US 11,926,587 B2
Process for converting raffinate butenes to propylene
Lei Zhang, Houston, TX (US); Pranit S. Metkar, Houston, TX (US); Majid Keyvani, Houston, TX (US); and Daniel F. White, Houston, TX (US)
Assigned to Lyondell Chemical Technology, L.P., Houston, TX (US)
Filed by Lyondell Chemical Technology, L.P., Houston, TX (US)
Filed on Sep. 14, 2021, as Appl. No. 17/474,953.
Claims priority of provisional application 63/078,661, filed on Sep. 15, 2020.
Prior Publication US 2022/0081376 A1, Mar. 17, 2022
Int. Cl. C07C 6/04 (2006.01)
CPC C07C 6/04 (2013.01) 18 Claims
OG exemplary drawing
 
1. A process for converting a C4 Raffinate stream to propylene, the process comprising:
a) providing a C4 Raffinate stream comprising 1-butene and 2-butene to a metathesis reactor, the metathesis reactor containing a metathesis catalyst system, wherein the C4 Raffinate stream is provided as a weight hourly space velocity ranging from 1 to 8.3/h;
b) contacting the C4 Raffinate stream with the metathesis catalyst system under conditions suitable for forming an intermediate product stream comprising propylene, a heavy (C4+) component, and ethylene; and
c) discharging the intermediate product stream to a first separation unit and separating the intermediate product stream into fractions comprising [1] a first product stream having a higher propylene concentration than the intermediate product stream and [2] a second product stream having a lower propylene concentration than the intermediate product stream, wherein the second product stream contains ethylene but in an amount less than 15 wt. %, wherein the second product stream is recycled by combining the second product stream with the C4 Raffinate stream or is recycled by introduction into the metathesis reactor, and
wherein the process for converting the C4 Raffinate stream to propylene is performed in the absence of added ethylene.