Abstract:
Improved process for the production of a methane-rich product gas stream comprising the following steps: partial oxidation of a hydrocarbonaceous fuel feed employing a H2O/fuel weight ratio of 2.2 to 2.9 and an atomic ratio of oxygen in the substantially pure oxygen to carbon in the fuel of 0.80 to 0.84 to produce a process gas stream comprising principally H2, CO and CH4 in which the mole ratio H2/CO is 1 to 2.5, the mole % CH4 is 15 or more, and the particulate carbon is 13 weight % (basis carbon in the fuel) or less; cooling the process gas stream and separating H2O, CO2, carbon, and gaseous impurities; reacting together the H2 and CO in said process gas stream in a catalytic methanation zone to produce a methane-rich gas stream principally comprising CH4 and containing gaseous members selected from the group consisting of H2, CO, H2O, CO2, and mixtures thereof; and removing said H2O and CO2 to produce a methane-rich product gas stream comprising about 93 mole percent of CH4. By means of the subject invention there is produced a high heating value clean fuel gas or a substitute natural gas of about 960 BTU per SCF or more.
Abstract:
An electrical indicator system is connected to a petroleum process where pneumatic controls are employed and where automatic shutdown will take place if any one of a plurality of parameters exceeds predetermined limits. The electrical system uses relays that are actuated by the pneumatic controls which indicate when a parameter goes outside limits. Each such relay has interlocking contacts with the circuits for all the other relays, so that the first actuated relay will lock out the remaining relays. This provides an indication of which condition was first outside limits.
Abstract:
IN A STEADY-STATE CONTINUOUS FLOW FIXED-BED WATER-GAS CATALYST SHIFT CONVERSION REACTOR COMPRISING A PLURALITY OF SEPARATE CATALYST BEDS IN SERIES AT A TEMPERATURE IN THE RANGE OF ABOUT 350*F. TO 1050*F. AND A PRESSURE IN THE RANGE OF ABOUT 1 TO 250 ATMOSPHERES, A GASEOUS FEED STREAM COMPRISING H2O AND CO IS CONVERTED INTO H2 AND CO2. A FRACTION OF THE EFFLUENT GAS STREAM FROM THE FIRST CATALYST BED IN THE REACTOR IS RECYCLED AND MIXED WITH A FRESH FEED STREAM OF PROCESS GAS E.G. SYNTHESIS GAS TO COMPRISE SAID GASEOUS FEED STREAM TO THE FIRST CATALYST BED. THE RESIDUAL FRACTION OF SAID EFFLUENT GAS STREAM IS COOLED AND INTRODUCED INTO THE SECOND CATALYST BED IN THE REACTOR. CO CONVERSION IS IMPROVED, PROCESS FEED STEAM REQUIREMENTS ARE REDUCED, LESS CATALYST IS NEEDED, UNDERSIRABLE BACK AND SIDE REACTIONS ARE MINIMIZED, AND THE SYSTEM IS STABILIZED. OPERATING THE SYSTEM AT HIGH PRESSURE ALSO REDUCES OVERALL CATALYST REQUIREMENTS.
Abstract:
Continuous process for the production of a gaseous stream comprising about 50 to 97 mole % methane (dry basis) or higher from a sulfur containing hydrocarbonaceous fuel without polluting the environment. A gaseous stream comprising H2 and CO produced by the partial oxidation of a hydrocarbonaceous fuel is subjected to water gas shift reaction to produce a gaseous stream rich in H2 and CO2. Acid gases i.e. CO2 and H2S are separately removed leaving a hydrogen-rich gas stream. At least a portion of the CO2 previously recovered is recombined with the hydrogen-rich stream to produce a gaseous mixture having a mole ratio H2/CO2 of about 4 to 10. This gas mixture is subjected to conventional catalytic methanation to produce a fuel gas comprising in mole % (dry basis) H2 45 to 1, and CH4 50 to 99. By using the reaction of CO2 and H2 rather than the reaction of CO and H2, a reduction of about 25% in the very large heat release encountered with the methanation reaction may be achieved. Optionally, substantially pure methane may be produced by adding a second portion of CO2 to the aforesaid fuel gas to produce a gaseous mixture having a mole ratio H2/CO2 of about 4, subjecting said gas mixture to conventional catalytic methanation to produce CH4 and H2O, and separating H2O from the process gas stream to produce substantially pure methane. Thus, the normally vigorous exothermic methanation reaction may be controlled better by the stepwise addition of CO2 to react with the hydrogen in the process gas stream.
Abstract:
Continuous process for the production of a gaseous stream comprising at least 90 mole % of methane (dry basis) from a sulfur containing hydrocarbonaceous fuel without polluting the environment including the steps of: partial oxidation of the hydrocarbonaceous fuel with air; cooling, cleaning, and purifying the process gas stream to produce a stream of feed gas comprising CO, H2 and containing N2 in the range of about 30 to 60 mole % (dry basis); two separate catalytic methanation steps with an intervening water-gas shift reaction step; and finally separating CO2 and N2 from the process gas stream to produce said methane stream. The large amount of nitrogen diluent in the reacting gas during the methanation step helps to control the normally vigorous exothermic methanation reaction. The product gas has a heating value in the range of about 900-1000 BTU/SCF. It may be used as a substitute for natural gas or as a feedstock for organic chemical synthesis.
Abstract:
This is an improved process for converting low-cost high-sulfur containing hydrocarbonaceous materials into a clean methane-rich gas stream which may be burned as a fuel without contaminating the atmosphere. A high-sulfur hydrocarbonaceous fuel is gasified by partial oxidation to produce a process gas stream which is cooled, cleaned and subjected to catalytic methanation over a sulfur-resistant catalyst comprising 0.8 to 10 atoms of an element selected from the group comprising Co, Cr, W or mixtures thereof per atom of an element selected from the group Mo, Ni, or mixtures thereof. The catalyst may be supported on a structure formed from Group III and IV elements e.g. alumina, silica stabilized alumina, zeolite. A distinct advantage of the subject process, is that the sulfur in the process gas stream is not removed prior to the methanation step. Rather, the sulfur is permitted to remain in the process gas stream in order to moderate the highly exothermic methanation reaction. After cooling and purification by removing one or more members of the group H2, CO, H2O, CO2, COS, H2S, Ar, and N2, the resulting methane-rich gas stream comprises about 10 to 95 mole % CH4. Optionally, the CH4 content of said methane-rich gas stream may be increased to about 98 mole % or more by the additional steps of water-gas shift conversion, catalytic methanation, cooling, drying and CO2 removal. The product gas would then have a gross heating value of about 1000 BTU/SCF.
Abstract:
Improved process for the production of substantially pure methane or clean synthetic natural gas (SNG) including the steps of partial oxidation of a hydrocarbonaceous fuel feed with substantially pure oxygen to produce a process gas stream comprising principally H2, and CO and having a critical mole ratio H2/CO in the range of 1.0 to below 1.5 and preferably 1.0 to 1.3; cooling the process gas stream and separating H2O, CO2 particulate carbon and gaseous impurities therefrom, reacting together the H2 and CO in said process gas stream in a catalytic methanation zone to produce a methane-rich gas stream containing gaseous impurities selected from the group consisting primarily of H2O, and CO2, along with minor amounts of H2, CO, N2, and Ar and mixtures thereof; and removing said H2O and CO2 to produce a product gas stream comprising substantially pure methane i.e. 95 mole % or higher (dry basis). The product gas may be used as a clean substitute natural gas having a gross heating value of about 980 BTU/SCF or higher.
Abstract:
A methane-rich gas stream is produced by catalytic methanation of synthesis gas feed comprising H2 and CO. When the mole ratio H2/CO of the synthesis gas feed is in the range of about 0.5 to 1.15, by adjusting the mole % H2O in the synthesis gas feed to a value in the range of about 0.1 to 15., the gross heating value of the product gas may be increased to a value above that obtained with a dry substantially CO2-free methanator feed gas. This effect of adding H2O becomes more pronounced as the H2/CO ratio drops further below the maximum value of 1.13. Further, in a preferred embodiment the gross heating value of the product gas (with H2O and CO2 removed) was maximized by adjusting the mole % H2O in the synthesis gas feed to the methanator to a critical value in the range of 1.0 to 3.0 and preferably 2.0 while maintaining the H2/CO mole ratio of the synthesis gas feed at a critical value in the range of about 1 to 1.15 and preferably 1.13.
Abstract:
A methane-rich gas stream is produced by catalytic methanation of synthesis gas feed comprising H2 and CO. When the mole % CO in the synthesis gas feed to the methanator is greater than 10 mole %, and the mole ratio H2/CO is in the range of greater than 1.0 to 3, by adjusting the mole % CO2 in the synthesis gas feed to the methanator to a value in the range of about 0.5 to 20, and the mole ratio H2/CO2 in the range of about 2 to 60 and preferably less than 3.9 it was unexpectedly found that a product gas is produced having a gross heating value which is greater than that which is obtained from a dry CO2-free methanator feed gas.
Abstract:
HIGH PRESSURE CONTINUOUS CATALYTIC WATER-GAS SHIFT CONVERSION PROCESS IN WHICH CO CONVERSION IS MAXIMIZED AND AN EFFLUENT GAS STREAM COMPRISING ESSENTIALLY H2 AND CO2 IS PRODUCED HAVING A SUBSTANTIALLY CONSTANT COMPOSITION AT ALL TIMES THROUGHOUT THE LIFE OF THE CATALYST. PROCESS DESIGN AND OPERATION ARE OPTIMIZED TO YIELD AN OVERALL CO CONVERSION OF ABOUT FROM 80 TO 98 MOLE PERCENT OVER A PERIOD OF TWO YEARS OR MORE ON STREAM. STEAM AND A CO CONTAINING GASEOUS FEEDSTREAM ARE REACTED IN AN ADIABATIC CATALYTIC REACTION ZONE COMPRISING ONE OR MORE FIXED BEDS OF IRON-CHROMIUM OXIDE CATALYST CONNECTED IN SERIES AND PROVIDED WITH INTERBED COOLING. THE CATALYST IS CHARACTERIZED BY ITS ACTIVITY INCREASING AS A FUNCTION OF PRESSURE OVER THE OPERATING RANGE OF ABOUT 35 TO 250 ATMOSPHERES. THIS IS CONTRARY TO THE PRESENT GENERAL IDEA THAT THE ACTIVITY OF AN IRON OXIDE SHIFT CATALYST LEVELS OUT AT ABOUT 400 P.S.I.G. THE TEMPERATURE OF THE GASES LEAVING EACH BED IS MAINTAINED IN THE RANGE OF ABOUT 30*F. TO 100*F. LESS THAN THE CORRESPONDING EQUILIBRIUM TEMPERATURE AND TO OFFSET CATALYST DEACTIVATION THE INLET AND EXIT TEMPERATURES OF THE GAS STREAM IN EACH BED IS INCREASED AS A LOGARITHMIC FUNCTION OF TIME ON STREAM.