US3922148A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of methane-rich gas
Assignee: Texaco Development Corp
•
Filing: 1974-05-16
•
Granted: 1975-11-25
•
Expires: 1994-05-16
Abstract
Abstract This is an improved continuous process for producing a clean methane-rich gas stream without the concomitant formation of particulate carbon which would ordinarily decrease the efficiency of the process and shorten the life of the catalyst. By-product superheated steam is simultaneously produced at a maximum temperature. The product stream may have a methane content up to 98 to 99 mole % or higher and a gross heating value up to 1000 BTU per SCF or more. Process steps include partial oxidation of a hydrocarbonaceous fuel under operating conditions that produce a synthesis gas containing 10 to 30 mole % methane (dry and CO2free basis) and a H2/CO mole ratio of 2.6 or higher, and reacting the methane-rich process gas stream in one to three catalytic methanation stages under critical operating conditions that increase the methane content in the process gas stream stepwise up to 98 mole % or higher without incipient soot formation for each corresponding CH4 content of the feed as one proceeds from one methanation step to another. Heat from the highly exothermic methanation reaction is used to make valuable by-product superheated steam. The product gas may be burned without polluting the atmosphere.
Inventors
- 👤 Edward T Child
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:33
CPC Classifications
C; C10; C10L; C10L3/00; C01; C01B; C01B3/00; C01B3/02; C01B3/22; C01B3/32; C01B3/34; C01B3/36; C07; C07C; C07C1/00; C07C1/02; C07C1/04; C07C1/0485; C07C7/00; C07C9/00; C07C9/02; C07C9/04; C07C2521/00; C07C2521/02; C07C2521/04; C07C2523/00; C07C2523/70; C07C2523/74; C07C2523/755; Y; Y02; Y02A; Y02A50/00; Y02A50/20
Claims Analysis
Total Claims: 58
Claim 1
Independent Claim
12 words
A PROCESS FOR PRODUCING A METHANE-RICH GAS STREAM COMPRISING THE STEPS OF
Claim 2
Dependent Claim
12 words
A PROCESS FOR PRODUCING A METHANE-RICH GAS STREAM COMPRISING THE STEPS OF
Claim 3
Dependent Claim
155 words
REACTING A HYDROCARBONACEOUS FUEL FEED BY PARTIAL OXIDATION WITH SUBSTANTIALLY PURE OXYGEN AND STEAM AT AN AUTOHENOUS TEMPERATURE IN THE RANGE OF ABOUT 1200* TO 2200:F., AND A PRESSURE IN THE RANGE OF ABOUT 25 TO 250 ATMOSPHERES GAUGE IN THE REACTION ZONE OF A FREE-FLOW UNPACKED NONCATALYTIC SYNTHESIS GAS GENERATOR, WHEREIN THE ATOMIC RATIO OF OXYGEN IN THE FREE -OXYGEN CONTAINING GAS TO CARBON IN THE HYDROCARBONACEOUS FUEL IS IN THE RANGE OF ABOUT 0.6 TO 1.2, THE WEIGHT RATIO OF STREAM TO HYDROCARBONACEOUS FUEL IS IN THE RANGE OF ABOUT 3 TO 5, AND THE STREAM OF EFFLUENT GAS LEAVING SAID SYNTHESIS GAS GENERATOR PRINCIPALLY COMPRISES H2 AND CO HAVING A MOLE RATIO (DRY BASIS) H2/CO OF 2.6 AND ABOVE, CH4 IN THE RANGE OF 10 TO 30 MOLE % (DRY, CO2-FREE BASIS), H2O, CO2, PARTICULATE CARBON, AND ACID GAS CONTAINING OF A GAS FROM THE GROUP CO2, H2S, COS, AND MIXTURES THEREOF;
Claim 4
Dependent Claim
155 words
REACTING A HYDROCARBONACEOUS FUEL FEED BY PARTIAL OXIDATION WITH SUBSTANTIALLY PURE OXYGEN AND STEAM AT AN AUTOHENOUS TEMPERATURE IN THE RANGE OF ABOUT 1200* TO 2200:F., AND A PRESSURE IN THE RANGE OF ABOUT 25 TO 250 ATMOSPHERES GAUGE IN THE REACTION ZONE OF A FREE-FLOW UNPACKED NONCATALYTIC SYNTHESIS GAS GENERATOR, WHEREIN THE ATOMIC RATIO OF OXYGEN IN THE FREE -OXYGEN CONTAINING GAS TO CARBON IN THE HYDROCARBONACEOUS FUEL IS IN THE RANGE OF ABOUT 0.6 TO 1.2, THE WEIGHT RATIO OF STREAM TO HYDROCARBONACEOUS FUEL IS IN THE RANGE OF ABOUT 3 TO 5, AND THE STREAM OF EFFLUENT GAS LEAVING SAID SYNTHESIS GAS GENERATOR PRINCIPALLY COMPRISES H2 AND CO HAVING A MOLE RATIO (DRY BASIS) H2/CO OF 2.6 AND ABOVE, CH4 IN THE RANGE OF 10 TO 30 MOLE % (DRY, CO2-FREE BASIS), H2O, CO2, PARTICULATE CARBON, AND ACID GAS CONTAINING OF A GAS FROM THE GROUP CO2, H2S, COS, AND MIXTURES THEREOF;
Claim 5
Dependent Claim
24 words
COOLING, AND PURIFYING THE EFFLUENT GAS STREAM FORM (1) IN A GAS COOLING AND PURIFICATION ZONE THEREBY REMOVING TICULATE CARBON, H2O, AND ACID GAS;
Claim 6
Dependent Claim
24 words
COOLING, AND PURIFYING THE EFFLUENT GAS STREAM FORM (1) IN A GAS COOLING AND PURIFICATION ZONE THEREBY REMOVING TICULATE CARBON, H2O, AND ACID GAS;
Claim 7
Dependent Claim
33 words
cooling, and purifying the effluent gas stream from (1) in a gas cooling and purification zone thereby removing from the process gas stream substantially all of said particulate carbon, H2O, and acid gas;
Claim 8
Dependent Claim
33 words
cooling, and purifying the effluent gas stream from (1) in a gas cooling and purification zone thereby removing from the process gas stream substantially all of said particulate carbon, H2O, and acid gas;
Claim 9
Dependent Claim
47 words
The process of claim 1 further provided with the steps of passing water in indirect heat exchange with the effluent gas stream from step (1) thereby producing superheated steam at a temperature in the range of about 750* to 850*F. while effecting said cooling in step (2).
Claim 10
Dependent Claim
28 words
cooling the effluent gas stream from (1) by indirect heat exchange with water thereby producing superheated steam at a temperature in the range of about 750* to 850*F.;
Claim 11
Dependent Claim
28 words
cooling the effluent gas stream from (1) by indirect heat exchange with water thereby producing superheated steam at a temperature in the range of about 750* to 850*F.;
Claim 12
Dependent Claim
29 words
purifying the effluent gas stream from (2) in a gas purification zone thereby removing from the process gas stream substantially all of said particulate carbon, H2O, and acid gas;
Claim 13
Dependent Claim
29 words
purifying the effluent gas stream from (2) in a gas purification zone thereby removing from the process gas stream substantially all of said particulate carbon, H2O, and acid gas;
Claim 14
Dependent Claim
82 words
preheating the process gas stream from (2) having a mole ratio (dry basis) H2/CO of 2.6 and above to a temperature in the range of about 400* to 500*F., feeding the preheated gas stream into a first catalytic methanation zone and reacting the H2 and CO in said process gas stream therein at a temperature in the range of about 1420* to 1570*F. and a pressure in the range of about 25 to 250 atmospheres without the concomitant formation of particulate carbon;
Claim 15
Dependent Claim
82 words
preheating the process gas stream from (2) having a mole ratio (dry basis) H2/CO of 2.6 and above to a temperature in the range of about 400* to 500*F., feeding the preheated gas stream into a first catalytic methanation zone and reacting the H2 and CO in said process gas stream therein at a temperature in the range of about 1420* to 1570*F. and a pressure in the range of about 25 to 250 atmospheres without the concomitant formation of particulate carbon;
Claim 16
Dependent Claim
32 words
PREHEATING THE PROCESS GAS STREAM FROM (29 HAVING A MOLE RATIO (DRY BASIS) H2/CO OF 2.6 AND ABOVE TO A TEMPERATURE RATIO (DRY BASIS) H2/CO OF 2.6 ND ABOVE TO A TEMPERATURE
Claim 17
Dependent Claim
32 words
PREHEATING THE PROCESS GAS STREAM FROM (29 HAVING A MOLE RATIO (DRY BASIS) H2/CO OF 2.6 AND ABOVE TO A TEMPERATURE RATIO (DRY BASIS) H2/CO OF 2.6 ND ABOVE TO A TEMPERATURE
Claim 18
Dependent Claim
202 words
The process of claim 1 further provided with the steps of (a) preheating said methane-rich process gas stream from step (5) to a temperature in the range of about 400* to 500*F., (b) introducing said preheated process gas stream having a H2/CO mole ratio of 2.6 or more into a second catalytic methanating zone and reacting the H2 and CO in said process gas stream therein at a temperature in the range of about 1060* to 1210*F. and a pressure in the range of about 25 to 250 atmospheres gauge without the concomitanat formation of particulate carbon; (c) withdrawing a methane-rich gas stream having a mole % CH4 (dry basis) from about 65 to 83 and a gross heating value in the range of about 770 to 910 BTU per SCF (dry basis); and (d) cooling the methane-rich gas stream from (c) to a temperature below the dew point to condense out and separate water by three sequential heat exchange steps comprising cooling first by heat exchange with water to produce superheated steam at a temperature in the range of about 600* to 700*F., second by preheating the methane-rich process gas stream in (a), and third by indirect heat exchange with water.
Claim 19
Dependent Claim
29 words
withdrawing a methane-rich gas stream from (3) containing about 40 to 60 mole % CH4 (dry basis) and having a gross heating value of at least 600 BTU/SCF; and
Claim 20
Dependent Claim
29 words
withdrawing a methane-rich gas stream from (3) containing about 40 to 60 mole % CH4 (dry basis) and having a gross heating value of at least 600 BTU/SCF; and
Claim 21
Dependent Claim
29 words
WITHDRAWING A METHANE-RICH GAS STREAM FORM (3) CONTAINING ABOUT 40 TO 60 MOLE % CH4 (BY BASIS) AND HAVING A GROSS HEATING VALUE OF AT LEAST 600 BTU/SCF; AND
Claim 22
Dependent Claim
29 words
WITHDRAWING A METHANE-RICH GAS STREAM FORM (3) CONTAINING ABOUT 40 TO 60 MOLE % CH4 (BY BASIS) AND HAVING A GROSS HEATING VALUE OF AT LEAST 600 BTU/SCF; AND
Claim 23
Dependent Claim
82 words
preheating the process gas stream from (3) having a mole ratio (dry basis) H2/CO of 2.6 and above to a temperature in the range of about 400* to 500*F., feeding the preheated gas stream into a first catalytic methanation zone and reacting the H2 and CO in said process gas stream therein at a temperature in the range of about 1420* to 1570*F. and a pressure in the range of about 25 to 250 atmospheres without the concomitant formation of particulate carbon;
Claim 24
Dependent Claim
82 words
preheating the process gas stream from (3) having a mole ratio (dry basis) H2/CO of 2.6 and above to a temperature in the range of about 400* to 500*F., feeding the preheated gas stream into a first catalytic methanation zone and reacting the H2 and CO in said process gas stream therein at a temperature in the range of about 1420* to 1570*F. and a pressure in the range of about 25 to 250 atmospheres without the concomitant formation of particulate carbon;
Claim 25
Dependent Claim
203 words
The process of claim 3 further provided with the steps of (1) preheating the methane-rich process gas stream from step (d) to a temperature in the range of about 400* to 500*F., (2) introducing said preheated methane-rich process gas stream having a H2/CO mole ratio of 2.6 or more into a third catalytic methanating zone and reacting the H2 and CO in said process gas stream therein at a temperature in the range of about 700* to 850*F., and a pressure in the range of about 25 to 250 atmospheres gauge without the concomitant formation of particulate carbon; (3) withdrawing a methane-rich gas stream having a mole % CH4 (dry basis) from about 90 to 98 and a gross heating value in the range of about 920 to 980 BTU per SCF (dry basis); and (4) cooling the methane-rich gas stream fromm (3) to a temperature below the dew point to condense out and separate water by three sequential heat exchange steps comprising cooling first by heat exchangE with water to produce superheated steam at a temperature in the range of about 550* to 650*F., second by preheating the methane-rich process gas stream in (1), and third by indirect heat exchange with water.
Claim 26
Dependent Claim
52 words
The process of claim 4 further provided with the step of removing any acid gas from the methane-rich stream from step (4) to produce a clean product gas stream containing about 98 to 99 mole % CH4 or higher and having a gross heating value of 1000 BTU per SCF or more.
Claim 27
Dependent Claim
30 words
withdrawing a methane-rich gas stream from (4) containing about 40 to 60 mole % CH4 (dry basis) and having a gross heating value of at least 600 BTU per SCF:
Claim 28
Dependent Claim
30 words
withdrawing a methane-rich gas stream from (4) containing about 40 to 60 mole % CH4 (dry basis) and having a gross heating value of at least 600 BTU per SCF:
Claim 29
Dependent Claim
54 words
COOLING BY THREE SEQUENTIAL HEAT EXCHANGE STEPS SAID METHANE-RICH GAS STREAM FROM (4) TO BELOW THE DEW POINT TEMPERATURE TO CONDENSE OUT AND SEPARATE WATR COMPRISING COOLING FIRST BY INDIRECT HEAT EXCHANGE WITH WATER TO PRODUCE STEAM, SECOND BY PREHEATING THE PROCESS GAS STREAM IN (3), AND THIRD BY INDIRECT HEAT EXCHANGE WITH WATER.
Claim 30
Dependent Claim
54 words
COOLING BY THREE SEQUENTIAL HEAT EXCHANGE STEPS SAID METHANE-RICH GAS STREAM FROM (4) TO BELOW THE DEW POINT TEMPERATURE TO CONDENSE OUT AND SEPARATE WATR COMPRISING COOLING FIRST BY INDIRECT HEAT EXCHANGE WITH WATER TO PRODUCE STEAM, SECOND BY PREHEATING THE PROCESS GAS STREAM IN (3), AND THIRD BY INDIRECT HEAT EXCHANGE WITH WATER.
Claim 31
Dependent Claim
54 words
cooling by three sequential heat exchange steps said methane-rich gas stream from (4) to below the dew point temperature to condense out and separate water comprising cooling first by indirect heat exchange with water to produce steam, second by preheating the process gas stream in (3), and third by indirect heat exchange with water.
Claim 32
Dependent Claim
54 words
cooling by three sequential heat exchange steps said methane-rich gas stream from (4) to below the dew point temperature to condense out and separate water comprising cooling first by indirect heat exchange with water to produce steam, second by preheating the process gas stream in (3), and third by indirect heat exchange with water.
Claim 33
Dependent Claim
54 words
cooling by three sequential heat exchange steps said methane-rich gas stream from (5) to below the dew point temperature to condense out and separate water comprising cooling first by indirect heat exchange with water to produce steam, second by preheating the process gas stream in (4), and third by indirect heat exchange with water;
Claim 34
Dependent Claim
54 words
cooling by three sequential heat exchange steps said methane-rich gas stream from (5) to below the dew point temperature to condense out and separate water comprising cooling first by indirect heat exchange with water to produce steam, second by preheating the process gas stream in (4), and third by indirect heat exchange with water;
Claim 35
Dependent Claim
40 words
The process of claim 1 wherein the pressure in steps (2) to (5) are substantially the same as the pressure in the reaction zone of the synthesis gas generator in step (1) less ordinary minor pressure drops in the line.
Claim 36
Dependent Claim
33 words
The process of claim 1 wherein the catayst in the first catalytic methanation zone comprises 33 to 78 weight percent of nickel oxide and about 12 to 25 weight percent of aluminum oxide.
Claim 37
Dependent Claim
20 words
preheating said methane-rich process gas stream from step (6) to a temperature in the range of about 400* to 500*F.;
Claim 38
Dependent Claim
20 words
preheating said methane-rich process gas stream from step (6) to a temperature in the range of about 400* to 500*F.;
Claim 39
Dependent Claim
64 words
introducing said preheated process gas stream having a H2/CO mole ratio of 2.6 or more into a second catalytic methanating zone and reacting the H2 and CO in said process gas stream therein at a temperature in the range of about 1060* to 1210*F. and a pressure in the range of about 25 to 250 atmospheres gauge without the concomitant formation of particulate carbon;
Claim 40
Dependent Claim
64 words
introducing said preheated process gas stream having a H2/CO mole ratio of 2.6 or more into a second catalytic methanating zone and reacting the H2 and CO in said process gas stream therein at a temperature in the range of about 1060* to 1210*F. and a pressure in the range of about 25 to 250 atmospheres gauge without the concomitant formation of particulate carbon;
Claim 41
Dependent Claim
38 words
A process for producing a clean product gas comprising 98 to 99 mole % methane or more having a gross heating value of 1000 British Thermal Units per Standard Cubic Foot or more and by-product superheated steam comprising:
Claim 42
Dependent Claim
38 words
A process for producing a clean product gas comprising 98 to 99 mole % methane or more having a gross heating value of 1000 British Thermal Units per Standard Cubic Foot or more and by-product superheated steam comprising:
Claim 43
Dependent Claim
35 words
withdrawing a methane-rich gas stream having a mole % CH4 (dry basis) from about 65 to 85 and a gross heating value in the range of about 770 to 910 BTU per SCF (dry basis);
Claim 44
Dependent Claim
35 words
withdrawing a methane-rich gas stream having a mole % CH4 (dry basis) from about 65 to 85 and a gross heating value in the range of about 770 to 910 BTU per SCF (dry basis);
Claim 45
Dependent Claim
40 words
The process of claim 8 wherein the pressure in steps (2) to (15) are substantially the same as the pressure in the reaction zone of the synthesis gas generator in step (1) less ordinary minor pressure drops in the line.
Claim 46
Dependent Claim
37 words
The process of claim 8 wherein the catalyst in the catalytic methanation zones in steps (4), (8), and (12) comprises 33 to 78 weight percent of nickel oxide and 12 to 25 weight percent of aluminum oxide.
Claim 47
Dependent Claim
67 words
cooling the methane-rich gas stream from (9) to a temperature below the dew point to condense out and separate water by three sequential heat exchange steps comprising cooling first by heat exchange with water to produce superheated steam at a temperature in the range of about 600* to 700*F., second by preheating the methane-rich process gas stream in (7), and third by indirect heat exchange with water;
Claim 48
Dependent Claim
67 words
cooling the methane-rich gas stream from (9) to a temperature below the dew point to condense out and separate water by three sequential heat exchange steps comprising cooling first by heat exchange with water to produce superheated steam at a temperature in the range of about 600* to 700*F., second by preheating the methane-rich process gas stream in (7), and third by indirect heat exchange with water;
Claim 49
Dependent Claim
20 words
preheating the methane-rich process gas stream from step (10) to a temperature in the range of about 400* to 500*F.;
Claim 50
Dependent Claim
20 words
preheating the methane-rich process gas stream from step (10) to a temperature in the range of about 400* to 500*F.;
Claim 51
Dependent Claim
65 words
introducing said preheated methane-rich process gas stream having a H2/CO mole ratio of 2.6 or more into a third catalytic methanating zone and reacting the H2 and CO in said process gas stream therein at a temperature in the range of about 700 to 850*F. and a pressure in the range of about 25 to 250 atmospheres gauge without the concomitant formation of particulate carbon;
Claim 52
Dependent Claim
65 words
introducing said preheated methane-rich process gas stream having a H2/CO mole ratio of 2.6 or more into a third catalytic methanating zone and reacting the H2 and CO in said process gas stream therein at a temperature in the range of about 700 to 850*F. and a pressure in the range of about 25 to 250 atmospheres gauge without the concomitant formation of particulate carbon;
Claim 53
Dependent Claim
35 words
withdrawing a methane-rich gas stream having a mole % CH4 (dry basis) from about 90 to 98 and a gross heating value in the range of about 920 to 980 BTU per SCF (dry basis);
Claim 54
Dependent Claim
35 words
withdrawing a methane-rich gas stream having a mole % CH4 (dry basis) from about 90 to 98 and a gross heating value in the range of about 920 to 980 BTU per SCF (dry basis);
Claim 55
Dependent Claim
68 words
cooling the methane-rich gas stream from (13) to a temperature below the dew point to condense out and separate water by three sequential heat exchange steps comprising cooling first by heat exchange with water to produce superheated steam at a temperature in the range of about 550* to 650*F., second by preheating the methane-rich process gas stream in (11), and third by indirect heat exchange with water; and
Claim 56
Dependent Claim
68 words
cooling the methane-rich gas stream from (13) to a temperature below the dew point to condense out and separate water by three sequential heat exchange steps comprising cooling first by heat exchange with water to produce superheated steam at a temperature in the range of about 550* to 650*F., second by preheating the methane-rich process gas stream in (11), and third by indirect heat exchange with water; and
Claim 57
Dependent Claim
18 words
removing any acid gas from the methane-rich stream from step (14) to produce said clean product gas stream.
Claim 58
Dependent Claim
18 words
removing any acid gas from the methane-rich stream from step (14) to produce said clean product gas stream.
References Cited (Backward Citations)
US3511624A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |