Processes and systems for the staged synthesis of alkyl bromides
Processes and systems for synthesizing hydrocarbon products, such as high molecular weight hydrocarbons, olefins or mixtures thereof, from alkyl bromides wherein one or more streams of alkyl bromides may be reacted in sequential or concurrent stages at different temperatures. The catalyst used in the synthesis stages may be the same or different and at least in one instance is chosen to form hydrocarbon products having a significant C 6+ paraffin content. The stages may be conducted in one or more reactors and the catalyst may be deployed in fixed beds or fluidized beds.
1. A process comprising:
providing alkyl bromides;
reacting at a portion of the alkyl bromides in a first synthesis state in the presence of a first catalyst and at a first temperature of about 150° C. to about 300° C. to form an effluent comprising a first hydrocarbon product having high molecular weight hydrocarbons, olefins or mixtures thereof, that contain a substantial C 6+ paraffin content;
introducing the effluent to a second synthesis stage;
reacting the effluent in the second synthesis stage in the presence of a second catalyst and at a second temperature of about 300° C. to about 450° C. to form a hydrocarbon product stream comprising a second hydrocarbon product containing at least hydrocarbons having high molecular weight hydrocarbons, olefins or mixtures thereof, that contain C 6+ fraction having primarily substituted aromatics; and
removing the hydrocarbon product stream from the second synthesis stage.
2. The process of claim 1 , wherein the process is a continuous process, and wherein the steps of reacting at least a portion of the alkyl bromides and reacting the effluent occurs concurrently.
3. The process of claim 1 wherein said first temperature is from about 225° C. to about 275° C.
4. The process of claim 1 wherein said second temperature is from about 350° C. to about 425° C.
5. The process of claim 1 wherein the step of reacting at least a portion of the alkyl bromides and the step of reacting the effluent are each performed at a pressure in the range of about 1 to about 100 bar.
6. The process of claim 1 further comprising: combining said first hydrocarbon product and said second hydrocarbon product.
7. The process of claim 1 wherein the first catalyst and the second catalyst are different.
8. The process of claim 1 wherein the first catalyst and the second catalyst are identical.
9. The process of claim 1 wherein the first catalyst is a crystalline alumino-silicate catalyst.
10. The process of claim 9 wherein said first catalyst is a zeolite catalyst.
11. The process of claim 1 wherein the second catalyst is a crystalline alumino-silicate catalyst.
12. The process of claim 11 wherein said second catalyst is a zeolite catalyst.
13. The process of claim 1 wherein said first hydrocarbon product is high molecular weight hydrocarbons, olefins or mixtures thereof.
14. The process of claim 1 wherein said second hydrocarbon product is high molecular weight hydrocarbons, olefins or mixtures thereof.