RECYCLE OF PROCESS CONDENSATE IMPURITIES IN TIGAS

Abstract

The present application relates to a plant and a hydrocarbon production process comprising the steps of (i) in a conversion step converting at least a feed stream thereby obtaining a conversion effluent stream comprising water, hydrocarbons such as raw gasoline, unreacted and/or partially reacted feed and/or inerts, (ii) In a separator separating the conversion effluent stream into at least a raw gasoline stream, a recycle stream and a process condensate stream comprising water and oxygenates, (iii) mixing the feed stream and the recycle stream upstream the conversion step, and (iv) adding at least part of the process condensate stream to the feed stream and/or the recycle stream and/or the mixed feed-recycle stream from step (iii).

Claims

1. A hydrocarbon production process comprising the steps of (i) in a conversion step converting at least a feed stream thereby obtaining a conversion effluent stream comprising water, hydrocarbons such as raw gasoline, unreacted and/or partially reacted feed and/or inerts, (ii) in a separator separating the conversion effluent stream into at least a raw gasoline stream, a recycle stream and a process condensate stream comprising water and oxygenates, (iii) mixing the feed stream and the recycle stream upstream the conversion step, and (iv) adding at least part of the process condensate stream to the feed stream and/or the recycle stream and/or the mixed feed-recycle stream from step (iii).

2. A hydrocarbon production process according to claim 1 wherein the oxygenates are separated from the process condensate and added to the feed stream and/or the recycle stream and/or the mixed feed-recycle stream as a recovered oxygenate stream.

3. A hydrocarbon production process according to claim 1, wherein the produced hydrocarbons comprise a mixture of hydrocarbons in the C2-C13 range, preferably comprising C5+.

4. A hydrocarbon production process according to claim 1, wherein the feed comprises methanol, raw methanol, other alcohols, ketones, aldehydes, ethers and/or H.sub.2/CO mixtures.

5. A hydrocarbon production process according to claim 1, wherein the mixing of at least part of the process condensate comprising oxygenates into the feed stream, recycle stream and/or mixed feed-recycle stream is carried out by quenching the at least part of the process condensate into the feed stream and/or the recycle stream and/or the mixed feed-recycle stream by a spray nozzle.

6. A hydrocarbon production process according to claim 1, wherein the process condensate is added to a stream upstream a heat exchanger.

7. A plant comprising a converter, means for feeding a feed stream to the converter, a separator, means for returning at least part of a recycle stream from the separator to the converter, and means for mixing at least part of a process condensate from the separator into the means for feeding the feed stream and/or into the means for returning at least part of the recycle stream upstream the converter.

8. A plant according to claim 7, comprising further means for separating oxygenates from the process condensate.

9. A plant according to claim 8 wherein the means for separating oxygenates from the process condensate comprises a distillation unit and/or a stripper unit.

10. Raw gasoline produced by the process according to claim 1.

11. Raw gasoline produced by the plant according to claim 7.

Description

[0029] FIG. 1 illustrates a process and plant 1 where feed 2 is mixed with recycle gas 3 and recovered oxygenate stream 4 is mixed into the feed/recycle gas stream at a mixing point 5.

[0030] Alternatively the recovered oxygenate stream is mixed into the recycle stream upstream the feed mix point 5 at a second mixing point 7. The mixing is preferable carried out by quenching the recovered oxygenate stream into the gas stream by means of a spray nozzle. Alternatively a static mixer can be used or the liquid and the gas can be mixed upstream of a heat exchanger.

[0031] Another alternative is to add the recovered oxygenate stream to the feed stream before the stream is evaporated or after the feed stream is evaporated as indicated by dotted lines 8 and 9. Another alternative is to spray/mix the liquid off-stream into the gas going to the reactor as indicated by dotted line 10.

[0032] The ketone, aldehydes and/or alcohols in the recovered oxygenate stream is together with the feed methanol converted to gasoline in the reactor 11. The effluent 12 is cooled/condensed in a series of heat exchangers 13 and the three phases are separated in the separator 14. The gas is recycled 15/purged 16 and the condensate 17 is sent to a distillation 18 for separation. The recovered oxygenate stream 4 from the separation comprises ketones, aldehydes and/or alcohols.