Catalytic conversion process and system for producing gasoline and propylene

Patent metadata

Field	Value
Publication number	US-11873457-B2
Application number	US-202017442055-A
Country	US
Kind code	B2
Filing date	Mar 17, 2020
Priority date	Mar 22, 2019
Publication date	Jan 16, 2024
Grant date	Jan 16, 2024

Abstract

A catalytic conversion process for producing gasoline and propylene includes the steps of 1) subjecting a feedstock oil to a first catalytic conversion reaction in a first catalytic conversion reaction device to obtain a first reaction product; 2) separating the first reaction product to obtain a propylene fraction, a gasoline fraction and a fraction comprising C 4 olefin; 3) carrying out an oligomerization reaction on the fraction comprising C 4 olefin in an oligomerization reactor to obtain an oligomerization product comprising C 12 olefin, and optionally separating the oligomerization product to obtain a fraction comprising C 12 olefin; 4) recycling the C 12 olefin-containing oligomerization product or fraction to the first catalytic conversion reaction device, and/or sending the C 12 olefin-containing oligomerization product or fraction to a second catalytic conversion reaction device for a second catalytic conversion reaction to obtain a second reaction product comprising propylene.

First claim

The invention claimed is:

1. A process for producing gasoline and propylene, comprising the steps of:
1) Subjecting a feedstock oil to a first catalytic conversion reaction in a first catalytic conversion reaction device to obtain a first reaction product comprising propylene, C 4 olefin and a gasoline component;
2) Separating the first reaction product to obtain a propylene fraction, a gasoline fraction, a first C 4 olefin-containing fraction having 40-100 wt % C 4 olefin, optionally a light cycle oil fraction and optionally a fluidized catalytic cracking gas oil (FGO) fraction;
3) Subjecting the first C 4 olefin-containing fraction obtained in step 2) or a combination of the first C 4 olefin-containing fraction obtained in step 2) and a C 4 olefin-containing fraction from an external source to olefin oligomerization in an oligomerization reactor to obtain an oligomerization product comprising C 12 olefin,
separating the oligomerization product to obtain a second C 4 olefin-containing fraction, a C 8 olefin-containing fraction, and a C 12 olefin-containing fraction, wherein the C 12 olefin-containing fraction has a C 12 olefin content of no less than 70 wt %, based on the weight of the C 12 olefin-containing fraction;
4) Sending the C 12 olefin-containing fraction to the first catalytic conversion reaction device, and/or sending the C 12 olefin-containing fraction to a second catalytic conversion reaction device for a second catalytic conversion reaction to obtain a second reaction product comprising propylene; and
5) Optionally, subjecting the FGO fraction to a first hydrotreatment in a first hydrotreating reactor to obtain a hydrogenated FGO, and recycling at least a part of the hydrogenated FGO to the first catalytic conversion reaction device and/or sending it to the second catalytic conversion reaction device, and/or recycling the light cycle oil fraction to the first catalytic conversion reaction device and/or sending it to the second catalytic conversion reaction device,
wherein the first catalytic conversion reaction device is a diameter-transformed riser reactor comprising a first reaction zone and a second reaction zone having a diameter greater than the first reaction zone along the direction of the reaction stream,
wherein the second catalytic conversion reaction device, when present, is a fluidized bed reactor that is a riser reactor or a composite reactor comprising a riser in combination with a dense phase bed, wherein the riser reactor is an equal-diameter riser reactor, a constant-linear-velocity riser reactor or a diameter-transformed riser reactor,
wherein the reaction conditions in the first reaction zone include a reaction temperature of about 450-620° C., a reaction time of about 0.5-2.0 seconds, a catalyst-to-feedstock weight ratio of about 3:1 to about 15:1, a steam-to-feedstock weight ratio of about 0.03:1 to about 0.3:1,
wherein the reaction conditions in the second reaction zone include a reaction temperature of about 460-550° C., a reaction time of about 2-30 seconds, a catalyst-to-feedstock weight ratio of about 4:1 to about 18:1, and a steam-to-feedstock weight ratio of about 0.03:1 to about 0.3:1, and
wherein:
the second C 4 olefin-containing fraction is sent to the oligomerization reactor,
the C 8 olefin-containing fraction is sent to the first reaction zone in the diameter-transformed riser reactor, and
the C 12 olefin-containing fraction is sent to the second reaction zone of the diameter-transformed riser reactor.

2. The process according to claim 1 , wherein the olefin oligomerization of step 3) is carried out in the presence of an oligomerization catalyst under conditions including:
a temperature of about 50-500° C., a pressure of about 0.5-5.0 MPa, and a weight hourly space velocity of about 0.1-100 h −1 ;
the oligomerization catalyst is one or more selected from the group consisting of phosphoric acid catalysts, acidic resins, silica-alumina solid acid catalysts, and zeolite solid acid catalysts;
wherein, the phosphoric acid catalyst is one or more selected from the group consisting of a catalyst formed by loading phosphoric acid on diatomite, a catalyst formed by loading phosphoric acid on activated carbon, a catalyst formed from phosphoric acid-soaked quartz sand, a catalyst formed by loading phosphoric acid on silica gel, and a catalyst formed by loading copper pyrophosphate on silica gel;
the silica-alumina solid acid catalyst is a catalyst formed by loading metal ion(s) on alumina and/or amorphous silica-alumina carrier, wherein the loaded metal ion(s) is selected from the group consisting of Group VIII metals, Group IVA metals, and a combination thereof; and
the zeolite solid acid catalyst comprises about 10-100 wt % of a zeolite and about 0-90 wt % of a matrix, based on the weight of the zeolite solid acid catalyst, wherein the zeolite is one or more selected from the group consisting of one-dimensional zeolites selected from MTW (ZSM-12), MTT (ZSM-23), and TON (ZSM-22) zeolites, two-dimensional zeolites selected from FER (ferrierite), MFS (ZSM-57), MWW (MCM-22) and MOR (mordenite) zeolites, and three-dimensional zeolites selected from beta zeolites.

3. The process according to claim 1 , wherein:
the optional light cycle oil fraction in step 2) has a distillation range of about 190-350° C.; the optional FGO fraction is a heavy fraction obtained at the bottom of the catalytic conversion fractionator; and
the C 12 olefin recycled to the first catalytic conversion reaction device and/or to the second catalytic conversion reaction device in step 4) accounts for about 0.1-80 wt %, of the total catalytic conversion feedstock.

4. The process according to claim 1 , further comprising:
subjecting the feedstock oil to a second hydrotreatment in a second hydrotreating reactor prior to step 1);
the second hydrotreatment is carried out in the presence of a second hydrotreating catalyst under conditions including:
a hydrogen partial pressure of about 3.0-20.0 MPa, a reaction temperature of about 300-450° C., a hydrogen-to-oil volume ratio of about 100-2000 standard cubic meter/cubic meter, and a volume space velocity of about 0.1-3.0 h −1 ;
the second hydrotreating catalyst comprises about 70-99 wt % of a carrier, which is one or more selected from the group consisting of alumina, silica and amorphous silica-alumina, and about 0.1-30 wt % of an active metal (calculated as oxide) selected from the group consisting of Group VIB metals, Group VIII metals, and a combination thereof.

5. The process according to claim 1 , wherein the first hydrotreatment is conducted in the presence of a first hydrotreating catalyst under conditions including:
a hydrogen partial pressure of about 3.0-20.0 MPa, a reaction temperature of about 300-450° C., a volume space velocity of about 0.1-10.0h −1 , and a hydrogen-to-oil volume ratio of about 100-1500 standard cubic meters/cubic meter;
the first hydrotreating catalyst comprises about 60-99 wt % of a carrier, which is one or more selected from the group consisting of alumina, silica and amorphous silica-alumina, and about 5-40 wt % of an active metal (calculated as oxide) selected from the group consisting of Group VIB metals, Group VIII metals, and a combination thereof.

6. The process according to claim 1 , wherein the catalyst for the first catalytic conversion reaction and the catalyst for the second catalytic conversion reaction, if present, are each independently selected from the group consisting of amorphous silica-alumina catalysts, zeolite catalysts, and a combination thereof, and wherein the zeolite in the zeolite catalyst is one or more selected from the group consisting of Y zeolite, HY zeolite, ultrastable Y zeolite, ZSM-5 series zeolite, high-silica zeolite having a pentasil stru

Assignees

• China Petroleum & Chem Corp
• Sinopec Res Inst Petroleum

Inventors

• Bai Xuhui
• Zuo Yanfen
• Xu Youhao
• Luo Yibin
• Shu Xingtian
• Wang Xieqing
• Wang Xin

Classifications

• C10G69/126 Primary

  polymerisation, e.g. oligomerisation · CPC title

• C10G11/05

  Crystalline alumino-silicates, e.g. molecular sieves · CPC title

• C10G11/18

  according to the "fluidised-bed" technique · CPC title

• C10G45/54

  containing crystalline alumino-silicates, e.g. molecular sieves · CPC title

• C10G50/00

  Production of liquid hydrocarbon mixtures from lower carbon number hydrocarbons, e.g. by oligomerisation · CPC title