Temperature-controlling measure for the hydrogenation slurry bed reactor and its design method and use

Abstract

A temperature-controlling measure for a hydrogenation slurry bed reactor has three control points that are set from low to high: cold hydrogen is injected automatically when the system reaches control point 1; cold oil in injected automatically when the system reaches control point 2; each pressure relief is opened automatically when the system reaches control point 3. The pressure relief point is set before and/or after the circulation pump of the reactor if internal circulation is set in the reactor; the pressure relief point is set at the reactor bottom if the internal circulation is not set; at least one pressure relief valve is set at each pressure relief point.

Claims

1. A temperature-controlling method employed in a hydrogenation slurry bed reactor system, comprising: setting three control points in turn from low to high: automatically injecting cold hydrogen in response to determining that the reactor system reaches control point 1; automatically injecting cold oil in response to determining that the reactor system reaches control point 2; wherein each pressure relief point is opened automatically in response to determining that the reactor system reaches control point 3; wherein the control point 1 is: 425° C.T<440° C. and/or P19 MPa; the control point 2 is: 440° C.T<455° C. and/or P19 MPa; the control point 3 is: T455° C. and/or P20 MPa; setting the pressure relief point before and/or after a circulation pump of the reactor in response to determining that internal circulation is set in the reactor system; and setting the pressure relief point at the bottom of the reactor system in response to determining that the internal circulation is not set in the reactor system, at least one pressure relief valve being set at each pressure relief point; wherein the at least one pressure relief valve is controlled by a temperature or pressure in the reactor system, a number of temperature measurement points being at least 1, a number of pressure measurement points being at least 1 and further comprising: setting a temperature self-control valve and/or hand control valve, the pressure relief valve opening and an alarm being triggered in response to determining that the reactor system operates at more than 455° C. or an operating pressure is more than 20 MPa; and opening all control valves and shutting down the reactor system in response to determining that the reactor system temperature is more than 465° C. and the operating pressure is more than 21.5 MPa.

2. The temperature-controlling method according to claim 1, wherein a number of hydrogenation reactors are used in series, the number of being 2-4, and the number of hydrogenation reactors with pressure relief points being more than 1.

3. The temperature-controlling method according to claim 1, wherein overtemperature and overpressure signals are transmitted to DCS and/or SIS systems simultaneously, in order to initiate corresponding measures.

4. The temperature-controlling method according to claim 1, wherein the at least one pressure relief valve also other pressure relief signal instructions.

5. The temperature-controlling method according to claim 1, wherein receipt of signal instructions are a signal of an abnormal pressure at a feed pump outlet of the reactor system, a signal of abnormal pressure at an outlet of a circulating hydrogen compressor or a fresh hydrogen compressor, or an abnormal reaction in the reactor system.

Description

FIGURE

(1) FIG. 1 shows a scheme of the reactor according to present the invention.

DETAILED DESCRIPTION OF THE INVENTION

(2) In order to explain the invention better, the combination of FIG. 1 and an embodiment will be illustrated below.

Embodiment

(3) This embodiment introduces a slurry bed hydrogenation reactor in one stage of the coal and oil mixing co-refining process. The pressure relief point is set at the inlet of the circulating pump, the amount of the pressure relief valve 7 is one, the depressurizing line 6 is the pipeline of the pressure relief valve 7, which is used to discharge the released medium.

(4) The feedstock 2 enters the reactor 1 through the feeding outlet of the feed distributor 3, in addition, there is an internal circulation system, which includes the circulating feed distributor 4, the circulation pump 5 and the inlet of internal circulation 9 in the reactor.

(5) The operating temperature of the outlet is not more than 455° C. during the normal operation of the reactor 1. As the hydrocracking reaction is exothermic, the temperature measurement point is set at the closest point from the outlet of the reactor 8 to detect the maximum operating temperature of the reactor. In order to avoid the failure measurement of the thermometer or sensor, three thermometers are set up by taking temperature readings from two of the three thermometers. The cold hydrogen is injected automatically when 425° C. is reached; the cold oil is injected automatically when 440° C. is reached; when 455° C. is reached, the alarm is triggered and the pressure relief valve 7 is started to open with transferring the signal to the DCS and SIS system. The pressure relief valve 7 is fully opened automatically when the operating temperature exceeds 465° C. and the device shuts down.

(6) The operating pressure at the inlet is not more than 18.5 MPa when the reactor 1 is operated normally. As the flow direction is from bottom to top, the pressure point is set at the closest point of the inlet of the reactor, i.e. the feeding outlet of the feed distributor 3, to detect the maximum operating pressure of the reactor. In order to avoid the failure measurement of the pressure gauge or sensor, three pressure gauges are set up by taking readings from two of the three thermometers. The pressure relief valve is started to open (controlling the temperature by controlling the pressure) when the operation pressure exceeds 20 MPa, and the signal is transferred to the DCS and SIS system. The pressure relief valve is fully opened and the device shuts down when the pressure exceeds 21.5 MPa. The pressure relief valve also accepts other signals outside the reaction system that need to start the depressurizing, such as the signal of an abnormal pressure at the outlet of the feed pump of the reactor, the signal of an abnormal pressure at the outlet of the circulating hydrogen compressor or the fresh hydrogen compressor, or the abnormal reaction in the reactor.

(7) This embodiment achieves a positive application effect in the hydrogenation slurry bed reactor through the practical verification in production. The measure designed is simple with high degree of automation, and it could also improve the safety of the reactor and production process and ensure the reactor has no safety issue for long term.

(8) The embodiment above is only an optimal specific embodiment of this invention, but the scope of the invention is not limited to it. Any changes which can be easily considered or replaced in the disclosure scope of the invention by a person skilled in this art, should be covered within the protection scope of the invention. As a result, the protection scope of the present invention shall be based on the protection scope of the claims.