1. 聚丙烯(xi)工藝的技術(shu)發展
聚丙烯(xi)(xi)(Polypropylene,PP)是(shi)以丙烯(xi)(xi)為單(dan)體經(jing)聚合(he)(he)反應(ying)而生成(cheng)的聚合(he)(he)樹脂。已經(jing)成(cheng)為我國經(jing)濟建設中不可缺(que)少的材(cai)料(liao)。具體應(ying)用在包裝材(cai)料(liao)、服裝用料(liao)、產業(ye)用料(liao)、過濾(lv)用料(liao)、衛生用料(liao)和(he)煙用絲束等。
四十(shi)多年(nian)來,聚丙(bing)(bing)烯的(de)催化(hua)劑(ji)不(bu)斷開發,不(bu)斷改性,尤其(qi)是近二十(shi)年(nian)來,其(qi)技術一次又一次飛躍(yue)式的(de)進步,極(ji)大地(di)簡(jian)化(hua)了聚丙(bing)(bing)烯的(de)工藝流(liu)程,使裝置的(de)投資和生產成本降到很低的(de)水(shui)平。
聚(ju)丙烯(xi)常用工藝(yi)方法包括淤漿法工藝(yi)和本體法工藝(yi)。
①. 淤漿(jiang)法(fa)(fa)工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)(Slurry Process)又稱漿(jiang)液法(fa)(fa)或(huo)溶劑法(fa)(fa)工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi),是(shi)世(shi)界上最早用于生(sheng)(sheng)(sheng)產(chan)(chan)聚(ju)丙(bing)(bing)烯的(de)(de)工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)技術。從1957年第一套工(gong)(gong)(gong)(gong)業化(hua)(hua)裝置(zhi)到現在(zai)一直是(shi)最主要(yao)的(de)(de)聚(ju)丙(bing)(bing)烯生(sheng)(sheng)(sheng)產(chan)(chan)工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)。典(dian)型工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)主要(yao)包括意大利 Montedison 工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)、美(mei)國Hercules 工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)、日(ri)(ri)本三井東壓化(hua)(hua)學(xue)工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)、美(mei)國Amoco 工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)、日(ri)(ri)本三井油化(hua)(hua)工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)以及索維爾工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)等。這些(xie)工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)的(de)(de)開發都基于當時的(de)(de)第一代(dai)催(cui)化(hua)(hua)劑,采(cai)用立式攪拌釜反(fan)應(ying)器(qi),需要(yao)脫灰(hui)(hui)和脫無規(gui)物(wu),因采(cai)用的(de)(de)溶劑不(bu)同,工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)流程和操(cao)作條(tiao)件有所不(bu)同。近(jin)年來(lai),傳(chuan)統的(de)(de)淤漿(jiang)法(fa)(fa)工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)在(zai)生(sheng)(sheng)(sheng)產(chan)(chan)中(zhong)的(de)(de)比例明(ming)顯減(jian)少(shao),保留的(de)(de)淤漿(jiang)產(chan)(chan)品主要(yao)用于一些(xie)高價值(zhi)領域,如特種BOPP薄(bo)膜、高相對(dui)分子質量吹塑膜以及高強度管(guan)材等。近(jin)年來(lai),人們對(dui)該(gai)方法(fa)(fa)進行了改進,改進后的(de)(de)淤漿(jiang)法(fa)(fa)生(sheng)(sheng)(sheng)產(chan)(chan)工(gong)(gong)(gong)(gong)藝(yi)(yi)(yi)(yi)使用高活性的(de)(de)第二代(dai)催(cui)化(hua)(hua)劑,可刪除(chu)催(cui)化(hua)(hua)劑脫灰(hui)(hui)步驟,能(neng)減(jian)少(shao)無規(gui)聚(ju)合(he)物(wu)的(de)(de)產(chan)(chan)生(sheng)(sheng)(sheng),可用于生(sheng)(sheng)(sheng)產(chan)(chan)均聚(ju)物(wu)、無規(gui)共(gong)聚(ju)物(wu)和抗沖共(gong)聚(ju)物(wu)產(chan)(chan)品等。目(mu)前(qian)世(shi)界淤漿(jiang)法(fa)(fa)PP的(de)(de)生(sheng)(sheng)(sheng)產(chan)(chan)能(neng)力(li)約占全(quan)球(qiu)PP總(zong)生(sheng)(sheng)(sheng)產(chan)(chan)能(neng)力(li)的(de)(de)13%。
②. 本體(ti)法(fa)(fa)工藝(yi)(yi)的(de)研究開發始(shi)于20世紀60年代,1964年美國Dart公司采用(yong)(yong)(yong)釜式反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)器(qi)建成了(le)世界上第一套工業化本體(ti)法(fa)(fa)聚(ju)丙烯(xi)(xi)生產(chan)(chan)裝置。1970年以(yi)后,日本住友、Phillips、美國EI Psao等公司都實(shi)現了(le)液(ye)相本體(ti)聚(ju)丙烯(xi)(xi)工藝(yi)(yi)的(de)工業化生產(chan)(chan)。與采用(yong)(yong)(yong)溶(rong)劑的(de)漿液(ye)法(fa)(fa)相比(bi),采用(yong)(yong)(yong)液(ye)相丙烯(xi)(xi)本體(ti)法(fa)(fa)進行聚(ju)合具有不(bu)使(shi)用(yong)(yong)(yong)惰性(xing)(xing)溶(rong)劑,反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)系統內(nei)單(dan)體(ti)濃度高(gao)(gao),聚(ju)合速率(lv)快,催化劑活性(xing)(xing)高(gao)(gao),聚(ju)合反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)轉化率(lv)高(gao)(gao),反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)器(qi)的(de)時空(kong)生產(chan)(chan)能(neng)(neng)力(li)更大(da),能(neng)(neng)耗(hao)低,工藝(yi)(yi)流程簡單(dan),設(she)備少,生產(chan)(chan)成本低,“三廢”量(liang)(liang)少;容易除去聚(ju)合熱,并使(shi)撤熱控制簡單(dan)化,可(ke)以(yi)提高(gao)(gao)單(dan)位反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)器(qi)的(de)聚(ju)合量(liang)(liang);能(neng)(neng)除去對產(chan)(chan)品(pin)(pin)性(xing)(xing)質有不(bu)良影響的(de)低分(fen)子量(liang)(liang)無規聚(ju)合物和催化劑殘渣,可(ke)以(yi)得到(dao)高(gao)(gao)質量(liang)(liang)的(de)產(chan)(chan)品(pin)(pin)等優點。不(bu)足之(zhi)處是反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)氣體(ti)需要氣化,冷凝(ning)后才能(neng)(neng)循(xun)環回(hui)反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)器(qi)。反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)器(qi)內(nei)的(de)高(gao)(gao)壓液(ye)態烴(jing)類(lei)物料容量(liang)(liang)大(da),有潛在的(de)危險性(xing)(xing)。此(ci)外(wai),反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)器(qi)中乙(yi)烯(xi)(xi)的(de)濃度不(bu)能(neng)(neng)太高(gao)(gao),否(fou)則在反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)器(qi)中形成一個(ge)單(dan)獨的(de)氣相,使(shi)得反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)器(qi)難以(yi)操(cao)作,因而(er)所(suo)得共聚(ju)產(chan)(chan)品(pin)(pin)中的(de)乙(yi)烯(xi)(xi)含量(liang)(liang)不(bu)會太高(gao)(gao)。
本體法不同工藝路線的區別主(zhu)要是(shi)反(fan)(fan)應(ying)器(qi)(qi)(qi)的不同。反(fan)(fan)應(ying)器(qi)(qi)(qi)可分(fen)為釜(fu)式(shi)反(fan)(fan)應(ying)器(qi)(qi)(qi)和環(huan)管(guan)反(fan)(fan)應(ying)器(qi)(qi)(qi)兩大(da)類。釜(fu)式(shi)反(fan)(fan)應(ying)器(qi)(qi)(qi)是(shi)利(li)用液(ye)體蒸(zheng)發的潛(qian)熱(re)(re)來除去反(fan)(fan)應(ying)熱(re)(re),蒸(zheng)發的大(da)部(bu)分(fen)氣體經(jing)循環(huan)冷(leng)(leng)凝后(hou)返回到反(fan)(fan)應(ying)器(qi)(qi)(qi),未冷(leng)(leng)凝的氣體經(jing)壓(ya)縮機升壓(ya)后(hou)循環(huan)回反(fan)(fan)應(ying)器(qi)(qi)(qi)。而(er)環(huan)管(guan)反(fan)(fan)應(ying)器(qi)(qi)(qi)則(ze)是(shi)利(li)用軸(zhou)流泵使漿液(ye)高速循環(huan),通過(guo)夾套(tao)冷(leng)(leng)卻(que)撤熱(re)(re),由于傳熱(re)(re)面積(ji)大(da),撤熱(re)(re)效(xiao)果好(hao),因(yin)此其單位(wei)反(fan)(fan)應(ying)器(qi)(qi)(qi)體積(ji)產率高,能耗低(di)。
本體法生產工(gong)(gong)藝按聚(ju)合工(gong)(gong)藝流程(cheng),可以(yi)分為間歇式(shi)聚(ju)合工(gong)(gong)藝和連續式(shi)聚(ju)合工(gong)(gong)藝兩(liang)種。
a. 間歇(xie)式本體法工藝
間歇(xie)本體法聚丙烯聚合(he)技(ji)術(shu)是我國自(zi)行研(yan)制(zhi)開發(fa)成功的生(sheng)(sheng)產(chan)(chan)技(ji)術(shu)。它具有(you)生(sheng)(sheng)產(chan)(chan)工藝技(ji)術(shu)可靠,對原(yuan)料(liao)丙烯質量(liang)要求不(bu)(bu)(bu)是很高(gao),所需催化劑國內有(you)保證,流程(cheng)簡單,投資省(sheng)、收效快,操(cao)作簡單,產(chan)(chan)品牌(pai)(pai)號(hao)轉換靈活(huo)、“三(san)廢少”,適(shi)合(he)中國國情等(deng)優點(dian),不(bu)(bu)(bu)足之處是生(sheng)(sheng)產(chan)(chan)規模小(xiao),難以產(chan)(chan)生(sheng)(sheng)規模效益;裝置手工操(cao)作較(jiao)多,間歇(xie)生(sheng)(sheng)產(chan)(chan),自(zi)動化控制(zhi)水(shui)平(ping)低,產(chan)(chan)品質量(liang)不(bu)(bu)(bu)穩定(ding);原(yuan)料(liao)的消耗(hao)定(ding)額(e)較(jiao)高(gao);產(chan)(chan)品的品種牌(pai)(pai)號(hao)少,檔次不(bu)(bu)(bu)高(gao),用(yong)途較(jiao)窄。目(mu)前,我國采用(yong)該法生(sheng)(sheng)產(chan)(chan)的聚丙烯生(sheng)(sheng)產(chan)(chan)能力約占全國總(zong)生(sheng)(sheng)產(chan)(chan)能力的24%。
b. 連續式本體法工(gong)藝(yi)
該工(gong)藝主要包(bao)括美(mei)國Rexall工(gong)藝、美(mei)國Phillips工(gong)藝以及日本Sumitimo 工(gong)藝。
2. Dow化學公司(si)Unipol 工藝
該(gai)工(gong)(gong)(gong)藝(yi)屬于Dow化學公司所有,Unipol聚丙烯工(gong)(gong)(gong)藝(yi)和其聚乙烯工(gong)(gong)(gong)藝(yi)類(lei)似。工(gong)(gong)(gong)藝(yi)過程主要包括原料精制、催化劑進料、聚合反應、聚合物脫(tuo)氣和尾氣回收(shou)、造粒、摻混和包裝碼垛等工(gong)(gong)(gong)段。
Unipol聚丙烯工藝流(liu)程,如(ru)圖5-107所示。

3. BASF公司的(de)Novolen 工藝
該(gai)工(gong)(gong)(gong)藝(yi)是由(you) BASF公(gong)司開發成(cheng)功的。1999年,該(gai)工(gong)(gong)(gong)藝(yi)擁有者(zhe) Targor 公(gong)司和ABB Lum-mus公(gong)司達成(cheng)協議。由(you)ABB Lummus 公(gong)司負(fu)責(ze)在全球范圍內推廣Novolen工(gong)(gong)(gong)藝(yi)。2000年9月,被ABB公(gong)司和Equistar公(gong)司所組成(cheng)的合資公(gong)司 Novolen Technology Holding(簡稱(cheng)NTH)收購。2008年,由(you)CB&-I整體收購了 Lummus,Novolen 工(gong)(gong)(gong)藝(yi)由(you)新成(cheng)立(li)的CB&-ILummus負(fu)責(ze)全球轉(zhuan)讓(rang)。
Novolen 包(bao)括原(yuan)料精制、催(cui)化(hua)劑配制、聚合(he)反應(ying)、聚合(he)物粉料的(de)凈化(hua)、擠壓造粒等工序,如(ru)圖(tu)5-108和圖(tu)5-109所示。


4. 某(mou)國外工程聚(ju)丙烯(xi)裝置布置實例(圖5-110)

