US 5,746,066 A · Pre-fractionation of cracked gas or olefins fractionation by one or two mixed refrigerant loops and cooling water

Abstract

The present invention is a plurality of stages for partial condensation and phase separation a process gas stream, preferably containing substantial amounts of light olefins, methane, and hydrogen, but containing initially at least substantial amounts of methane and ethylene. Each condensation and separation stage is refrigerated with a subcooled and flashed high pressure liquid of a mixed refrigerant refrigeration loop, wherein throughout the loop the relative component ratios of the mixed refrigerant components are constant, contrasted with the several mixed refrigerant processes of the prior art where for all the streams of each closed refrigeration loop. In addition, rectification and/or stripping sections of an ethylene separation train have a common support construction taking advantage of relatively similar column diameters to reduce the total number of columns in the process.

Claims24

Dependent claims

A process for partial condensation of a process gas which initially comprises significant amounts of methane and ethylene comprising:

(a) a plurality of sequential. condensation and separation stages comprising, at each condensation and separation stage, condensation of at least part of the process gas and separation of the resulting condensate and remaining process gas;
and
(b) supplying refrigeration for condensation at each condensation and separation stage by a first mixed refrigerant refrigeration loop, wherein a first mixed refrigerant used therein is comprised substantially of ethylene, ethane, and propylene and the relative proportions of those components remain constant through the first mixed refrigerant refrigeration loop.

A process for partial condensation of a process gas which initially comprises significant amounts of methane and ethylene comprising:

(a) a plurality of sequential condensation and separation stages comprising, at each condensation and separation stage, condensation of at least part of the process gas and separation of the resulting condensate and remaining process gas, providing the resulting condensate for use as at least part of the refluxing liquid to rectification stages for the process gas;
and
(b) supplying refrigeration for condensation at each condensation and separation stage by a first mixed refrigerant refrigeration loop, wherein a first mixed refrigerant used therein is comprised substantially of ethylene, ethane, and propylene and the relative proportions of those components remain constant through the first mixed refrigerant refrigeration loop.

Dependencies are inferred from the claim text.

Pre-fractionation of cracked gas or olefins fractionation by one or two mixed refrigerant loops and cooling water

Life of this patent

Pre-fractionation of cracked gas or olefins fractionation by one or two mixed refrigerant loops and cooling water

Life of this patent

Abstract

Claims24