2007年-外文翻譯--加氫脫硫過程中烯烴的反應(yīng)活性

1、<p>　　Applied Catalysis B: Environmental 70 (2007) 542–547</p><p>　　www.elsevier.com/locate/apcatb</p><p>　　Reactivity of ole?ns in the hydrodesulfurization of</p><p>　　FCC gas

2、oline over CoMo sul?de catalyst</p><p>　　加氫脫硫過程中烯烴的反應(yīng)活性</p><p>　　Makoto Toba *, YasuoMiki, Takashi Matsui, Masaru Harada, Yuji Yoshimura</p><p>　　National Institute of Advanced Indu

3、strial Science and Technology, Tsukuba Central-5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan</p><p>　　Available online 21 June 2006</p><p><b>　　Abstract</b></p><p>

4、　　To achieve selective hydrodesulfurization (HDS) of ?uid catalytic-cracked (FCC) gasoline for producing sulfur-free gasoline (S < 10 ppm), the</p><p>　　reactivity of various ole?ns contained in FCC gasol

5、ine on CoMoP/Al2O3 sul?de catalysts was investigated. Isomerization of the C C double bond</p><p>　　from the terminal position to an internal position was observed. The steric hindrance around the C C double

6、 bond suppresses the reactivity of</p><p>　　ole?n hydrogenation. The sul?dation temperature of the catalyst has a major in?uence on ole?n hydrogenation active sites. Addition of the</p><p>　　app

7、ropriate amount of cobalt (Co/Mo ratio approximately 0.6) contributes to the suppression of ole?n hydrogenation at high reaction temperature</p><p>　　(260 8C). From the comparison of catalytic performance an

8、d characterization of our CoMoP/Al2O3 catalyst with an analogous commercial</p><p>　　catalyst, it is suggested that the hydrogenation of ole?ns depends not only on the state of the Mo CUS but also on the ste

9、ric effects of both ole?n</p><p>　　structure and MoS2 crystalline structure.</p><p>　　# 2006 Elsevier B.V. All rights reserved. </p><p>　　Keywords: FCC gasoline; Hydrogenation; Ole?

10、n; Cobalt molybdenum catalyst; Hydrodesulfurization</p><p>　　1. Introduction</p><p>　　FCC gasoline, which is one of the major components of</p><p>　　motor gasoline, contains high le

11、vels of sulfur derived from</p><p>　　heavy gas oil and atmospheric residues used as FCC feedstock.</p><p>　　More than 90% of the sulfur content in gasoline blendstocks</p><p>　　deri

12、ves from FCC gasoline. Reduction of sulfur content in FCC</p><p>　　gasoline is the most effective strategy for sulfur-free</p><p>　　(S < 10 ppm) gasoline production. FCC gasoline also contain

13、s</p><p>　　valuable ole?ns which contribute to the octane number of the</p><p>　　motor gasoline. Octane-boosting ole?ns in the FCC gasoline</p><p>　　are often saturated during the h

14、ydrotreating reaction. There-</p><p>　　fore, selective HDS which minimizes octane loss is highly</p><p>　　desired in response to ever-tightening controls on sulfur</p><p>　　content

15、[1–3].</p><p>　　To clarify the structure of the active sites responsible for</p><p>　　ole?n conversion, the hydrogenation of typical ole?ns in</p><p>　　model feedstock containing su

16、lfur compounds has been</p><p>　　extensively studied. Stevens and Edmonds showed by using</p><p>　　edge-plane-rich and basal-plane-rich MoS2 that the hydro-</p><p>　　* Corresponding

17、 author. Tel.: +81 29 861 4740; fax: +81 29 861 4532.</p><p>　　E-mail address: m.toba@aist.go.jp (M. Toba).</p><p>　　0926-3373/$ – see front matter # 2006 Elsevier B.V. All rights reserved.</

18、p><p>　　doi:10.1016/j.apcatb.2005.12.026</p><p>　　genation of butenes is a highly structure-sensitive reaction</p><p>　　[4]. Okamoto et al. reported that HDS selectivity depends on<

19、/p><p>　　the S/Mo ratio and surface structure of MoS2 catalyst [5].</p><p>　　Based on the inhibiting effect of H2S and various ole?ns,</p><p>　　Hatanaka et al. [1] proposed that on the

20、 sul?ded CoMo/Al2O3</p><p>　　catalyst there are three types of active sites for: (1) HDS, (2)</p><p>　　n-ole?n hydrogenation and (3) isoole?n hydrogenation.</p><p>　　However, the au

21、thors did not mention the structure of the</p><p>　　active sites. Choi et al. [6] examined the hydrogenation of</p><p>　　2,3-dimethyl-2-butene and 1-hexene in the presence of 3-</p><p

22、>　　methylthiophene over sul?ded CoMo/Al2O3 with different tin</p><p>　　loadings. They proposed that interfacial sites between the</p><p>　　sul?de phase and the hydroxyl groups of the support

23、play an</p><p>　　important role in ole?n hydrogenation. However, the results</p><p>　　obtained by these kinds of experiments using a model</p><p>　　feedstock do not always adequatel

24、y represent the real</p><p>　　catalytic system. In fact FCC gasoline contains complex</p><p>　　mixture of ole?ns whose reactivity towards hydrogenation</p><p>　　might be in?uenced b

25、y the presence of other ole?ns,</p><p>　　hydrocarbons and sulfur compounds.</p><p>　　In this study, the reactivity of various ole?ns contained in</p><p>　　FCC gasoline in selective

26、HDS over CoMo/Al2O3 catalyst was</p><p>　　investigated to clarify the relationship among reaction</p><p>　　conditions, active sites of catalysts and selectivity of HDS.</p><p><b

27、>　　簡要</b></p><p>　　為了實(shí)現(xiàn)流體催化裂化選擇性脫硫加氫，不產(chǎn)生硫雜質(zhì)氣（硫的濃度小于10ppm），在以CoMoP/Al2O3為催化劑的催化裂化反應(yīng)中，我們對不同種類的烯烴反應(yīng)活性做了研究，還觀察了碳碳雙鍵從末尾位置變化到中間位置的主要機(jī)理。碳碳雙鍵周圍的位阻抑制了烯烴加氫反應(yīng)過程中的活性。催化劑在硫化作用中的不同溫度對脫硫加氫的反應(yīng)活性產(chǎn)生了重要的影響。額外添加適量的鈷(比率

28、大約為0.6)有助于抑制烯烴加氫的反應(yīng)的溫度（260 ℃）。我們對CoMoP/Al2O3催化劑和類似的工業(yè)催化劑在性能上做了比較，發(fā)現(xiàn)烯烴的加氫不僅取決于Mo CUS的狀態(tài)，還與烯烴的結(jié)構(gòu)和二硫化鉬晶體結(jié)構(gòu)有關(guān)。</p><p><b>　　1簡介</b></p><p>　　FCC汽油，是機(jī)動(dòng)車用油的主要組成之一，其含有高濃度的硫元素，而這些硫主要來源于重瓦斯油和大

29、氣殘留，之后又會(huì)被作為催化裂化原材料。在車用油中，超過90%的硫含量來源于FCC汽油。在FCC汽油中降低硫含量是實(shí)現(xiàn)汽油無硫化（硫濃度小于10ppm）的最有效的策略。FCC汽油還包含高價(jià)值的烯烴，這些烯烴可以產(chǎn)生車用汽油所需的辛烷，辛烷在加氫處理反應(yīng)中烯烴鍵經(jīng)常處于飽和狀態(tài)?，F(xiàn)在對硫含量[1–3]的控制日趨嚴(yán)厲，因此我們非常期望能提高加氫脫硫的選擇性來最大限度地減少辛烷的損失量。</p><p>　　為了清晰闡明

30、烯烴轉(zhuǎn)換過程中的結(jié)構(gòu),我們對典型的烯烴加氫反應(yīng)模型進(jìn)行了廣泛的研究。通過使用棱面與基面原理，史蒂文斯和埃德蒙茲表示二硫化鉬丁烯的加氫反應(yīng)是一個(gè)高度結(jié)構(gòu)敏感反應(yīng)[4].，Okamoto等人表示,脫硫加氫反應(yīng)（HDS）的選擇性取決于S / Mo的比率和二硫化鉬催化劑[5]的表面結(jié)構(gòu)。基于硫化氫和各種烯烴的抑制效果,Hatanaka等人提出CoMo/Al2O3在三種類型的硫化反應(yīng)過程中起催化作用：(1)脫硫加氫反應(yīng)(2)雙烯烴加氫反應(yīng)(3)單

31、烯烴加氫反應(yīng)。然而,這些人并沒有提到這種結(jié)構(gòu)的活躍點(diǎn)。崔 [6]等人檢驗(yàn)了的加氫反應(yīng)過程中，不同程度錫的量對2,3二甲基，2丁烯和1，己烯的3甲基噻吩硫化物的影響。他們認(rèn)為在烯烴加氫反應(yīng)的過程中，各個(gè)羥基的連接點(diǎn)的支持發(fā)揮著重要的作用。然而,通過這些實(shí)驗(yàn)?zāi)Ｐ偷玫降慕Y(jié)果并不總是充分代表了真實(shí)催化體系。事實(shí)上FCC汽油包含復(fù)雜的烯烴混合物，這些烯烴的活性可能會(huì)受到其他烯烴、碳?xì)浠衔锖土虻幕衔锏挠绊憽?lt;/p><p&g

32、t;　　在這項(xiàng)研究中,專家們研究了FCC汽油中包含的各種烯烴的反應(yīng)活性以此來證明反應(yīng)過程中反應(yīng)條件、催化劑活躍點(diǎn)以及HDS反應(yīng)選擇性之間的關(guān)系。</p><p>　　M. Toba et al. / Applied Catalysis B: Environmental 70 (2007) 542–547</p><p><b>　　543</b></p>

33、<p>　　2. Experimental</p><p><b>　　Table 1</b></p><p>　　Properties of FCC gasoline</p><p>　　CoMoP/Al2O3 sul?de catalysts were prepared by incipient</p><p

34、>　　wetness impregnation of g-alumina (surface area: 195 m2/g)</p><p>　　with a mixed solution obtained from molybdenum oxide, cobalt</p><p>　　carbonate, a phosphate salt and a special ligand.

35、CoO and MoO3</p><p>　　contents were 2.3 and 12.0 wt.% (Co/Mo = 0.36 (mol/mol)), 3.1</p><p>　　and 12.0 wt.% (Co/Mo = 0.50 (mol/mol)), 3.9 and 12.0 wt.%</p><p>　　(Co/Mo = 0.62 (mol/mo

36、l)) and 5.4 and 12.0 wt.% (Co/</p><p>　　Mo = 0.85 (mol/mol)), respectively. A commercial CoMoP/</p><p>　　Al2O3 sul?de catalyst (3.1 wt.%CoO and 12.0 wt.%MoO3 (Co/</p><p>　　Mo = 0.50

37、 (mol/mol)) was used for comparison purpose. All</p><p>　　catalysts were sul?ded in situ under of 5%H2S/H2 ?ow (200 ml/</p><p>　　min) between 298 and 360 8C for 3 h before being used in the</

38、p><p><b>　　reaction.</b></p><p><b>　　3</b></p><p>　　Sulfur (wt. ppm)（硫）</p><p>　　H/C (atom/atom)（原子）Average molecular weight（平均分子質(zhì)量）</p><

39、;p><b>　　GC-RONa</b></p><p><b>　　GC-MONb</b></p><p><b>　　T90 (8C)</b></p><p>　　Hydrocarbon (vol.%)</p><p>　　Paraf?ns (P)</p>

40、<p>　　Isoparaf?ns (I)</p><p>　　Ole?ns (O)</p><p>　　Naphthenes (N)</p><p>　　Aromatics (A)</p><p>　　Full range</p><p><b>　　0.733</b></p

41、><p><b>　　158.9</b></p><p><b>　　1.93</b></p><p><b>　　101.5</b></p><p><b>　　90.5</b></p><p><b>　　79.5<

42、/b></p><p><b>　　165.9</b></p><p><b>　　5.5</b></p><p><b>　　37.6</b></p><p><b>　　26.3</b></p><p><b>

43、　　9.2</b></p><p><b>　　21.4</b></p><p><b>　　Heavy A</b></p><p><b>　　0.771</b></p><p><b>　　234.1</b></p><

44、p><b>　　1.83</b></p><p><b>　　111.5</b></p><p><b>　　88.9</b></p><p><b>　　78.2</b></p><p><b>　　176.6</b><

45、/p><p><b>　　4.8</b></p><p><b>　　32.4</b></p><p><b>　　19.7</b></p><p><b>　　12.4</b></p><p><b>　　30.8</

46、b></p><p><b>　　Heavy B</b></p><p><b>　　0.780</b></p><p><b>　　61.8</b></p><p><b>　　1.80</b></p><p><b&

47、gt;　　114.6</b></p><p><b>　　89.5</b></p><p><b>　　78.6</b></p><p><b>　　182.3</b></p><p><b>　　4.4</b></p><

48、p><b>　　25.8</b></p><p><b>　　25.5</b></p><p><b>　　12.6</b></p><p><b>　　31.7</b></p><p>　　The selective HDS of FCC gaso

49、line was carried out in a</p><p>　　high-pressure ?xed-bed continuous-?ow reactor as described</p><p>　　previously [7]. The products were collected using a liquid–gas</p><p>　　separa

50、tor at À15 8C and atmospheric pressure. The reaction</p><p><b>　　a</b></p><p><b>　　b</b></p><p>　　GC-RON: research octane number calculated by the resul

51、t of GC analysis.</p><p>　　GC-MON: motor octane number calculated by the result of GC analysis.</p><p>　　was performed under 1–2 MPa of hydrogen pressure, at 220–</p><p>　　260 8C, l

52、iquid hourly space velocity (LHSV) 4 hÀ1, and a</p><p>　　volumetric ratio hydrogen (NTP) to feed of 100.</p><p>　　The hydrocarbon compositions of feedstock and products</p><p>

53、　　were analyzed using a PIONA-GC (Agilent 6890N (JIS K2536)</p><p>　　Yokogawa Analytical Systems Co. GPI system). The total</p><p>　　sulfur content was measured by elemental analysis (Mitsubishi

54、</p><p>　　Chemicals Co., TS-100V). Sulfur compounds were analyzed</p><p>　　using a GC-SCD (Agilent 6890-Sievers 355).</p><p>　　The HDS and conversion of ole?n (HDO) were calculated

55、as</p><p><b>　　follows:</b></p><p>　　HDS ð%Þ ¼ ½ðSfeed À SproductÞ=Sfeed?  100</p><p>　　C7 (7.2 vol.% (heavy A) and 9.1 vol.% (h

56、eavy B) in total</p><p>　　hydrocarbons) ole?ns are the main components in the two kinds</p><p>　　of heavy FCC gasoline. Table 2 shows in details the</p><p>　　composition of the C6 o

57、le?n contained in the three kinds of</p><p>　　FCC gasoline. Internal ole?ns prevailed on the terminal ones.</p><p>　　The compositions of C5 and C7 ole?n compositions are similar</p><p

58、>　　to that for C6 ole?ns. Four kinds of C6 ole?ns (2-hexene, 3-</p><p>　　hexene, 4-methyl-2-pentene and 3-methyl-2-pentene) have</p><p>　　trans and cis isomers. Due to steric effect it is exp

59、ected that the</p><p><b>　　Table 2</b></p><p>　　C6 ole?ns contained in three kinds of FCC gasoline</p><p>　　where Sfeed and Sproduct indicate the amount of sulfur in the

60、 feed</p><p><b>　　Ole?n</b></p><p>　　Composition (% in total acyclic C6 ole?ns)</p><p>　　and product, respectively.</p><p>　　Full range</p><p>

61、<b>　　Heavy A</b></p><p><b>　　Heavy B</b></p><p>　　HDO ð%Þ ¼ ½ðT feed À T productÞ=T feed?  100</p><p>　　where Tf eed

62、 and Tproduct indicate the ole?n concentration deter-</p><p>　　mined by GC analysis in the feed and products, respectively.</p><p>　　Three kinds of FCC gasoline were used: (a) full-range FCC<

63、/p><p>　　gasoline, (b) heavy A (60 8C + distillate of full-range FCC</p><p>　　gasoline (a)) and (c) heavy B (heavy FCC gasoline supplied from</p><p>　　another re?nery). Their propertie

64、s are summarized in Table 1.</p><p>　　High sulfur FCC gasoline was prepared by mixing thiophene</p><p>　　Terminal ole?ns（末端烯烴）</p><p><b>　　RCH CH2</b></p><p&g

65、t;　　1-Hexene1（己烯）</p><p>　　3-Methyl-1-pentene（3甲基1戊烯）</p><p>　　4-Methyl-1-pentene43,3-Dimethyl-1-butene（3、3二甲基1丁烯）</p><p><b>　　R1R2C CH2</b></p><p>　　2-Meth

66、yl-1-pentene(2甲基1戊烯)</p><p>　　2-Ethyl-1-butene（2甲基1丁烯）</p><p>　　2,3-Dimethyl-1-butene（2,3甲基1丁烯）</p><p><b>　　9.9</b></p><p><b>　　5.0</b></p>

67、;<p><b>　　2.7</b></p><p><b>　　1.8</b></p><p><b>　　0.3</b></p><p><b>　　11.3</b></p><p><b>　　8.7</b><

68、;/p><p><b>　　0</b></p><p><b>　　2.7</b></p><p><b>　　6.3</b></p><p><b>　　4.3</b></p><p><b>　　1.2</b>

69、</p><p><b>　　0.8</b></p><p><b>　　0</b></p><p><b>　　8.1</b></p><p><b>　　6.8</b></p><p><b>　　0</b>

70、;</p><p><b>　　1.3</b></p><p><b>　　7.6</b></p><p><b>　　5.2</b></p><p><b>　　1.5</b></p><p><b>　　0.9<

71、/b></p><p><b>　　0</b></p><p><b>　　8.5</b></p><p><b>　　7.1</b></p><p><b>　　0</b></p><p><b>　　1.4<

72、;/b></p><p>　　(S = 480.2 wt. ppm), 2-methylthiophene (S = 480.2 wt. ppm)</p><p>　　and benzothiophene (S = 960.4 wt. ppm) with heavy FCC</p><p>　　gasoline (heavy B).</p>&l

73、t;p>　　3. Results and discussion</p><p>　　3.1. Composition of ole?ns contained in FCC gasoline</p><p>　　The distributions of ole?ns contained in the three kinds of</p><p>　　FCC ga

74、soline were determined by GC analysis. C5 (8.6 vol.%</p><p>　　in total hydrocarbon) and C6 (6.7 vol.% in total hydrocarbon)</p><p>　　ole?ns are the main components in the full-range FCC gasoline

75、.</p><p>　　Most C5 ole?ns are removed by distillation and C6 (5.9 vol.%</p><p>　　(heavy A) and 5.8 vol.% (heavy B) in total hydrocarbons) and</p><p>　　Internal ole?ns內(nèi)部烯烴</p>

76、<p><b>　　R1CH CHR2</b></p><p>　　trans-2-Hexene</p><p>　　cis-2-Hexene</p><p>　　trans-3-Hexene</p><p>　　cis-3-Hexene</p><p>　　trans-4-Methy

77、l-2-pentene</p><p>　　cis-4-Methyl-2-pentene</p><p>　　R1R2C CHR3</p><p>　　2-Methyl-2-pentene2甲基2丁烯</p><p>　　trans-3-Methyl-2-pentene3甲基2丁烯</p><p>　　cis-3-Me

78、thyl-2-pentene</p><p>　　R1R2C CR3 R4</p><p>　　2,3-Dimethyl-2-butene23甲基2丙烯</p><p><b>　　40.0</b></p><p><b>　　14.6</b></p><p><b&g

79、t;　　8.4</b></p><p><b>　　7.4</b></p><p><b>　　2.6</b></p><p><b>　　5.3</b></p><p><b>　　1.7</b></p><p>&l

80、t;b>　　38.8</b></p><p><b>　　16.1</b></p><p><b>　　13.9</b></p><p><b>　　8.8</b></p><p><b>　　0</b></p><p

81、><b>　　0</b></p><p><b>　　40.9</b></p><p><b>　　16.3</b></p><p><b>　　9.9</b></p><p><b>　　8.0</b></p>

82、<p><b>　　2.6</b></p><p><b>　　3.3</b></p><p><b>　　0.9</b></p><p><b>　　44.7</b></p><p><b>　　17.2</b></

83、p><p><b>　　17.7</b></p><p><b>　　9.8</b></p><p><b>　　0</b></p><p><b>　　0</b></p><p><b>　　41.8</b>&l

84、t;/p><p><b>　　16.6</b></p><p><b>　　10.0</b></p><p><b>　　8.0</b></p><p><b>　　2.9</b></p><p><b>　　3.3</

85、b></p><p><b>　　1.0</b></p><p><b>　　42.1</b></p><p><b>　　17.5</b></p><p><b>　　15.5</b></p><p><b>　　

86、9.1</b></p><p><b>　　0</b></p><p><b>　　0</b></p><p><b>　　2實(shí)驗(yàn)</b></p><p>　　CoMoP/Al2O3催化劑是濕潤浸漬的氧化鋁(面積:195平方米/克)以及氧化鉬、鈷碳酸、磷酸鹽和一個(gè)特

87、殊的配位體的混合物。CoO和MoO3的含量分別是2.3和12.0 wt. %(Co / Mo = 0.36(摩爾/摩爾)),3.1和12.0 wt. %(Co / Mo = 0.50(摩爾/摩爾)),3.9和12.0 wt. %(Co / Mo = 0.62(摩爾/摩爾))和5.4和12.0 wt. %( Co / Mo= 0.85(摩爾/摩爾)我們和工業(yè)上使用的CoMoP/Al2O3催化劑(3.1 wt. % CoO和12.0 wt.

88、 % MoO3(Co /Mo= 0.50(摩爾/摩爾))進(jìn)行了比較。在進(jìn)行這個(gè)硫化反應(yīng)之前，所有的催化劑在含有5%的H2S/H2 氣流中(200毫升/分) 在298℃和 360℃溫度中進(jìn)行三個(gè)小時(shí)。</p><p>　　就像前文討論到的一樣，F(xiàn)CC汽油選擇性加氫脫硫的反應(yīng)是要在的高壓固定流動(dòng)反應(yīng)器中進(jìn)行。產(chǎn)物需在氣液分離器A15 8 c和大氣壓環(huán)境下才能收集到。這個(gè)反應(yīng)的條件是1 - 2 MPa的氫氣壓力，22

89、0℃ -260℃的溫度，LHSV為4 hÀ1以及氫氣的比達(dá)到100。我們使用了PIONA-GC(安捷倫6890 n(JIS K2536)日本橫河分析系統(tǒng)有限公司價(jià)格指數(shù)系統(tǒng))來分析了原料和產(chǎn)品的碳?xì)浠衔锝M成，用元素分析(三菱化工有限公司,ts - 100 v)測定了總的硫含量，用GC-SCD(安捷倫6890 –斯文355)分析了硫化合物的含量。</p><p>　　烯烴的加氫脫硫的轉(zhuǎn)換率轉(zhuǎn)換(HDO)

90、計(jì)算如下:</p><p>　　HDS ð%Þ ¼ ½ðSfeed À SproductÞ=Sfeed?  100</p><p>　　HDO ð%Þ ¼ ½ðT feed À T productÞ=T feed?  100&l

91、t;/p><p>　　三種類型的FCC汽油使用情況如下:(a)全程FCC汽油,(b)重型A(60. 8℃+全程餾出物FCC汽油(a))和(c)重型B(從另一個(gè)精煉廠獲得的重型FCC汽油)。表1中列出了一些他們的屬性。高硫含量的FCC汽油是由混合噻吩(S = 480.2 wt. ppm),2 -甲基噻吩(S = 480.2 wt. ppm)和苯并噻吩(S = 960.4 wt. ppm)以及重型 FCC汽油(重型B)混

92、合組成。</p><p><b>　　3 結(jié)果與討論</b></p><p>　　3.1 FCC汽油中烯烴的合成</p><p>　　GC分析在三種不同類型的FCC汽油烯烴的分散中三種起著決定性作用。C5(占碳?xì)浠衔锟偭康?.6 vol. %)和C6(占碳?xì)浠衔锟偭康?.7 vol. %)的烯烴化合物是全程FCC汽油中的主要構(gòu)成物質(zhì)。

93、大多數(shù)C5烯烴化合物都在蒸餾過程中除去， C6(5.9 vol. %(重型A)5.8vol. %(重型B)和C7(7.2 vol. %(重型A)和9.1 vol. %(重型B)是兩種組成重型FCC汽油的主要物質(zhì)。</p><p><b>　　544</b></p><p>　　M. Toba et al. / Applied Catalysis B: Environm

94、ental 70 (2007) 542–547</p><p>　　Fig. 1. Effect of temperature on isomerization of carbon skeleton of C6 acyclic</p><p>　　hydrocarbons contained in the full-range FCC gasoline: (*) branched C6&l

95、t;/p><p>　　acyclic hydrocarbons; (~) linear C6 acyclic hydrocarbons; catalyst, CoMoP/</p><p>　　Al2O3 (3.1 wt.%CoO–12.0 wt.%MoO3 (Co/Mo = 0.50 (mol/mol))); reaction</p><p>　　pressure, 1

96、 MPa; feedstock, FCC gasoline (full-range).</p><p>　　reactivity of internal ole?n and trans isomers is lower than that</p><p>　　of terminal ole?n and cis isomers, respectively. Therefore, it is&

97、lt;/p><p>　　expected that the ole?n composition of FCC gasoline, which is</p><p>　　rich in internal ole?ns and trans isomers, improves the</p><p>　　selectivity of hydrodesulfurization

98、reaction (selective HDS).</p><p>　　3.2. Reactivity of ole?ns in the hydrodesulfurization of</p><p>　　FCC gasoline</p><p>　　Fig. 1 shows the effect of temperature on the skeletal<

99、/p><p>　　isomerization of the C6 acyclic hydrocarbons contained in the</p><p>　　full-range FCC gasoline. The ratio between linear (the sum of</p><p>　　n-hexane, 1-hexene, 2-hexene (tra

100、ns, cis) and 3-hexene (trans,</p><p>　　cis)) and branched C6 acyclic hydrocarbons did not depend on</p><p>　　the reaction temperature and remained almost constant. This</p><p>　　res

101、ult indicates that skeletal isomerization did not occur under</p><p>　　Fig. 2. Effect of temperature on composition of C6 acyclic hydrocarbons</p><p>　　contained in the full-range FCC gasoline:

102、(*) paraf?ns and isoparaf?ns;</p><p>　　(^) RCH CH2 type ole?ns; (~) R1R2C CH2 type ole?ns; (*)</p><p>　　R1CH CHR2 type ole?ns; (~) R1R2C CHR3 type ole?ns; ( )</p><p>　　R1R2C CR3R4 t

103、ype ole?n; catalyst, CoMoP/Al2O3 (3.1 wt.%CoO–</p><p>　　12.0 wt.%MoO3 (Co/Mo = 0.50 (mol/mol))); sul?dation temperature of cata-</p><p>　　lyst, 319 8C; reaction pressure, 1 MPa; feedstock, FCC g

104、asoline (full-range).</p><p>　　temperature, while conversion of terminal ole?ns remained</p><p>　　almost constant in the range of 220–260 8C.</p><p>　　Table 3 shows the effects of o

105、le?n structures on their</p><p>　　hydrogenation activity in the hydrodesulfurization of full-range</p><p>　　FCC gasoline over CoMoP/Al2O3 catalyst. The conversion</p><p>　　rates of

106、total C6 ole?n hydrogenation at 220, 240 and 260 8C</p><p>　　are 2.2%, 12.6% and 19.9%, respectively. The conversions of</p><p>　　terminal ole?ns (x-methyl-1-pentene) and cis ole?ns are much<

107、/p><p>　　higher than those of total C6 ole?n conversions. ‘Negative</p><p>　　conversion’ means formation of less reactive ole?ns, such as</p><p>　　internal and trans ole?ns, from more

108、reactive ole?ns such as</p><p>　　terminal and cis ole?ns through C C isomerization. The</p><p><b>　　Table 3</b></p><p>　　Effect of ole?n structures on their hydrogenatio

109、n activity in the hydrodesulfur-</p><p>　　ization of full-range FCC gasoline</p><p>　　this set of reaction conditions. Fig. 2 shows the effect of</p><p>　　temperature on the composi

110、tion of C6 acyclic hydrocarbons</p><p><b>　　Ole?n</b></p><p>　　Conversion of each temperature (%)</p><p>　　contained in full-range FCC gasoline. At 220 8C the percentage

111、</p><p>　　of the saturated acyclic hydrocarbons, such as paraf?ns and</p><p>　　x-Methyl-1-pentene</p><p><b>　　220 8C</b></p><p><b>　　240 8C</b>&

112、lt;/p><p><b>　　260 8C</b></p><p>　　isoparaf?ns, is slightly increased (from 61.7 to 62.5% of the</p><p>　　total amount of C6 acyclic hydrocarbon) at 220 8C. This means</

113、p><p>　　that the hydrogenation of ole?ns occurred to a minor extent. At</p><p>　　220 8C, the percentages of terminal ole?ns are decreased, while</p><p>　　the amounts of internal ole?ns

114、 are increased. These results</p><p>　　suggest that the C C double bond is isomerized from the</p><p>　　terminal position to an internal position. As in general, the</p><p>　　octane

115、 value of an internal ole?n is higher than that of its</p><p>　　corresponding terminal ole?n (e.g. 1-hexene: RON = 76.4,</p><p><b>　　x =2</b></p><p><b>　　x =3</

116、b></p><p><b>　　x =4</b></p><p>　　x = 5 (=1-Hexene)</p><p>　　y-Methyl-2-pentene</p><p><b>　　y =2</b></p><p>　　y = 3 (trans)</p

117、><p>　　y = 3 (cis)</p><p>　　y = 4 (trans)</p><p>　　y = 4 (cis)</p><p><b>　　30.4</b></p><p><b>　　58.6</b></p><p><b>

118、　　50.8</b></p><p><b>　　56.9</b></p><p><b>　　À11.9</b></p><p><b>　　À17.2</b></p><p><b>　　À7.8</b><

119、;/p><p><b>　　À1.9</b></p><p><b>　　19.9</b></p><p><b>　　32.9</b></p><p><b>　　67.1</b></p><p><b>　　60

120、.4</b></p><p><b>　　58.8</b></p><p><b>　　À0.8</b></p><p><b>　　À7.5</b></p><p><b>　　À0.3</b></p>

121、;<p><b>　　16.8</b></p><p><b>　　37.4</b></p><p><b>　　37.8</b></p><p><b>　　67.8</b></p><p><b>　　64.4</b>

122、;</p><p><b>　　60.7</b></p><p><b>　　9.0</b></p><p><b>　　À1.1</b></p><p><b>　　5.5</b></p><p><b>　　

123、27.9</b></p><p><b>　　45.6</b></p><p>　　trans-2-hexene: RON = 92.7, cis-2-hexene: RON = 92.7), the</p><p><b>　　z-Hexene</b></p><p>　　isomer

124、ization of the C C double bond from the terminal</p><p>　　position to an internal position may contribute to octane-</p><p>　　boosting and depression of ole?n hydrogenation. Hydrogena-</p>

125、<p>　　tion of internal ole?ns increased with increasing reaction</p><p>　　z = 2 (trans)</p><p>　　z = 2 (cis)</p><p>　　z = 3 (trans)</p><p>　　z = 3 (cis)</p>