Process for increasing production of light olefin hydrocarbon from hydrocarbon feedstock

1. A process for increasing production of a light olefin hydrocarbon compound from a hydrocarbon feedstock, comprising the following steps of:

feeding a hydrocarbon feedstock into a pyrolysis furnace to conduct a pyrolysis reaction;

separating reaction products, which are generated from the pyrolysis reaction, into a stream containing hydrogen and C 4 or lower hydrocarbons, and a stream containing C 5 + hydrocarbons, through a compression and fractionation process;

recovering hydrogen, and C 2 , C 3 and C 4 olefin and paraffin hydrocarbons, respectively from the stream containing hydrogen and C 4 or lower hydrocarbons;

separating pyrolysis gasolines and a C 9 + hydrocarbon-containing fraction from the stream containing C 5 + hydrocarbons, using hydrogenation and separation processes;

feeding a mixture of the separated pyrolysis gasolines, a hydrocarbon feedstock, and hydrogen into at least one reaction area;

converting the mixture in the presence of a catalyst in the reaction area into an aromatic hydrocarbon compound which is rich in benzene, toluene, and xylene through dealkylation/transalkylation reactions, and into a non-aromatic hydrocarbon compound which is rich in liquefied petroleum gas through a hydrocracking reaction;

separating reaction products of the mixture converting step into an overhead stream, which contains hydrogen, methane, ethane, and liquefied petroleum gas, and a bottom stream, which contains aromatic hydrocarbon compounds, and a small amount of hydrogen and non-aromatic hydrocarbon compounds, using a gas-liquid separation process;

circulating the overhead stream into the compression and fractionation process; and

recovering the aromatic hydrocarbon compounds from the bottom stream.

2. The process as set forth in claim 1 , further comprising the step of circulating at least a portion of the C 2 -C 4 paraffin hydrocarbons which are respectively recovered in the hydrogen and C 4 or low hydrocarbon recovering step into the pyrolysis furnace.

3. The process as set forth in claim 1 , wherein, in the overhead steam circulating step, a portion of the overhead stream is separated and then recycled into the reaction area of the hydrocarbon feedstock converting step, or the entire overhead stream is recycled into the compression and fractionation process.

4. The process as set forth in claim 1 , further comprising the step of separating the aromatic hydrocarbon compounds which are recovered in the aromatic hydrocarbon recovering step into benzene, toluene, xylene, and C 9 + aromatic compounds, respectively.

5. The process as set forth in claim 1 , wherein 10-95 wt % zeolite, which is at least one selected from a group consisting of mordenite, a beta type of zeolite, and a ZSM-5 type of zeolite and which has a silica/alumina molar ratio of 200 or less, is mixed with 5-90 wt % inorganic binder to produce a support, and platinum/tin or platinum/lead is supported on the mixture support to produce the catalyst.

6. The process as set forth in claim 1 , wherein the hydrocarbon feedstock is selected from a group consisting of reformate, pyrolysis gasoline, fluidized catalytic cracking gasoline, C 9 + aromatic-containing mixture, naphtha, and a mixture thereof.

7. A process for increasing production of a light olefin hydrocarbon compound from a hydrocarbon feedstock, comprising the following steps of:

feeding a hydrocarbon feedstock into a pyrolysis furnace to conduct a pyrolysis reaction;

separating reaction products, which are generated from the pyrolysis reaction, into a stream containing hydrogen and C 4 or lower hydrocarbons, and a stream containing C 5 + hydrocarbons, through a compression and fractionation process;

recovering hydrogen, and C 2 , C 3 and C 4 olefin and paraffin hydrocarbons from the stream containing hydrogen and C 4 or lower hydrocarbons;

separating pyrolysis gasolines and a C 9 + hydrocarbon-containing fraction from the stream containing C 5 + hydrocarbons, using hydrogenation and separation processes;

feeding a mixture of the separated pyrolysis gasolines, a hydrocarbon feedstock, and hydrogen into at least one reaction area;

converting the mixture in the presence of a catalyst in the reaction area into an aromatic hydrocarbon compound which is rich in benzene, toluene, and xylene through dealkylation/transalkylation reactions, and into a non-aromatic hydrocarbon compound which is rich in liquefied petroleum gas through a hydrocracking reaction;

separating reaction products of the mixture converting step into an overhead stream, which contains hydrogen, methane, ethane, and liquefied petroleum gas, and a bottom stream, which contains aromatic hydrocarbon compounds, and a small amount of hydrogen and non-aromatic hydrocarbon compounds, using a gas-liquid separation process;

circulating the overhead stream into the compression and fractionation process;

separating the bottom stream into a stream containing the aromatic hydrocarbon compounds and a stream containing a small amount of hydrogen and non-aromatic hydrocarbon compounds; and

circulating the stream, which is separated in the bottom stream separating step and contains a small amount of hydrogen and non-aromatic hydrocarbon compounds, into the pyrolysis furnace.

8. The process as set forth in claim 7 , further comprising the step of circulating at least a portion of the C 2 -C 4 paraffin hydrocarbons which are respectively recovered in the hydrogen and C 4 or lower hydrocarbon recovering step into the pyrolysis furnace.

9. The process as set forth in claim 7 , wherein, in the overhead stream circulating step, a portion of the overhead stream is separated and then recycled into the reaction area of the hydrocarbon feedstock converting step, or the entire overhead stream is recycled into the compression and fractionation process.

10. The process as set forth in claim 7 , wherein 10-95 wt % zeolite, which is at least one selected from a group consisting of mordenite, a beta type of zeolite, and a ZSM-5 type of zeolite, and which has a silica/alumina molar ratio of 200 or less, is mixed with 5-90 wt % inorganic binder to produce a support, and platinum/tin or platinum/lead is supported on the mixture support to produce the catalyst.

11. The process as set forth in claim 7 , wherein the hydrocarbon feedstock is selected from a group consisting of reformate, pyrolysis gasoline, fluidized catalytic cracking gasoline, C 9 + aromatic-containing mixture, naphtha, and a mixture thereof.

12. A process for increasing production of a light olefin hydrocarbon compound from a hydrocarbon feedstock, comprising the following steps of:

feeding a hydrocarbon feedstock into a pyrolysis furnace to conduct a pyrolysis reaction;

separating reaction products, which are generated from the pyrolysis reaction, into a stream containing hydrogen and C 4 or lower hydrocarbons, and a stream containing C 5 + hydrocarbons, through a compression and fractionation process;

recovering hydrogen, and C 2 , C 3 and C 4 olefin and paraffin hydrocarbons from the stream containing hydrogen and C 4 or lower hydrocarbons;

introducing fluidized catalytic cracking gasolines to the stream containing C 5 + hydrocarbons, and separating pyrolysis gasolines and a C 9 + hydrocarbon-containing fraction from the resulting stream using hydrogenation and separation processes;

feeding a mixture of the separated pyrolysis gasolines, a hydrocarbon feedstock, and hydrogen into at least one reaction area;

converting the mixture in the presence of a catalyst in the reaction area into an aromatic hydrocarbon compound which is rich in benzene, toluene, and xylene through dealkylation/transalkylation reactions, and into a non-aromatic hydrocarbon compound which is rich in liquefied petroleum gas through a hydrocracking reaction;

separating reaction products of the mixture converting step into an overhead stream, which contains hydrogen, methane, ethane, and liquefied petroleum gas, and a bottom stream, which contains aromatic hydrocarbon compounds, and a small amount of hydrogen and non-aromatic hydrocarbon compounds, using a gas-liquid separation process;

circulating the overhead stream into the compression and fractionation process;

separating the bottom stream into a stream containing the aromatic hydrocarbon compounds and a stream containing a small amount of hydrogen and non-aromatic hydrocarbon compounds; and

circulating the stream, which is separated in the bottom stream separating step and contains a small amount of hydrogen and non-aromatic hydrocarbon compounds, into the pyrolysis furnace.

13. The process as set forth in claim 12 , further comprising the step of circulating at least a portion of the C 2 -C 4 paraffin hydrocarbons which are respectively recovered in the hydrogen and C 4 or lower hydrocarbon recovering step into the pyrolysis furnace.

14. The process as set forth in claim 12 , wherein, in the overhead stream circulating step, a portion of the overhead stream is separated and then recycled into the reaction area of the hydrocarbon feedstock converting step, or the entire overhead stream is recycled into the compression and fractionation process.

15. The process as set forth in claim 12 , wherein 10-95 wt % zeolite, which is at least one selected from a group consisting of mordenite, a beta type of zeolite, and a ZSM-5 type of zeolite and which has a silica/alumina molar ratio of 200 or less, is mixed with 5-90 wt % inorganic binder to produce a support, and platinum/tin or platinum/lead is supported on the mixture support to produce the catalyst.

16. The process as set forth in claim 12 , wherein the hydrocarbon feedstock is selected from a group consisting of reformate, pyrolysis gasoline, fluidized catalytic cracking gasoline, C 9 + aromatic-containing mixture, naphtha, and a mixture thereof.