CONTROL OF INLET TEMPERATURE FOR CONVERSION STEP

Abstract

The present relates to a method for controlling the inlet temperature T.sub.i to a conversion process, said method comprising the steps of: Providing a feed for a conversion process; In a first temperature control step regulating the temperature of the feed in a waste heat boiler; In a second temperature control step injecting a water stream into the feed downstream the waste heat boiler in an amount and/or at a temperature to obtain the desired inlet temperature into the conversion process.

Claims

1. Method for controlling the inlet temperature T.sub.i to a conversion process, said method comprising the steps of Providing a feed for a conversion process In a first temperature control step regulating the temperature of the feed in a waste heat boiler, In a second temperature control step injecting a water stream into the feed downstream the waste heat boiler in an amount and/or at a temperature to obtain the desired inlet temperature into the conversion process.

2. Method according to claim 1, wherein the water stream is boiler feed water and/or process condensate from one or more process steps.

3. Method according to claim 1, wherein the conversion is a high-temperature shift conversion.

4. Method according to claim 1, wherein the temperature of the water stream is 0-200 C.

5. Method according to claim 1, wherein the temperature of the feed for the conversion process is measured upstream the conversion process.

6. Method according to claim 1, wherein the temperature of the feed after the first temperature control step is higher than the inlet temperature T.sub.i.

7. Method according to claim 1, wherein the inlet temperature T.sub.i of the feed for the conversion process is adjusted based on optimal temperature condition and/or reactor/conversion condition.

8. Method according to claim 1, applied in a plant or process with a reduced S/C ratio upstream the BWR.

9. Plant comprising a reformer, a first temperature control point, a second temperature control point, a reactor, one or more temperature measuring means, wherein the first temperature control point comprises a waste heat boiler and the second temperature control point comprises means for adding water into a feed stream for the reactor.

10. Plant comprising a reformer, a first temperature control point, a second temperature control point, a reactor downstream of the first and second temperature control point, one or more temperature measuring means, wherein the plant is arranged for the method according to claim 1.

Description

[0020] FIG. 1 shows an exemplary plant section 1 and illustrates the method according to the present invention.

[0021] The plant comprises a feed stream 2 which passes through a first temperature control step 3 and a second temperature control step 4 before being fed to a conversion step 5. In the present example the feed stream is the effluent from a secondary reformer 6 and the conversion 5 is a high temperature conversion.

[0022] The injection of the water 7 into the second temperature control step may be controlled by means of a valve 8. The valve 6 may receive/be controlled by one or more temperature sensors e.g. from a TIC 9.

[0023] In the first temperature control step 3, a waste heat boiler (WHB) may for example be a 120 B WHB wherein the WHB temperature control at least partly is exchanged by temperature control through water injection at a second temperature control step.

[0024] In the present example the temperature of effluent from the reforming step (the feed) is approximately 1050 C. After the first temperature control point the temperature is approx. 425 C and after the second temperature control point the feed has reached a desired inlet temperature T.sub.i=360 C.

[0025] The effluent from the conversion step may e.g. be sent to a second boiler and for any further processing.