CN100548942C - Catalyticreactor and method - Google Patents

Abstract

The synthetic catalytic reactor device (10) of the compactness that defines passage of using of fischer-tropsch is carried out, and is breathable catalytic structure (16) in the passage, extends between this channel set case (18).When this reactor assembly provided at least two group successive passages that connected by the collection case (14,14a) for fischer-tropsch is synthetic, this synthesized at least two stages and carries out.Gas flow rate by first channel is enough high so that be no more than 65% carbon monoxide and transform.Gas was cooled (25) in the collection case between two stages, so that condensed water steam, and, make the less than 65% of residual carbon monoxide transform then with sufficiently high gas flow rate process second passage.This has reduced the dividing potential drop of water vapor and thereby has restrained the oxidation of catalyzer.

Description

Catalyticreactor and method

The present invention relates to a kind of chemical process, also relate to and be suitable for the catalyticreactor that when carrying out this method, uses.

In the method that patent WO 01/51194 (Accentus plc) describes, methane and steam react in first catalyticreactor and generate carbon monoxide and hydrogen; Then, the gaseous mixture that obtains at last is used for carrying out fischer-tropsch (Fischer-Tropsch) in second catalyticreactor synthetic.The long and is that methane conversion is high-molecular weight hydrocarbon more, and it is generally liquid or solid-state under envrionment conditions.Two stages of this method, i.e. steam/methane reformation and fischer-tropsch are synthetic, need different catalyzer, and have described the catalyticreactor that uses for each stage.When reaction was respectively thermo-negative reaction and thermopositive reaction, correspondingly, catalyticreactor can make heat be transferred to reactant gases or can make heat transmit from reactant gases; The steam/methane needed heat of reforming is provided by gaseous combustion.A kind of known fischer-tropsch synthetic catalyzer that is used for has used small particles of cobalt on ceramic monolith, but find, under the situation that has water vapor to participate in, this catalyzer to experience oxidation or with the irreversible reaction of ceramic monolith, and be accompanied by active final reduction.Now found a kind of improving one's methods of this method of carrying out.

According to the invention provides a kind of fischer-tropsch synthetic method that is used to carry out, this method is used at least one compact catalytic reactor device, this catalytic reactor device defines the passage that is used for F-T synthesis reaction, has the breathable catalytic structure in the described passage, wherein, the gas that contains carbon monoxide carries out fischer-tropsch and synthesizes at least two continuous stages, gas flow rate in the fs is enough high to carry out this building-up reactions so that be no more than 70% carbon monoxide in the fs, described gas is cooled between described continuous stages so that condensed water steam, and the gas flow rate in subordinate phase is enough high carries out this building-up reactions so that be no more than 70% residual carbon monoxide in subordinate phase.

Preferably, in described fs and subordinate phase, air speed all is higher than 1000/hr, but preferably is no more than 15000/hr.Preferably, control this method so that water vapor is no more than 20mole%.Preferably, in each stage, be no more than 65% carbon monoxide and transform.

Air speed in this manual is defined as the void volume of the rate of volume flow (measuring) of the gas of supply response device divided by reactor under standard temperature and pressure (STP).Like this, if reactor is under the pressure of 210 ℃ and 2.5Mpa, the gas flow hourly of the air speed correspondence of 5000/hr (under operational condition) is approximately 354 times void volume so, thus and the corresponding residence time that is approximately 10s.

Like this, the present invention also provides a kind of being used for to carry out fischer-tropsch synthetic method on the gas of hydrogeneous and carbon monoxide, use at least one compact catalytic reactor device, this catalytic reactor device defines the passage that is used for F-T synthesis reaction, has the breathable catalytic structure in the described passage, wherein, described synthesizing carries out at least two continuous stages with sufficiently high gas flow rate, water vapor is no more than 20mole%, and gas is cooled between continuous stages so that condensed water steam.

The present invention also provides a kind of such fischer-tropsch synthetic device that is used to carry out.This can be compact catalytic reactor device, and it comprises the collection case that connects the successive gas channel, is useful on condensed water steam in the described collection case and removes the device of coagulating liq from the collection case.This catalytic reactor device preferably includes a plurality of metal sheets, and these a plurality of metal sheets are set to a stacked assembly and link together be defined for fischer-tropsch synthetic passage, and this fischer-tropsch synthesizes for heat exchange flow is moving along with passage hockets.Preferably, synthesize the interior temperature of passage greater than 190 ℃, for example 200 ℃.Paper tinsel, wire netting or the corrugated of corrugated or band lacuna or folding metal felt can be as the substrates of catalytic structure in the flow passage, to strengthen heat transfer and catalyst surface area.

Preferably, each of continuous stages takes place in the respective sets of passage, and the cross-sectional area of a plurality of second passages is less than the cross-sectional area of a plurality of first channels.

Can recognize that the material of making this reactor will suffer aggressive atmosphere in use.This reactor can be made with for example aluminiferous ferritic steel, and for example, it can comprise the iron (for example Fecralloy (trade mark)) that has 15% chromium, 4% aluminium and 0.3% yttrium.When this metal was heated in air, it can form the zone of oxidation of adhering to of aluminum oxide, prevented that this alloy is by further oxidation; This zone of oxidation prevents that also this alloy is corroded.When this metal was used as catalyst substrate and scribble the ceramic layer that has added catalystic material, the aluminum oxide zone of oxidation on this metal was considered to combine with oxide coating, so just guarantee that catalystic material is attached on this metal substrate.Also can use other stainless steel.The plate that is used to limit passage also is chosen as aluminum.

Now, by example also with reference to the accompanying drawings, will do further and more detailed description the present invention.Wherein:

Fig. 1 shows the sectional view that is suitable for carrying out fischer-tropsch synthetic reactor, shows a plate planar; With

Fig. 2 shows a kind of distortion of the reactor of Fig. 1.

It is synthetic to the present invention relates to fischer-tropsch, and it can form methane conversion is the part of long chain hydrocarbon method more.Fischer-tropsch is synthetic to be reaction between carbon monoxide and the hydrogen, and this gaseous mixture for example can be reformed by steam/methane and produce.In fischer-tropsch was synthetic, these gas reactions generated a kind of longer chain hydrocarbon, that is:

n?CO+2n?H ₂→(CH ₂) _n+n?H ₂O

Participate in and have under the situation of promotor having such as the catalyzer of iron, cobalt or fused magnetite, this reaction is a thermopositive reaction that takes place under High Temperature High Pressure, high temperature is normally between 190 ℃ to 350 ℃, for example 210 ℃, and high pressure normally at 2Mpa between the 4Mpa, 2.5Mpa for example.The concrete kind of the organic compound that this reaction forms depends on the ratio of temperature, pressure and catalyzer and carbon monoxide and hydrogen.

A kind of preferred catalyzer comprises that one deck specific surface area is 140～450m ²The gama-alumina of/g, it has the cobalt of about 10%～40% (with the weight ratio of aluminum oxide), also has ruthenium/platinum promotor, and this promotor is 0.01%～10% of a weight of cobalt.Alkaline promoter such as gadolinium sesquioxide also can be arranged.This activity of such catalysts and selectivity depend on the dispersity of cobalt metal on carrier, and the optimum dispersion level of cobalt is usually in 0.1～0.2 scope, so that 10%～20% atom is presented on the surface in the cobalt atoms metal.Significantly, the crystallite dimension of cobalt metal is more little, and dispersity is just big more, and its crystallite dimension is normally in the scope of 5～15nm.The cobalt granule of this size provides high-caliber catalytic activity, but can be oxidized under the situation that has water vapor to participate in, and this can cause their catalytic activity significantly to reduce.The degree of this oxidation depends near hydrogen and the ratio of water vapor and their temperature the granules of catalyst, and the two can both strengthen the degree of oxidation the water vapor ratio of higher steam temperature and Geng Gao.

With reference now to Fig. 1,, be used for fischer-tropsch synthetic reactor 10 and comprise a folded Fecralloy steel plate 12, every block of plate all is orthogonal basically, 450mm is long, 150mm is wide and 6mm is thick, only is that the mode with example provides these sizes.On the upper surface of every block of such plate 12, have degree of depth 5mm, by ridge 15 separated rectangular tanks 14 (showing eight such grooves), but groove 14 has three kinds of different configurations.In plate 12 shown in the drawings, groove 14 tiltedly extends with 45 with respect to the longitudinal axis of plate 12 to the bottom right over the ground from upper left as shown in FIG..In the plate 12 of second type, groove 14a (shown in dotted line) takes a kind of mirror image mode, tiltedly extends over the ground with 45 ° from the lower-left to upper right as shown in FIG..In the plate 12 of the 3rd type, groove 14b (shown in long and short dash line) is parallel to longitudinal axis and extends.

These plates 12 assemble in stacked mode, and the plate 12 of each piece the 3rd type (having longitudinal slot 14b) is at the plate that has skewed slot 14 and have between the plate of mirror image skewed slot 14a, and are made into this tinkertoy module with a space rectangles plate after the many plates 12 of assembling.These plates 12 be pressed on together and through heat-treated to form diffusion bonding or to weld them together, so they are sealed each other.Undulatory Fecralloy Alloy Foil 16 (only showing one) is 50 micron thickness, is coated with the ceramic layer with the catalytic material dipping on it, and paper tinsel 16 has suitable shape, and the high 5mm of its ripple, and it can slip into each such skewed slot 14 or 14a.

More preferably, before paper tinsel 16 slipped into groove 14 or 14a, paired undulatory (ripple high about 2.4mm), the paper tinsel 16 that scribbles catalyzer were laminated in the planar between them, the paper tinsel that scribbles catalyzer, and by spot-welded together.

Collection case 18 is welded on this tinkertoy module along each side, and two fins 20 that also are welded on this tinkertoy module of each collection case 18 usefulness define three compartments.Fin 20 be positioned at from each end of this tinkertoy module begin, along 1/3rd on the path of the length direction of tinkertoy module, and consistent on the position with every ridge 15 (or not having slotted part on the plate) that has the plate 12 of skewed slot 14 or 14a.The cooling agent collection case 22 of rectangular cover shape is soldered on each end of tinkertoy module, and 14b is connected with longitudinal slot.(not shown) in a kind of distortion, the collection case 18 of each three compartment can substitute with three adjacent collection casees, and in three adjacent collection casees each all is the rectangular cover that is similar to collection case 22.The coolant tubes 25 that the whole height of extend through tinkertoy module is all arranged in each collection case 18 intermediary compartment.An outlet pipe (not shown) is all arranged at the bottom of each in these intermediate compartment, and the liquid of condensation can discharge by this outlet pipe on pipe 25.In order to use, it is in substantially horizontal plane that this reactor 10 is configured to plate 12, so that coolant tubes 25 is vertical basically.

When using reactor 10, the mixture of carbon monoxide and hydrogen is input to two collection casees 18 at the compartments of end of tinkertoy module (left hand end as shown in the figure), and by the synthetic gas that produces of fischer-tropsch by two collection casees 18 shown in the compartment at right hand extreme place discharge.For example, the flowing-path of mixture that is input to left upper collecting chamber compartment is for (as shown in the figure): pass skewed slot 14 enter in next part case compartment, flow then and pass that the skewed slot 14a in another piece plate enters right upper collecting chamber compartment in this tinkertoy module.Cooling agent is input to collection case 22 in the same end of tinkertoy module, the temperature in the reactor 10 is remained on about 210 ℃, so the maximum location cooling agent of heat generation is in its minimum temperature in the fs.Therefore, flowing of reactant gases and cooling agent is in the same way at least in part.Such purpose is a convergence isothermal condition on whole reactor 10; This advantage that has is can be with any following risk minimization, if promptly local temperature drops to approximately below 190 ℃, wax (promptly very long chain hydrocarbon) can stop up flow passage towards outlet from reaction channel.(if the deposition of wax, 5 ℃～15 ℃ of temperature that can be by rising cooling agent are also injected hydrogen rich off gas and are passed reactor and remove.) flow rate (air speed) of reactant gases is between 1000～15000/hr, so that when guaranteeing that gas arrives the intermediate compartment of collection case 18, the transformation efficiency of carbon monoxide only is about 60% or littler.

Be in a differing temps and be supplied to coolant tubes 25, so that make them become water cooler as the cooling agent of 150 ℃ (being lower than the boiling point under the pressure of water in reactor).Subsequently, water vapor (with some longer chain hydrocarbons) condenses at the outside surface of coolant tubes 25, and discharges from the outlet pipe (not shown) of tinkertoy module bottom along those pipes 25.This has reduced the dividing potential drop of water vapor in the gaseous mixture that flows among next group skewed slot 14 or the 14a significantly.The result be fischer-tropsch synthetic be to take place two continuous stages---the fs, to be gas flow to intermediate compartment from the inlet compartment of collection case 18; Subordinate phase is that gas flows to the outlet compartment from intermediate compartment---and from gas stream, removed before it enters subordinate phase at least partially in the water vapor that the fs produces.

Be appreciated that reactor 10 can be out of shape in every way, particularly plate 12 can have different thickness.For example, defining the skewed slot 14 at the synthetic place of generation fischer-tropsch and the plate 12 of 14a can be that 10mm is thick, its groove depth 9mm; And the plate 12 that has the longitudinal slot 14b that is used for cooling agent can be only thick for 4mm, its groove depth 3mm.In this example, corrugated foils 16 can replace with the folded corrugated foils that for example three or four spot-welded together and height overalls are 9mm.The advantage that this darker troughed belt comes is: even produced any wax-like materials, so also be not easy to form and stop up.The passage darker than about 2mm improved the large vol transportation performance of corrugated catalysis insert 16; In this fischer-tropsch synthetic example, this can discharge and remove product liquid effectively and transmit the surface of reactant gases to catalyzer.The line spacing of corrugated foils 16 or pattern can change so that regulate catalytic activity along channel of reactor 14 or 14a, and thereby provide in reactor 10 on the difference control to temperature or speed of reaction.Further, skewed slot can yet may dwindle the degree of depth along its length reduced width, so that change fluid flow conditions and heat or coefficient of mass transfer.

In this synthetic reaction process, gas volume diminishes, and the suitable convergent by groove 14 can keep gas velocity in reaction process, to keep target conversion.The another kind of mode that keeps gas velocity is to reduce the quantity of flow passage, as shown in Figure 2 and with reference now to Fig. 2.The view corresponding with Fig. 1 is shown here.Only difference is to define the skewed slot 14 (and 14a) of the synthetic subordinate phase of fischer-tropsch, promptly, separated by wideer ridge 30 at the collection intermediate compartment of case 18 and the groove 14 (and 14a) between the right hand compartment, so that three such grooves are only arranged in every block of plate 12.

The reactor that is further appreciated that a kind of distortion can provide the more stage, three stages Fischer-Tropsch reaction device for example, and collection case 18 limits four successive compartments along each side of reactor, and each of two intermediate compartment all has prolong 25.Total transformation efficiency is basic identical, and for example two 60% transformation stage and three s' 50% transformation stage all can provide and surpass 80% total conversion rate.

Remove dividing potential drop that water vapor on the prolong 25 and low boiling hydrocarbon not only reduced water vapor and thereby restrained the oxidation of catalyzer, be exactly to have removed at least some will on catalytic structure, form the hydrocarbon of liquid level but also have further benefit.Any such liquid level all can stop contacting of gaseous mixture and granules of catalyst, and stops the product hydrocarbon to leave from the granules of catalyst diffusion, makes these diffusional resistances reduce to minimum so remove this hydrocarbon liquid.

In Fig. 1 and Fig. 2, in each intermediate compartment, only show four prolongs 25, but be appreciated that the pipe that different numbers can be arranged, for example ten or more.And every pipe 25 can have fin to strengthen heat transfer, and preferably, the fin longitudinal extension so just can not stop that the liquid that is condensed flows along prolong.Be not only water vapor condensation on pipe, and the entrained drop of air-flow also be easy to stagnation the pipe 25 the surface and thereby from air-flow, spin off.As a kind of possibility of heat exchanger tube 25 or other heat exchange surface, can in the intermediate compartment of collection case 18, provide the spray condenser system, it can use fischer-tropsch to synthesize renewable product in about 150 ℃ of generations as refrigerant fluid.When having wax deposit to pollute the risk of heat-exchanger surface, this will be very helpful so.

Selectively, cool off and condense and to separate with reactor and to carry out in the reactor outside.For example, three as shown in Figure 1, but in the collection case, can not be arranged in parallel to transport air-flow with the reactor 10 of cooling tube 25, by control reaction temperature and air speed, the transformation efficiency of CO is limited in below 65%.The discharge gas that comes from three reactors is connected to condenser device via an effuser, and water vapor and liquid hydrocarbon product are condensed in this condenser device.Then, the residual gas that has low water partial pressure is imported into single such reactor 10 (also not having cooling tube 25), so that there is about 60% CO to carry out building-up reactions in remaining unreacted CO again.By being reduced to one from three, the number of reactor assembly adapts to dwindling of gas volume between fs and the subordinate phase---because a large amount of gases have synthesized and have formed liquid, so that keep high flow velocity.

Another benefit of high gas flow rate is that the heat that comes from the thermopositive reaction of catalyst surface place by promotion is re-assigned in the gas phase, can reduce the temperature variation across the whole reactor passage.It also helps liquid reaction product is entrained in the air-flow, and keeps catalyst surface not have wax deposit.

Claims (14)

1. one kind is used to carry out fischer-tropsch synthetic method, use at least one compact catalytic reactor device (10), this catalytic reactor device defines the passage (14 that is used for F-T synthesis reaction, 14a), has breathable catalytic structure (16) in the described passage, it is characterized in that, the gas that contains carbon monoxide carries out fischer-tropsch and synthesizes at least two continuous stages, gas flow rate in the fs is enough high to carry out this building-up reactions so that be no more than 70% carbon monoxide in the fs, described gas is cooled between described continuous stages (25) so that condensed water steam, and the gas flow rate in subordinate phase is enough high carries out this building-up reactions so that be no more than 70% residual carbon monoxide in subordinate phase.

2. method according to claim 1, use single reactor assembly (10) to carry out this method, wherein, each stage of described building-up reactions all carries out in one group of passage in reactor assembly (14,14a), and described gas is in be cooled in collection case (18) between the continuous stages (25).

3. method according to claim 1 and 2, wherein, the air-flow that contains carbon monoxide flows through a plurality of parallel first channels (14,14a) in the fs, flow through a plurality of parallel second passages (14,14a) then in subordinate phase, the cross-sectional area of described a plurality of second passages (14,14a) is less than the cross-sectional area of described a plurality of first channels (14,14a).

4. method according to claim 3, wherein, the quantity of second passage (14,14a) is less than the quantity of first channel (14,14a).

5. method according to claim 1 and 2, wherein, air speed all is higher than 1000/hr in described fs and subordinate phase.

6. method according to claim 5, wherein, air speed all is no more than 15000/hr in described fs and described subordinate phase.

7. method according to claim 1 and 2, wherein, water vapor is no more than 20mole%.

8. method according to claim 1 and 2, wherein, the gas flow rate by fs and subordinate phase is enough high to carry out described building-up reactions so that be no more than 65% carbon monoxide.

9. method according to claim 1 and 2, wherein, the catalytic reactor device of described compactness (10) comprises a folded plate that defines described passage (14,14a), described breathable catalytic structure (16) has substrate, and described substrate comprises corrugated or paper tinsel, wire netting or the corrugated of band lacuna or folding metal felt.

10. fischer-tropsch synthetic equipment that is used to carry out described in preceding arbitrary claim comprises:

At least one compact catalytic reactor device (10), this catalytic reactor device define the passage that is used for F-T synthesis reaction (14,14a), have breathable catalytic structure (16) in the described passage;

Be connected the coupling device (18) between the successive channel group (14,14a); With

Condensed water steam and from air-flow, remove the refrigerating unit of coagulating liq (25) in coupling device.

11. equipment according to claim 10, wherein, described successive channel group (14,14a) is in same reactor assembly (10), and described coupling device (18) is the collection case.

12. according to claim 10 or 11 described equipment, wherein, the cross-sectional area that carries from fluidic fluid channel that coupling device (18) comes out (14,14a) is less than the cross-sectional area that carries the fluidic fluid channel that will enter coupling device (18) (14,14a).

Be less than the quantity that carries the fluidic fluid channel that will enter coupling device (18) (14,14a) 13., wherein, carry the quantity of (14,14a) according to claim 10 or 11 described equipment from fluidic fluid channel that coupling device (18) comes out.

14., comprise that also the temperature of guaranteeing in the synthetic passage (14,14a) is no more than 210 ℃ device (14b) according to claim 10 or 11 described equipment.