Patent ID: 11932816
Assignee: EXXONMOBIL CHEMICAL PATENTS INC.
Field: Chemical engineering (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 20:
21. A process for upgrading a furnace effluent from a steam cracker operating in on-stream decoking mode, the process comprising:
contacting the furnace effluent with a first quench liquid to produce a quenched mixture, wherein the first quench liquid comprises a first steam cracker naphtha, a first steam cracker gas oil, a first steam cracker quench oil, or a mixture thereof, wherein the furnace effluent is at a temperature of about 425° C. to about 850° C. and the first quench liquid is at a temperature of about 30° C. to 200° C. when the furnace effluent is contacted with the first quench liquid, and wherein the furnace effluent comprises coke, tar, or a mixture thereof;
introducing the quenched mixture into a first inlet of a centrifugal separator drum;
introducing a second quench liquid comprising a second steam cracker naphtha, a second steam cracker gas oil, a second steam cracker quench oil, or a mixture thereof into a second inlet of the centrifugal separator drum at a second quench liquid flow rate, wherein the centrifugal separator drum contains the quenched mixture;
separating a vapor product and a centrifugal drum bottoms from the quenched mixture and the second quenched liquid, wherein the centrifugal drum bottoms comprises at least a portion of the coke, tar, or the mixture thereof;
recovering the centrifugal drum bottoms from a first outlet of the centrifugal separator drum;
introducing a recycle fluid tangentially onto a frustoconical inner wall of the centrifugal separator drum through a recycle fluid inlet of the centrifugal separator drum, wherein the recycle fluid comprises at least a portion of the centrifugal separator drum bottoms;
measuring a centrifugal separator drum bottoms flow rate between the first outlet and the recycle fluid inlet; and
increasing the flow rate of the second quench liquid when the centrifugal separator drum bottoms flow rate is ≤90% of a maximum recycle rate of the centrifugal separator drum bottoms.