Chemical apparatus and process disinfecting – deodorizing – preser – Analyzer – structured indicator – or manipulative laboratory... – Means for analyzing gas sample
Reexamination Certificate
1999-07-09
2003-03-25
Warden, Jill (Department: 1743)
Chemical apparatus and process disinfecting, deodorizing, preser
Analyzer, structured indicator, or manipulative laboratory...
Means for analyzing gas sample
C422S086000, C422S083000, C436S037000, C436S181000, C436S178000, C436S167000
Reexamination Certificate
active
06537500
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a process for the detection of a product in the discharge of a catalytic material of a plurality of catalytic materials which are exposed to a reaction gas.
The development of new, especially more effective catalysts is required to improve the yield of many standard processes. In order to produce and characterise catalysts, the potentially active carrier and catalyst components are combined in a supposedly suitable manner and the multi-component mixtures thus created are tested with a suitable test reaction under defined conditions usually determined by technical limitations. Whilst the synthesis of such materials can often still be managed with reasonable time consumption, the testing of the catalysts on the contrary represents a very time- and labour-consuming step. The material to be tested is generally poured into a laboratory test reactor specially designed for the purpose and tested under prescribed parameters for its suitability for the given conversion of an educt mixture.
Gas chromatographic or spectroscopic methods are chiefly used to characterise catalysts. These methods, however, have only a limited suitability for the simultaneous testing of many catalysts. Whereas gas chromatography has the drawback that it requires a certain period of time, the spectroscopic methods have the drawback that, in the case of complicated reactions, they give insufficient information about the selectivities of the catalysts. Both methods also have the drawback that they only function sequentially and involve an elaborate and costly analysis.
Nonetheless, progress has been made with the applicability of both these methods. Through the computer-controlled combination of several columns, for example, an improvement has been achieved in the analysis quality and the analysis speed in gas chromatography (Stockinger, J. H., Callen, R. B., Kaufman, W. E., J. Chromatogr. Sci. 16, 1978, 418).
The use of spectroscopic methods for characterising samples is described in connection with a process for investigating chemical reactions in reactors connected in parallel (Windhab, N., Miculka, C., Hoppe, H.-U., DE 196 32 779).
A method of testing catalyst pellets with the aid of infrared thermography has also been published (Moates, F. C., Somani, M., Annamalai, J., Richardson, J. T., Luss, D., Willson, R. C., Ind. Eng. Chem. Res. 35, 1996, 4801). This method, however, is limited to reactions with great heat of reaction. An additional drawback with this method lies in the fact that, with partial oxidations for example, the hottest catalyst is not the one with the greatest selectivity for the desired product.
WO 97/32208 describes a catalyst testing process, in which a plurality of differently composed catalysts in the form of pellets or suchlike are arranged in a multi-cell holder and brought into contact with an inflow of a mixture. The measurement takes place spectroscopically, thermographically or with the aid of other commonly used measuring methods, whereby the measurement is always carried out directly on the catalysts.
DE 196 33 779 A1 describes a process for investigating chemical reactions in miniature reactors connected in parallel. The supplied educt is led past a catalyst in each case, as a result of which a reaction mixture arises which in turn is passed in each case into a cell drill-hole and separated out via the latter. For the measurement, an infrared beam extends in each case through one of the cell drill-holes which are arranged in the manner of an nxn matrix.
In the light of the prior art, the problem of the present invention is to make available an economically practicable process for the detection of a product in the discharge of a catalytic material of a plurality of catalytic materials which are exposed to a reaction gas, in order to establish the selectivity and activity of the catalytic materials.
Furthermore, the problem of the invention is to provide a method for the testing of catalytic materials that is as cost-effective, simple and efficient as possible.
The process should further be able to be carried out without taking a great deal of time and effort.
BRIEF SUMMARY OF THE INVENTION
These problems, as well as other problems not explicitly stated but which can readily be derived or inferred from the context discussed herein, are solved by the measures described in claim
1
. Expedient modifications of the process according to the invention are protected in the sub-claims related back to claim
1
.
By disposing an adsorbent selective for the product to be determined in the discharge of each catalytic material, which changes at least one of its properties through the contact with the product to be determined, and then by ascertaining the change in the property of the adsorbent, it is possible to ascertain the selectivity and activity of the catalytic materials.
On the one hand, the process is cost-effective and efficient, and on the other hand the process can be carried out without taking a great deal of time and effort.
The arrangement for the analysis can be spatially separate from the catalytic material. The analysis of the products can thus be carried out by means of methods that cannot be used under the reaction conditions of the catalytic conversion, because for example the adsorbent is not stable at the temperatures at which the catalysed reaction must take place. If the adsorbent is not destroyed by the selected reaction conditions, it can however also be spatially very close to the catalytic material.
By means of a suitable arrangement of various adsorbents, different products of the catalytic reaction can be determined simultaneously. It is thus possible in a very elegant manner to determine, apart from the activity of a catalytic material in respect of a desired product, also the concentration of undesired by-products, so that the selectivity of the catalytic material can also be determined.
Preferred forms of embodiment of the process according to the invention are characterised by the fact that the adsorbent is a solid or a liquid applied to a solid carrier.
Preferably, an optical property, especially in the infrared, visible or ultraviolet region, is changed by the contact with the product to be determined.
It is particularly preferable for a colour change to occur through the contact of the adsorbent with the product of the catalytic conversion to be determined, so that for example a colour formation or a decolourisation can be ascertained.
It is further preferred that the property of the adsorbent changing through the contact with the product to be determined is a fluorescence.
A further property that can be changed by the contact with the product to be determined is the weight of the adsorbent.
A further preferred modification of the process according to the invention employs the temperature of the adsorbent to determine a product of the catalytic reaction.
A further property of the adsorbent that can be changed by the contact with the product to be determined is the refractive index of a liquid applied to a solid carrier.
Furthermore, the pH of the adsorbent is a property that can be changed by the contact with the product to be determined, especially when the adsorbent is a liquid applied to a solid carrier.
It is particularly preferable for a change in the conductivity of the adsorbent to occur through the contact with the product to be determined.
The product to be determined can also be dissolved out of the adsorbent with the aid of a solvent, after which a property, such as for example the refractive index, the pH value and the conductivity, of the solution thus obtained is determined.
Preferred forms of embodiment of the process according to the invention are characterised in that the product to be determined is maleic anhydride and the adsorbent is an N,N-dimethylindoanyline applied in ethanol solution onto a filter paper, whereby the colour of the adsorbent changes from blue to colourless upon contact with the maleic anhydride.
In a preferred form of embodiment of an adsorbent described above, re
Brenner Armin
de Oliveira Armin Lange
Schunk Stephan
Schuth Ferdi
Stichert Wolfram
Heslin Rothenberg Farley & & Mesiti P.C.
hte Aktiengesellschaft
Siefke Sam P.
Warden Jill
LandOfFree
Process for the detection of a product in the discharge of a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for the detection of a product in the discharge of a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the detection of a product in the discharge of a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3024495