Heavy Oil Hydrotreating System and Heavy Oil Hydrotreating Method

Patent metadata

Field	Value
Publication number	US-2018346828-A1
Application number	US-201615775694-A
Country	US
Kind code	A1
Filing date	Nov 1, 2016
Priority date	Nov 12, 2015
Publication date	Dec 6, 2018
Grant date	—

Abstract

A heavy oil hydrotreating system has a prehydrotreating reaction zone, a transition reaction zone, and a hydrotreating reaction zone that are connected in series successively, sensor units, and a control unit. In the initial reaction stage, the prehydrotreating reaction zone includes at least two prehydrotreating reactors connected in parallel, and the transition reaction zone includes or doesn't include prehydrotreating reactors; in the reaction process, the control unit controls material feeding to and material discharging from each prehydrotreating reactor in the prehydrotreating reaction zone according to pressure drop signals of the sensor units, so that when the pressure drop in any of the prehydrotreating reactors in the prehydrotreating reaction zone reaches a predetermined value, the prehydrotreating reactor in which the pressure drop reaches the predetermined value is switched from the prehydrotreating reaction zone to the transition reaction zone.

First claim

1 . A heavy oil hydrotreating system, comprising a prehydrotreating reaction zone, a transition reaction zone, and a hydrotreating reaction zone that are connected in series, and sensor units and a control unit, wherein the sensor units are configured to detect pressure drop in each prehydrotreating reactor in the prehydrotreating reaction zone, and the control unit is configured to receive pressure drop signals from the sensor units;
in the initial reaction stage, the prehydrotreating reaction zone includes at least two prehydrotreating reactors connected in parallel, and the transition reaction zone includes or doesn't include prehydrotreating reactors; in the reaction process, the control unit controls material feeding to and material discharging from each prehydrotreating reactor in the prehydrotreating reaction zone according to pressure drop signals of the sensor units, so that when the pressure drop in any of the prehydrotreating reactors in the prehydrotreating reaction zone reaches a predetermined value, the prehydrotreating reactor in which the pressure drop reaches the predetermined value is switched from the prehydrotreating reaction zone to the transition reaction zone.

2 . The system according to claim 1 , wherein the predetermined value of pressure drop in the prehydrotreating reactor is 50%-80% of a design upper limit of pressure drop for the prehydrotreating reactors, or is 60%-70% of the design upper limit of pressure drop.

3 . The system according to claim 1 , wherein in the initial reaction stage, the prehydrotreating reaction zone includes 3-6 prehydrotreating reactors, or 3-4 prehydrotreating reactors;
the hydrotreating reaction zone includes 1-5 hydrotreating reactors connected in series, or includes 1-2 hydrotreating reactors connected in series.

4 . The system according to claim 3 , wherein in the initial reaction stage, the transition reaction zone doesn't include any prehydrotreating reactor;
moreover, the control unit controls material feeding to and material discharging from the prehydrotreating reactors in the prehydrotreating reaction zone according to pressure drop signals from the sensor units, so that: when the pressure drop in one prehydrotreating reactor reaches the predetermined value, the prehydrotreating reactor is switched from the prehydrotreating reaction zone to the transition reaction zone, and is named as a cut-out prehydrotreating reactor I, and the prehydrotreating reaction zone, the cut-out prehydrotreating reactor I, and the hydrotreating reaction zone are connected in series successively; when the pressure drop in the next one prehydrotreating reactor reaches the predetermined value, the prehydrotreating reactor is switched from the prehydrotreating reaction zone to the transition reaction zone, and is named as a cut-out prehydrotreating reactor II, and the prehydrotreating reaction zone, the cut-out prehydrotreating reactor II, the cut-out prehydrotreating reactor I, and the hydrotreating reaction zone are connected in series successively; the other prehydrotreating reactors are treated in the above-mentioned method, till all of the prehydrotreating reactors are connected in series.

5 . The system according to claim 1 , wherein in the prehydrotreating reaction zone, the discharge outlet of any one prehydrotreating reactor is connected through a pipeline with a control valve to the feed inlets of other prehydrotreating reactors and the feed inlet of the hydrotreating reaction zone, the feed inlet of any one prehydrotreating reactor is connected through a pipeline with a control valve to a supply source of mixed flow of heavy oil raw material and hydrogen, wherein the control unit controls material feeding and discharging by controlling the control valves corresponding to the prehydrotreating reactors.

6 . A heavy oil hydrotreating method, comprising: mixing the heavy oil raw material with hydrogen, and then feeding the mixture through the prehydrotreating reaction zone, transition reaction zone, and hydrotreating reaction zone that are connected in series; wherein,
in the initial reaction stage, the prehydrotreating reaction zone includes at least two prehydrotreating reactors connected in parallel, and the transition reaction zone includes or doesn't include prehydrotreating reactors; in the reaction process, when the pressure drop in any one of the prehydrotreating reactors in the prehydrotreating reaction zone reaches a predetermined value, the prehydrotreating reactor in which the pressure drop reaches the predetermined value is switched to the transition reaction zone, wherein the predetermined value of pressure drop in the prehydrotreating reactors is 50%-80% of a design upper limit of pressure drop for the prehydrotreating reactors, or is 60%-70% of the design upper limit of pressure drop.

7 . The method according to claim 6 , wherein in the initial reaction stage, the prehydrotreating reaction zone includes 3-6 prehydrotreating reactors, or 3-4 prehydrotreating reactors.

8 . The method according to claim 7 , wherein in the initial reaction stage, the transition reaction zone doesn't include any prehydrotreating reactor;
in addition, when the pressure drop in one prehydrotreating reactor reaches the predetermined value, the prehydrotreating reactor is switched from the prehydrotreating reaction zone to the transition reaction zone, and is named as a cut-out prehydrotreating reactor I, and the prehydrotreating reaction zone, the cut-out prehydrotreating reactor I, and the hydrotreating reaction zone are connected in series successively; when the pressure drop in the next one prehydrotreating reactor reaches the predetermined value, the prehydrotreating reactor is switched from the prehydrotreating reaction zone to the transition reaction zone, and is named as a cut-out prehydrotreating reactor II, and the prehydrotreating reaction zone, the cut-out prehydrotreating reactor II, the cut-out prehydrotreating reactor I, and the hydrotreating reaction zone are connected in series successively; the other prehydrotreating reactors are treated in the above-mentioned method, till all of the prehydrotreating reactors are connected in series.

9 . The method according to claim 6 , wherein the pressure drops in all of the prehydrotreating reactors are controlled so that they don't reach the predetermined value at the same time, or, the time difference between the times when the pressure drops in two adjacent prehydrotreating reactors in which the pressure drops are closest to the predetermined value of pressure drop reach the predetermined value of pressure drop is not smaller than 20% of the entire running period, or is 20%-60% of the entire running period.

10 . The method according to claim 9 , wherein the pressure drops in each prehydrotreating reactor in the prehydrotreating reaction zone are controlled so that they don't reach the predetermined value of pressure drop at the same time by setting operating conditions and/or utilizing the differences in the properties of the catalyst bed layers, or, the pressure drops in each prehydrotreating reactor in the prehydrotreating reaction zone are controlled so that they don't reach the predetermined value of pressure drop at the same time, by controlling one or more of different catalyst packing heights in each prehydrotreating reactor, different feed rates of each prehydrotreating reactor, different properties of the feed materials, different operating conditions, and different catalyst packing densities under a condition of the same packing height.

11 . The method according to claim 10 , wherein in the case that the approach of controlling different catalyst packing densities in each prehydrotreating rea

Assignees

• China Petroleum & Chem Corp
• Fushun Res Institute Of Petroleum And Petrochemicals Sinopec Corp

Inventors

• Liu Tiebin
• Geng Xinguo
• Weng Yanbo
• Li Hongguang

Classifications

• C10G2300/1007

  Used oils · CPC title

• C10G65/00 Primary

  Treatment of hydrocarbon oils by two or more hydrotreatment processes only · CPC title

• C10G65/08 Primary

  at least one step being a hydrogenation of the aromatic hydrocarbons · CPC title

• C10G45/72

  Controlling or regulating · CPC title