Effects of composition distribution of catalytic slurry oils on optical texture of mesophase pitch

doi:10.11949/0438-1157.20200237

Abstract

Abstract:

Using SLO-LH, SLO-SH and SLO-YN catalytic cracking oil slurry as raw materials, mesophase pitch was prepared by thermal polycondensation method. The hydrocarbon composition distribution, boiling point distribution and nuclear magnetic structure characteristics of the oil slurry were systematically analyzed and related to mesophase pitch. The results show that the molecular weight and composition distribution of SLO-SH and SLO-YN are relatively narrow. The mesophase pitch was prepared under the given reaction conditions at 430 ℃ and 0.7 MPa. The obtained mesophase texture is mainly composed of domain and flow domain, and with less mosaic structure. The SLO-SH and SLO-YN optical texture index (OTI) are 45 and 50, respectively. Compared with SLO-SH and SLO-YN, the hydrocarbon composition and boiling point distribution of SLO-LH samples are significantly evacuated. The mesophase obtained from SLO-LH is mainly composed of a mosaic structure and a small domain. The results show that concentrated distribution and high aromatics content are conducive to high-quality mesophase pitch with high yield and high OTI value. Separation of oil slurry components is a necessary way to prepare high-quality mesophase pitch and needle coke.

Key words: catalytic slurry oil, composition, separation, distribution, mesophase pitch, microstructure

摘要：

以SLO-LH、SLO-SH和SLO-YN催化裂化油浆为原料，利用热缩聚法制备中间相沥青，系统分析了油浆的烃组成分布、沸点分布以及核磁结构特征，关联了中间相沥青光学织构与原料性质组成关系。结果表明，SLO-SH和SLO-YN油浆中的分子量和组成分布较窄，在给定反应条件(430℃、0.7 MPa)下制备中间相沥青的光学织构指数(OTI)值分别为45和50，中间相织构主要由大面积的域及流域组成，镶嵌结构较少。相对于SLO-SH与SLO-YN，SLO-LH样品的烃组成与沸点分布明显疏散，得到的中间相主要由镶嵌组织与小域构成。结果表明集中分布且芳烃含量高有利于得到高收率与高OTI值的优质中间相沥青，对油浆组分进行分离是制备高品质中间相沥青和针状焦的必要途径。

关键词: 催化裂化油浆, 组成, 分离, 分布, 中间相沥青, 显微结构

CLC Number:

TE 624

Xiaoyu DAI, Yuan en MA, Zhiming XU, Linzhou ZHANG, Suoqi ZHAO, Chunming XU. Effects of composition distribution of catalytic slurry oils on optical texture of mesophase pitch[J]. CIESC Journal, 2020, 71(6): 2678-2687.

代晓玉, 马远恩, 许志明, 张霖宙, 赵锁奇, 徐春明. 催化裂化油浆组成分布对中间相沥青光学织构的影响[J]. 化工学报, 2020, 71(6): 2678-2687.

Figures/Tables 11

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Properties	SLO-LH	SLO-YN	SLO-SH
carbon residue/%(mass)	8.16	10.83	16.08
ash/%(mass)	0.16	0.23	0.32
density/(cm³/g)	0.99	1.07	1.09
SARA/%(mass)
saturate	31.29	14.41	14.64
aromatic	45.49	71.78	59.39
resin	17.85	9.54	16.17
asphaltene	1.16	1.55	2.69
element/%(mass)
C	88.97	91.56	91.17
H	10.67	7.89	7.81
O	0.59	0.40	0.45
N	0.33	0.15	0.48
S	0.30	0.71	0.51
metal content/(μg/g)
Ni	5.20	2.40	11.30
V	<0.1	4.60	0.60
Al	76.00	279.00	638.00
Ca	3.10	3.30	12.60
Fe	14.30	6.80	34.50
Na	4.50	2.40	52.10

Properties	SLO-LH	SLO-YN	SLO-SH
carbon residue/%(mass)	8.16	10.83	16.08
ash/%(mass)	0.16	0.23	0.32
density/(cm³/g)	0.99	1.07	1.09
SARA/%(mass)
saturate	31.29	14.41	14.64
aromatic	45.49	71.78	59.39
resin	17.85	9.54	16.17
asphaltene	1.16	1.55	2.69
element/%(mass)
C	88.97	91.56	91.17
H	10.67	7.89	7.81
O	0.59	0.40	0.45
N	0.33	0.15	0.48
S	0.30	0.71	0.51
metal content/(μg/g)
Ni	5.20	2.40	11.30
V	<0.1	4.60	0.60
Al	76.00	279.00	638.00
Ca	3.10	3.30	12.60
Fe	14.30	6.80	34.50
Na	4.50	2.40	52.10

Type	Size/shape	Index(OTI)
mosaic	<10 μm	1
small domain	10—60 μm	5
domain	>60 μm	50
flow domain	>60 μm long,>10 μm wide	100

Type	Size/shape	Index(OTI)
mosaic	<10 μm	1
small domain	10—60 μm	5
domain	>60 μm	50
flow domain	>60 μm long,>10 μm wide	100

Sample	M_n	M_w	Dispersion coefficient
SLO-LH	574	2188.66	3.81
SLO-YN	263	333.74	1.27
SLO-SH	276	384.22	1.39