JPS58208101A - Manufacture of hydrogen - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This application is a continuation-in-part of an application filed May 7, 1962.

The present invention relates to hydrogen iodide, and more particularly to a method for producing gaseous hydrogen km by catalytically decomposing liquid hydrogen iodide using a homogeneous catalyst.

Government contracts awarded by the U.S. Department of Energy
- has rights in this invention pursuant to ACIJ2-80ET26225.

Background of the Invention Various methods have been proposed to obtain hydrogen from water.
Some of them produce oxygen as a by-product.

One such "water splitting" process produces hydrogen iodide as part of a series of closed cycle chemical reactions and is described by John H.
US Pat. It is disclosed in detail in No. 89,94L1. The process is based on the Bunze formula and involves the reaction of sulfur dioxide, aqueous water, and hydrogen iodide to produce wax d and hydrogen iodide. This hydrogen iodide must then be decomposed into H2 (the desired product) and 2, and this hydrogen iodide is recovered and returned to the main reaction.

Hydrogen iodide was described by Dennis R. Okeefe et al. in 19616.
Published on the 24th of the month, 4.2! b 8,02
As shown in No. 6, it has been discovered that it can be resolved enantiomerically in liquid form using a supported catalyst such as ruthenium on a titania substrate or Yamajaku on a sulfur/liquid barium substrate. Although it is considered to be a viable method for this type of process since the conversion capacity is low at low levels, the use of this type of heterogeneous catalyst to decompose liquid uI is...
4. Catalysts, especially platinum, have a non-negligible amount of water in one bottle of HI, requiring a certain type of catalyst recovery and remanufacturing process. . TG like this! Although inclusion and remanufacturing are common in the chemical industry, they add significantly to the complexity and wholesale and capital costs of the entire process. Therefore, other equally effective or more effective dimensions were sought.

SUMMARY OF THE INVENTION A liquid hydrogen iodide cracking process involving homogeneous catalyst warpage and a combined countercurrent bath agent extraction system for catalyst circulation have been developed. It is believed that the soluble platinum group salts are incubated with an aqueous phase that serves as a support for the catalyst and participates in the catalytic reaction. The two liquid phases, one almost dry and one aqueous, allow the catalyst to be circulated through the reactor and this pyrolysis process is effective as part of the overall moisture side process mentioned above. It is something that makes it possible for the people and the people to be different.

[Brief explanation of the drawing]

Figure 1 shows a model of a system for carrying out a liquid hydrogen iodide decomposition process that fully embodies the various types of color removal of the present invention, and also includes the recovery scheme and shield ring of a homogeneous catalyst. This is palladium iodide. Figure 2 is a partial model created by Ikusuke: - To please everyone, it depicts another embodiment of a part of the system shown in Figure 1. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS It has been discovered that the concept of homogeneous catalysis has potential for the decomposition of liquid HI. An aqueous @liquid is used as a support for the catalyst, and the catalyst is sufficiently active in the decomposition reaction that proper bath decomposition is rare and reasonable in-system protection is required. Should. i5T in HI-H,0 mixture
It has been discovered that the melting of Yamajaku metals is extremely effective in such homogeneous catalytic reactions of thermal decomposition of hostile HI. In particular, the halogenated salts have a desirable @4 degree, and these platinum group metal salts in aqueous hydriodic acid are sufficiently active to provide the desired reaction rates. The decomposition is preferably carried out at the critical temperature of pure H1, i.e. about 42'5
It is carried out at a power below about 35 LIK and above. However, if a mixture is present, the HI may be dissolved in a separate component, namely the melt, and approximately 52
Temperatures as high as 5 mm may be used at pressures up to about 600 atmospheres. Generally, from about 25 atmospheres to about 6
Temperatures between about 6 DDK and about 525 DDK at a pressure of 1,000 atmospheres may be used. The more common platinum group metals are preferred from an economic point of view, namely Pd, Rh and Pt. The solubility of the salts need not be particularly high, since catalytic efficiencies of less than 1 molar are generally suitable, and the enlightened f(I plays a role in the solubility of these salts. Apart from the solubility of the various platinum group metals, there is no significant difference in reaction rates at a given temperature when they are first used. Unthinkable.The reaction rate of specific platinum group metals changes somewhat with the seismic intensity.In general, a raw salt in a water bath, or a salt soluble in hydrogen iodide J, may be used.Pd and Pt halides are More preferably, Pd halides are preferred at temperatures of about 650° C. and above.
, , RhCl3. PtI2 and H2P tci? a
including. RhCl3 is Rh(J'3-3f(,0,!:
l, Manually, H2PtC & H2PtC4”
Available as 6 HaO. Although water@liquid is commonly used as a support for homogeneous catalysts,
Separate actual and laboratory tests have shown that the presence of water is necessary for homogeneous catalysts to be fully active, so it is believed that water is responsible for the catalytic reaction in that it binds the sU. . Sufficient water is poured into the decomposition reaction to destroy the necessary pffj medium to provide the desired decomposition rate within the desired residence time frame. If you grill it, one sword will be heated at a temperature of about 425℃. ) U Ki 1 King's pressure, about 1 kill 500
The molar ratio of PdI2 (Pd■2-HI) is approximately 4
Residence time and reaction rate are major factors for equipment and overall process design. The general basis for the separation of the catalyst from the product source and its effective circulation is that the two liquid phases are Hl, H, O
Within a certain composition range of these components, and within a certain pressure range and at the critical temperature of HI (at that temperature, there is no chisel 1 in the vapor phase l/rC). ) or less or approximately 1. It is premised on the fact that when mixed with Hl, above this temperature, it exists in equilibrium. The subject matter is disclosed in detail in U.S. Pat. No. 4,360,374 in the name of Dennis R., Okeyhue et al., the disclosure of which is incorporated herein by reference. In part, the basis for separating catalysts and effectively carrying out decomposition reactions lies in supporting the catalyst in another liquid phase in contact with liquid 1. Such two-liquid phase systems are Species f(I-H,0-I) exist in solid state for the system, in which case one phase is HI and 12 very dry, dry phases, and the other phase is water curved. Mizusumi j and some I
A wet phase or an aqueous phase containing 2. A single homogeneous catalytic reactor tends to concentrate in this aqueous phase, and this aqueous phase can be recycled to the HI fractional reactor as a catalyst support and without the need for particular catalyst recovery. As a vehicle, it has been discovered that it does both. FIG. 1 shows a schematic system for carrying out a flow sheet for a recursive process embodying the various features of the present invention and illustrating the preferred use of catalyst Pd2. This flow sheet shows the implementation of the pyrolysis of hydrogen iodide, which may be carried out in conjunction with the moisture-side comprehensive method described above, which is sometimes be quoted. Therefore, the present decomposition method f: can be used as a source of hydrogen iodide without the column I, since it is set in that way.More temporally, the feed stream 11 of HI is core 416
11: Feed starvation, where catalytic pyrolysis occurs. Typically, feed stream 11 is substantially pure HI, although the presence of some very minor impurities such as H2O and I2 is allowed. In this world, it is preferable that the confluence is brought to a pressure of about 150 atmospheres by 2 TJ and heated to a temperature of about 425 degrees before being supplied to the reactor 16. mixed. pure f
(Since the critical temperature of I is about 424°C, stream 11 is heated to a somewhat lower temperature and stream 15 is heated to a slightly higher temperature to obtain approximately the desired reaction temperature inside reactor 16. The vessel 16 was previously operated with one thermal gradient over its length, allowing temperatures near the exit to be higher than the critical temperature of Chaos HI.Currently, it is approximately 25 atmospheres and approximately 60 atmospheres. Although it is not believed that it is possible to carry out a thermal zero solution at pressures within a fairly wide range of temperatures and between the corresponding parts of about 6 uO° and 525°, It is considered desirable to carry out the reaction in darkness between about 4 UDK and 425 UDK and at a pressure of about 100 to 175 atm. Since 1 decomposition reaction can actually be carried out at a corresponding pressure of about 650 liters,
, - and at dark temperatures of about 525°. One example of a suitable reactor 16 is a cocurrent extrusion flow reactor with internal baffles to ensure that intimate mixing of the incoming streams occurs. Preferably, the two streams 11 and 15 enter at the bottom of the reactor and a difference of -117 exits at the top of the reactor. The dimensions of the reactor 16 will, of course, depend on the desired residence time and the overall flow rate of the fluid passing therethrough. When using the above-mentioned catalyst, about 4δ% at about 6L1% or more
Conversions of up to 100% can be achieved in about 4 seconds or so using the catalyst described above.
1. In μ? ``It is felt that it can be obtained by writing at the time of death. Flow 1b: water kiinu 1 arsenic acid and resin medium, the (?? Some 12 crabs from the excretion process that turn blue) Circulation and drifting - OTpre 11 and jlji 1 power and the cut is 7'f, 1
It enters at a temperature of 1 or slightly higher crystallinity. This popular 6
In the case of the problem of Flowing Milk 11 and 15, the composition of the two combined incoming flows is warped, and two liquid phases exist due to the temperature and power within δ. It is controlled to enter the desired top cough. The catalyst is supported in the wet γ phase, and the phase inversion provides HI to the reaction, which is believed to take place almost entirely in the wet phase.
2 Extract the product. 12 and gaseous substance H2 are produced in the reactor as a result of catalytic pyrolysis of HI. The overhead stream 17 leaving the reactor 16 consists of a gas composition which, in addition to the liquid, is in equilibrium with the liquid and contains essentially all of the produced leaves. 7X iodide is present in the gas phase according to its equilibrium partial pressure, and there is also a small amount of iodide vapor and water vapor that are mentioned in the Nkoha Gin to understand the overall process.・Fewer songs that are unnecessary. There are three phases in the reactor (liquid - vapor), and all three phases are 1 (I is decomposed into hydrogen and iodine, so the length of the reactor from the population to the outlet is 9. It should be understood that the composition will vary. The composition and flow rates of streams 11 and 15 are controlled such that the final gA formation at the outlet consists only of the aqueous liquid phase of the tank in equilibrium with the gas phase. However, this is preferable and has several advantages for general use.
The outlet composition may be such that two liquid phases exist in equilibrium with the gas phase at the outlet. Effluent fii7 is sent to a gas-liquid separator '19 of standard design where the gaseous composition exits as overhead stream 21 and the melt-phase or two-phase liquid exits as bottoms stream 26. The column Tji phase 21 is sent to the condenser 426, where the H101 fraction and all of the accompanying water, fish, gas, and iodine vapor are condensed into a liquid, and the second gas is then sent to the feces separation submerged tank 25. . Minute; HI liquid flow 27 is the v effect
Takumi Tanicho 29, who probably sees a small residual HI in Hydrogen Kayopi
and generate. Hydrogen is purified using conventional I2 purification methods to return residual E(I) and traces of enemy I2 to the system.
Enter the 嬬 to be removed, Shirindan, and Izaku. It has also been proposed to recover some work by replacing the gas turbine to reduce the pressure of the gas from about 15 LJ to pipeline quality of about 50 atm.The expansion cooling that occurs is also part of the purification process. You may act as a sentinel as a division. The condensed HI dispersion stream] 7 is separately heated and then combined with another HI i main stream 61, which will be described later, to form the desired concentrated composite stream 66 which is fed to a co-current iodine extractor 65. Combined stream 66 is heated to near the temperature of stream 23 from the contact reactor and gas-liquid separator 19, ie, to about 425°C. The waste-containing stream 25 from the mixed reactor separated from the gas phase in the separator 19 is fed to the upper part of the countercurrent extractor 65. This phase stream 26 preferably includes water, all of the catalyst, all of the iodine produced during the reaction,
It also contains some hydrogen iodide, so it can be considered that mtL-C is the hydrogen iodide in the water/liquid between the fertile rice and the hydrogen iodide. This melt tj forms a distinct two-water mixture with the nearly dry HI riser which is being fed to the bottom as stream 66. The purpose of the countercurrent extractor 65 is to remove I2 from each primary stream, so that a purer HI liquid phase can ultimately be recycled to the main reactor 16, thereby providing a better Conversion rate is maintained in reactor 16. The practice of indulging in the dark interface of two distinct phases, as the lighter HI phase rises in the extractor 65, the penetrating humid phase, and the intercalary phase descends, removes virtually everything from the humid phase. Have the iodine extracted. Furthermore, this humidity! Some key water from the interphase is transferred to the rising dry HI phase, forming the upper flow 26
85 mol of HI entering the soil rises to the dry phase 4
go The wet liquid coming out of the bottom of the extractor 65 contains mostly water, almost all the catalyst and some HI; for example, for every 2 moles of E(, O) It may be possible to get 1 mole of HI.
Preferably, at least 95 moles of the catalyst are introduced in a controlled manner during this phase phase, and,
Using palladium iodide at about 425 degrees,
99 mol % tl of catalyst is removed from the extractor 65 in a wet interphase stream 6
It was discovered that it was carried in 7. Flow 67 is rawhide 1
The dry phase from reactor 65 exits as overhead stream 69 and contains hydrogen iodide and substantially all of the iodine plus 1 mole of catalyst. By operating the iodine extractor at approximately the same temperature and pressure as the catalytic cracking reaction, virtually all of the gas and liquid A third of the less molar acid in stream 26 being fed from separator 19 is extracted by the relatively dry HIi. Since we practice the rising Qian +7-5, the outflow flow 69's minute mole forging is the outflow flow 67 that circulates and souls to the anti-1 core and 10.
It's far more than 1 minute. The overhead stream 69 is subjected to a second extraction stage and the catalyst is recovered in an extractor 41, referred to as a same-flow I catalyst extractor, into which the overhead stream 69 is fed into one bottom. be done. Extraction 4
To the top of 41, flow 46, which has a wet phase that is substantially in equilibrium with the dry phase of flow 69, is shown by Hong, @saγ.
Sign. The source of the flow n46 will be explained later. In the countercurrent extractor 41, the dark interface between the two phases is such that the rising dry phase contains virtually all the catalyst and the iodide water is the bath liquid. A much larger percentage of the water becomes precipitated and damp! It is an interface that is lost to the @ phase. For example, the mole percent of the wet phase that is water may be more than 25 times the mole percent of water in the dry, chestnut phase. For one column, the ratio of the mole percent of water in the wet phase to the mole percent of water in the dry d+IJ is approximately 26.2.
: 1, and virtually all of the catalyst is in the extractor 41
From the bottom of the wet column phase 45,! 1, that's it; it comes out of the hole. Stream 451, which may be hydrogen iodide-4, for example about 6 moles of HI for each mole of H2O, is combined with a larger volume of tC Together they create a circulating stream 15, which feeds into the catalytic reaction 416. The dry phase from the same stream catalyst extraction d41 exits as a stream 47 containing hydrogen iodide, iodine, and 9 parts of water. This stream 47 is then sent to a drift distillation CEi 49, which uses reflux to separate the iodide solution from the distillate as vapor. Streams 46a and 45 are used to provide a wet, phase flow 46 for the run-through catalyst extractor 41.
A pair of b and b are taken from the distillation column 49 at the middle:Bi position to provide the desired f(I-I2-H20 composition.In actual purchase, all the water is stiffened and the water is strained in two medium and thin streams. Except for
The desired final ratio of hydrogen iodide and natural gas is obtained simultaneously. Under certain peak conditions, it may be possible to find a point in the distillation column with exactly this desired ratio, but if the two middle streams are It seems more necessary to combine Sipison et al., and then to condense the desired group bV, which constitutes the wet phase flow 46, to confront the first group.It probably carries the iodine of the trace device. iodine hydrogen vapor flow 5
As 1, the top force of the distillation column is removed, 4 is reduced to 1, and re/JOIf is carried out. Stream 51 is split and a large portion thereof is mixed with hydrogen iodide stream 11 returning to the catalytic reactor as stream 52. A smaller portion, perhaps about 15 parts of that stream, mixes with stream 27 from the gas-liquid separator 25 to form a dry phase stream 66 and is fed to the bottom of the liquid separator 65. ■2 Raw 5
y, the snout emerges as the bottom of the valley i53. It can be seen that the countercurrent extraction operation is a good method for extracting the liquid flow iodine produced in the pyrolysis reactor so that this flow can be immediately returned to the reactor. As a result, the total efficiency is such that the combined flow of streams 11 and 15 entering the decomposition reactor 13 contains only about 2 moles of HI per mole of glutinous rice harvested. I can buy things. The temperature at which the main fibers ripen, ie preferably about 55 UK and about 425 degrees. ml, the outgoing gas stream absorbs about 2 mol of H2 from the fH vapor, which together makes this part of the reaction energy efficient, allowing it to be absorbed from the H2 stream and washed away. The minimum level of HI to be achieved should be 1'. Under the Ruru condition, the density inversion is combined with the wet Z1 leap phase and the dry deep phase, and as shown in Figure 2, there is a slight change in the iodine extraction plan. I need. For a given temperature and composition 26-, the density of the dry, mulberry phase will be greater than the density of the wet, leap phase when a low Tenrai D percentage is involved. In such a case, the co-current extractor has two parts 35. as depicted in FIG. and 35b. Stream 26 entering from the main air stream continues to feed the top of the device 35a and flows downward in a countercurrent arrangement with the drying phase rising therein. The column is dimensioned such that the 1i extraction ends at a point where the 5 degree difference is still small enough to separate the denser aqueous phase from the less dense dry phase stream. . The point at C is v'rC, and the bottom of the 65g part exits as a flow hole 66a. The water mixed with the flow 66b of the second extraction section 35b forms the main stream 66c. Circulating the water-based part eliminates the +EI density difference between the water-based 1 and the relatively dense dry 7 chestnut HI liquid eggplant 66. The outflow from the top of the ridge from part 35b is a stream 67 that does not enrich the upper part of the river, and the mixture of a part of it and stream 36- is a natural enemy. A very mature aqueous phase is produced which, under certain wet conditions, is fed by the incoming flow hole 66 (■) which is much smaller than the liquid phase.
The chestnut phase flows out from the extractor 35b as a flow 36d, which is fed to the bottom of the extractor 65α, in which it still contains a considerable amount of natural material. The humidity, which exits this part +, is low; the flow 66a is also low.
') Fill the extractor 65 with A and raise it through the soil 55a in exactly the same way as in the 7th section described above. What is this dry leaf used for? The main system is rusted, and the descending mixer 7 is made by N26.
1'iJ) and exits from the top of the column from the extraction section 65a as stream 9. Wetting, @trigram and drying of the catalyst extractor 41;:
Since both have low iodine levels, the reversal of can and ni is Satoru 41.
The embodiment shown in FIG. 1 should be useful throughout the interior of the column. However, if something like this reversal of density occurs,
By using an arrangement similar to that illustrated in Figure 2 and described above, the situation is! @Popular Although the invention has been described with reference to preferred embodiments thereof, changes and modifications apparent to those of ordinary skill in the art may be made without departing from the scope of the invention as defined in the claims. That should be dissociated. If the operation at a pressure of 5 atmospheres or more is the same, the HI of the cage with the fluorine mixture (the sum of HI and H2O is 57 as the total standard)
Rice is placed in the flow hole that says (more than % weight) @ call permit No. 4.
330, 374, and as shown in this article, it is also preferred for the purpose of protecting the two night suns, and also for the purpose of repelling and figuratively abrasive insects. 1 Permanent residence of the royal power, 1 (I each 4. It is also effective. The noble chief of the present invention is strongly A in accordance with 11) There is. 4. [υU explanation of Figure 1] ・Moon 115A performs the various color removal of the present invention one by one, and also recovers the catalyst; It is a matata-type drawing with the center drawing.5. Erosion is palladium iodide for the sake of explanation. This is a diagram of the Matamata type. Kari Toshi, Misato / - A Chikunoroshi's Incorporated Representative 4 Hitoben dialect experts C = - and = Knee (4 others)

Claims (1)

[Claims] 1. In the presence of an aqueous solution of f(I and a soluble catalyst), HI is subjected to thermal decomposition at a dark pressure of about 25 atmospheres and 3OL of 1 atmosphere, and HI is separated from the decomposition mixture, This decomposition mixture is treated to extract substantially all of the products, and then a mixture of substantially all of the above-mentioned I2 compounds containing at least 95 moles of the above-described catalyst is extracted. A method for producing islands from deformed HI, comprising the steps of returning all the above to the pyrolysis stage.2. 6. The method according to claim 1, paragraph 2, wherein the catalyst is a halokenide of Pd, Rh, or pt. 4. The process of claim 1, wherein the feed stream is subjected to recirculation I2 extraction to produce a first liquid effluent stream containing mostly water and at least about 99% of the catalyst. 5. The above-mentioned countercurrent flow containing substantially all of the I2 and a small amount of the above-mentioned particulate matter; is then further countercurrently flowed with a feed stream containing a significant amount of water to form a third liquid effluent containing the remainder of the catalyst, and this second effluent is returned to the pyrolysis step. The method of claim 4. 6. Separating HI from the decomposition mixture together with the hydrogen and then condensing it from the hydrogen, and
Process according to claim 5, wherein this condensed HI forms at least part of the feed stream in the recirculation I2 extraction step. 2. The method of claim 1, wherein said step is carried out at a temperature of about 40 tJK and about 425 ml and at a pressure of about 175 atm and about 175 atm.ml. 8. A method for producing a liquid mixture containing HI and I (20) at a temperature of at least about 350 but below the critical temperature of the wetted mixture and at a pressure of at least about 25 atmospheres. And the above H2O of the above liquid mixture
The HI is subjected to thermal decomposition by contact with a flexible catalyst dissolved therein together with the HI, and the HI is separated from the decomposition mixture. A method that consists of things. 9. The method according to claim 8, wherein the catalyst is a platinum group halogenated salt. 10. The above catalyst is Pd 12 , PdCA, Rh
Cl3. P t I2. Claim 9 selected from the group consisting of I(jP tC& and mixtures thereof.
The method described in section. ii. J: The fertilizer liquid mixture is maintained at a pressure of at least about 25 atmospheres, and the mixture is composed of two liquid phases, i.e., a partially desiccated HI phase and a wet iodized water phase. 10. A method as claimed in claim 10, comprising a mass forming a phase. 12. The method of claim 11, wherein the catalyst is pdC&. 1.5. HQO,I (all streams containing I and the circular catalyst are exposed to temperatures of at least 40°C to induce decomposition of II; and one power is such that there are two liquid phases, a relatively dry HI phase and a moist water-iodized water phase; separating h from this decomposition mixture; to separate said liquid phase and extract substantially all of the 12 product from said wet phase; The substantially intact wet phase is returned for another pass through the pyrolysis step; a method for producing liquid HI from liquid HI, developed by Yasuto Taniko et al. 14. 16. The method according to Patent E Seigyu-no-han, item 16, wherein the catalyst is Shirogane Watari-Man's salt. 15. Claims, wherein the catalyst is Pd, Rh, or pt 7-rogenide. The method described in $14m. 16. The above extraction process is carried out using
Utilizing a countercurrent I2 extraction with a first feed stream of I, the step produces a first effluent stream of the wet phase enriched with a majority of f(,0) and at least about 99 moles of the catalyst;
A method according to claim 16. 1Z The dry HI phase passes through the above two I2 extraction steps as a second effluent containing substantially all of the above I2 and the remainder of the catalyst; this second effluent is then combined with this This second effluent stream leaves this countercurrent extraction step as a third effluent stream containing the remainder of the catalyst, and is further subjected to a countercurrent extraction with the second feed stream, which refers to the entire amount of water being extracted. and returning this third effluent stream together with the iodine-free wet interphase to the pyrolysis plant for another pass. 18. The method of claim 16, wherein said pressure is maintained between about 25 atmospheres and about 311 O atmospheres. 19. f(I) is separated from the cracked mixture together with the first feed stream, and the condensed HI characterizes at least a portion of the first feed stream. 20. The decomposition is carried out at a dark temperature of about 400 K and about 425° and a dark pressure of about 100 atmospheres and about 175 atmospheres, A method according to claim 16.