Abstract: A process for the high-yield recovery of ethylene and heavier hydrocarbons from the gas produced by pyrolysis of hydrocarbons in which the liquid products resulting from the fractionated condensation of a cracking gas for the recovery of almost all the ethylene, are supplied to a distillation column, called a de-ethanizer, at different intermediate levels. At the top of the de-ethanizer the vapor of the column distillate is treated directly in an acetylene hydrogenation reactor, the effluent containing virtually no acetylene being separated by a distillation column called a de-methanizer, into an ethylene- and ethane-enriched tail product, while the head product is recycled by compression or treated for subsequent recovery of ethylene.

Abstract: Process for the high-yield recovery of ethylene and heavier hydrocarbons from the gas produced by pyrolysis of hydrocarbons (1) in which the liquid products (12-15, 23) resulting from the fractionated condensation of the cracking gas (1) for the recovery of almost all the ethylene, are supplied to a distillation column (C1), called the de-ethanizer, at different intermediate levels, at the top of which the vapor (31) of the column distillate is treated directly in an acetylene hydrogenation reactor (R1), the effluent containing virtually no acetylene being separated by a distillation column (C2) called the de-methanizer, into an ethylene- and ethane-enriched tail product (43), while the head product (44) is recycled by compression or treated for subsequent recovery of ethylene.

Abstract: A method and an apparatus for the largest recovery of ethylene and propylene from gas produced by the pyrolysis of hydrocarbons, wherein any liquid current produced by the fractional condensation of the raw gas up to a definite temperature is directly fed to an ethane fractionating column (deethanizer) the bottom product of which is the purified current containing almost all propylene, while any current condensed at lower temperature is fed to a methane separating column (demethanator) provided with a reboiler in which the partial condensation of the overhead vapor of the deethanizer occurs, and the bottom product of the demethanator contains all ethylene.

Abstract: The present invention relates to a method and an apparatus for producing ethylene. This apparatus comprises essentially a phase separator connected to an ethylene fractionating unit. The fractionating unit comprises a first or lower-pressure fractionating column and a second or higher-pressure fractionating column, the second column being fed with an intermediate liquid fraction from the first column and having its head connected to the heating circuit of the reboiling system associated with the first column to at least partially condense the head fraction of the second column. Thus, the invention allows high-purity ethylene to be produced with minimum energy consumption.

Abstract: A method of making ethylene consisting in processing an ethylene gas condensate which is passed through a de-ethanizer to separate as gases the C.sub.2 -hydrocarbons with two carbon atoms, cooling said hydrocarbons to condensate a part thereof, feeding said hydrocarbons into a separator where the condensed phase is separated and recycled to the de-ethanizer, and feeding the non-condensed fraction of said hydrocarbons into an ethylene-recovering unit with which is associated a reboiling system for heating the fluid taken from said unit prior to recycling it to the latter, and further comprising the step of exchanging heat between the hydrocarbons from the de-ethanizer and the reflux fluid from said reboiling system so as to at least partially condensate the hydrocarbons fed to said separator.

Abstract: A method of processing through low temperature heat exchanges natural gases and cracked gases consisting in using a cooling cycle including compressing and then cooling a cycle mixture of gases consisting of C1 hydrocarbons, C2 hydrocarbons and C3 hydrocarbons through outer coolers with attendant total liquefaction of the cycle mixture under pressure; subsequently effecting a sub-cooling of the mixture within heat exchanges in counter-current relation to one expanded part thereof and/or cold returns and rejects of products processed in the cycle and finally expanding said sub-cooled mixture in at least one exchanger where various cooling processes of the treated products are carried out at successive temperature levels.

Abstract: A process for the high-yield recovery of ethylene and heavier hydrocarbons from the gas produced by pyrolysis of hydrocarbons in which the liquid products resulting from the fractionated condensation of a cracking gas for the recovery of almost all the ethylene, are supplied to a distillation column, called a de-ethanizer, at different intermediate levels. At the top of the de-ethanizer the vapor of the column distillate is treated directly in an acetylene hydrogenation reactor, the effluent containing virtually no acetylene being separated by a distillation column called a de-methanizer, into an ethylene- and ethane-enriched tail product, while the head product is recycled by compression or treated for subsequent recovery of ethylene.