Patent ID: 6037515
Filing Date: 2000-03-14
Classification: C10G,Y02P,Y10S

Abstract:
In a process for producing ethylene from a hydrocarbon feedstock comprising:(a) subjecting the hydrocarbon feedstock to cracking;(b) quenching resultant crude gas with water;(c) subjecting resultant quenched crude gas to compression;(d) subjecting resultant compressed crude gas to drying and precooling;(e) separating resultant precooled crude gas in a C2/C3 separation step into a C2- stream and a C3+ stream;(f) subjecting said C2- stream to hydrogenation; and(g) separating said C3+ stream in a C3/C4 separation step into a C3 stream and a C4+ stream, the improvement comprising:upon start-up of the process, feeding foreign ethylene, foreign C3, or both to the crude gas compression (c); andmerging a stream from C2- hydrogenation (f) and a C3 stream from the C3/C4 separation (g), and recycling the merged stream as a first recycle stream before the crude gas compression (c).