Claims
- 1. A process for producing, from a desulfurized hydrocarbon-containing feedstock, a synthesis gas having essentially the stoichiometric composition required for methanol synthesis and low CO.sub.2 content, consisting essentially of:
- (a) dividing said feedstock into two fractions, the first fraction representing 30 to 95 percent of the total feedstock,
- (b) subjecting the first fraction from (a) to a primary steam reforming reaction under a pressure higher than 40 atmospheres, by mixing said fraction with steam, and heating the mixture thereof by indirect heat exchange, in the presence of a reforming catalyst, to form a gaseous effluent including hydrogen to a temperature between 700.degree. and 850.degree. C.,
- (c) preheating the second fraction from (a), by indirect heat exchange, to a temperature such that, after mixing said fraction with the gas effluent from (b) in the subsequent step, the mixture thereof is at a minimum temperature of 600.degree. C.,
- (d) combining effluent gas streams from (b) and (c) to obtain a gas mixture at a minimum temperature of 600.degree. C. and containing a minimum of 35 percent methane equivalent,
- (e) preheating a free oxygen-rich gas to a temperature above 350.degree. C. by indirect heat exchange,
- (f) reacting in a single step the gas mixture from (d) with the oxygen rich gas from (e) in a single stage secondary reforming reactor operating under essentially adiabatic conditions, and consisting essentially of a gas mixing zone and a reaction zone, the total amount of free oxygen injected in said mixing zone constitutes the total amount of free oxygen supplied in the process for reaction with the combined effluent gas stream mixture from (d) to produce the synthesis gas and being sufficient to initiate therein the partial oxidation reaction, and the mixing of the reacting gases in said mixing zone being accomplished through a mixing apparatus designed to obtain quasiinstantaneously a homogeneous mixture before the partial oxidation reaction proceeds significantly, and said reaction zone containing a single bed of catalyst or catalysts, whereby the total homogeneous mixture is passed only once through the whole catalyst bed thus producing a synthesis gas containing a percent methane equivalent of less than one-tenth of that of the gas mixture from (d), and a CO.sub.2 content of less than 8 percent by volume.
- 2. A process according to claim 1, wherein the effluent gas temperature from the primary steam reforming step (b) is between 750.degree. and 820.degree. C.
- 3. A process according to claim 1 or 2, wherein the effluent gas temperature from the secondary oxygen reforming step (f) is between 900.degree. and 1200.degree. C.
- 4. A process according to claim 1 or 2, wherein the free oxygen-rich gas used in the secondary reforming contains less than 5 percent by volume of nitrogen and rare gases.
- 5. A process according to claim 1 or 2, wherein the operating pressure of the primary steam reforming and the secondary oxygen reforming is between 40 and 120 atm.
- 6. A process according to claim 1 or 2, wherein the ratio between the number of steam moles used in the primary steam reforming to the number of hydrocarbon carbon atoms treated in said primary steam reforming is between about 1.2 and 5.0.
- 7. A process for producing, from a desulfurized hydrocarbon containing feedstock, a synthesis gas having a molal H.sub.2 /CO ratio below 2.5, consisting essentially of:
- (a) dividing said feedstock into two fractions, the first fraction representing 5 to 40 percent of the total feedstock,
- (b) subjecting the first fraction from (a) to a primary steam reforming reaction under a pressure higher than 40 atmospheres, by mixing said fraction with steam, and heating the mixture thereof by indirect heat exchange, in the presence of a reforming catalyst, to form a gaseous effluent including hydrogen at a temperature between 700.degree. and 850.degree. C.,
- (c) preheating the second fraction from (a), by indirect heat exchange, to a temperature such that, after mixing said fraction with the gas effluent from (b) in the subsequent step, the mixture thereof is at a minimum temperature of 600.degree. C.,
- (d) combining effluent gas streams from (b) and (c) to obtain a gas mixture at a minimum temperature of 600.degree. C. and containing a minimum of 35 percent methane equivalent,
- (e) preheating a free oxygen-rich gas to a temperature above 350.degree. C. by indirect heat exchange,
- (f) reacting in a single step the gas mixture from (d) with the oxygen-rich gas from (e) in a secondary reforming reactor operating under essentially adiabatic conditions, and consisting essentially of a gas mixing zone and a reaction zone, the total amount of free oxygen injected in said mixing zone constituting the total amount of free oxygen supplied in the process for reaction with the combined effluent gas stream mixture from (d) to produce the synthesis gas and being sufficient to initiate therein the partial oxidation reaction, and the mixing of the reacting gases in said mixing zone being accomplished through a mixing apparatus designed to obtain quasi-instantaneously a homogenous mixture before the partial oxidation reaction proceeds significantly, and said reaction zone containing a single bed of catalyst or catalysts, whereby the total homogeneous mixture is passed only once through the whole catalyst bed thus producing a synthesis gas containing a percent methane equivalent of less than one-tenth of that of the gas mixture from (d).
- 8. A process according to claim 7, wherein the effluent gas temperature from the primary steam reforming step (b) is between about 750.degree. and 820.degree. C.
- 9. A process according to claim 7 or 8, wherein the effluent gas temperature from the secondary oxygen reforming step (f) is between about 900.degree. and 1200.degree. C.
- 10. A process according to claim 7 or 8, wherein the free oxygen-rich gas used in the secondary reforming contains less than 5 percent by volume of nitrogen and rare gases.
- 11. A process according to claim 7 or 8, wherein the operating pressure of the primary steam reforming and the secondary oxygen reforming is between 40 and 120 atm.
- 12. A process according to claim 7 or 8, wherein the ratio between the number of steam moles used in the primary steam reforming to the number of hydrocarbon carbon atoms treated in said primary steam reforming is between 1.2 and 5.0.
- 13. A process for producing, from a desulfurized hydrocarbon-containing feedstock, a synthesis gas having essentially the stoichiometric composition required for methanol synthesis and low CO.sub.2 content, consisting essentially of:
- (a) dividing said feedstock into two fractions, the first fraction representing 30 to 66.7 percent of the total feedstock,
- (b) subjecting the first fraction from (a) to a primary steam reforming reaction under a high pressure, by mixing said fraction with steam, and heating the mixture thereof by indirect heat exchange, in the presence of a reforming catalyst, to form a gaseous effluent including hydrogen to a temperature at or above 700.degree. C.,
- (c) preheating the second fraction from (a), by indirect heat exchange, to a temperature such that, after mixing said fraction with the gas effluent from (b) in the subsequent step, the mixture thereof is at a minimum temperature of 600.degree. C.,
- (d) combining effluent gas streams from (b) and (c) to obtain a gas mixture at a minimum temperature of 600.degree. C. and containing a minimum of 35 percent methane equivalent,
- (e) preheating a free oxygen-rich gas to an elevated temperature above 350.degree. C. by indirect heat exchange,
- (f) reacting in a single step the gas mixture from (d) with the oxygen rich gas from (e) in a secondary reforming reactor operating under essentially adiabatic conditions, and consisting essentially of a gas mixing zone and a reaction zone, the total amount of free oxygen injected in said mixing zone constituting the total amount of free oxygen supplied in the process for reaction with the combined effluent gas stream mixture from (d) to produce the synthesis gas and being sufficient to initiate therein the exothermic partial oxidation reaction which raises the temperature of the reaction mixture, and the mixing of the reacting gases in said mixing zone being accomplished through a mixing apparatus designed to obtain quasi-instantaneously a homogeneous mixture before the partial oxidation reaction proceeds significantly, and with said reaction zone containing a single bed of catalyst or catalysts, whereby the total homogeneous mixture is passed only once through the whole catalyst bed thus producing a synthesis gas containing a percent methane equivalent of less than one-tenth of that of the gas mixture from (d), a CO.sub.2 content of less than 8 percent by volume, and CO, CO.sub.2, and H.sub.2 in essentially a stoichiometric ratio for methanol synthesis.
- 14. A process for producing, from a desulfurized hydrocarbon containing feedstock, a synthesis gas having a molal H.sub.2 /CO ratio below 2.5, consisting essentially of:
- (a) dividing said feedstock into two fractions, the first fraction representing 5 to 40 percent of the total feedstock,
- (b) subjecting the first fraction from (a) to a primary steam reforming reaction under a high pressure, by mixing said fraction with steam, and heating the mixture thereof by indirect heat exchange, in the presence of a reforming catalyst, to form a gaseous effluent including hydrogen at a temperature at or above 700.degree. C.,
- (c) preheating the second fraction from (a), by indirect heat exchange, to a temperature such that, after mixing said fraction with the gas effluent from (b) in the subsequent step, the mixture thereof is at a minimum temperature of 600.degree. C.,
- (d) combining effluent gas streams from (b) and (c) to obtain a gas mixture at a minimum temperature of 600.degree. C. and containing a minimum of 35 percent methane equivalent,
- (e) preheating a free oxygen-rich gas to an elevated temperature above 350.degree. C. by indirect heat exchange,
- (f) reacting in a single step the gas mixture from (d) with the oxygen rich gas from (e) in a secondary reforming reactor operating under essentially adiabatic conditions, and consisting essentially of a gas mixing zone and a reaction zone, the amount of free oxygen injected in said mixing zone constituting the total amount of free oxygen supplied in the process for reaction with the combined effluent gas stream mixture from (d) to produce the synthesis gas and being sufficient to initiate therein the exothermic partial oxidation reaction which raises the temperature of the reaction mixture, and the mixing of the reacting gases in said mixing zone being accomplished through a mixing apparatus designed to obtain quasi-instantaneously a homogeneous mixture before the partial oxidation reaction proceeds significantly, and said reaction zone containing a single bed of catalyst or catalysts, whereby the total homogeneous mixture is passed only once through the whole catalyst bed thus producing a synthesis gas containing a percent methane equivalent of less than one-tenth of that of the gas mixture from (d) and a molal H.sub.2 /CO ratio below 2.5.
- 15. A process according to claim 13 or 14 in which the percent methane equivalent in the feed to the secondary reformer ranges from 37 to 76 percent, and the percent methane equivalent in the effluent of said reformer ranges from 1.3 to 2.2 percent.
- 16. A process according to claim 13 or 14, wherein the effluent gas temperature from the secondary oxygen reforming step (f) is between 900.degree. C. and 1200.degree. C.
- 17. A process according to claim 13 or 14, wherein the free oxygen-rich gas used in the secondary reforming contains less than 5 percent by volume of nitrogen and rare gases.
- 18. In a process for producing, from a desulfurized hydrocarbon-containing feedstock, a synthesis gas having essentially the stoichiometric composition required for methanol synthesis and low CO.sub.2 content by (a) dividing said feedstock into two fractions, the first fraction representing about 30 to 66.7 percent of the total feedstock, (b) subjecting the first fraction from (a) to a primary steam reforming reaction under a high pressure, by mixing said fraction with steam, and heating the mixture thereof by indirect heat exchange, in the presence of a reforming catalyst, to form a gaseous effluent including hydrogen, (c) preheating the second fraction from (a), by indirect heat exchange and mixing said fraction with the gas effluent from (b), (d) combining effluent gas streams from (b) and (c) to obtain a gas mixture at a minimum temperature of 600.degree. C. and containing a minimum of 35 percent methane equivalent, and (e) preheating a free oxygen-rich gas to an elevated temperature above 350.degree. C. by indirect heat exchange;
- the improvement wherein the gas mixture from (d) is reacted in a single step with the oxygen rich gas from (e) in a secondary reforming reactor operating under essentially adiabatic conditions, and consisting essentially of a gas mixing zone and a reaction zone, the total amount of free oxygen injected in said mixing zone constituting the total amount of free oxygen supplied in the process for reaction with the combined effluent gas stream mixture from (d) to produce the synthesis gas and being sufficient to initiate therein the partial oxidation reaction, and the mixing of the reacting gases in said mixing zone being accomplished through a mixing apparatus designed to obtain quasi-instantaneously a homogeneous mixture before the exothermic partial oxidation reaction proceeds significantly, and with said reaction zone containing a single bed of catalyst or catalysts, whereby the total homogeneous mixture is passed only once through the whole catalyst bed thus producing a synthesis gas containing a percent methane equivalent of less than one-tenth of that of the gas mixture from (d), a CO.sub.2 content of less than 8 percent by volume, and CO, CO.sub.2 and H.sub.2 in a stoichiometric ratio for methanol synthesis.
- 19. In a process for producing, from a desulfurized hydrocarbon containing feedstock, a synthesis gas having a molal H.sub.2 /CO ratio below 2.5, in which after, (a) dividing said feedstock into two fractions, the first fraction representing about 5 to 40 percent of the total feedstock, (b) subjecting the first fraction from (a) to a primary steam reforming reaction under a high pressure, by mixing said fraction with steam, and heating the mixture thereof by indirect heat exchange, in the presence of a reforming catalyst, to form a gaseous effluent including hydrogen (c) preheating the second fraction from (a), by indirect heat exchange, and mixing said fraction with the gas effluent from (b), (d) combining effluent gas streams from (b) and (c) to obtain a gas mixture at a minimum temperature of 600.degree. C. and containing a minimum of 35 percent methane equivalent, and (e) preheating a free oxygen-rich gas to an elevated temperature above 350.degree. C. by indirect heat exchange;
- the improvement wherein the gas mixture from (d) is reacted in a single step with the oxygen-rich gas from (e) in a secondary reforming reactor operating under essentially adiabatic conditions, and consisting essentially of a gas mixing zone and a reaction zone, the total amount of free oxygen injected in said mixing zone constituting the total amount of free oxygen supplied in the process for reaction with the combined effluent gas stream mixture from (d) to produce the synthesis gas and being sufficient to initiate therein the exothermic partial oxidation reaction which raises the temperature of the reaction mixture, and the mixing of the reacting gases in said mixing zone being accomplished through a mixing apparatus designed to obtain quasiinstantaneously a homogeneous mixture before the partial oxidation reaction proceeds significantly, and said reaction zone containing a single bed of catalyst or catalysts, whereby the total homogeneous mixture is passed only once through the whole catalyst bed thus producing a synthesis gas containing a percent methane equivalent of less than one-tenth of that of the gas mixture from (d) and a molal H.sub.2 /CO ratio below 2.5.
Priority Claims (1)
Number |
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77 08459 |
Mar 1977 |
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Parent Case Info
This application is a continuation of application Ser. No. 502,985 filed June 10, 1983 which is a continuation-in-part of my copending patent application Ser. No. 70,671 filed Aug. 29, 1979, which is a continuation-in-part of my copending application Ser. No. 934,075 filed Aug. 16, 1978, which is a continuation-in-part of my copending patent application Ser. No. 810,209 filed June 27, 1977 all abandoned.
US Referenced Citations (5)
Foreign Referenced Citations (1)
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2372116 |
Jun 1978 |
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Continuations (1)
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502985 |
Jun 1983 |
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Continuation in Parts (3)
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70671 |
Aug 1979 |
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Parent |
934075 |
Aug 1978 |
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Parent |
810209 |
Jun 1977 |
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