US 5,626,034 A · Mixed refrigerants in ethylene recovery

Abstract

The present invention is a process of high efficiency rectification zone separation of cracked or other ethylene-containing gas chilled primarily by two closed mixed refrigerant loops and at least part of the dephlegmated overhead gas. The composition of the mixed refrigerants is optimally chosen to obtain an extremely close approach between the process condensation temperatures in the high efficiency rectification zone and the temperature of the chilling streams. An approach of about 3.degree. F. to 8.degree. F. can be achieved for the full condensation curve in the high efficiency rectification zone operating with either ethane or naphtha derived cracked gas. Highly reliable and stable operation is obtained by closed refrigeration loops in the present invention, in addition to reducing high efficiency rectification zone design cost.

Claims12

Dependent claims

A process for ethylene recovery comprising:

(a) a first gas substantially comprising hydrogen, methane and ethylene;
(b) passing the first gas through a high efficiency rectification zone first to a lower section and then to an upper section to recover to a first liquid from the lower section substantially all the ethylene in the first gas;
(c) providing heat interchange between the upper section and a first closed, mixed refrigerant loop;
and
(d) providing heat interchange between the lower section and a second closed, mixed refrigerant loop.

2 more elements

Dependencies are inferred from the claim text.

Mixed refrigerants in ethylene recovery

Life of this patent

Mixed refrigerants in ethylene recovery

Life of this patent

Abstract

Claims12