초록 ▼

A method of and a plant for recovering liquid hydrocarbons in a gaseous batch, the plant comprising a compressor for the gaseous batch, a column for absorbing C5 and heavier hydrocarbons associated with a debutanization column; a column for absorbing C3 and heavier hydrocarbons associated with a de-

A method of and a plant for recovering liquid hydrocarbons in a gaseous batch, the plant comprising a compressor for the gaseous batch, a column for absorbing C5 and heavier hydrocarbons associated with a debutanization column; a column for absorbing C3 and heavier hydrocarbons associated with a de-ethanization column and with a heat exchange system connected to a refrigeration cycle, the plant providing from a gaseous batch issuing from a catalytic cracking unit a debutanized gasoline, a liquefied gas cut (C3 and C4-hydrocarbons) and a gaseous cut (C2 and lighter hydrocarbons) wherein the losses of C3 and higher C-hydrocarbons are much smaller than that occurring with existing plants.

대표청구항 ▼

A method for recovering liquid hydrocarbons contained in a gaseous batch containing light hydrocarbons of less than 3 carbons atoms and heavier hydrocarbons of 3 or more carbon atoms, compressing the batch, condensing it partially and injecting it into a first absorber provided with an upper portion

A method for recovering liquid hydrocarbons contained in a gaseous batch containing light hydrocarbons of less than 3 carbons atoms and heavier hydrocarbons of 3 or more carbon atoms, compressing the batch, condensing it partially and injecting it into a first absorber provided with an upper portion and a lower portion to produce at the upper portion a pretreated gas and at the lower portion heavier hydrocarbons which are treated in a first distillation column wherein light hydrocarbons are removed leaving heavier hydrocarbons, washing and drying the thus treated gas then cooling it and injecting it into a second absorber to produce at an upper portion the treated gas and at a lower portion liquid hydrocarbons which are treated in a second distillation column wherein light hydrocarbons are removed to produce heavier hydrocarbons, comprising: injecting the heavier hydrocarbons at the lower portion of the first absorber into a debutinization column to obtain at a lower portion of the debutinization column, a liquid cut which contains all of the hydrocarbons of 6 of more carbon atoms, at least 90% of the hydrocarbons of 5 carbon atoms, at most 2% of the hydrocarbons of 4 carbon atoms present in the branch and being free of hydrocarbons of 3 or fewer carbon atoms while at the upper portion of the same column a liquid cut rich in C4 and lighter hydrocarbons is obtained and reinjected as a reflux into said column and as a feed into the upper portion of the first absorber, and a gaseous distillate is recycled into the gaseous batch upstream of the first absorber, injecting the liquid hydrocarbons from the lower portion of the second absorber after reheating into a de-ethanization column to obtain at the lower portion of said de-ethanization column a liquid cut which contains at least 90% of the hydrocarbons of 3 carbon atoms and the total amount of the hydrocarbons of 4 carbon atoms present in the treated gas and obtaining at the upper portion of said column a liquid cut rich in hydrocarbons of 2 or fewer carbon atoms, reinjecting the same as a reflux into said column and as a gaseous distillate rich in hydrocarbons of 2 or fewer carbon atoms which after cooling and at least partial condensation is injected as a feed into the upper portion of the second absorber, whereby at least 90% of the hydrocarbons of 3 carbon atoms and at least 99.9% of the of 4 or more carbon atoms hydrocarbons contained in the gaseous batch are recovered, and the pretreated gas issuing from the first absorber contains all of the hydrocarbons of 3 or fewer carbon atoms, at least 98% of the hydrocarbons of 4 carbon atoms and at most 1% of the hydrocarbons of 5 carbon atoms, while being free of hydrocarbons of 6 or more carbon atoms.