一、聚丙烯工藝簡介(jie)
聚丙(bing)(bing)烯(xi)(xi)是以丙(bing)(bing)烯(xi)(xi)為單體(ti)經(jing)聚合反應而生(sheng)成(cheng)的聚合樹(shu)脂。四十多(duo)年來，聚丙(bing)(bing)烯(xi)(xi)技(ji)術一(yi)次(ci)(ci)又(you)一(yi)次(ci)(ci)飛躍式的進步，極大地簡化了(le)聚丙(bing)(bing)烯(xi)(xi)的工藝(yi)流程，使裝置的投(tou)資和生(sheng)產(chan)成(cheng)本降到很低的水平。聚丙(bing)(bing)烯(xi)(xi)常用工藝(yi)方法包(bao)括淤(yu)漿法工藝(yi)和本體(ti)法工藝(yi)。
①. 淤漿法工藝
又稱漿液(ye)法或溶劑(ji)法工(gong)藝(yi)，是(shi)世界上(shang)最(zui)早用(yong)于生產聚丙(bing)(bing)烯的(de)工(gong)藝(yi)技術。從1957年第(di)一套工(gong)業化裝置(zhi)到現在一直是(shi)最(zui)主要(yao)的(de)聚丙(bing)(bing)烯生產工(gong)藝(yi)。
②. 本體法(fa)工藝
開發始于(yu)20世紀60年(nian)代，1964年(nian)美國Dart公司采(cai)用(yong)(yong)釜(fu)式反(fan)(fan)(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)(qi)(qi)建成了世界上第一套(tao)工業化(hua)本體(ti)(ti)(ti)法聚(ju)丙烯生產(chan)裝置。與采(cai)用(yong)(yong)溶劑的漿液(ye)(ye)法相比，工藝流程簡(jian)單，設(she)備少，生產(chan)成本低，“三廢”量少，可以得到高質量的產(chan)品(pin)等優點(dian)。不(bu)足之處(chu)是(shi)反(fan)(fan)(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)氣體(ti)(ti)(ti)需要氣化(hua)、冷(leng)凝(ning)后才能循(xun)環(huan)(huan)回(hui)反(fan)(fan)(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)(qi)(qi)。本體(ti)(ti)(ti)法不(bu)同工藝路線(xian)的區(qu)別主要是(shi)反(fan)(fan)(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)(qi)(qi)的不(bu)同。反(fan)(fan)(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)(qi)(qi)可分(fen)為釜(fu)式反(fan)(fan)(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)(qi)(qi)和環(huan)(huan)管反(fan)(fan)(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)(qi)(qi)兩(liang)大類。釜(fu)式反(fan)(fan)(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)(qi)(qi)是(shi)利(li)用(yong)(yong)液(ye)(ye)體(ti)(ti)(ti)蒸發的潛熱來除去反(fan)(fan)(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)熱，蒸發的大部分(fen)氣體(ti)(ti)(ti)經循(xun)環(huan)(huan)冷(leng)凝(ning)后返回(hui)到反(fan)(fan)(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)(qi)(qi)，未冷(leng)凝(ning)的氣體(ti)(ti)(ti)經壓(ya)縮機升壓(ya)后循(xun)環(huan)(huan)回(hui)反(fan)(fan)(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)(qi)(qi)。而環(huan)(huan)管反(fan)(fan)(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)(qi)(qi)則是(shi)利(li)用(yong)(yong)軸流泵(beng)使(shi)漿液(ye)(ye)高速循(xun)環(huan)(huan)，通過夾套(tao)冷(leng)卻散(san)熱，由(you)于(yu)傳熱面積大，散(san)熱效(xiao)果好，因此其單位反(fan)(fan)(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)(qi)(qi)體(ti)(ti)(ti)積產(chan)率高，能耗低。
本體法生產工藝按聚(ju)合工藝流程，可以分(fen)為間歇式聚(ju)合工藝和連續式聚(ju)合工藝兩種。
1. 間(jian)歇本體法工藝
間(jian)(jian)歇(xie)本體法(fa)聚(ju)丙烯(xi)聚(ju)合(he)(he)技(ji)(ji)術是(shi)我(wo)國自(zi)行(xing)研制開發成功(gong)的(de)(de)生(sheng)(sheng)(sheng)(sheng)產(chan)(chan)(chan)(chan)(chan)(chan)技(ji)(ji)術。它具有生(sheng)(sheng)(sheng)(sheng)產(chan)(chan)(chan)(chan)(chan)(chan)工(gong)藝技(ji)(ji)術可靠(kao)、對原料(liao)丙烯(xi)質(zhi)量(liang)要求不(bu)是(shi)很(hen)高、所需催化劑國內有保證、流(liu)程簡(jian)單、投資省、收效快、操(cao)作(zuo)簡(jian)單、產(chan)(chan)(chan)(chan)(chan)(chan)品(pin)牌(pai)號轉換靈(ling)活、三廢(fei)少、適合(he)(he)中國國情等優點(dian)，不(bu)足之處是(shi)生(sheng)(sheng)(sheng)(sheng)產(chan)(chan)(chan)(chan)(chan)(chan)規(gui)模(mo)小，難以產(chan)(chan)(chan)(chan)(chan)(chan)生(sheng)(sheng)(sheng)(sheng)規(gui)模(mo)效益；裝(zhuang)置手(shou)工(gong)操(cao)作(zuo)較(jiao)(jiao)多，間(jian)(jian)歇(xie)生(sheng)(sheng)(sheng)(sheng)產(chan)(chan)(chan)(chan)(chan)(chan)，自(zi)動化控(kong)制水平低，產(chan)(chan)(chan)(chan)(chan)(chan)品(pin)質(zhi)量(liang)不(bu)穩定；原料(liao)的(de)(de)消耗定額(e)較(jiao)(jiao)高；產(chan)(chan)(chan)(chan)(chan)(chan)品(pin)的(de)(de)品(pin)種牌(pai)號少，檔次不(bu)高，用(yong)途(tu)較(jiao)(jiao)窄。目前，我(wo)國采用(yong)該法(fa)生(sheng)(sheng)(sheng)(sheng)產(chan)(chan)(chan)(chan)(chan)(chan)的(de)(de)聚(ju)丙烯(xi)生(sheng)(sheng)(sheng)(sheng)產(chan)(chan)(chan)(chan)(chan)(chan)能力約(yue)占全(quan)國總生(sheng)(sheng)(sheng)(sheng)產(chan)(chan)(chan)(chan)(chan)(chan)能力的(de)(de)24.0％。
2. 連(lian)續本體法工藝
該工藝主要包括美(mei)(mei)國Rexall工藝、美(mei)(mei)國Phillips 工藝以(yi)及日(ri)本Sumitimo 工藝。
二、Dow化(hua)學公司Unipol 工藝
該工(gong)藝(yi)(yi)屬于Dow化學公(gong)司所有(you)，Unipol聚(ju)丙(bing)烯工(gong)藝(yi)(yi)與聚(ju)乙烯工(gong)藝(yi)(yi)類(lei)似。工(gong)藝(yi)(yi)過程主要包(bao)括原(yuan)料精制、催化劑(ji)進料、聚(ju)合(he)反應、聚(ju)合(he)物脫氣和尾氣回(hui)收、造粒(li)、摻混和包(bao)裝碼垛等工(gong)段，Unipol聚(ju)丙(bing)烯工(gong)藝(yi)(yi)流(liu)程圖如圖2.17所示。
三、BASF公(gong)司的Novolen 工藝
該(gai)工藝(yi)(yi)(yi)是由(you)BASF公(gong)司開發成(cheng)功的(de)。1999年(nian)，該(gai)工藝(yi)(yi)(yi)擁有者Targor公(gong)司達成(cheng)協議。由(you)ABB Lummus公(gong)司負責在全球范圍內推廣(guang) Novolen工藝(yi)(yi)(yi)。Novolen 工藝(yi)(yi)(yi)包括原料精制、催(cui)化劑配制、聚合(he)反(fan)應、聚合(he)物(wu)粉料的(de)凈化，擠壓造粒(li)等工序，見圖2.18和圖2.19。
四、聚(ju)丙(bing)烯裝置的配管設計
主要是對塔、換(huan)熱器、罐、泵、反應器等設(she)備的配管(guan)設(she)計(ji)。
