Method and apparatus for managing the conversion of hydrocarbons into olefins
An apparatus and method are provided for processing hydrocarbon feeds. The method enhances the conversion of hydrocarbon feeds into ethylene. In particular, the present techniques expose feed containing hydrocarbons to high-severity operating conditions in a pyrolysis reactor and separate the reactor product from the reactor into a first product having hydrogen and a second product including ≧90 mole percent of the acetylene in the reactor product. Then, the second product is reacted with a catalyst in a converter to form ethylene.
1. A hydrocarbon conversion method comprising:
exposing a pyrolysis feed under thermal pyrolysis high-severity operating conditions in a regenerative pyrolysis reactor to produce a reactor product comprising hydrogen, ethylene, and X mole % acetylene per mole of reactor product, wherein the thermal pyrolysis high-severity operating conditions include (i) a Gaussian-like temperature profile, and (ii) a severity threshold temperature, (iii) a residence time in the range of from 0.5 seconds to 0.001 seconds, and (iv) a peak pyrolysis gas temperature that is greater than the severity threshold temperature;
reacting at least a portion of the reactor product with a catalyst in a converter operated in at least partially in the vapor phase to form a conversion product comprising 0.0 mole % to Z mole % acetylene per mole of the conversion product, the at least a portion of the reactor product comprising Y mole % of acetylene per mole of the at least a portion of the reactor product and the at least a portion of the reactor product having a hydrogen to acetylene molar ratio in the range of from 1.0 and 10.0; and
wherein (i) X<90.0% of a first acetylene non-autodecomposition amount, (ii) Y<90.0% of a second acetylene non-autodecomposition amount, and (iii) Y>Z.
2. The method of claim 1 , further comprising separating from the conversion product a converter recycle product comprising ethylene, and combining the converter recycle product with the at least a portion of the reactor product upstream of the reacting.
3. The method of claim 2 , comprising: determining the X mole % acetylene per mole of reactor product; and adjusting the amount of converter recycle product mixed with the at least a portion of the reactor product to maintain the mixture Y<89.0% of the second acetylene non-autodecomposition amount.
4. The method of claim 2 , further comprising:
determining the hydrogen content of the at least a portion of the reactor product; and adjusting the flow rate of at least one of
(i) the converter recycle product, based on the X≦90.0% of a first acetylene non-autodecomposition amount, or
(ii) the hydrogen to or from the at least a portion of the reactor product.
5. The method of claim 1 , further comprising separating hydrogen from the reactor product upstream of the reacting.
6. The method of claim 5 , wherein the hydrogen is separated by means of a membrane.
7. The method of claim 5 , further comprising: determining the hydrogen content of the reactor product; and adjusting the amount of hydrogen separated from the reactor product to regulate the hydrogen content of the reactor product.
8. The method of claim 2 , further comprising compressing the converter recycle product prior to combining the converter recycle product with the at least a portion of the reactor product.
9. The method of claim 1 , wherein the peak pyrolysis gas temperature is ≧1450.0° C.
10. The method of claim 1 , wherein the reactor product has a C 3+ to C 2 unsaturate weight ratio ≦0.5.
11. The method claim 1 , further comprising polymerizing at least a portion of the conversion product.