Processes and systems for the staged synthesis of alkyl bromides
Processes and systems for synthesizing alkyl bromides to hydrocarbon products, such as high molecular weight hydrocarbons, olefins or mixtures thereof, wherein one or more streams of alkyl bromides may be synthesized 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 least a first portion of the alkyl bromides in the presence of a first catalyst and at a first temperature sufficient to form a first hydrocarbon product containing at least hydrocarbons having at least 5 carbon atoms and having a substantial C 6+ paraffin content; and
reacting at least a second portion of the alkyl bromides in the presence of a second catalyst and said first hydrocarbon product and at a second temperature sufficient to form a second hydrocarbon product containing at least hydrocarbons having at least 5 carbon atoms and having a substantial substituted aromatic content, wherein the steps of reacting at least the first portion of the alkyl bromides and reacting at least the second portion of the alkyl bromides occur sequentially.
2. The process of claim 1 wherein said first temperature is from about 150° C. to about 300° C.
3. The process of claim 2 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 300° C. to about 450° C.
5. The process of claim 4 wherein said second temperature is from about 350° C. to about 425° C.
6. The process of claim 1 wherein the steps of reacting at least the first portion of the alkyl bromides and reacting at least the second portion of the alkyl bromides occurs concurrently.
7. The process of claim 1 wherein the first catalyst and the second catalyst are identical.
8. The process of claim 1 wherein the first catalyst is a crystalline alumino-silicate catalyst.
9. The process of claim 8 wherein said first catalyst is a zeolite catalyst.
10. The process of claim 1 wherein the second catalyst is a crystalline alumino-silicate catalyst.
11. The process of claim 10 wherein said second catalyst is a zeolite catalyst.
12. The process of claim 1 wherein said first temperature is from about 150° C. to about 300° C. and said second temperature is from about 300° C. to about 450° C.
13. The process of claim 1 further comprising:
combining said first hydrocarbon product and said second hydrocarbon product.
14. The process of claim 13 further comprising:
removing hydrogen bromide from said first hydrocarbon product and said second hydrocarbon product.
15. The process of claim 1 wherein the first catalyst and the second catalyst are different.
16. The process of claim 1 wherein the steps of reacting at least the first portion of the alkyl bromides and reacting at least the second portion of the alkyl bromides occurs in separate reactors.
17. The process of claim 1 further comprising:
heating at least the second portion of the alkyl bromides prior to reacting at least the second portion of the alkyl bromides in the presence of the second catalyst and the first hydrocarbon product.
18. The process of claim 1 wherein the step of reacting at least the first portion of the alkyl bromides is performed at a pressure in the range of about 1 to about 100 bar.
19. The process of claim 1 wherein the step of reacting at least the second portion of the alkyl bromides is performed at a pressure in the range of about 1 to about 100 bar.