Ethane recovery process and alkylation process with ethane recovery

1. A process for the recovery of ethane, comprising:

feeding a first stream comprising methane, ethane, and ethylene to a reboiled absorber column;

contacting the first stream with an absorbent-reactant in the reboiled absorber column to absorb essentially all of the ethane and ethylene, producing a rich oil bottoms stream comprising the absorbent-reactant, ethylene, and ethane, and a vapor stream comprising methane, wherein the contacting is performed operating the reboiled absorber column at a bottoms temperature in the range from about 150° C. to about 220° C. and an overhead pressure in the range from about 200 psig to about 500 psig;

reacting the ethylene and the absorbent-reactant in a reaction zone, producing a reaction zone effluent comprising ethane and a reaction product;

stripping the effluent in a stripper to produce a lean oil bottoms stream and an overhead vapor stream consisting essentially of ethane and including essentially no ethylene, methane, and hydrogen;

wherein the reboiled absorber column comprises multiple reboilers configured to sequentially extract heat from the lean oil bottoms stream from the stripper;

extracting heat from the lean oil bottoms stream from the stripper via one or more stripper side reboilers.

2. The process of claim 1 , wherein the first stream and the vapor stream each further comprise one or more of nitrogen, hydrogen, carbon monoxide, and carbon dioxide.

3. The process of claim 1 , further comprising:

operating the stripper at a bottoms temperature in the range from about 200° C. to about 280° C.

4. The process of claim 1 , further comprising recycling at least a portion of the lean oil bottoms stream from the stripper to the reboiled absorber column as the absorbent-reactant.

5. The process of claim 4 , further comprising introducing the absorbent-reactant proximate an upper end of the reboiled absorber column at a temperature in the range from about −20° C. to about 50° C.

6. The process of claim 1 , further comprising contacting the lean oil bottoms stream in indirect heat exchange with the reaction zone effluent and/or the rich oil bottoms stream.

7. The process of claim 6 , further comprising withdrawing a portion of the lean oil stream intermediate the contacting in indirect heat exchange and introduction of a remaining portion of the lean oil stream to the reboiled absorber column.

8. The process of claim 7 , further comprising admixing fresh and/or make-up adsorbent-reactant with the remaining portion of the lean oil stream.

9. The process of claim 1 , further comprising feeding the overhead vapor stream comprising ethane to a cracker.

10. A process for the recovery of ethane, comprising:

feeding a first stream comprising methane, ethane, and ethylene to a reboiled absorber column;

contacting the first stream with an absorbent-reactant in the reboiled absorber column to absorb essentially all of the ethane, producing a rich oil stream comprising the absorbent-reactant, ethylene, and ethane, and a vapor stream comprising methane, where the contacting is performed operating the reboiled absorber column at a bottoms temperature in the range from about 150° C. to about 220° C. and an overhead pressure in the range from about 200 psig to about 500 psig;

reacting the ethylene and the absorbent-reactant in a reaction zone, producing an effluent comprising ethane and a reaction product;

stripping the effluent in a stripper to produce a lean oil bottoms stream and an overhead vapor stream consisting of ethane and any entrained absorbent-reactant and reaction product, and wherein the overhead vapor stream includes essentially no ethylene, methane, and hydrogen;

contacting the overhead vapor stream with a first portion of a second absorbent-reactant in a first scrubber to absorb the entrained absorbent-reactant and reaction product in the overhead vapor stream and to produce a first scrubber bottoms stream comprising the second absorbent-reactant and a first scrubber overhead stream consisting essentially of ethane;

contacting the vapor stream comprising methane with a second portion of the second absorbent-reactant in a second scrubber to absorb ethane, ethylene, and/or absorbent-reactant present in the vapor stream and to produce a second scrubber bottoms stream comprising the second absorbent-reactant and a second scrubber overhead stream comprising methane;

wherein the reboiled absorber column comprises multiple reboilers configured to sequentially extract heat from the lean oil bottoms stream from the stripper;

extracting heat from the lean oil bottoms stream from the stripper via one or more stripper side reboilers.

11. The process of claim 10 , wherein the absorbent-reactant comprises benzene, the second absorbent-reactant comprises poly-ethylated benzenes, and the reaction product comprises ethylbenzene.

12. The process of claim 10 , wherein the first stream and the vapor stream each further comprise nitrogen and/or hydrogen.

13. The process of claim 10 , further comprising:

operating the stripper at a pressure in the range from about 100 psig to about 450 psig.

14. The process of claim 10 , further comprising recycling at least a portion of the lean oil bottoms steam from the stripper to the reboiled absorber column as the absorbent-reactant, wherein the absorbent-reactant in introduced to the reboiled absorber column at a temperature in the range from about −20° C. to about 50° C.