PROCEDURE FOR THE CATALYTIC TRANSFORMATION FROM ISO BUTTER ACID TO METHACRYLSAEURE

The invention refers to a procedure for the transformation by oxide hydrogenation from ISO butter acid to Methacrylsäure. Regarding the oxide hydrogenation of low satisfied mono carbonic acids for production the appropriate C, S-insatiated acids is present a considerable state of the art. The first work in this area was the thermal influence of the oxide hydrogenation mentioned by the vapor phase reaction of the acid substrate with iodine and oxygen. This attempt did not receive much attention as potentially passable way for the technical execution of the associated reaction. This is to that extent understandably, when iodine is expensive, extremely corrosive characteristics exhibits and of the relative to problems regarding the complete recovery large quantities, which are necessary hievon in the procedure, cause gives. From the following state of the art the heterogeneous catalytic method is out seen, substantially more attractive for the execution of the oxide hydrogenation reaction, from the point of view of the potential technical applicability. The last state of the art in this area concentrated mainly on the use of two kinds of catalyst compositions for this purpose Is. A kind generally covers the Heteropolysäuren, of which a typical representative is 12-Molybdophosphorsäure, whereby if necessary in a similar structural arrangement the elements can be present vanadium and/or tungsten. The other kind of catalyst covers the systems, which have a calcined iron phosphate matrix together. Those the calcination of subjected Eisenphosphate are present in a multiplicity of crystalline phases or kinds. Although it is accepted that the pair of redox connected with the underlying reaction is to be attributed to the Eisenphosphat, could not be identified, which kind or which kinds is catalytically active. There is however signs available that an additional Metallkompenente favours the education of the catalytically active kind with the production. For example the US-PS Nr.3, 948.959 teaches that for this purpose a Alkalioder Erdalkali2s metal is effective as additional metal component. The invention is an advancement of the existing state of the art in this special area. Therefore concerns D e invention procedures for catalytic transformation of ISO butter acid to Methacrylsäure in course oxide hydrogenation reaction, whereby iron phosphate catalyst with gaseous filling stream containing ISO butter acid substrate and oxygen S0 with temperature ven 300 to 550°C in contact brought, which marked by is that oxide hydrogenation reaction in present modified Eiscnphosphatkatalysators empirical gram atomic formula FeM0, 01 _tPI_2 0x accomplished, where M stands for aluminum or gallium and the number of oxygen atoms bound to the other elements in their respective oxidation conditions, in which they in the catalyst are present, means x. In accordance with a special characteristic of the invention a catalyst is used, where M stands for that for aluminum and the gram atomic formula FeA1Q, 05 _0, 11 a catalyst assigned, where M stands for gallium and which remains active the gram atomic formula FaGa0,11 catalyst during long time periods. Contrary to the iron phosphate catalyst, which lost its activity in the course of the time, the catalyst modified with aluminum showed that it maintained its activity in attempts of 100 h duration. There is much number of techniques, which can be used for production according to invention of the catalyst usable in the procedure. One of these techniques, u.zw. the simplest method, is the production of the total composition before calcining. This can take place via that one uses the so-called Aufschlämmethode or precipitation method. The latter method covers the production of an aqueous solution of salts of the considered metals and phosphoric acid and the following neutralization with a suitable base, in order to precipitate the mixed Metallphospbate. The precipitation is preferably carefully washed, in order to remove all traces from lugs soluble in the water to, according to which it is dried before calcining. Alternatively one can add ammonium phosphate for the solution of the metal salts, in order to fall directly the Metallphesphate. As previously mentioned, can each water-soluble Eisenoder aluminum salt be used. Due to the favorable solubility characteristics however the nitrate salts are to be preferred, L the so-called Aufschlämmethode are still more favourably to be accomplished under other reasons, why them represent the preferential method in connection with the invention. After this procedure an aqueous solution Eisenund of aluminum salts as well as the Phosporsäure is manufactured. The solution is continuously heated up, until the mass cannot be agitated any longer longer. The arrears are then divided and heated up recently at moderate temperatures in the order of magnitude from for instance 120°C to the complete drying process. The dried mass is cut up on that and calcined. Suitable calcining temperatures lie generally in a range from 400 to 1000°C, in particular in a range from 400 to 850°C. In the course of each of these procedures a carrier catalyst can be manufactured, for example can with the Aufschlämmethode colloidal silicic acid or colloidal alumina or another form hievon before the distance of the water be admitted. If colloidal alumina is used, it can serve also as additional source for the aluminum cations, which improve the activity and the Langlebigkelt of the catalyst, which were observed in the iron phosphate catalyst modified with aluminum. Carriers, like alumina, silicic acid, titanium dioxide etc. can be admitted before the distance of the water. The carrier can also in a solution of the metal phosphate soaked and dries to be left. Tränkungsund drying stages can be so for a long time repeated, until the desired number of layers of the dried MetalIphosphats will receive, in the same way can in the descriptive alternative method the precipitation of the metal phosphates in presence of the suspended particles of the desired carrier take place. In typical technical catalyst production the spray drying is used, with which a Aufsehlämmung is supplied to a spray drier, according to which the dry product is tablettiert or calcined extruded and then. The new catalyst compositions can be used in a fluidized-bed reactor, in an agitating anchoring actuator or in a fixed bed reactor. Due to the advantages, which the use of a fixed bed reactor in the small firm offers, as example in connection with the invention such a reactor is used. In accordance with a preferential function the reactor filling consists of a gaseous mixture before-heated up of the substrate, molecular oxygen, steam and inert dilution gas. Usually a preheating temperature is used within the range of 300 to 350°C. A broad range from applicable reaction temperatures is to temperatures with 250 to 550°C, for the achievement of optimal Verfahrensbedlngungen from 350 to 450°C is usually used. The molar ratio from molecular oxygen to substrate is with 0,2 to 1.5, preferably with 0,5 to 1,0. Although for the execution of the reaction water vapour is not necessarily necessary, its presence in the filling leads to an improvement of the yield on desired product. An useful molar ratio from water to the substrate in the filling is with 1 to 75. The optimal relationship lies more in the order of magnitude of approximately 10 to a far important parameter is the concentration of the substrate in the filling. Expressed in mol % the concentration of the substrate generally lies in a range from 0,1 to 20%. By the point of view of the achievement of an acceptable throughput with an acceptable yield amounts to combined the concentration of the substrate in the filling 3 to 6 mol %. The concentration is controlled by in the filling stream the course genes quantity of water and of inert gas. The preferential dilution gas is nitrogen, although also different gases, like carbon dioxide, are suitable &5 ltelium, argon u.dgl. If it permits the desired concentration of the substrate, air can be naturally used as suitable diluted Oxydatlonsmittel. Another parameters drawable in consideration is the time of contact. The time of contact is defined divided as the catalyst volume by the volume fiasbeschiekung/s at reaction temperature. The catalyst volume is the mass volume. which of the catalyst in the reactor is taken. The expression catalyst in this sense covers not only the modifzierte Eisenphosphat, but also the firm diluent or the carrier, if such is present. hnnehmbare times of contact lie in a range from 0,05 to 50 s, in particular in the order of magnitude of 0,1 to 20 S. the reaction with atmospheric pressure are accomplished. Regulation 1: The above-mentioned Aufschlämmethode is described for the production according to invention of a catalyst useful for the purposes. Eisennitratnonahydrat in a quantity of 122 g was solved together with 11,33 g Aluminiumnitratnonahydrat in 250 ml water. For the solution of these metal salts under agitating phosphoric acid in a quantity of 42,4 g was added. The solution was agitated on that and heated up, until the largest quantity of water had evaporated. The resulting paste was further so for a long time dried with 125°C, until it could be divided, according to which the firm mass in 12 mm small or smaller parts of coming up skates and 16 h was calcined long in an air flow with 450°C. The calcined material was cut up and gesiebt before the use on a mesh size 12/20 (12/20 mesh). The empirical gram atomic formula calcined mixed Eisen-und of aluminophosphates is the following: FeA10, 11 regulation 2: It describes the production one with aluminum of modified iron phosphate catalyst with a higher relationship from phosphorus to aluminum than the catalyst in accordance with regulation 1st Eisennitratnonahydrat in a quantity of 610,0 g together with 62,2 g Aluminiumnitratnonahydrat in 1,2 to 1 distilled water was solved. Concentrated phosphoric acid was added in a quantity of 250 g. The remaining Arheitsweise corresponded in regulation to the i indicated. The empirical gram atomic formula calcined mixed Eisenund of aluminophosphates was the following: FeAI0, 11 regulation 3: It describes the production one with aluminum of modified iron phosphate catalyst of the empirical gram breath formula FeA10, to 05 quantity of 128,6 g together with 5,86 g Aluminiumnitratnonahydratin 250 ml distilled water was solved. Concentrated phosphoric acid was added in a quantity of 50,0 g. The remaining function entspraoh in regulation 1 the indicated. Regulation 4: It describes the production one with aluminum of modified iron phosphate catalyst of the empirical gram atomic formula FeAl0, to 11 empirical gram atomic formula like the catalyst in accordance with regulation i. this catalyst differs however from the catalyst in accordance with regulation i insoferne, when during the production the use of additional water was avoided. The catalyst in accordance with regulation 4 was manufactured by mixing 610 g Eisennitratnonahydrat and 56.65 g Aluminiumnitratnonahydrat. This mixture was heated up up to melting and shifted with 212 g 85 of iger phosphoric acid under agitating. The remaining function entspraoh in regulation the I indicated. Regulation 5: It describes the production one with gallium of modified iron phosphate catalyst of the empirical gram atomic formula FeGa 0.11 P 1.1 ex " Eisennitratnonahydrat in a quantity of 71,0 g together with 5,0 g Galliumnitratnonahydrat in 100 ml wet was solved. Then concentrated Phosphoräsure in a quantity of 24,8 g was added. The remaining function corresponded in regulation 1 to the indicated. Regulation 6: It describes the production one with gallium of modified iron phosphate catalyst of the empirisehen gram atomic formula FeGa0, i1 P 1.44 ex " Eisennitratnonahydrat in a quantity of 71,0 g together with 5,0 g Galliumnitratnonahydrat in 100 ml to water was solved and with 29,3 g of concentrated phosphoric acid shifted. The remaining function entspraeh in regulation 1 the indicated. Regulation 7: It describes the production of an iron phosphate catalyst, which had not been modified by additive of a Fremdmetalles. Eisennitratnonahydrat in a quantity of 101 g was solved in 200 ml water. Then concentrated Phosphoräsure in a quantity of 29,1 g was added. The remaining function corresponded in regulation 1 to the indicated. The empirical gram atomic formula of the calcined Eisenphosphats was FePOx. Example: It describes the use of the catalyst compositions of the preceding regulations at the time of the execution of the oxydativen dehydrogenation of ISO butter acid (IBA}. The reactor and the general way of the execution of the reaction were alike for everyone of the enumerated throughput. The catalyst became with quartz chips (1 volume part catalyst on 4 rel. - Parts of quartz chips) dilutes and into a conventional Abstrom tubular reactor brought. The tests were accomplished with 400 to 425°C. Function existed therein that a Beschiekung of of a before-warmed up mixture of ISO butter acid, oxygen, nitrogen and water vapour through, a stainless steel tube with an outside diameter of 13 mm (InnendurohmesL - _ more ser 9 mm) and a length of approximately 457 mm, which were passed through the test catalyst in form one cma packed bed, which was on the reaction temperature used in the respective throughput. The relationship from water to ISO butter acid in the filling amounted to 20:1, the relationship from oxygen to ISO butter acid 1:1, the time of contact lay in the order of magnitude of 0,4 to 0.5 S. these conditions results in a filling mixture containing to 4 mol % ISO butter acid, 78 mol % water, 4 mol % oxygen and 14 mol % dilution nitrogen. The Vorerhitzer consisted in a pipe length of stainless steel similarly the reactor pipe, which was packed with filasperlen however. The condensed organic product was taken up and analyzed by gas chromatography. The gaseous products were separately by gas chromatography examined. With individual throughput received of results are summarized in the following table. The received results regarding selectivity and transformation are likewise in this table eflthalten. The transformation is the molar ratio of the used up substrate to the substrate brought into the reactor. The selectivity against Methacrylsäure (MMA) represents the molar ratio of the Methacrylsäure found in the reactor discharge to that the IBA used in the reaction. The catalyst, whose production is descriptive in regulation 1 and was used in the way described in the example, in order to cause the oxide hydrogenation of ISO butter acid, was 100 h in enterprise, without showing indications of a deactivation. zo catalyst in accordance with regulation 1 1 1 1 2 2 3 3 4 4 6 7 7 temperature °C 401,406 4O2 399,420,420,421,399,408,409,409,416,397,413,412,411 table operation hours in the river 100 12 8 24 8 4 22 42 IBA transformation, 96 98 97 97 95 97 95 94 97 98 93 89 69 99 62 MAA selectivity, IL 69 69 68 67 73 69 67 69 72 67 53