Hydrogenation of acetylenes in a hydrocarbon stream
A system for hydrogenation C 3 and C 4 acetylenes contained within a hydrocarbon stream generated in a stream cracker unit where a debutanizer is placed upstream of a depropanizer for more economical processing of the hydrocarbon stream to produce lighter hydrocarbons, where the system requires only one stripper tower downstream of hydrogenation to remove residual hydrogen.
1. A system for hydrogenating acetylenes in a hydrocarbon stream, the system comprising:
a debutanizer comprising a debutanizer overhead stream;
a condenser downstream of the debutanizer and configured to condense the debutanizer overhead stream to yield a condensed debutanizer overhead stream;
a C 4 acetylene hydrogenation reactor downstream of the condenser and configured to selectively hydrogenate the condensed debutanizer overhead stream while maintaining the condensed debutanizer overhead stream in liquid phase;
a depropanizer downstream of the debutanizer and the C 4 acetylene hydrogenation reactor;
a methyl acetylene and propadiene (MAPD) reactor downstream of the depropanizer; and
a stripper column downstream from the depropanizer for venting off residual unreacted H 2 .
2. The system of claim 1 , wherein the stripper column is located downstream of the MAPD reactor to receive a crude propylene stream therefrom.
3. The system of claim 1 , wherein the C 4 acetylene hydrogenation reactor comprises an outlet stream directed to the depropanizer, and the depropanizer comprises a bottoms crude butadiene product stream.
4. The system of claim 3 , wherein there is no stripping column additional to the stripper column for venting off residual unreacted H 2 from the crude butadiene product stream.
5. The system of claim 1 , wherein the condenser comprises a refrigeration medium.
6. An ethylene plant comprising:
a system for hydrogenating acetylenes in a hydrocarbon stream, the system comprising:
a debutanizer comprising a debutanizer overhead stream;
a condenser downstream of the debutanizer and configured to condense the debutanizer overhead stream to yield a condensed debutanizer overhead stream;
a C 4 acetylene hydrogenation reactor downstream of the condenser and configured to selectively hydrogenate the condensed debutanizer overhead stream while maintaining the condensed debutanizer overhead stream in liquid phase;
a depropanizer downstream of the debutanizer and the C 4 acetylene hydrogenation reactor;
a methyl acetylene and propadiene (MAPD) reactor downstream of the depropanizer; and
a stripper column downstream from the depropanizer for venting off residual unreacted H 2 .
7. The ethylene plant of claim 6 , wherein the stripper column is located downstream of the MAPD reactor to receive a crude propylene stream therefrom.
8. The ethylene plant of claim 6 , wherein the C 4 acetylene hydrogenation reactor comprises an outlet stream directed to the depropanizer, and the depropanizer comprises a bottoms crude butadiene product stream.
9. The ethylene plant of claim 8 , wherein there is no stripping column additional to the stripper column for venting off residual unreacted H 2 from the crude butadiene product stream.
10. The ethylene plant of claim 6 , wherein the condenser comprises a refrigeration medium.