0. 5 mm to 0. 8 mm)第6期曹玉霞等:催化加氫法提高乙二醇質(zhì)量·1603·結(jié)果表明,當(dāng)溫度低于371K時(shí),提高溫度,結(jié)果表明,隨著LHSV的減小,乙二醇的U值和雜質(zhì)去除率增大,220、275、350m處UV值都有提高,在220mm和275nm處的雜質(zhì)去的雜質(zhì)去除率明顯提高,且X30m>X2m>除率提高較為明顯。因?yàn)長(zhǎng)HSⅤ的降低,保證了X25m。一方面溫度的升高增加了反應(yīng)分子的動(dòng)乙二醇在催化劑床層有足夠的停留時(shí)間,使得乙二能,單位時(shí)間內(nèi)反應(yīng)速率增大,雜質(zhì)去除率提高;醇中的雜質(zhì)和氫氣在催化劑作用下充分反應(yīng),當(dāng)另一方面使乙二醇黏度變小,乙二醇在催化劑表面LHSV為30h"時(shí)乙二醇在220、275、350mm處的擴(kuò)散速度增大,也提高了反應(yīng)的速度。但隨著溫的UV值由原來(lái)的49.6%、88,2%、97.7%分別度的繼續(xù)升高,UV值和雜質(zhì)去除率有所下降,原提高至84.2%95.0%99.6%雜質(zhì)去除率分因可能是高溫伴有乙二醇中其他雜質(zhì)的副反應(yīng)的產(chǎn)別達(dá)到75.5%、59.2%、82.8%,已達(dá)到國(guó)際UV生?？紤]到多效蒸發(fā)器出口物料溫度在353K左右,值指標(biāo)要求,綜合效率與效果,LHSv以30h1故以此溫度為加氫條件,工藝上不需要額外加熱。較為合適2.3空速的影響2.4氫氣壓力的影響乙二醇的液時(shí)空速(LHSV=單位時(shí)間乙二醇圖5結(jié)果表明,在所選的0.2~1.0MPa實(shí)驗(yàn)進(jìn)料體積/催化劑床層體積)對(duì)UV值和雜質(zhì)去除條件下,氫氣壓力的變化對(duì)乙二醇的UV值影響率影響較大,改變LHSV可以改變乙二醇在催化不大。在高于0.2MPa的氫壓下,催化劑表面已劑表面的停留時(shí)間。圖4顯示了乙二醇LHSV對(duì)有足夠的氫濃度及吸附量滿足對(duì)微量不飽和雜質(zhì)的UV值的影響催化轉(zhuǎn)化。說(shuō)明此加氫條件非常適合將此加氫單△△△△△△△35010$05⑩6△350nm0204060801001206081.0pressure/MPa80△350nmx 275 nmD 220 nm020406080100120LHSV/h圖4乙二醇LHSV對(duì)UV值和雜質(zhì)去除率的影響Fig 4 Effect of ethylene glycol space velocity圖5氫氣壓力對(duì)乙二醇UV值和雜質(zhì)去除率的影響on UV transmittance of ethylene glycol andFig 5 Effect ofmoval efficiency of impuritiesethylene glycol and removal efficiency of impuritiesHydrogenation condition: 353 K, Hr mass space(hydrogenation condition: EG liquid hourly space velocityvelocity 0.02g·ml-1·h1,0.25MPa, cataly30 h, H2 mass space velocity 0. 02 g.ml-1. h-l,353K.particle size ranging fromto 0.8 mm)catalyst particle size ranging from 0. 5 mm to 0. 8 mm)1604·工學(xué)報(bào)第59卷元嵌入多效蒸發(fā)與乙二醇精餾脫水工藝之間,不需(2)通過(guò)對(duì)催化條件的優(yōu)化,在反應(yīng)溫度353要增加較多的乙二醇輸壓頭,有利于工業(yè)化應(yīng)用。K、乙二醇LHSV30h-1、壓力0.25MPa、氫氣2.5催化劑穩(wěn)定性實(shí)驗(yàn)質(zhì)量空速0.02g·ml1·h-條件下,催化劑連續(xù)對(duì)骨架鎳催化劑的活性穩(wěn)定性進(jìn)行了90d的運(yùn)行90d,乙二醇含水料在220、275、350mm的運(yùn)行考察,結(jié)果見(jiàn)圖6。UV值由原來(lái)的49.6%、88.2%、97.7%平均提高到73.8%、93.2%、99.7%,精餾后的成品乙二醇的UV值穩(wěn)定在84.2%、95.1%、99.9%,醛含量小于5g·g-1。本方法不影響原工藝運(yùn)行,裝置改造簡(jiǎn)單、催化效率高、催化劑壽命長(zhǎng)、耗氫少、無(wú)三廢、操作040簡(jiǎn)單、運(yùn)行成本低,并得到了1000t·a的工藝275mm側(cè)線實(shí)驗(yàn)驗(yàn)證,具有很好的應(yīng)用前景220nmReferenceseaction time/d[1] Albright David E, Dictz Edward A. Method reducing UV(a)Uv transmittance of ethylene glycol after hydrogenateabsorption in ethylene glycols, water, and mixturesUS,5770777.1998[2] Chen Hong (W:r). Research the influencing factor ofethylene glycol UV transmittance. petrochemicalTechmology in Jinshan(金山油化纖),1997(3):30[31 Albright David E, Dietz Edward A. Method for producingUV absorption in ethylene glycols, water, and mixturesCA,2203485.1997△350nm[4] Schmitt Thomas Martin, Davis Pauls, Allen George Mark.x275nMethod for purification of ethylene glycols CAD 220 nm[5] Zhang Yuhong, Feng Yuan, Lu Wenkui, Identification ofreaction time/dtransmittance. J. Chromatography A, 2000, 904: 87(b) UV transmittance of ethylene glycol after rectification[6] Zhang Yongbin(張勇斌), Liu Dinghua(劉定華),Ma圖6催化劑的穩(wěn)定性engel(馬正飛), Liu Xiaogin(劉曉勤), Yao hugingFig 6 Stability of catalyst(姚虎卿). Effect of NY catalyst on UV transmittance of(hydrogenation condition: EG liquid hourly spaceethylene glycol synthesized by homogeneous catalyticelocity 30h, H; mass space velocity 0. 02 g ml-1. h-1hydration. Petrochemical Technology(石油化工),2004353K, 0. 25 MPa, catalyst particle siz33(5):460ranging from 0. 5 mm to o 8 mm)[7] Su Keman(蘇克曼), Pan Tieying'(潘鐵英), zhang結(jié)果表明,催化劑在運(yùn)轉(zhuǎn)90d后,加氫后的lan(張長(zhǎng)蘭). The Analytical Method of Spectromatric(波譜解析法). Shanghai; east China University of Science乙二醇含水料在220、275、350nm處的UV值穩(wěn)Technology Press, 2002:定在73.8%、93.2%、9.7%,精餾后的成品乙[81 Baars Hendrikus Jacob, Aloisius nicolaas rene bos,Jete二醇的UV值平均為84.2%、95.1%、99.9%,separating ethylene glycUS,6525229.2003成品的醛含量由原來(lái)的11.5wg·g-1下降到3.7[9 Xu Tao(徐濤), Liu Xiaoqin(劉曉勤), Liu dinghua(劉μg·g-1。其他各項(xiàng)指標(biāo)也均高于國(guó)家標(biāo)準(zhǔn),推測(cè)定華), Yao Huqing(姚虎卿). Modification of adsorbents催化劑的穩(wěn)定性能滿足工業(yè)化的需要。and their adsorption for micro-amount impurities in ethyleneglycol. Chemical Industry and Engineering Progress(HL結(jié)論工進(jìn)),2006,25(10):1158(1)催化加氫法提高乙二醇質(zhì)量具有操作高 Reiche C R, Heckman J A. Method of producing glycolsUS,3970711.1976便、成本低、處理效率高、實(shí)施方便等優(yōu)點(diǎn)。[11] Paggini Alberto, Romano Ugo, Furlone Donato第6期曹玉霞等:催化加氫法提高乙二醇質(zhì)量1605Sanfilippo Domenico. Method for the production of high[17 He mingyang(何明陽(yáng)), Chen Qun(陳群), Zhu Ye(朱蹕), Zhang Yifeng(張益峰), Cao Yuxia(曹玉廢).A[12] Husain Mansoor. Glycol purification: US, 6187973 2001catalyst for improving the quality of ethylene glycol[13] Sanderson John R, Marquis Edward T. Improved glycolpurification: wO, 9958483 1999[18】 Cao Yuxia(曹玉薇), Sun Jiaxing(孫家興), Chen Qun[14] Briody Robert G, Cummings Frances M. Method for(陳群), He Mingyang(何明陽(yáng)). Preparingncreasing the ultra-violet light transmittance of ethylenehydrogenation catalysts for improving the Uv transmittanceglycol:Us,4289593.1981of ethylene glycol. Chemical Industry and engineering[15 Schmitt Thomas M, Allen George M, Davis Pauls. ProcessProgress(化工進(jìn)展),2007,26(1);1648for improving the ultraviolet light transmittance of ethylene[19] Chen qun(陳群), He Mingyang(何明陽(yáng)), Zhangglycol:Us,4647705,1987Yifeng(張益峰), Zhu Ye(朱曄), Cao Yuxia(曹玉霞[16] Hoffman William C, Dever Johe P. Method for separatingA method for improving the quality of ethylene glycol: CNcompounds in processes streams: US, 5440058 1995101058526.2007啟事(一)本刊2008年第2期發(fā)表的文章“介孔TO2晶須及其擔(dān)載RuO2的電容性能”(呂玲紅,胡煜艷,朱育丹,呂志華,劉暢,馮新,陸小華)所屬項(xiàng)目由國(guó)家自然科學(xué)基金(20706029)資助,特此補(bǔ)充說(shuō)明。(二)本刊2008年第5期發(fā)表的文章“兩種咪唑類(lèi)離子液體對(duì)杉木粉的溶解性能”(郭立穎,史鐵鈞,李忠,段衍明)所屬項(xiàng)目由國(guó)家自然科學(xué)基金(50773017)資助,特此補(bǔ)充說(shuō)明。《化工學(xué)報(bào)》編輯部