WO2008151907A2 - Verfahren zur herstellung von melamin - Google Patents
Verfahren zur herstellung von melamin Download PDFInfo
- Publication number
- WO2008151907A2 WO2008151907A2 PCT/EP2008/056223 EP2008056223W WO2008151907A2 WO 2008151907 A2 WO2008151907 A2 WO 2008151907A2 EP 2008056223 W EP2008056223 W EP 2008056223W WO 2008151907 A2 WO2008151907 A2 WO 2008151907A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- catalyst
- melamine
- zeolite
- weight
- ppm
- Prior art date
Links
- 229920000877 Melamine resin Polymers 0.000 title claims abstract description 30
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 title claims abstract description 28
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 6
- 239000003054 catalyst Substances 0.000 claims abstract description 67
- 239000010457 zeolite Substances 0.000 claims abstract description 33
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 claims abstract description 28
- 229910021536 Zeolite Inorganic materials 0.000 claims abstract description 24
- 239000011159 matrix material Substances 0.000 claims abstract description 21
- 239000004202 carbamide Substances 0.000 claims abstract description 16
- XSQUKJJJFZCRTK-UHFFFAOYSA-N urea group Chemical group NC(=O)N XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims abstract description 16
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 15
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 13
- 239000002734 clay mineral Substances 0.000 claims abstract description 11
- 239000000654 additive Substances 0.000 claims abstract description 7
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 7
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 6
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 5
- YAIQCYZCSGLAAN-UHFFFAOYSA-N [Si+4].[O-2].[Al+3] Chemical class [Si+4].[O-2].[Al+3] YAIQCYZCSGLAAN-UHFFFAOYSA-N 0.000 claims abstract description 3
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims abstract description 3
- 235000012239 silicon dioxide Nutrition 0.000 claims abstract 2
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims abstract 2
- 238000000034 method Methods 0.000 claims description 36
- 239000000203 mixture Substances 0.000 claims description 13
- 238000005299 abrasion Methods 0.000 claims description 10
- 238000000354 decomposition reaction Methods 0.000 abstract description 4
- 239000007789 gas Substances 0.000 description 20
- 238000006243 chemical reaction Methods 0.000 description 16
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 14
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 8
- 230000015572 biosynthetic process Effects 0.000 description 8
- 238000003786 synthesis reaction Methods 0.000 description 8
- 229910021529 ammonia Inorganic materials 0.000 description 7
- 238000002360 preparation method Methods 0.000 description 7
- OWIKHYCFFJSOEH-UHFFFAOYSA-N Isocyanic acid Chemical compound N=C=O OWIKHYCFFJSOEH-UHFFFAOYSA-N 0.000 description 6
- XLJMAIOERFSOGZ-UHFFFAOYSA-N anhydrous cyanic acid Natural products OC#N XLJMAIOERFSOGZ-UHFFFAOYSA-N 0.000 description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 5
- 239000002245 particle Substances 0.000 description 5
- 229910052761 rare earth metal Inorganic materials 0.000 description 5
- 150000002910 rare earth metals Chemical class 0.000 description 5
- 239000010703 silicon Substances 0.000 description 5
- 229910052710 silicon Inorganic materials 0.000 description 5
- -1 aluminum silicates Chemical class 0.000 description 4
- 229910052739 hydrogen Inorganic materials 0.000 description 4
- 238000005342 ion exchange Methods 0.000 description 4
- 229910000323 aluminium silicate Inorganic materials 0.000 description 3
- 238000001354 calcination Methods 0.000 description 3
- 230000003197 catalytic effect Effects 0.000 description 3
- 239000005995 Aluminium silicate Substances 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 2
- 241000282326 Felis catus Species 0.000 description 2
- 229910052779 Neodymium Inorganic materials 0.000 description 2
- 229910052777 Praseodymium Inorganic materials 0.000 description 2
- 235000012211 aluminium silicate Nutrition 0.000 description 2
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 2
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 2
- 235000011130 ammonium sulphate Nutrition 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 238000006555 catalytic reaction Methods 0.000 description 2
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 2
- 239000004927 clay Substances 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000011065 in-situ storage Methods 0.000 description 2
- 229910052809 inorganic oxide Inorganic materials 0.000 description 2
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 2
- 229910052746 lanthanum Inorganic materials 0.000 description 2
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 229910052566 spinel group Inorganic materials 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 description 2
- FIDRAVVQGKNYQK-UHFFFAOYSA-N 1,2,3,4-tetrahydrotriazine Chemical compound C1NNNC=C1 FIDRAVVQGKNYQK-UHFFFAOYSA-N 0.000 description 1
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 241000282836 Camelus dromedarius Species 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- MXRIRQGCELJRSN-UHFFFAOYSA-N O.O.O.[Al] Chemical compound O.O.O.[Al] MXRIRQGCELJRSN-UHFFFAOYSA-N 0.000 description 1
- 229920005372 Plexiglas® Polymers 0.000 description 1
- 238000010306 acid treatment Methods 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical class [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- VXAUWWUXCIMFIM-UHFFFAOYSA-M aluminum;oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Al+3] VXAUWWUXCIMFIM-UHFFFAOYSA-M 0.000 description 1
- 229910001680 bayerite Inorganic materials 0.000 description 1
- 239000000440 bentonite Substances 0.000 description 1
- 229910000278 bentonite Inorganic materials 0.000 description 1
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
- 229910001593 boehmite Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 150000001728 carbonyl compounds Chemical class 0.000 description 1
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- GUJOJGAPFQRJSV-UHFFFAOYSA-N dialuminum;dioxosilane;oxygen(2-);hydrate Chemical compound O.[O-2].[O-2].[O-2].[Al+3].[Al+3].O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O GUJOJGAPFQRJSV-UHFFFAOYSA-N 0.000 description 1
- 229910001648 diaspore Inorganic materials 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012013 faujasite Substances 0.000 description 1
- 238000005243 fluidization Methods 0.000 description 1
- 229910001679 gibbsite Inorganic materials 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910000271 hectorite Inorganic materials 0.000 description 1
- KWLMIXQRALPRBC-UHFFFAOYSA-L hectorite Chemical compound [Li+].[OH-].[OH-].[Na+].[Mg+2].O1[Si]2([O-])O[Si]1([O-])O[Si]([O-])(O1)O[Si]1([O-])O2 KWLMIXQRALPRBC-UHFFFAOYSA-L 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052901 montmorillonite Inorganic materials 0.000 description 1
- 239000012452 mother liquor Substances 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910001682 nordstrandite Inorganic materials 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004926 polymethyl methacrylate Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 229910052903 pyrophyllite Inorganic materials 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 125000004436 sodium atom Chemical group 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 238000000859 sublimation Methods 0.000 description 1
- 230000008022 sublimation Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 230000000725 urealytic effect Effects 0.000 description 1
- 239000002966 varnish Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
- 238000010626 work up procedure Methods 0.000 description 1
- 238000004876 x-ray fluorescence Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D251/00—Heterocyclic compounds containing 1,3,5-triazine rings
- C07D251/02—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
- C07D251/12—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
- C07D251/26—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
- C07D251/40—Nitrogen atoms
- C07D251/54—Three nitrogen atoms
- C07D251/56—Preparation of melamine
- C07D251/60—Preparation of melamine from urea or from carbon dioxide and ammonia
Definitions
- the invention relates to a process for the preparation of melamine by thermal decomposition of urea and catalytic reaction of the resulting isocyanic acid and the use of a specific catalyst in such a process.
- melamine resins by reaction with carbonyl-containing compounds.
- the resins are used, inter alia, as plastics and in paints and varnishes.
- the production of melamine by decomposition of urea is a known reaction used by the chemical industry in several variants. In principle, a distinction is made between the high-pressure and the low-pressure method.
- the high pressure process is carried out at pressures of> about 80 bar (abs.) And temperatures> 370 0 C, wherein the melamine synthesis takes place in a non-catalytic manner.
- the low pressure process is carried out at pressures of about 1 to 10 bar (abs.) And temperatures of 370 to 430 0 C with catalysis.
- the reaction takes place in two steps. In the first, endothermic step, urea decomposes into ammonia and isocyanic acid, which in the second, exothermic step trimerizes to melamine with the release of CO 2 .
- the following equations reflect the individual reactions.
- the DSM Stamicarbon process is a one-step process that is carried out at about 7 bar (abs.).
- the catalysts used are aluminum silicates or zeolite-containing catalysts which are used in a fluidized bed.
- the fluidizing gas is pure ammonia, which is recovered from the workup stage.
- the fluidized bed is also used, alumina or alumina / silica catalysts being used.
- the gas used for the fluidized bed is the cycle-derived circulating gas containing NH 3 and CO 2 , which has previously been freed of impurities.
- active catalysts for melamine synthesis can be obtained by mixing Al 2 O 3 with zeolites or zeolites with metal cations.
- Zeolite-containing catalysts for melamine synthesis are also available from Albemarle Corporation (USA) under the designation CAMEL 25®.
- the object of the invention is to provide a process with which high conversions and melamine yields can be achieved, in particular when using a mixture of ammonia and CO 2 as fluidizing gas.
- the object is achieved by a process for the catalytic production of melamine by decomposition of urea on zeolite-containing catalysts which contain a low content of nickel and vanadium.
- the invention therefore provides a process for the preparation of melamine by decomposition of urea using a catalyst, wherein the catalyst
- zeolite a) 10 to 90% by weight of zeolite, b) 10 to 90% by weight of a matrix containing silica, alumina, silicon-aluminum oxides and / or clay minerals, and c) 0 to 10% by weight of additives
- Another object of the invention is the use of said catalyst for the production of melamine.
- the catalyst used according to the invention contains as main components zeolite, a matrix of silicon and / or aluminum oxide and / or clay minerals, and optionally additives.
- the zeolite component (a) preferably contains synthetic zeolites of the faujasite type, more preferably Y and silicon-rich Y zeolites, optionally also in a mixture.
- zeolites are used which have been subjected to ion exchange, ie the original sodium atoms are replaced by hydrogen and / or rare earth metals (SE) (H, SE or H, SE-Y zeolites).
- SE rare earth metals
- the sodium content (as Na 2 O) is generally ⁇ 1% by weight.
- ammonium sulfate or rare earth chloride solutions are generally used for the H and SE form.
- the NH 4 form generally obtainable via ion exchange with ammonium sulfate solutions, is heated to convert to the H form, whereby NH 3 escapes.
- the proportion of rare earth metals is generally 0-20, preferably 0-15 wt .-%.
- rare earth metals lanthanum (La), cerium (Ce), neodymium (Nd) and praseodymium (Pr) are preferable. Particularly preferred is a mixture of lanthanum and cerium with lower levels of neodymium and praseodymium.
- the Si / Al ratio of the zeolite is generally between 2 and 8, preferably 3 and 6, more preferably about 5 for conventional Y zeolite and between 10 and 15, preferably 11 and 12 for silicon-rich Y zeolites (SR-Y).
- the size of the unit cell is generally between 2.460 nm and 2.465 nm for the Y zeolites, and about 2.450 for silicon-rich Y zeolites.
- the size of the zeolite crystals is generally 0.5 to 5 ⁇ m.
- the zeolite component of the catalyst may also contain mixtures of different zeolites, for example a mixture of Y zeolite and silicon-rich Y zeolite or additions of ZSM-5 zeolite, mordenite, offretite or silicalite.
- the proportion of zeolite in the catalyst is generally from 10 to 90 wt .-%, preferably 10 to 60 wt .-%, particularly preferably 12.5 to 50 wt .-%, most preferably 15 to 40 wt .-%.
- the preparation of the zeolite component is carried out by known methods known to the person skilled in the art, as described, for example, in Atlas of Zeolite Structure Types, W.H. Meier and D.H. Olson, 3rd Ed. Butterworth-Heineman, 1992.
- the zeolite component can also be formed in situ together with the matrix component.
- the matrix component (b) contains silica, alumina, aluminosilicates and / or clay minerals. It is a porous, inorganic oxide matrix that bonds the other components, provides abrasion resistance and may even contribute to catalytic activity.
- the matrix component (b) usually contains a synthetic fraction, such as amorphous silica, alumina or aluminosilicate, and a natural portion, usually one or more clay minerals. If the zeolite component is prepared in situ from calcined clay, the matrix component also usually contains calcined clay.
- a synthetic fraction such as amorphous silica, alumina or aluminosilicate
- a natural portion usually one or more clay minerals. If the zeolite component is prepared in situ from calcined clay, the matrix component also usually contains calcined clay.
- the matrix optionally contains boehmite, pseudo-boehmite, diaspore, ⁇ , ⁇ , ⁇ , ⁇ , ⁇ and p alumina or aluminum hydroxides, such as gibbsite, bayerite, nordstrandite and doilite.
- the matrix component optionally contains one or more optionally modified clay minerals, such as kaolin, bentonite, attactogen, montmorillonite, hectorite and pyrophyllite.
- the clay minerals are optionally subjected to mild base or acid treatment prior to use in the matrix to remove contaminants and interfering metal ions.
- a calcination of the clay minerals for example, a conversion of kaolin into a spinel / mullite mixture by calcination at about 1000 0 C and subsequent leaching with base.
- the catalysts according to the invention generally have a BET surface area of 50-800, preferably 100-600, particularly preferably 150-400 m 2 / g
- amorphous silica containing matrix components usually additionally contain one or more natural clay minerals, and matrix components of modified, preferably calcined clay minerals.
- the proportion of the matrix in the catalyst used according to the invention is generally from 10 to 90, preferably 40 to 90, particularly preferably 50 to 85 wt .-%.
- the catalyst used according to the invention typically contains from 0 to 10% by weight of additives.
- additives examples include inorganic oxides, such as magnesium oxide, mixed oxides of rare earth metals and spinels, for example cerium-doped spinels.
- the catalysts used according to the invention are characterized by a low content of Ni and V.
- the total content of these metals is ⁇ 500 ppm, preferably ⁇ 200 ppm, more preferably ⁇ 100 ppm, most preferably 0 to 50 ppm.
- the catalyst is substantially free of Ni and V.
- the preparation of the catalyst is carried out by known, familiar to those skilled in the process.
- the catalyst can be produced in a known manner from an inorganic sol mixed with the zeolite component and further additives by drying, ion exchange, calcination and subsequent steam treatment.
- the matrix and zeolite components of the catalyst generally have a different average pore size.
- the mean pore size of the matrix is generally 0.4 to 500 nm, preferably 0.5 to 250 nm, more preferably 5 to 50 nm.
- the average particle size d 50 of the catalyst is generally below 300 .mu.m, preferably between 10 and 200 .mu.m, more preferably between 40 and 100 .mu.m, wherein the fines (d ⁇ 10 microns) is preferably as low as possible.
- catalysts may be subjected to the abrasion test described below. As a result, it provides an abrasion rate which describes the strength of the particles.
- a precisely weighed sample of the catalyst (m 0 , catalyst), which is prescreened with a 45 micron sieve, placed on a 32 micron sieve with 192 mm diameter.
- a slot nozzle (0.5 mm slit width) rotates at a distance of 10 mm at 32 rpm "1 , from which 100 m 3 -h " 1 nitrogen escapes at the speed of sound.
- the catalyst which has been accelerated by the jet, bounces against a Plexiglas lid, which is 8 mm above the screen.
- the sample material is subjected to intensive mechanical stress. The trial period is 3 hours.
- the resulting abrasion comes out with the gas through the mesh.
- the mass of the remaining particles is determined quantitatively at intervals of about 15 minutes by weighing.
- the abrasion rate AR expressed in g-kg "1 -h " 1 , is calculated as the quotient of the mass loss within the last hour of the test m A b ⁇ eb [gh "1 ] and the mass of the catalyst remaining after the experiment m Ka taiysator trial end [kg]:
- Suitable catalysts for fluidized bed processes have an abrasion rate of less than 60 g-kg "1 -h " 1 , preferably less than 30 g-kg "1 -h " 1 .
- the abrasion rate of the catalyst is generally ⁇ 20 g / kgh, preferably ⁇ 15 g / kgh, more preferably ⁇ 10 g / kgh, especially 1-7 g / kgh
- the catalyst belongs to the so-called Geldard group A (D. Kunii, A. Levenspiel, Fluidization Engineering, 2nd edition, Butterworth-Heinemann, 1991).
- urea is thermally decomposed in a first step to form isocyanic acid and ammonia, and the isocyanic acid formed is subsequently trimerized catalytically with the release of CO 2 to form melamine.
- Both reaction steps are preferably carried out in one reactor, but they can also be carried out in two separate reactors.
- the process is preferably carried out as a fluidized bed process. It is in general at temperatures of 350 to 450 0 C, preferably 380 to 420 0 C, an absolute pressure of generally 1 to 15 bar, preferably 1 to 10 bar, in particular 1, 5 to 8 bar, a residence time over the Fluidized bed of 1 to 50 s, preferably 2 to 30 s and a catalyst loading of 20 to 700 kg urea / t (cat) • h, preferably 50 to 500 kg urea / t (cat) • h operated.
- the fluidizing gas used is pure NH 3 or an NH 3 / CO 2 mixture, the mixture used in the latter case predominantly being the mixture formed during the synthesis.
- the educt urea is preferably introduced into the reactor as a melt.
- heat is supplied to the reaction mixture, preferably via heating coils in which a molten salt circulates.
- Catalyst particles can be retained in the reactor by cyclone separators.
- the formed in the synthesis, gaseous melamine is isolated from the fluidizing gas by quenching with aqueous mother liquor ("washing with water”) and subsequent crystallization or by cooling the reaction gases with cold reaction gas (sublimation).
- the gas mixture can be cooled from the reactor into a first gas cooler to a temperature at which by-products (eg Meiern) crystallize and the precipitated by-products are deposited together with the catalyst dust contained in the gas stream in gas filters. Then the filtered gas stream in a crystallizer with process gas having a temperature of about 140 0 C, are mixed, wherein the melamine crystallized in a purity of at least 99.9%.
- by-products eg Meiern
- the melamine prepared in this way can generally be reacted directly without further purification steps, for example for the preparation of melamine resins by reaction with carbonyl compounds.
- urea was converted to melamine at a temperature of about 400 ° C.
- the amount of fluidizing gas (NH 3 / CO 2 ) was about 110 Nm 3 / h.
- Catalyst 1 (Comparative Example 1) is a zeolite-containing, commercially available for melamine synthesis catalyst with a Ni / V content of 3900 ppm in the batch tested.
- Catalyst 2 (Comparative Example 2) is a zeolite-free catalyst based on Si (VAI 2 Os having a Ni / V content below the detection limit which was 100 ppm (measurement method: X-ray fluorescence).
- Catalyst 3 (Example 1) is a zeolite-containing catalyst according to the invention with a Ni / V content of ⁇ 100 ppm.
- the zeolite-free catalyst shows a similar conversion as the catalyst of the invention, but has other disadvantages such as grain (“Geldart B” leads to poorer heat transfer coefficients and thus poorer heat transfer into the fluidized bed) and an unfavorable Abriebsindex.
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- Organic Chemistry (AREA)
- Catalysts (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
RU2010100912/04A RU2535350C2 (ru) | 2007-06-14 | 2008-05-21 | Способ получения меламина |
US12/664,426 US8415265B2 (en) | 2007-06-14 | 2008-05-21 | Method for producing melamine |
EP08759828A EP2158187A2 (de) | 2007-06-14 | 2008-05-21 | Verfahren zur herstellung von melamin |
UAA201000304A UA102521C2 (ru) | 2007-06-14 | 2008-05-21 | Способ получения меламина |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP07110305.5 | 2007-06-14 | ||
EP07110305 | 2007-06-14 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2008151907A2 true WO2008151907A2 (de) | 2008-12-18 |
WO2008151907A3 WO2008151907A3 (de) | 2009-04-09 |
Family
ID=39967208
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2008/056223 WO2008151907A2 (de) | 2007-06-14 | 2008-05-21 | Verfahren zur herstellung von melamin |
Country Status (7)
Country | Link |
---|---|
US (1) | US8415265B2 (de) |
EP (1) | EP2158187A2 (de) |
AR (1) | AR067019A1 (de) |
CL (1) | CL2008001772A1 (de) |
RU (1) | RU2535350C2 (de) |
UA (1) | UA102521C2 (de) |
WO (1) | WO2008151907A2 (de) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA2832887A1 (en) | 2011-04-11 | 2012-10-18 | ADA-ES, Inc. | Fluidized bed method and system for gas component capture |
WO2014047354A1 (en) | 2012-09-20 | 2014-03-27 | ADA-ES, Inc. | Method and system to reclaim functional sites on a sorbent contaminated by heat stable salts |
CN106902799B (zh) * | 2017-02-17 | 2020-03-27 | 鲁西催化剂有限公司 | 一种合成高铝硅胶的制备方法 |
CN114887657B (zh) * | 2022-06-10 | 2024-01-26 | 宁波中科远东催化工程技术有限公司 | 一种合成三聚氰胺的催化剂及其制备方法 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1992009585A1 (en) * | 1990-11-29 | 1992-06-11 | Dsm N.V. | Process for the preparation of melamine from urea |
WO2004065371A1 (de) * | 2003-01-17 | 2004-08-05 | Basf Aktiengesellschaft | Zweistufiger reaktor für die melaminsynthese |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20010070002A (ko) * | 1999-07-29 | 2001-07-25 | 고오사이 아끼오 | 내산성 촉매 시트 및 이의 제조방법 |
EP2072504A1 (de) * | 2007-12-20 | 2009-06-24 | DSMIP Assets B.V. | Herstellungsverfahren für Melamin |
RU2361669C1 (ru) * | 2007-12-26 | 2009-07-20 | Открытое акционерное общество "Новомосковский институт азотной промышленности" | Способ получения катализатора для синтеза меламина из карбамида |
-
2008
- 2008-05-21 WO PCT/EP2008/056223 patent/WO2008151907A2/de active Application Filing
- 2008-05-21 RU RU2010100912/04A patent/RU2535350C2/ru not_active IP Right Cessation
- 2008-05-21 US US12/664,426 patent/US8415265B2/en not_active Expired - Fee Related
- 2008-05-21 UA UAA201000304A patent/UA102521C2/ru unknown
- 2008-05-21 EP EP08759828A patent/EP2158187A2/de not_active Withdrawn
- 2008-06-13 AR ARP080102559A patent/AR067019A1/es not_active Application Discontinuation
- 2008-06-13 CL CL2008001772A patent/CL2008001772A1/es unknown
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1992009585A1 (en) * | 1990-11-29 | 1992-06-11 | Dsm N.V. | Process for the preparation of melamine from urea |
WO2004065371A1 (de) * | 2003-01-17 | 2004-08-05 | Basf Aktiengesellschaft | Zweistufiger reaktor für die melaminsynthese |
Non-Patent Citations (1)
Title |
---|
DATABASE CAPLUS [Online] CHEMICAL ABSTRACTS SERVICE, COLUMBUS, OHIO, US; JIANG, YI ET AL: "Study on the preparation of the catalysts for synthesis of melamine from urea" XP002513760 gefunden im STN Database accession no. 2001:442523 in der Anmeldung erwähnt & TIANRANQI HUAGONG , 26(2), 23-25, 56 CODEN: THTKEF; ISSN: 1001-9219, 2001, * |
Also Published As
Publication number | Publication date |
---|---|
US8415265B2 (en) | 2013-04-09 |
US20100184976A1 (en) | 2010-07-22 |
AR067019A1 (es) | 2009-09-30 |
RU2535350C2 (ru) | 2014-12-10 |
WO2008151907A3 (de) | 2009-04-09 |
EP2158187A2 (de) | 2010-03-03 |
RU2010100912A (ru) | 2011-07-20 |
UA102521C2 (ru) | 2013-07-25 |
CL2008001772A1 (es) | 2009-09-25 |
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