The application requires to enjoy in the right of priority of U. S. application 61/738,740 of submitting on December 18th, 2012, the full content of this application and disclose incorporated herein.
Embodiment
Term used herein only, for the object of describing particular, is not intended to limit the present invention.Unless clearly shown other situation in context, singulative " " and " being somebody's turn to do " also comprise plural form as used herein.It should also be understood that, the term using in this manual " comprises " and/or has illustrated when " including " and have described feature, entirety, step, operation, parts and/or member, but do not hinder existence or the interpolation of one or more other features, entirety, step, operation, parts group, member and/or member group.
For example " comprise ", term and the variant thereof of " comprising ", " having ", " containing " or " relating to " should understand widely, and comprises listed main body and equivalent, also has unlisted other main body.In addition, when " being comprised " by transitional term, " comprising " or " containing " while drawing component, parts group, technique or method steps or any other statement, be to be understood that and also considered identical component, parts group, technique or method steps herein, or there is any other statement of transitional term before the record of this component, parts group, technique or method steps or any other statement " substantially by ... composition ", " by ... composition " or " choosing freely ... the group of formation ".
If applicable words, the device of corresponding structure, material, action and all functions in claim or the equivalent of step comprise that the miscellaneous part for specifically stating with claim carries out any structure, material or the action of function in combination.Specification sheets of the present invention provides for the object of introducing and describe, but be not exhaustive or limit the invention to disclosed form.Do not departing under the prerequisite of scope and spirit of the present invention, many changes and variant are apparent for the person of ordinary skill of the art.Here select and described some embodiments, object is that principle of the present invention and practical application are carried out to best explanation, and other those of ordinary skill that make this area can be understood different embodiments of the present invention and have multiple variation, as being suitable for this specific end use.Correspondingly, although the present invention is described according to embodiment, but those skilled in the art will recognize that, the present invention can change to some extent ground and implement within the spirit and scope of claims.
Now with detailed reference to specific disclosed theme.Although disclosed theme is described in connection with cited claim, however be appreciated that they not by disclosed subject matter restricted in these claims.On the contrary, disclosed theme has covered all replacement schemes, change and equivalent, within these can be contained in the scope of disclosed theme defined by the claims.
Can come with industrial-scale production prussic acid (" HCN ") according to Andrussow method or by BMA method.In Andrussow method, methane, ammonia and at the temperature higher than 1000 DEG C, under the existence of catalyzer, react containing oxygen raw material, to prepare the prussic acid crude product that comprises HCN, hydrogen, carbon monoxide, carbonic acid gas, nitrogen, residue ammonia, residue methane and water.Sweet natural gas is typically as methane source, and air, oxygen-rich air or pure oxygen can be as oxygen sources.Catalyzer typically is silk screen platinum/rhodium alloy or silk screen platinum/iridium alloy.Other catalyst component be can use, platinum metals, platinum-group metal alloy, loading type platinum family metal or loading type platinum family metal alloy included but not limited to.Also other catalyst configuration be can use, vesicular structure, silk screen, tab inserts, spheroid, block, foam, Dipping and coating cleaning included but not limited to.In BMA method, methane and ammonia use as United States Patent (USP) 7,429, and 370 described platinum catalysts react, and this patent is contained in herein by reference.
Say haply, Fig. 1 has shown HCN synthesis system 100.Generally preparation in reaction component 102 of HCN, reaction component 102 comprises mixing vessel 104 and reaction vessel 106.In Andrussow method, comprise that oxygen-containing gas feedstream 108, methane-containing gas feedstream 110 and the reactant gases containing ammonia gas feedstream 112 are incorporated in mixing vessel 104.Mixing vessel 104 comprises at least one adjuster 122 that flows as described herein.As shown in Figure 1, methane-containing gas feedstream 110 and can be transported to the top of oxygen-containing gas feedstream 108 containing ammonia gas feedstream 112.In some embodiments, methane-containing gas feedstream 110 and can mixing before being incorporated in mixing vessel 104 containing ammonia gas feedstream 112.In one embodiment, mixing vessel 104 can comprise one or more static mixing zones as described herein, for the preparation of the ternary gas mixture 114 of mixing completely.Static mixing zone can be positioned at the downstream of the adjuster 122 that flows.Mixing vessel 104 has straight wall, and described straight wall aligns with the mobile of ternary gas mixture 114 among reaction vessel 106.
Ternary gas mixture 114 is left mixing vessel 104, and touches the catalyzer being included within reaction vessel 106, to form the prussic acid crude product 116 that comprises HCN.Catalyzer can be within catalyst bed 118.In one embodiment, can ternary gas mixture 114 be transported in reaction vessel 106 with grid distributor 120.Grid distributor 120 can also be used to distribute equably ternary gas mixture, and as required strategic point further mixed by ternary gas mixture.Can in ammonia recovery part 130, from prussic acid crude product 116, reclaim ammonia, and by pipeline 132, ammonia be returned.Can also HCN be refined into the desired purity of intended use in HCN refining part 134.In some embodiments, HCN can be highly purified HCN, comprises the water that is less than 100mpm weight.
Reactant gases 108,110 and 112 is introduced with flow angle in the scope from 5 ° to 90 ° and the normally perpendicular angle of the ternary gas mixture 114 with respect in mixing vessel 104.The rotation of this meeting induced reaction gas, this rotation has produced less desirable flow pattern.Less desirable flow pattern may cause the productive rate of HCN to reduce and lower HCN income.The present invention is by using at least one mobile adjuster 122 to there is no the plug flow of rotation and provide completely the ternary gas mixture 114 of mixing to reduce the rotational flow in mixing vessel 104 to obtain, thereby advantageously improved performance.By realize substantially the temperature of bed uniformly on catalyst bed, this has improved income.Uniformly bed tempertaure has been avoided the difference causing because of the focus on catalyst bed or cold spot.Aspect bed tempertaure, exist the catalyst bed of larger variation to be easy to break, this can cause the by-pass flow of reactant and the loss of productive rate.
The adjuster 122 that flows can provide the plug flow that there is no or only have little rotation of reactant gases in mixing vessel before reactant gases mixes.Preferably, plug flow has basic velocity profile uniformly on mobile adjuster 122.This has reduced may be by reactant gases being transported to any rotation causing in mixing vessel 104.
In addition, reactant gases may tend to flow through the middle part of mixing vessel 104, thereby concentrate on central region, make the wall place of mixing vessel 104 there is flowing of less reactant gases, and cause oxygen-containing gas to mix with methane-containing gas with containing the bad of ammonia gas.Static mixer laterally extends from the inwall of mixing vessel, and the centre that makes mixing vessel is what open wide.Therefore, in the time that reactant gases is not uniformly distributed along the circle diameter of mixing vessel, may produce mix bad.Mobile adjuster 122 of the present invention has intermediate, be used for making reactant gases away from ground, middle part and towards the wall of mixing vessel to external diffusion.This intermediate is typically positioned to the medullary ray of mixing vessel overlapping at least in part.This intermediate has advantageously improved mixing by stoping the middle part of the process mixing vessel that flows.This intermediate is preferably conical or pyramid.
In Fig. 2, show the sectional view of the mixing vessel 104 with mobile adjuster 122 and mobile adjuster 160.Mixing vessel 104 is manufactured and is preferably the ternary gas mixture 114 of mixing completely, and it is by downstream end 156 and in HCN reaction vessel 106.Mixing vessel 104 comprises long and narrow pipeline 140, and this long and narrow pipeline 140 can touch or extend in reaction vessel 106 on the flow direction of ternary gas mixture 114.The size of mixing vessel can change, but can there is 1-5m, be for example the length of 1.2-2.5m, and 5-60cm, the interior diameter of 10-35cm preferably.Be provided with in one embodiment the first entry port 136(also referred to as upper entrance), it is used for introducing and is selected from least one reactant gases of organizing below, and described group comprises methane-containing gas, contains ammonia gas, oxygen-containing gas and their mixture.Preferably, introduce methane-containing gas 110 and contain ammonia gas 112 by the first entry port 136.The adjuster 160 that flows can be placed in the downstream of the first entry port 136, and produces the plug flow of the reactant gases of introducing by the first entry port 136.
Can also be by the second entry port 138(also referred to as bottom entrance) other reactant gases is incorporated in pipeline 140.The adjuster 122 that flows can be placed in the downstream of the second entry port 138, and produces reactant gases and those plug flows from the reactant gases of the first entry port 136 of introducing by the second entry port 138.In one embodiment, the reactant gases of introducing by the second entry port 138 can be selected from following group, and described group comprises methane-containing gas, contains ammonia gas, oxygen-containing gas and their mixture.Preferably, can introduce oxygen-containing gas stream 108.As shown in Figure 2, the second downstream of entry port 138 in the first entry port 136.Because just can form ternary gas mixture when oxygen-containing gas until introduce, therefore preferably pipeline 140 introduce oxygen-containing gas 108 compared with bottom, thereby reduce the volume of ternary gas mixture 114.
The adjuster 122 that flows comprises one or more radial plate 124 that are arranged on intermediate 126.The adjuster 122 that flows has integrated component, and radial plate 124 is connected on intermediate 126 rigidly.The adjuster 122 that flows can use suitable stainless steel, for example 310SS or 316SS.The size of mobile adjuster 122 can change with the size of mixing vessel.Be provided with in one embodiment from 1 to 10 radial plate 124, for example, preferably have 2 to 6 radial plate.Intermediate 126 can be arranged in long and narrow pipeline 140 with one heart.Intermediate 126 can be arranged in long and narrow pipeline 140, makes radial plate align or setover with tab inserts (tab) 148, for example, in the angle of 45 °.In an example, the adjuster 160 that flows can have the structure similar to mobile adjuster 122.
Radial plate 124 have on the flow direction of ternary gas mixture 114, extend, for example smooth surface extending longitudinally in long and narrow pipeline 140.Due to the diameter of radial plate extend through pipeline, therefore each radial plate can have the length of the half that is roughly pipe diameter.Each radial plate 124 has the height from 0.05y to 0.3y, the diameter that wherein y is pipeline.Exemplary mobile adjuster 122 can have highly for such as 4-16cm of 1-20cm(), thickness is such as 0.5-1.5cm of 0.1-3cm() radial plate.Each radial plate can have circular upstream edge, and described upstream edge is equilateral about the upstream point of intermediate 126.In certain embodiments, upstream edge can be for gradual change, edge of a knife shape, square or blunt.The radial plate of mobile adjuster 122 and 160 can have similar size and dimension.
In one embodiment, radial plate 124 stretches out from intermediate 126, and is connected to the inwall 154 of long and narrow pipeline 140.In one embodiment, as shown in Figure 5, radial plate 124 can stretch out and be connected to circular rings 180.Circular rings 180 can be connected to the inwall 154 of long and narrow pipeline.In one embodiment, circular rings 180 can be slidably matched to, be welded to or otherwise be connected on inwall 154.
Intermediate 126 with the angle from 5 ° to 65 ° from upstream edge substrate downstream 128 gradual changes.As shown in accompanying drawing 3A/3B and 4A/4B, intermediate 126,126 ' can have various shape, includes but not limited to taper shape, pyramid, prismatic, the irregular four limit bodily forms etc.Intermediate 126 can be solid or hollow.Intermediate 126 has downstream substrate 128, and downstream substrate 128 can be circle, trilateral, square, rhombus, rectangle, pentagon or hexagon.Fig. 3 B has shown the square downstream substrate 128 of pyramid intermediate 126.In the time that intermediate 126 is pyramid, radial plate 124 can touch the bight of pyramid.Fig. 4 B has shown conical 126 ' circular downstream substrate 128 '.Radial plate 124 ' in Fig. 4 A/4B can be equidistantly spaced apart each other on conical intermediate 126 '.In one embodiment, downstream substrate has the maximum diameter from 0.1*x to 0.5*x, the radical length that wherein x is radial plate.
Long and narrow pipeline 140 also comprises one or more static mixing zones 142,144 that are used for producing the ternary gas mixture 114 of mixing completely.As shown in Figure 2, each static mixing zone 142 and 144 downstream in the adjuster 160 and 122 that flows respectively.In one embodiment, be provided with the first static mixing zone 142 arranging adjacent to the first entry port 136.The first static mixing zone 142 also can be spaced apart with mobile adjuster 160.The adjuster 160 that flows can have the structure of radial plate 162 and intermediate 164, is similar to the adjuster 122 that flows.In some embodiments, the adjuster 160 that flows can not have intermediate, and is only included in the radial plate 162 that region intermediate connects.
The setting of the first static mixing zone 142 is used for mixing by methane-containing gas 110 with containing ammonia gas 112, and this carries out with before the mixing of oxygen-containing gas 108 at them.The first static mixing zone 142 can form the binary gas of methane and ammonia.Before this binary gas and oxygen-containing gas are mixed, preferably allow reactant gases pass through the adjuster 122 that flows, there is roughly the horizontal sliding of velocity profile uniformly and flow in the second static mixing zone 144 to provide.The second static mixing zone 144 arranges adjacent to the second entry port 138, or is arranged on the downstream of the second entry port 138, and preferably spaced apart with mobile adjuster 122.The second static mixing zone 144 mixes oxygen-containing gas with other reactant gases, to produce ternary gas mixture 114.
In one embodiment, the second static mixing zone 144 should be use up maximum actual capabilities and be installed near the catalysts bed (not shown) in reaction vessel 106, and the volume of the ternary gas mixture in mixing vessel 104 and the residence time are minimized.
Although shown an entrance for port one 36 and 138 in Fig. 2, but multiple the first entry ports and the second entry port can be set in one embodiment.Can be provided with multiple conveying entrances around the whole circumference of long and narrow pipeline 130.Carry each in entrance can be with respect to the flow direction of ternary gas mixture the angle in 5 ° to 90 °.The primary transfer line of reactant can be connected to round the annular region (not shown) of multiple the first entry ports and/or the second entry port.Can have multiple (unshowned) hole, it defines entry port and the entrance of the conveying from annular region to long and narrow pipeline 140 is provided.Do not wish to be bound by theory, can think that, in the time that reactant is transported in mixing vessel 104, described multiple holes can stop rotation, i.e. whirlpool.
In another embodiment, the first entry port 136 and the second entry port 138 can extend in the cavity of long and narrow pipeline 140.This can allow reactant to be incorporated into the centre of long and narrow pipeline 140.Do not wish to be bound by theory, can think that extended entrance can stop reactant not contact tab inserts 148 just through mixing vessel 104.Preferably, the second entry port 138 of delivering oxygen extends to the middle part of pipeline 130.
Each in static mixing zone 142,144 includes one or more row 146 of tab inserts 148.Due to the rotating fluid of the minimizing of the ternary gas mixture being produced by the adjuster 122 and 160 of flowing, the mixing therefore being produced by tab inserts 148 improves significantly.In addition, the mixing of this improvement is to have stoped ternary gas to flow through the middle part of pipeline owing to having the mobile adjuster of intermediate, and forces this ternary gas mixture to contact the tab inserts extending out from inwall.Each static mixing zone 142,144 can comprise one to ten row tab inserts 148.In one embodiment, the line number in the second static mixing zone 144 can be more than or equal to the line number in the first static mixing zone 142.For example, the second static mixing zone 144 can have one to three row.Each row 146 can comprise one to ten tab inserts 148, and preferably includes two to six tab inserts 148.In each row 146, tab inserts 148 is preferably spaced apart around the even circumferential ground of pipeline 140.Along with the quantity of tab inserts in line number and/or every row increases, the pressure drop in mixing vessel also can increase.Therefore, desired is to provide completely and mix with the combination of row and tab inserts, keeps the pressure drop that is less than 35kPa, is for example less than 25kPa simultaneously.But, due to the low CoV realizing by reducing rotating fluid, use ternary gas mixture that still less energy forms can realize and the similar performance of technique of more high energy that uses larger pressure drop.
Before the downstream of the second static mixing zone 144 outlet 156 at mixing vessel 104, can there is dummy section 158.Dummy section 158 allows ternary gas mixture to have non-mixed region.Dummy section 158 can have the height from 0.1*d to 10*d, and wherein d is the interior diameter of long and narrow pipeline 140.
In one embodiment, tab inserts can be installed on inwall 154, or penetrates the groove (not shown) in inwall 154 and be welded to the outside surface of long and narrow pipeline 140.Each tab inserts 148 can have strut member 152, and strut member 152 is l shape, I shape, T shape, U-shaped or V-arrangement.Strut member 152 can provide rigidity for tab inserts 148, to stop the deformation under the pressure change that turbulent flow was caused due in reactor.Turbulent flow may cause the huge pressure that is greater than 5MPa, is for example greater than 13MPa to increase.
In one embodiment, tab members 150 has the upstream face 152 bending on flow direction.Bending angle can change between 5 ° to 45 ° and more preferably between 20 ° to 35 °.Downstream surface can have the angle approximate with upstream face.Tab inserts in a line can have roughly approximate angle, for example, within ± 5 °, more preferably within ± 1 °.The angle of the tab inserts between the tab inserts between adjacent lines and different mixing regions can be different.In an exemplary embodiment, it is the tab inserts of 30 ° that the first mixing region 142 can have angle, is the tab inserts of 25 ° and the second mixing region 144 can have angle.In another exemplary embodiment, it is the tab inserts of 30 ° that the first static mixing zone 142 can have angle, is the tab inserts of 45 ° and the second static mixing zone 144 can have angle.
In one embodiment, tab inserts 148 does not preferably have inclined-plane, and tab inserts 148 is not distortion, and it aligns on the inwall of pipeline 140, to be parallel to haply flowing of ternary gas mixture.In one embodiment, the obliquity of tab inserts 148 is from 0 ° to 7 °, for example, from 0 ° to 3 °.Have and be greater than the slight inclination degree of 8 ° and can cause very poor mixed performance, the latter may cause increase and/or the less desirable pressure drop of the temperature variation of bed to increase.
Tab inserts 148 in pipeline 140 operates as fluid paper tinsel, and described fluid paper tinsel is along with reacting gas flow is crossed mixing vessel 104 and has the larger hydrodynamicpressure that presents for their upstream face 150 and for their hydrodynamicpressure of reduction of downstream surface.The adjuster 122 that flows provides the plug flow that will touch the reactant gases of upstream face 150.The adjacent pressure difference with mutual reverse lip-deep fluid of each tab inserts 148 causes the longitudinal flow flowing through from each tab inserts 148 to relocate, and has therefore caused increasing cross-stream component radially in the longitudinal flow of the fluid by pipeline 140.Fluid on the edge of each tab inserts flows and inwardly causes upstream face that fluid is bent and upward deflect, thereby the tip place at each tab inserts produces the multipair vortex that oppositely rotates and be mainly a fluid stream formula, and by the connected downstream hair fastener vortex of adjacent a fluid stream formula vortex being produced by single tab inserts.Each this paired vortex has the each other reverse rotation round turning axle, this turning axle a fluid stream formula fluid flow direction along the longitudinal and along the annular space location between two border surfaces haply.The turbulent mixing being produced by static mixing zone 142 and 144 has produced the ternary gas mixture of mixing completely with the variation factor (CoV) that is less than 0.1.
That the shape of the upstream face 150 of tab inserts 148 can comprise is trapezoidal, square, parallelogram, half elliptic, rounded square or rectangle.Can use the tab inserts of the convergent of for example trapezium-shaped.In addition, tab inserts can slight bending or curve.In one embodiment, in the moving direction of main flow line, the longitudinal size of tab inserts does not exceed the twice of the width of tab inserts.
The size of mixing vessel 104 can vary widely, and can depend on to a great extent the capacity of reaction vessel 106.Herein in disclosed one exemplary embodiment of the present invention, mixing vessel 104 has in from 2 to 20 scope length of outer side and the diameter ratio of (for example from 2 to 10).
As shown in Figure 2, although be provided with two entry ports and two static mixing zones, but in other embodiment, also can be provided with an entry port and a static mixer.In addition, can be provided with two entry ports and one and be arranged on the static mixer of the near-end of bottom entry port.Within the scope of the invention, can use other entry port and the structure of static mixer.
Ternary gas mixture 114 can enter into from mixing vessel 104 entry port of reaction vessel 106.In one embodiment, one or more grid distributors 120 can be set equally distributed ternary gas mixture is provided on catalyst bed.Can also use spark arrester in conjunction with grid distributor, so that ternary gas is distributed on catalyst bed.Preferably, grid distributor should not cause being greater than for example, pressure drop in reaction vessel 35kPa, that be more preferably less than 25kPa.In one embodiment, within reaction vessel, there is a grid distributor in the upstream arrangement of entrance downstream and spark arrester.Grid distributor can have the diameter that is greater than entry port and is less than the maximum diameter of reaction vessel.Grid distributor has the dummy section by one or more hole formations, dummy section be at least grid distributor area 50% to 80%.The tapered feature that dummy section can have lifting in upstream face spreads ternary gas mixture.Grid distributor can also comprise solid area, and this solid area is alignd with the central point of entry port, preferably medially alignment.In one embodiment, grid distributor can be web material.
In other embodiment, static mixing zone can be for generating the tab inserts mixing tank of whirlpool.
for applicable passive mixing parts, it is used in can be from Chemineer, in the high efficiency static state mixing tank that Inc. buys, as the efficient whirlpool of HEV() part of production line.Haply, HEV mixing tank comprises trapeziform tab inserts, this tab inserts is installed on mixer case with certain angle, and produce the alternately most advanced and sophisticated whirlpool of rotation, be used for minimum pressure loss mix the fluid stream of process, keep the velocity profile with turbulent relevant relatively flat simultaneously.
The ternary gas mixing completely for object of the present invention has the variation factor (CoV) that is less than 0.1 on the diameter of catalyst bed, or is more preferably less than 0.05 and be even more preferably less than 0.01 variation factor.Aspect scope, CoV can be formed as 0.001 to 0.1, or more preferably from 0.001 to 0.05.Low CoV has advantageously increased reactant and has been converted to the productive rate of HCN.CoV is defined as the ratio of standard deviation and average deviation μ.CoV is low as much as possible ideally, for example, be less than 0.1, as 0.05.HCN unit can be operation on 0.1 at CoV, and CoV is 0.2 also unrare, in 0.01 to 0.2 or 0.02 to 0.15 scope.But at CoV higher than 0.1 o'clock, running cost is higher and HCN productive rate is lower, for example low by 2% to 7%, this is equivalent to the loss of annual millions of dollars in service of continous way business.The ternary gas mixing completely has advantageously increased HCN productive rate, and the HCN of return higher output yield.Can realize by implement roughly uniform bed tempertaure on catalyst bed the improvement of performance.
In the time that CoV exceeds 0.1, reactant gases may be in the concentration outside the safety operation scope of catalyst bed.For example, in the time operating under the higher oxygen gas concentration in ternary gas, larger CoV may cause oxygen to increase, and this has caused backflow.In addition, in the time that CoV is larger, catalyst bed may be exposed under more methane, and this may cause the gathering of carbon precipitates.Carbon precipitates may reduce catalyst life and performance.Therefore, under larger CoV, may have higher raw materials consumption.
Mixing vessel can operate from the temperature of 50 DEG C to 120 DEG C.In mixing vessel, can use higher temperature, reactant gases is carried out to preheating.In one embodiment, preferably mixing vessel with the temperature operation lower than reaction vessel.The working pressure of mixing vessel can have a greater change, from 130kPa to 400kPa, and more preferably from 130kPa to 300kPa.Say haply, mixing vessel can with the similar pressure of reaction vessel under operate.
Reactant gases mixes under the minimized condition of pressure drop that can make in mixing vessel.In one embodiment, the pressure drop in mixing vessel is less than 35kPa, is preferably less than 25kPa.Pressure drop is minimized to the peak pressure that can reduce ternary gas, and therefore reduce the pressure in potential blast situation.Reducing pressure drop also minimizes the energy associated with mixed phase (for example compression energy).
Reactant gases is fed in mixing vessel so that ternary gas mixture to be provided, this ternary gas mixture has ammonia-oxygen mol ratio of from 1.2 to 1.6 (for example from 1.3 to 1.5), ammonia-methane mol ratio of from 1 to 1.5 (for example from 1.1 to 1.45), and methane-oxygen mol ratio of from 1 to 1.25 (for example from 1.05 to 1.15).For example, ternary gas mixture can have ammonia-oxygen mol ratio of 1.3 and methane-oxygen mol ratio of 1.2.In another exemplary, ternary gas mixture can have ammonia-oxygen mol ratio of 1.5 and methane-oxygen mol ratio of 1.15.Oxygen concn in ternary gas mixture can change with these mol ratios.Therefore, in some embodiments, ternary gas mixture comprises the oxygen of at least 25% volume, for example the oxygen of at least 28% volume.In some embodiments, ternary gas mixture comprises the oxygen of from 25% to 32% volume, for example the oxygen of from 26% to 30% volume.Can regulate reacting gas flow by various control system.For example, can use and can measure flow velocity, the temperature and pressure of reactant gases feedstream and allow Controlling System to provide the under meter feeding back through " in real time " of the flow velocity of pressure and temperature compensation for operator and/or control device.
As understood by one of ordinary skill in the art, aforementioned function and/or method may be embodied as system, method or computer program.For example, function and/or method may be embodied as the executable programmed instruction of computer, this instruction is recorded in computer-readable memory device, and in the time retrieving and carry out this instruction by computer processor, it controls computer system to carry out function and/or the method for above-mentioned embodiment.In one embodiment, computer system can comprise one or more central processing unit, computer memory (for example read-only storage, random access storage device) and data storage device (for example hard disk drive).The executable instruction of computer can be used any applicable computer programming language (such as C++, JAVA etc.) to encode.Correspondingly, the form (comprise firmware, resident software, microcode etc.) of entirety for the embodiment of software can be taked in aspects more of the present invention, or combines the embodiment of software aspect and hardware aspect.
In one embodiment, in the time that reactant gases is mixed, desired is the side reaction of avoiding in mixing vessel.Side reaction can comprise the oxidation of methane or ammonia.In mixing vessel, also should avoid deflagration under unfavorable operational condition or risk and the impact of blast, this by keeping velocity of flow of the flame front that is greater than ternary gas to realize in mixing vessel.Term " deflagration " used herein refers to the combustion wave of propagating with subsonic velocity before being in close proximity to flame with respect to unburned gas." blast " refers to sentence before being in close proximity to flame with respect to unburned gas the combustion wave of Supersonic transport.Deflagration typically causes appropriate increased pressure, and blast may cause excessive increased pressure.The invention provides a kind of favourable solution and come fast and fully reactant gases to be mixed, in mixing process, pressure drop is minimized, and avoid undesired side reaction, for example oxidation and deflagration simultaneously.
The material that is used for the structure of mixing vessel and mobile adjuster can be different, and can be any material compatible with ternary gas mixture, described material can bear design temperature in mixing vessel and pressure and significant degeneration not, and it can not promote the reaction of the gas in ternary gas mixture.Use comprises that the structure of the stainless steel producing material material of 310SS and 316SS has reached gratifying result.
In one embodiment, reduce the catalyst activity on the surface, inside of mixing tank by the surface finish that those is exposed to air-flow with the specific surface area (roughness) that reduces internal surface.For example, the surfaceness that the interior diameter of mixing vessel is worked into about 125 microinchs (3.2 microns) can significantly reduce catalyst activity.
Mixing vessel 104 can be provided with one or more applicable analysers, is used for measuring leaving the first static mixing zone 142 and/or second methane of static mixing zone 144 and the concentration of ammonia.The analyser of this online and offline is known in the prior art.The example of the indefiniteness of this analyser comprises infrared spectrum analyser, Fourier transform infrared analyser, gas chromatographic analysis instrument and mass spectrometer.Similarly, the second static mixing zone 144 can be provided with one or more applicable analysers, is used for measuring the oxygen concentration in ternary gas mixture.
In the unshowned optional embodiment of Fig. 2, upper entrance 136 and bottom entrance 138 are provided with the rare gas element joint with automatic valve, make can to purge if desired the reactant in the pipeline of mixing vessel 104, for example, stop work or the shut-down of reactor for safeguarding.
End, upstream at mixing vessel 104 is provided with pressure release setter 170, will discuss to it more completely herein.Such as rupture disc of pressure release setter 170() can be arranged in the vent-pipe 172 of mixing vessel 104.Pressure release setter 170 has limited the pressure in long and narrow pipeline 140, and therefore limit the total mass and the potential energy that between the first static mixing zone 142 and (unshowned) catalytic bed, comprise, therefore can under disadvantageous operational condition, reduce the impact of burning or risk and the impact of blast.In one embodiment, pressure release setter 170 has 110% to 115% the pressure release setting point from the working pressure of mixing vessel 104.
The upstream extremity that is supported on the first static mixing zone 142 when pressure release setter 170, with can extend to draft tube liner 172 in stacking 174 and be communicated with time, has obtained good result.Therefore, under the excess pressure forming in mixing vessel 104, pressure release setter 170 is opened, and the gas heating discharges from reaction vessel 106 and mixing vessel 104.Can purify near vapor capacity pressure release setter 170 with nitrogen purge stream.
In the production of HCN, every kind of reactant gases is processed by applicable raw material preparation system respectively.The source of corresponding reactant gases can be transported in each corresponding raw material preparation system as pipeline, go-cart, boat or track etc. by any applicable delivery system well known in the prior art.
Can be provided by oxygen feed preparation system containing oxygen source, this oxygen feed preparation system comprises for regulating and is incorporated into the device of the pressure containing oxygen source in technological process and is used for fine particle from the unfiltered strainer containing removing oxygen source.Increasing containing the oxygen content of oxygen source is favourable for the size that increases reaction yield and minimizing treatment unit.Increase the oxygen content of air and also increased conventionally the inflammableness for flammable material in air.For example, if do not remove metallic particles (iron or steel) and/or other pollutents and the by product carried secretly in feedstream, may cause the condition of a fire of oxygen channel.Can remove carried secretly metallic particles and other pollutent from unfiltered containing oxygen source with any applicable mechanism, described mechanism is strainer, cyclonic separator, coalescer, anti-smog device and mist eliminator for example.In the time requiring compression containing the source of oxygen air inlet, use oil free compressor well known by persons skilled in the art and the Seal Design also can pollution remission.Oxygen-containing gas can comprise air, oxygen-rich air or pure oxygen.For oxygen-rich air, perhaps need compressor.
Term " air " refers to the gaseous mixture that composition is roughly the same with the original composition of gas of taking from atmosphere (conventionally at ground place) as used herein.In some instances, air is taken from surrounding environment.Air has following composition, comprises oxygen, the argon gas of approximately 1% volume and the carbonic acid gas of approximately 0.04% volume of the nitrogen of approximately 78% volume, approximately 21% volume, and other a small amount of gas.
Term " oxygen-rich air " refers to that composition comprises than the gaseous mixture of existing more oxygen in air as used herein.Oxygen-rich air has following composition, comprise be greater than 21% volume oxygen, be less than 78% volume nitrogen, be less than the argon gas of 1% volume and be less than the carbonic acid gas of 0.04% volume.In some embodiments, oxygen-rich air comprises the oxygen of at least 28% volume, for example oxygen of at least 80% volume, for example oxygen of at least 95% volume, or the oxygen of at least 99% volume.
For example utilize, containing the high oxygen concentration in oxygen source (rare gas element of low levels, such as nitrogen) and provide and reduced the size of downstream unit and the chance of running cost that must process in other cases the inert nitrogen of large volume.In one embodiment, oxygen-containing gas comprises the oxygen that is greater than 21% volume, for example, be greater than the oxygen of 28% volume, is greater than the oxygen of 80% volume, is greater than the oxygen of 90% volume, is greater than the oxygen of 95% volume or is greater than the oxygen of 99% volume.
Along with the lifting of the oxygen content containing oxygen source, can control more accurately the purity containing methane source.As understood by one of ordinary skill in the art, the source of methane can be different, and can obtain from reproducible source, the scrap heap of for example landfill, agriculture and animal husbandry field, the biogas of fermentation, or from fossil oil as Sweet natural gas, oily, coal gas and gas hydrate, as VN Parmon " Source of Methane for SustainableDevelopment ", Pages273-284 and Derouane, eds.Sustainable Strategies for theUpgrading of Natural Gas:Fundamentals, Challenges, in and Opportunities (2003), further describe.For purposes of the present invention, methane purity and significant containing the uniform component in methane source.In some embodiments, this technique can comprise the methane content of determining containing methane source, and purifying should be containing methane source in the time that methane content is defined as being less than 90% volume.Methane content can use the measurement based on gas-chromatography (comprising Raman spectrum) to determine.Methane content is METHOD FOR CONTINUOUS DETERMINATION in real time, maybe when new containing to determine when methane source is incorporated in technique as required.In addition, in order to reach higher purity, when methane content is during higher than 90% volume, for example, from 90% volume to 95% volume, can purifying containing methane source.Can adopt known purification technique to carry out purifying containing methane source, to remove oil, condensation product, water, C2+ hydrocarbon (as ethane, propane, butane, pentane, hexane and isomer thereof), sulphur and carbonic acid gas.State after methane can purify, with half state purifying or be transported in HCN synthesis system with impure state.
Sweet natural gas is for example the not pure state of methane.That is to say, Sweet natural gas is the gas that can be used to the carbon of the HCN that provides prepared in technique of the present invention substantially.But except methane, Sweet natural gas may comprise pollutent, for example hydrogen sulfide, carbonic acid gas, nitrogen, water, and more the hydrocarbon polymer of high molecular is as ethane, propane, butane, pentane etc., all these productions to HCN in the time existing are harmful to.Gas component can be significantly different along with the difference in source.The component of the Sweet natural gas being provided by pipeline also may be along with the time changes significantly, and even noticeable change in very short time span, because can open or cut off gas source for pipeline.The variation of this component causes being difficult to maintaining best and stable processing performance.Along with inertia load reduces by the oxygen concentration containing oxygen source, HCN synthesis technique becomes more serious to the susceptibility of these variations.
Can be provided by methane feed preparation system containing methane source, this methane feed preparation system comprises for concentrated methane and by more hydrocarbon polymer, carbonic acid gas, hydrogen sulfide and the water of high molecular remove and filter Sweet natural gas to remove the device of particulate from Sweet natural gas.For example, the purification of Sweet natural gas provide highly concentrated have methane containing methane inlet air flow, should there is the component that significantly reduces and the change degree of fuel value containing methane inlet air flow.When with oxygen-containing gas with containing ammonia gas while mixing, the methane-containing gas of purification provides such ternary gas mixture, and than using the stream of the gas raw material containing methane not purifying, it can more predictably react in the synthesizing of HCN.More lasting purification to methane-containing gas and control can stabilization process, and allow to judge and control the optimum mole ratio of methane/oxygen and ammonia/oxygen, therefore this caused higher HCN productive rate.
With purify Sweet natural gas obtain methane-containing gas feedstream, comprise pure haply methane feedstream with manufacture HCN also promoted catalyst life and HCN productive rate.Especially, use pure haply methane-containing gas: (1) has been reduced and can have been brought detrimentally affect or the concentration to the unhelpful impurity of technique to downstream, and described impurity is for example sulphur, CO
2and H
2o; (2) make remaining component be stabilized in consistent level, to (a) allow the synthetic optimization of the HCN in downstream, and (b) make it possible to use highly enriched or pure oxygen-containing gas by alleviating large temperature departure in HCN synthesis step, wherein said temperature departure is typically relevant with the content of higher hydrocarbon, and is (for example loss of catalyst breakage, interlocking and working hour) being harmful to for best output and operability; And (3) for example reduce higher hydrocarbon (for example C2 and higher hydrocarbon), to reduce the formation of the senior nitrile (acetonitrile, vinyl cyanide and propionitrile) in building-up reactions, and reduced HCN loss of yield relevant while removing nitrile.
In addition, use the pure haply gas containing methane (1) (for example it is by the content of carbon and hydrogen and fuel value stabilization) to be eliminated or to be minimized to the mutability in raw material, and therefore by whole HCN synthesis system 100 stabilizations, thereby allow judge and control the ratio of best methane and oxygen and the ratio of ammonia and oxygen, for stable operation and the most effective HCN output; (2) relevant temperature spike and the catalyst breakage causing are eliminated or minimized; And (3) carbonic acid gas is minimized, therefore reduced in the regenerative process that is present in ammonia with ammonia stream regeneration or recirculation in the amount of carbonic acid gas, wherein said ammonia stream is from the regenerative process of ammonia that may be positioned at reaction vessel downstream.In the regenerative process of this ammonia and in ammonia stream regeneration or recirculation, carbonic acid gas is eliminated or minimized and reduced the possibility that forms carbamate, the formation of carbamate can cause obstruction and/or the dirt deposition of pipeline and other process units.
Before mixing with oxygen-containing gas and methane-containing gas in mixing vessel, " synthesizing " or fresh ammonia flow by the processing of fresh ammonia raw material preparation system.Haply, the major function of fresh ammonia raw material preparation system be in being incorporated into mixing vessel containing ammonia gas before from fresh ammonia stream removal of impurity, for example water, oil and iron.In the life-span that may reduce catalyzer containing the impurity in ammonia gas, this causes low reaction yield.Fresh ammonia raw material preparation system can comprise treatment facility, and for example vaporizer and the strainer for " synthetic " or fresh ammonia stream, to provide treated fresh ammonia stream.
For example, can in vaporizer, process the available liquid ammonia of business, so that the first liquid stream that the ammonia vapour stream of part purification is provided and comprises water, iron, iron granules and other non-volatile impurities.Impurity and any liquid during the ammonia vapour stream that can use for example ammonia separator of ammonia mist eliminator to isolate present part purification exists, thereby prepare treated fresh ammonia stream (roughly pure ammonia vapour stream), and include carried secretly impurity and be present in the second liquid stream of any ammonia liquor in the ammonia vapour stream that part purifies.
In one embodiment, the first liquid stream that comprises water, iron, iron granules and other non-volatile impurities is transported in the second vaporizer, wherein make a part of evaporation of liquid flow form the ammonia vapour stream that second section purifies, and the more concentrated second liquid stream that comprises water, iron, iron granules and other non-volatile impurities that can further process as cascading water or waste streams.The ammonia vapour stream that second section purifies can be transported to ammonia separator.In another embodiment, the more concentrated second liquid stream that comprises water, iron, iron granules and other non-volatile impurities is transported in the 3rd vaporizer, further to reduce ammonia content before cascading water or waste streams processing.
Formation of foam in vaporizer can limit the rate of evaporation of ammonia and reduce the purity of prepared ammonia steam.Generally stop formation of foam by defoamer being introduced directly in vaporizer or being incorporated in the feedstream of vaporizer.Defoamer belongs to sensu lato polymeric material and the solution that can eliminate or significantly reduce the ability of the formation foam of liquid and/or liquid and gaseous mixture.Defoamer suppresses bubble formation by the surface tension that reduces solution in the liquid stirring.The example of defoamer comprises silicone resin, organophosphate and alcohols.In one embodiment, the defoamer of q.s is added in fresh ammonia stream, anti-foam agent concentration is remained in the scope from 2mpm to 20mpm in fresh ammonia stream 180.The example of an indefiniteness of defoamer is Unichemof Hobbs, NM(New Mexico) UNICHEM7923 of manufacturing.
Fresh ammonia raw material preparation system can also be provided with filtering system, to remove particulate from handled fresh ammonia stream, thereby stops the poisoning of catalyst in reaction vessel.Filtering system can be single strainer or multiple strainer.
Ammonia also separates and regeneration in ammonia regeneration part, as flowing by the recycle of ammonia of individual curing in recycle of ammonia raw material preparation system.Recycle of ammonia raw material preparation system can comprise treatment facility, is used for filtering and heating recycle of ammonia stream, to produce treated recycle of ammonia stream.The recycle of ammonia stream that heating is carried by pipeline can assist to stop the deposition on inner-walls of duct.Treated recycle of ammonia stream can combine with treated fresh ammonia stream.
The HCN building-up reactions occurring in reaction vessel is thermo-negative reaction, under its temperature of reaction in 1000 DEG C to 1250 DEG C scopes and 100kPa under the pressure in 400kPa scope, carry out.Catalyzer typically is silk screen platinum/rhodium alloy or silk screen platinum/iridium alloy.In one aspect, can in plane support of the catalyst, use 85/15 platinum/rhodium alloy.Also can support and use 90/10 platinum/rhodium alloy in the corrugated than plane support of the catalyst with larger surface-area.Other catalyst component be can use, platinum metals, platinum-group metal alloy, loading type platinum family metal or loading type platinum family metal alloy included but not limited to.Also can use other catalyzer to form, include but not limited to pore structure, silk screen, tab inserts, spheroid, block, spumescence, Dipping and coating cleaning.Catalyst cupport in reaction vessel, until in 0.7 to 1.4(g catalyzer) catalyst cupport in/(kg unstripped gas/hour) scope.Ternary gas mixture contacts with catalyzer in reaction vessel, thereby the reaction product containing prussic acid is provided.
In one embodiment, the catalyst bed that the ternary gas of heating can be changed into HCN is supported by supporting component, and by reducing, platinum silicide forms and optimize the thermal stresses resistance of pipe reactor to described supporting component and the material of dirt deposition forms.Catalyzer supporting component is arranged adjacent to catalyst bed haply.Spark arrester is spatially arranged on catalyst bed, so that space to be provided there.Spark arrester can extinguish the indoor upstream burning causing owing to refluxing of any internal-response.Ceramic foam along define internal-response chamber and catalyzer housing inwall at least a portion arrange.In the time that reactor is closed, ceramic foam minimizes the by-pass flow of shrinking caused unstripped gas due to catalyzer.Be arranged in the formation that ceramic foam on catalyst bed minimized, reduced pressure drop for the operating process at reactor by the volume of ternary gas and suppresses free radical.In each outlet of housing, be furnished with lasso, it provides the fluid between catalyst bed and the upper section of waste heat boiler to be communicated with.There is the lower support of roughly cell structure roughly adjacent to the lower surface arrangement of catalyst support member, be used for reducing the pressure drop across lower support.
Spark arrester can be manufactured by any suitable material well known in the prior art, as long as spark arrester can be carried out any in following function: (1) extinguishes the burning of upstream in the situation from the backflow of catalyst bed in existence; (2) as flow distributor to ensure Uniform Flow on catalyst bed and the region of eliminating the low gas velocity that may reflux; (3) reduce the reactant volume in reactor as space-filling device, with by there potential energy minimum; And/or provide thermal isolation between ternary gas mixture in the part of the top of thermocatalyst bed and reactor.The spark arrester adopting can be manufactured by such material, and described material (1) has minimum catalytic effect; (2) at the temperature adopting at manufacture HCN, be heat-staple; (3) can cracked ammonium; (4) can not trigger oxidation.The example of the material that can adopt in the time of structure spark arrester is the ceramic refractory in any stable form, includes but not limited to: ceramic pellet body, ceramic foam, ceramic fiber coating, aluminium-silica fireproof material, non-weaving coating and their combination etc.The indefiniteness example of applicable ceramic refractory composition comprises alumina, the alumina of 94% weight and the alumina of 95% weight of 90% weight.In addition, in the time constructing spark arrester with ball body as material, the size and dimension of ball body can be different, as long as the ball body using in spark arrester can be carried out above-mentioned functions.
It will be appreciated that, the use of spark arrester has reduced the ternary gas mixture heating significantly by the possibility becoming as explosive of changing from deflagration to blast.For example, if judge that the flame velocity of ternary gas mixture at 304kPa and 100 DEG C is 1.2m/sec, the superfacial velocity of the ternary gas mixture through preheating of the ball shape bed of the ball body that by spark arrester, for example comprises 3/8 inch of (9.5mm) diameter should obviously be greater than 1.2m/sec, has stoped whereby propagation of flame by ball shape bed.Although the size of the ball body using in ball shape bed can be different widely, but the diameter dimension of ball body is generally from 1/8 inch to 1/2 inch (3mm is to 13mm).
The feature (for example degree of depth of ball shape bed) of spark arrester is chosen as the pressure drop of the ternary gas mixture through preheating on spark arrester is balanced by the open spaces of the minimizing between the speed of the increase of ternary gas mixture and spark arrester and catalyst bed, thereby the potential energy discharging in deflagration is minimized, and can not impair significantly the backflow of the pressure release device in mixing vessel.In one embodiment, the degree of depth of ball shape bed is at least 0.4m.
Can be clear from above-mentioned explanation, the present invention can be well suited for realize target and reach mentioned advantage and disclosure institute inherent advantages here.Although described for the purpose of this disclosure preferred embodiment of the present invention, but be understandable that, can carry out the apparent and change that can complete to those skilled in the art under spirit of the present invention.
The present invention can further understand with reference to following example.
Example 1
As shown in Figure 2, the mobile adjuster with four radial plate and pyramid intermediate as shown in Fig. 3 A-3B is arranged at the downstream of the upstream (being the upstream of the tab inserts in static mixing zone) of the static mixing zone in mixing vessel and the annular entry of oxygen-containing gas.Mixing vessel has the length of diameter and the 214.4cm of 25.4cm.The second normal moveout remover also with four radial plate and pyramid intermediate is arranged at the upstream of the second static mixing zone in mixing vessel and the downstream of methane gas and ammonia entrance.Each mobile adjuster is that 10.2cm is high and 0.95cm is thick.Each mobile adjuster is formed by 310SS structure, and has the circular rings of the inner side that is welded to mixing vessel.Mobile adjuster has stoped the rotating fluid that can promote bad mixing.Pyramid intermediate has blocked the middle part of mixing vessel, thereby prevents that reactant gases from just flowing through mixing vessel without mixing.Each static mixer all has tab inserts.Mixing vessel moves under low-energy situation, and pressure drop is less than 35kPa.After ammonia-oxygen mol ratio transport of reactant gases body of the methane-oxygen mol ratio with 1.2 and 1:1.5, the oxygen that ternary gas mixture comprises about 28.5% volume.As the result of mixing, ternary gas mixture has the CoV that is less than 0.1.Ternary gas mixture enters into the adjacent reaction vessel that has spark arrester and contain the catalyst bed of 85/15 platinum/rhodium catalyst.Under reaction conditions, catalyst bed has the bed tempertaure variation of 15 DEG C to 25 DEG C in bed both sides.This bed tempertaure changes and will show the gaseous mixture mixing completely.
Example 2
Mixing vessel with example 1 in similarly under condition, move, difference is that each mobile adjuster has the conical intermediate as shown in Fig. 4 A/4B.This mobile adjuster has been realized effect same as Example 1.
Comparative example A
The mixing vessel of contrast has mixing vessel same as Example 1, but does not flow adjuster.The rotation of reactant gases can cause bad mixing.In addition, reaction gas is known from experience without the center of mixedly flowing through mixing vessel.Ternary gas mixture is formed by reactant ratio same as Example 1, and the oxygen that comprises approximately 28.5% volume.Under similar reaction conditions, the bed tempertaure in bed both sides in catalyst bed changes greatly, is 35 DEG C to 100 DEG C.In the situation that not flowing adjuster, ternary gas mixture stream mixes bad.The increase of bed tempertaure has reduced the productive rate of prussic acid, and the by-pass flow that has improved reactant because of the cracking in catalyst bed.
Comparative example B
The mixing vessel of contrast has mixing vessel same as Example 1, but the adjuster that flows is not established intermediate.Reaction gas is known from experience without the center of mixedly flowing through mixing vessel.Ternary gas mixture is formed by reactant ratio same as Example 1, and the oxygen that comprises approximately 28.5% volume.With the similar reaction conditions of example 1 under, the bed tempertaure in bed both sides in catalyst bed changes greatly, is 35 DEG C to 100 DEG C.In the situation that there is no intermediate, ternary gas mixture stream mixes bad.The increase of bed tempertaure has reduced the productive rate of prussic acid, and the by-pass flow that has improved reactant because of the cracking in catalyst bed.
Comparative example C
The mixing vessel of contrast has mixing vessel same as Example 1, but does not establish mobile adjuster in the downstream of the annular entry of oxygen-containing gas.Once oxygen combines with methane and ammonia, just cannot stop the rotation of reactant gases.Ternary gas mixture is formed by reactant ratio same as Example 1, and the oxygen that comprises approximately 28.5% volume.With the similar reaction conditions of example 1 under, the bed tempertaure in bed both sides in catalyst bed changes greatly, is 35 DEG C to 100 DEG C.In the case of the downstream of the annular entry of oxygen do not establish the adjuster that flows ternary gas mixture stream exist mix bad.The increase of bed tempertaure has reduced the productive rate of prussic acid, and the by-pass flow that has improved reactant because of the cracking in catalyst bed.