硫化物和硫/磷化合物的添加方式对石脑油热裂解结焦影响的研究

doi:10.11949/0438-1157.20200332

摘要/Abstract

摘要：

以石脑油为裂解原料，考察了硫化物和硫/磷化合物的添加方式对热裂解结焦行为的影响。采用Raman光谱、XRD、SEM和XPS等检测手段表征了HP40试样的氧化层和焦炭的形貌与结构。结果表明，原料连续注入硫化物条件下，磷化物的加入使得焦炭结构改变，显示出优异的抗结焦效果。硫化物和硫/磷化合物预处理导致氧化层中Fe含量升高，抑制结焦效果有限。硫/磷预处理与原料连续注入硫/磷化合物联合方式与原料连续注入硫/磷化合物方式的抗结焦效果接近，但前者在初期的抑制效果更明显。所有添加方式都会引起结焦层中无定形焦炭含量升高，焦炭的石墨化程度降低。热裂解焦炭缩合程度较高，硫化物和硫/磷化合物减少了催化结焦的生成，在一定程度上提高了焦层中氢含量。

关键词: 热裂解反应, 热裂解结焦, 硫化物自由基, 硫/磷化合物, 添加方式, 合金氧化层

Abstract:

Using naphtha as raw material for cracking, the effects of adding sulfides and sulfur/phosphorus compounds on the coking behavior of thermal cracking were investigated. The morphologies and structures of the pretreated HP40 alloy specimen and coke deposits were characterized by Raman spectroscopy, XRD, SEM and XPS. The results showed that the addition of phosphide into the sulfide additives led to the change in the structure of coke deposits under the condition of continuous addition of additives into the feed. The method with continuous addition of sulfur/phosphorus-based compounds showed excellent anti-coking properties. The surface pretreatment with sulfur or sulfur/phosphorus-based compounds made the increase of Fe content in the oxide film on the specimen. So anti-coking effect was limited when the pretreatment method was applied. The coking inhibition property of the application of surface pretreatment with sulfide/phosphide followed by continuous addition of sulfur/phosphorus-based compounds were similar to that of the application of continuous addition of sulfur/phosphorus-based compounds in the feed. However, the combination method showed the better anti-coking effect during the initial cracking process. All the addition methods led to the increased amounts of amorphous coke in the coke layer and the decreased graphitization degree of cokes. The results of the low H/C ratios showed the highly condensed structure of the coke deposits during thermal cracking process. The addition of sulfur and sulfur/phosphorus-based compounds could influence the dehydrogenation reaction to some extent during the coke formation by reducing catalytic coking.

Key words: thermal cracking reaction, thermal cracking coking, sulfur-based radical intermediates, sulfur/phosphorus-based compounds, addition methods, oxidation film on alloy

中图分类号:

TE 624

王志远,丁旭东,王博研,邢志宏. 硫化物和硫/磷化合物的添加方式对石脑油热裂解结焦影响的研究[J]. 化工学报, 2020, 71(11): 5320-5336.

Zhiyuan WANG,Xudong DING,Boyan WANG,Zhihong XING. Addition methods of sulfur and sulfur/phosphorus-based compounds on coking behavior during thermal cracking of naphtha[J]. CIESC Journal, 2020, 71(11): 5320-5336.

图/表 22

表1 实验参数

Table 1 Experimental conditions for each experimental step

参数	数值
空气预氧化实验
温度/K	1073
空气流量/(ml/min)	700
时间/min	600
清焦
温度/K	1073-1123
空气流量/(ml/min)	500
时间/min	20
硫化物和硫/磷化合物预处理实验
温度/K	1103
去离子水流量/(ml/min)	1
DMDS质量浓度/(μg/g_water)	500
TPPI质量浓度/(μg/g_water)	100
时间/min	120
热裂解实验
温度/K	1123
石脑油流量/(ml/min)	2
去离子水流量/(ml/min)	0.7

表2 实验方案

Table 2 Experimental plans for each experimental step

流程	方案
空气预氧化处理	preoxidation
采用DMDS预处理	Pre S
采用DMDS& TPPI预处理	Pre S/P
原料连续添加 DMDS+ thiophene+benzothiophene+TEP	sulfides/TEP
原料连续添加 DMDS+thiophene+benzothiophene+TPPI	sulfides/TPPI
采用DMDS预处理，随后原料连续添加 DMDS	Pre S + S
采用DMDS& TPPI预处理，随后原料连续添加DMDS+thiophene+benzothiophene+TPPI	Pre S/P + sulfides/TPPI

图1 不同预处理条件下HP40合金表面氧化层的Raman光谱

Fig.1 Raman spectra of the oxide films on HP40 alloys

图2 不同预处理条件下HP40合金表面氧化层的XRD谱图

Fig.2 XRD patterns of the oxide films on HP40 alloys

图3 不同预处理条件下HP40合金表面氧化层的SEM照片和EDS分析

Fig.3 SEM photos and EDS analysis of the oxide films on HP40 alloys

表3 不同预处理条件下HP40合金表面氧化层元素分布

Table 3 Element concentrations of the oxide films on HP40 alloys

加速电压/ kV	分析区域	Cr原子浓度/%	Mn原子浓度/%	Fe原子浓度/%	Ni原子浓度/%	O原子浓度/%	Si原子浓度/%
10(h≤0.53 μm)	Ⅰ	13.66	2.25	1.83	—	82.25	—
	Ⅱ	13.76	1.85	1.50	—	82.88	—
	Ⅲ	16.86	1.71	—	—	81.42	—
15(h≤1.04 μm)	I	25.36	3.47	6.97	4.42	58.35	1.40
	Ⅱ	27.58	3.56	4.48	2.05	61.44	0.88
	Ⅲ	31.46	3.07	2.89	1.53	59.54	1.50

图4 原料中添加硫化物后，HP40合金氧化层表面焦炭的SEM图

Fig.4 SEM images of cokes on HP40 alloys with the addition of sulfides ( Csulfur= 136 μg/g)

图5 裂解时间1 h条件下，未添加/添加二甲基二硫后HP40合金氧化层表面碳纤维的SEM图

Fig.5 SEM images of carbon fibers on HP40 alloys in the absence/presence of DMDS after cracking time of 1 h

图6 裂解时间3 h条件下，添加硫化物/磷化物混合物后HP40合金氧化层表面焦炭的SEM图

Fig.6 SEM images of cokes on HP40 alloys in the presence of S/P compounds after cracking time of 3 h

图7 裂解时间1 h和3 h条件下，添加硫化物后HP40合金表面焦炭沉积量情况

Fig.7 The amounts of coke formed on HP40 alloys with the addition of sulfides after cracking time of 1 h and 3 h

图8 裂解时间1 h和3 h、实验方案为“Pre S/P”条件下，HP40合金表面焦炭的SEM图和丝状焦的EDS分析

Fig.8 SEM images of cokes on HP40 alloys under the condition of “ Pre S/P” after cracking time of 1h and 3 h; EDS of cokes on HP40 alloys

图9 裂解时间1 h和3 h、实验方案为Pre S条件下，HP40合金表面焦炭的SEM图和表面丝状焦的EDS分析

Fig.9 SEM images of cokes on HP40 alloys under the condition of Pre S after cracking time of 1h and 3 h；EDS of cokes on HP40 alloys

图10 裂解时间1 h和3 h条件下，不同添加方式对HP40合金表面焦炭沉积量的影响

Fig.10 The amounts of coke formed on HP40 alloys with varying the addition methods after cracking time of 1 h and 3 h

图11 裂解时间1 h和3 h、实验方案为Pre S + S条件下HP40合金表面焦炭的SEM图和表面丝状焦的EDS分析

Fig.11 SEM images of cokes on HP40 alloys under the condition of Pre S + S after cracking time of 1 h and 3 h； EDS of coke on HP40 alloys

图12 裂解时间1 h和3 h条件下，硫/磷组分预处理与原料连续注入硫/磷化合物联合操作方式下HP40合金表面焦炭的SEM图

Fig.12 SEM photos of cokes on HP40 alloys with the pretreatment of DMDS/TPPI followed by continuous addition of mixed sulfides/TPPI after cracking time of 1 h and 3 h

图13 不同添加方式下HP40合金表面焦炭的Raman光谱图

Fig.13 Raman spectra of cokes on HP40 alloys with varied addition methods

表4 热裂解结焦一阶拉曼光谱的分峰拟合参数[20-21]

Table 4 The parameters of curve fits for the first-order Raman spectra of cokes on HP40 alloys

拟合峰	Raman位移/cm^-1	振动模式	拟合方式
G	1580	理想石墨晶格 (E_2g-symmetry)	Lorentzian
D1	1350	无序石墨晶格 (graphene layer edge, A_1g-symmetry)	Lorentzian
D2	1620	无序石墨晶格(surface graphene layers, E_2g-symmetry)	Lorentzian
D3	1500	无定形碳	Gaussian
D4	1200	无序石墨晶格(A_1g-symmetry), polyenes, ionic impurities	Lorentzian

表5 热裂解结焦拉曼光谱的分峰拟合结果

Table 5 Fitting results of Raman spectra of coke deposits

样品	Γ_D1 /cm^-1	Γ_D2 /cm^-1	Γ_D3 /cm^-1	Γ_D4/cm^-1	Γ_G/cm^-1	I_D1/I_G	I_D3/I_G	I_G/I_All
preoxidation	167.02	23.32	171.24	112.63	58.04	2.54	0.47	0.27
DMDS	179.87	32.68	160.33	110.39	59.51	3.05	0.50	0.23
thiophene	157.91	39.13	173.89	106.49	56.41	3.51	0.68	0.18
benzothiophene	182.63	37.72	150.61	120.18	63.15	3.59	0.52	0.21
sulfides/TPPI	178.29	35.27	163.70	114.37	58.09	3.76	0.78	0.12
Pre S	150.36	38.29	170.56	126.80	57.73	2.84	0.58	0.23
Pre S+ sulfides	173.09	39.38	157.12	124.15	62.63	3.61	0.56	0.18
Pre S/P	163.53	34.37	169.85	116.62	58.74	2.70	0.47	0.25
Pre S/P+sulfides/TPPI	156.61	42.41	180.63	138.05	56.54	4.14	0.90	0.08

图14 连续添加DMDS及硫/磷化合物条件下HP40合金表面焦炭的C 1s XPS光谱图

Fig.14 C1s XPS spectra of cokes on HP40 alloys with the continuous addition of DMDS and sulfides/TPPI

表6 热裂解结焦的sp3/sp2比值

Table 6 sp3/sp2ratio of coke deposits

方案	sp³/sp²比值
preoxidation	0.17
sulfides/TPPI	0.23
DMDS	0.29

图15 连续添加硫/磷化合物条件下HP40合金表面焦炭的S 2p和P 2p XPS光谱图

Fig.15 S 2p and P 2p XPS spectra of cokes on HP40 alloys with the continuous addition of sulfides/TPPI

表7 热裂解结焦的H/C比值(质量比)

Table 7 TheH/C massratios of coke deposits

方案	H/C 比值
preoxidation	0.69
sulfides/TPPI	2.56
连续添加DMDS	1.25
Pre S	0.82

参考文献 32

1	Sarris S A, Olahova N, Verbeken K, et al. Optimization of the in-situ pretreatment of high temperature Ni-Cr alloys for ethane steam cracking[J]. Industrial & Engineering Chemistry Research, 2017, 56(6): 1424-1438.
2	Reyniers M F, Froment G F. Influence of metal surface and sulfur addition on coke deposition in the thermal cracking of hydrocarbons[J]. Industrial & Engineering Chemistry Research, 1995, 34(3): 773-785.
3	Singh A, Paulson S, Farag H, et al. Role of presulfidation and H₂S cofeeding on carbon formation on SS304 alloy during the ethane-steam cracking process at 700℃[J]. Industrial & Engineering Chemistry Research, 2018, 57(4): 1146-1158.
4	Wang J, Reyniers M F, Van Geem K M, et al. Influence of silicon and silicon/sulfur-containing additives on coke formation during steam cracking of hydrocarbons[J]. Industrial & Engineering Chemistry Research, 2008, 47(5): 1468-1482.
5	Kumar S. Triethyl phosphite additive-based fouling inhibition studies[J]. Industrial & Engineering Chemistry Research, 1999, 38(4): 1364-1368.
6	Wang J D, Reyniers M F, Martin G B. The influence of phosphorous containing compounds on steam cracking of n-hexane[J]. Journal of Analytical and Applied Pyrolysis, 2006, 77(2): 133-148.
7	Bao B B, Liu J L, Xu H, et al. Effect of selective oxidation and sulphur/phosphorus-containing compounds on coking behaviour during light naphtha thermal cracking[J]. The Canadian Journal of Chemical Engineering, 2017, 95(8): 1480-1488.
8	屈笑雨, 刘京雷, 徐宏, 等. 25Cr35NiNb 合金表面Al-Si-Cr 涂层抑制结焦性能[J]. 化工学报, 2015, 66(3): 1059-1065.
	Qu X Y, Liu J L, Xu H, et al. Anti-coking characteristics of Al-Si-Cr coating on 25Cr35NiNb alloy[J]. CIESC Journal, 2015, 66(3): 1059-1065.
9	Bao B B, Liu J L, Xu H, et al. Inhibitory effect of MnCr₂O₄ spinel coating on coke formation during light naphtha thermal cracking[J].RSC Advances, 2016, 6(73): 68934-68941.
10	Yan N, Luo J L, Chuang K T. Improved coking resistance of direct ethanol solid oxide fuel cells with a Ni-S_x anode[J]. Journal of Power Sources, 2014, 250(15): 212-219.
11	Sanchez-Tovar R, Leiva-Garcia R, Garcia-Anton J. Characterization of thermal oxide films formed on a duplex stainless steel by means of confocal-Raman microscopy and electrochemical techniques[J]. Thin Solid Films, 2015, 576(2): 1-10.
12	Ramya S, Anita T, Shaikh H, et al. Laser Raman microscopic studies of passive films formed on type 316LN stainless steels during pitting in chloride solution[J]. Corrosion Science, 2010, 52(6): 2114-2121.
13	Oblonsky L J, Devine T M. A Surface enhanced Raman spectroscopic study of the passive films formed in borate buffer on iron, nickel, chromium and stainless steel[J]. Corrosion Science, 1995, 37(11): 17-41.
14	Olahova N, Sarris S A, Reyniers M F, et al. Coking tendency of 25Cr-35Ni alloys: influence of temperature, sulfur addition, and cyclic aging[J]. Industrial & Engineering Chemistry Research, 2018, 57(9): 3138-3148.
15	Wang B, Wang S X, Liu B, et al. Oxide film prepared by selective oxidation of stainless steel and anti-coking behavior during n-hexane thermal cracking[J]. Surface & Coating Technology, 2019, 378(25): 12492-12499.
16	Boehm H P. Carbon from carbon monoxide disproportionation on nickel and iron catalysts: morphological studies and possible growth mechanisms[J]. Carbon, 1973, 11(6): 583-595.
17	Bennett M J, Chaffey G H, Myatt B L, et al. Inhibition by sulfur poisoning of the heterogeous decomposition of acetone[C]// Lyle F A, Baker R T K. Coke Formation on Metal Surfaces. Washington D C, America: America Chemical Society, 1982: 223-238.
18	Salaha M B, Sabot R, Refait P, et al. Passivation behaviour of stainless steel (UNS N-08028) in industrial or simplified phosphoric acid solutions at different temperatures[J]. Corrosion Science, 2015, 99: 320-332.
19	Zhou J X, Xu H, Luan X J, et al. Influence of the SiO₂/S coating and sulfur/phosphorus-containing coking inhibitor on coke formation during thermal cracking of light naphtha[J]. Fuel Processing Technology, 2012, 104: 198-203.
20	Reshetenko T V, Avdeeva L B, Ismagilov Z R, et al. Catalytic filamentous carbon: structure and textural properties[J]. Carbon, 2003, 41(8): 1605-1615.
21	Sadezkv A, Muckernhuber H, Grothe H, et al. Raman microspectroscopy of soot and related carbonaceous materials: Spectral analysis and structural information[J]. Carbon, 2005, 43(8): 1731-1742.
22	Sheng C D. Char structure characterised by Raman spectroscopy and its correlations with combustion reactivity[J]. Fuel, 2007, 86(15): 2316-2324.
23	Qian Z H, Zhang H F, Dai D J, et al. Study on occurrence of sulfur in different group components of Xinyu clean coking coal[J]. Journal of Fuel Chemistry and Technology, 2014, 42(11): 1286-1294.
24	Kicinski W, Szala M, Bystrzejewski M. Sulfur-doped porous carbon: synthesis and application[J]. Carbon, 2014, 68: 1-32.
25	Bu J, Loh G, Gwie C G, DeWiyanti S, et al. Desulfurization of diesel fuels by selective adsorption on activated carbons: competitive adsorption of polycyclic aromatic sulfur heterocycles and polycyclic aromatic Hydrocarbons[J]. Chemical Engineering Journal, 2011, 166(1): 207-217.
26	Timko M T, Wang J A, Burgess J, et al. Roles of surface chemistry and structural defects of activated carbons in the oxidative desulfurization of benzothiophenes[J]. Fuel, 2016, 163(1): 223-231.
27	Niakolas D K. Sulfur poisoning of Ni-based anodes for solid oxide fuel cells in H/C-based fuels[J]. Applied Catalysis A: General, 2014, 486(22): 123-142.
28	Yang Y, Zhang H P, Yan Y. Synthesis of CNTs on stainless steel microfibrous composite by CVD: effect of synthesis condition on carbon nanotube growth and structure[J]. Composites Part B, 2019, 160(1): 369-383.
29	Yu X, Kang Y, Park H S. Sulfur and phosphorus co-doping of hierarchically porous graphene aerogels for enhancing supercapacitor performance[J]. Carbon, 2016, 101: 49-56.
30	Cui S H, Li J H, Jayakumar A, et al. Effects of H₂S and H₂O on carbon deposition over La_0.4Sr_0.5Ba_0.1TiO₃/YSZ perovskite anodes in methane fueled SOFCs[J]. Journal of Power Source, 2014, 250(15): 134-142.
31	刘玉新, 许志明, 赵锁奇, 等. 哈萨克斯坦及俄罗斯渣油馏分中的硫化物裂解色谱分析[J]. 燃料化学学报, 2008, 36(6): 712-719.
	Liu Y X, Xu Z M, Zhao S Q, et al. Analysis of sulfur species in the residue fractions of Kazakhstan and Russia crude oils pyrolysis-gas chromatography[J]. Journal of Fuel Chemistry and Technology, 2008, 36(6): 712-719.
32	Ren Y, Mahinpey N, Feeitag N. Kinetic model for the combustion of coke derived at different coking temperatures[J]. Energy and Fuels, 2007, 21(1): 82-87.

[1]	郑志航, 马郡男, 闫子涵, 卢春喜. 提升管射流影响区内压力脉动特性研究[J]. 化工学报, 2023, 74(6): 2335-2350.
[2]	高靖博, 孙强, 李青, 王逸伟, 郭绪强. 考虑水合物结构转变的含氢气体水合物相平衡模型[J]. 化工学报, 2023, 74(2): 666-673.
[3]	李怀旭, 孙晓岩, 陶少辉, 夏力, 项曙光. 基于分子热力学性质和密度峰聚类的脱硫汽油集总[J]. 化工学报, 2022, 73(12): 5449-5460.
[4]	陈昇, 王梦钶, 鲁波娜, 李秀峰, 刘岑凡, 刘梦溪, 范怡平, 卢春喜. 原料油汽化特性对催化裂化反应结焦过程影响的CFD模拟[J]. 化工学报, 2022, 73(7): 2982-2995.
[5]	郑万鹏, 高小永, 朱桂瑶, 左信. 原油作业过程优化的研究进展[J]. 化工学报, 2021, 72(11): 5481-5501.
[6]	刘晓艺, 李秀萍, 赵荣祥, 张豪. ZrO₂/SiO₂催化剂的制备及其氧化脱硫性能研究[J]. 化工学报, 2021, 72(11): 5653-5663.
[7]	刘美佳,王刚,张忠东,许顺年,王皓,党法璐,何盛宝. 碳五烷烃裂解制低碳烯烃反应性能的分析[J]. 化工学报, 2021, 72(10): 5172-5182.
[8]	赵岩, 李秀萍, 赵荣祥. 苯酚型低共熔溶剂中硫酸钛作为催化剂高效氧化脱硫[J]. 化工学报, 2021, 72(8): 4391-4400.
[9]	王景效, 贺翔宇, 龚剑洪, 许建良, 刘海峰. 新型催化裂解快速流化床内颗粒浓度分布实验研究[J]. 化工学报, 2021, 72(8): 4104-4110.
[10]	忻睦迪, 邢恩会. 三甲基膦和金属氧化物复合改性ZSM-5分子筛及其裂解性能研究[J]. 化工学报, 2021, 72(5): 2657-2668.
[11]	魏彬, 周鑫, 王耀伟, 郭振莲, 陈小博, 刘熠斌, 杨朝合. 基于改进NSGA-Ⅱ算法的FCC分离系统多目标优化[J]. 化工学报, 2021, 72(5): 2735-2744.
[12]	朱慧红, 茆志伟, 杨涛, 冯翔, 金浩, 彭冲, 杨朝合, 王继锋, 方向晨. 催化剂形貌对沸腾床渣油加氢Ni-Mo/Al₂O₃ 催化剂活性位的影响机制[J]. 化工学报, 2021, 72(4): 2076-2085.
[13]	隋宝宽, 施尧, 林见阳, 刘文洁, 袁胜华, 耿新国, 段学志. 焙烧气氛和孔结构对加氢脱金属催化剂性能的影响[J]. 化工学报, 2021, 72(2): 993-1000.
[14]	吴沛文, 荀苏杭, 蒋伟, 李华明, 朱文帅. 离子液体反应型萃取燃油脱硫研究进展[J]. 化工学报, 2021, 72(1): 276-291.
[15]	张睿, 董淑媛, 伍洛, 刘植昌, 徐春明, 刘海燕, 孟祥海. 小分子烷烃与烯烃在离子液体中的溶解性能[J]. 化工学报, 2020, 71(10): 4674-4687.