CATALYST TO THE TC AND TNB MEASUREMENT WITH WATER TESTS AS WELL AS ITS USE

The invention concerns a procedure for the regulation that totally carbon (TC) - and totally nitrogen bound (TNb) - values of water tests, in particular of waste water samples, with which the water test is burned in the oxygen current at temperatures across 700 °C, led across a catalyst, separated from the water by condensation and examined then on CO2-Konzentration IR-spectroscopically and concerning the NO concentration by means of chemoluminescence and a calibration curve. The invention concerns auß erdem a catalyst for the employment with the regulation of TCund TNb values of water tests as well as procedures for the production in of auß EN heated reactors in heiß EN gas flow of applicable catalyst.

The TNb and TC-values are for the monitoring of the water quality of high force of expression. They are likewise very important for the current enterprise of a purification plant, because to this way the loads be promptly considered and the entire plant can be stopped to it. From the WHERE 94/07134 A1 is a procedure well-known, with which water tests are burned at temperatures over 700 °C in the oxygen current. The gases are led by the equipment, whereby into the reactor subordinate condensate separator the gas of größ ten part of the humidity one releases. It is to be planned also possible dryers separately, in order to take the residual moisture away. This well-known state of the art plans however only the determination of nitrogen, whereby first with the burn nitrogen monoxide develops. For this if a not neglecting portion of more oxygen-rich nitrogen oxides is present in the relationship, these are transferred in a NOx NO converter in nitrogen monoxide. Under addition of ozone the nitrogen monoxide is transferred in nitrogen dioxide, before it passes a chemoluminescence detector. The radiation energy determined here is proportional and permitted thus the original NO concentration its quantitative regulation. The DE-OS 42 31 620 describes a device, those the total content of organic carbon and of nitrogen in the water miß t. The measurement takes place in a gas analyzer, the two double-sided cuvettes with in each case a half for the Meß gas and a half for a comparison gas possess. Over addition of modulated rays of light chambers are through-radiated, which are filled with one of the components of the Gasprobe which can be determined in each case, an area with CO2 the other one with NO. the appropriate device than very complex and besides trouble-prone showed up, so that for the TNb portion the chemoluminescence method is essentially used, while CO2 is IR-spectroscopically determined according to separation the water. The chemoluminescence method is a comparative method, i.e. the TCbzw. the TNb content of a sample is determined by means of a calibration curve. The calibration according to DIN takes place consisting for the carbon regulation with a standard of Kaliumhydrogenphthalat (KHP) and consisting for the Stickstoffbestimmung of a mixture and pool of broadcasting corporations of 50% Kaliumnitrat (KNO3) and 50% ammonium sulphate ((NH4)_2SO4), with the burn process in this procedure the bound nitrogen is converted depending upon substance class differently well to nitrogen oxides. With some connections substantial nitrogen less findings are determined, since with the thermal decomposition more or less elementary nitrogen (N2) is set free, which withdraws itself from this detection procedure. Thus it is necessary to accomplish for a problematic material class a separate calibration. This is very complex and can make the whole procedure unattractive from the costs.

The invention is the basis from there the task, a procedure for determination reliable in service and the simple of the TCund of TNb values of water tests to create as well as a catalyst suitable for it and its simple manufacturing process.

The task becomes gemäß the invention by the fact solved that the uncooled gases are brought after the burn with a catalyst in connection, which the education is trained at the same time by nitrogen oxides depending upon substance continuously and the conversion of all carbon compounds quantativ as CO2 securing, whereupon by means of IR spectroscopy and chemoluminescence the TCund of TNb values is determined after pretreatment that gases.

With the help of erfindungsgemäß EN of procedure is first of all possible it to determine the TCund of TNb values with the help of the calibration method and/or the calibration curves without those arise above far negative characteristics descriptive with the state of the art, i.e. without any nitrogen less findings to determine is. Rather altogether and constant results gleichmäß iges classifying of the appropriate values, whereby for all material classes, also for the quite problematic material classes, a separate calibration must not be accomplished. It can work rather with a calibration and/or work a calibration curve, which brings substantial advantages for the total evaluation with itself. Responsible for it the developed catalyst as well as the certain guidance that are above all purposeful gases after the burn. It participates favourable that not only with the TNb regulation the regaining rates of different substances are continuous, but also with the TC-regulation. Thus a altogether optimal and thus regulation determination reliable in service of the TCund of TNb values can be realised, this in particular also, because the which is used catalyst converts carbon compounds quantitatively to CO2, so that they are to be evaluated likewise easily with well-known method.

After one zweckmäß it igen training of the invention is intended that the catalyst in one of auß EN heatable burn reactor between an upper and a lower layer quartz wool is fixed used. By this special arrangement and integration of the catalyst between the quartz wool layers the catalyst material is clamped favorably and so the mechanical abrasion with injecting the sample is prevented. Thus such procedures can be accomplished over long time with the same reactor, without a replacing of the catalyst material becomes necessary.

The procedure leaves itself with a catalyst particularly well realises, which is made of a granular pumice stone, to that with a mixture from cobalt nitrate, Ammoniumdichromat and water transferred, then dried and anschließ end at 1000 °C one glows. The pumice stone keeps surprisingly one gleichmäß ige layer all around, so that this catalyst can be used as described in the burn reactor surely and well working. The pumice stone is suitable due to its surface to take up appropriate quantities of cobalt nitrate and Ammoniumdichromat whereby from the glowing accordingly hard and surely adhering oxides result, which furnish and/or guarantee the descriptive effect of the catalyst.

The sufficient metallic oxide quantity can be attained in particular by the fact that the pumice stone with a blocking layer out with the glow procedure developing cobalt (II/CIII) - oxide and chrome (III) - oxide is provided, whereby the layers are produced in each case in separate coating procedures, in order to produce so in any case a sufficiently thick metallic oxide quantity on the surface of the pumice stone. The catalyst finished then is matt black colored and operational without further treatment and as described during long periods.

A catalyst optimally suitable for the employment with the regulation of TCund TNb values exists gemäß the invention from a porous substrate, on whose surface cobalt (II/CIII) - oxides and chrome (III) - oxides are applied. This applying the oxides is made by Brennbzw. Glow procedure, with ∼ 1000 °C. The appropriate catalyst grains or spherical particles are described like further in front, in the burn reactor between two fibre glass layers arranged and can notice so their task favourably, i.e. the influence and transformation of gases in CO2 and into different final connections, thus nitrogen connections, whose concentration becomes surely with the help of a simple calibration then possible.

Around one gleichmäß ige coating of the individual substrate grains to ensure, is intended that those cobalt (II/CIII) - oxides and chrome (III) - oxides as mixture on the substrate in two separated coating procedures are burned out, there in the first coating procedure possibly not gleichmäß ige coating thickness by the second coating procedure balanced will can. Thus it is guaranteed that all around a sufficient coating thickness is present, which possible the following employments in the burn reactor make.

As particularly zweckmäß iges substrate is erfindungsgemäß a pumice stone intended, which makes once a safe coating and on the other hand a safe employment possible as catalyst. It is intended that the substrate is a pumice stone of the granulation 0.5 - 5.0 mm, preferably 0.8 - 3.0 mm. Such a granulation can be processed also favourably well in the burn reactor, gives however because of that groß EN surface, particularly with later employment, the necessary working reliability in principle, even if the operating crew does not work as prescribed carefully.

It was described further above that the catalyst that for the TNb and TC-Meß rate important material in a double coating one lays on, whereby gemäß the invention on the substrate of a mixture of cobalt nitrate, Ammoniumdichromat and water consists each of the two layers, which after drying under transformation in cobalt (II/CIII) - oxide and chrome (III) - oxide is burned out. Important it is thus that with both coating procedures the same mixture is used, around the Gleichmäß igkeit the coating to ensure and an always safe operating result.

That far catalyst descriptive in front becomes in a certain way, i.e. in a certain procedure manufactured, what gives security that an always same catalyst is made available. This procedure is characterised by the fact that a porous substrate with a mixture from cobalt nitrate (CO (NO3)₂ · 6H2O), Ammoniumdichromat ((NH4)_2Cr2O7) and water shifts, after Abfiltern of the surplus mixture dried and anschließ end at 1000 °C one glows. The descriptive mixture can be applied in simple and safe way on the porous substrate, thus the pumice stone, in order to then cover by drying and burning its surface. The pumice stone with its rauen surface ensures then for the fact that the developing oxides adhere reliably and firmly.

In order to guarantee that the received catalyst grain quantity exhibits an always safe and effective coating, it is intended that the coating procedure einschließ lich glow procedure is repeated several times, preferably a second time. Over this double coating procedure a round around coating is guaranteed, at the same time however reached that the production process remains financially within limits, since a concrete check of the individual grains of the catalyst is redundant.

Oxidizing and/or the glowing the coating of the catalyst resulting in components is optimized by the fact that the substrate with the coating with 125 °C dried and anschließ end for ∼ 2 hours with ∼ 1000 one glows °C. It is prevented by the previous drying process of the substrate that water vapour is included within the coating. By this procedure guidance it remains guaranteed that the surface of the appropriate grain of the catalyst proves as continuous and smoothly.

Those according to mixture and also on the substrate mixture, which can be applied which can be treated, exists gemäß the invention from 10,0 g cobalt nitrate (CO (NO3)₂ · 6H2O) (34.4 mmol), 2.0 g Ammoniumdichromat ((NH4)_2Cr2O7) (7.9 mmol) and 8.0 g water, with ∼ 7.0 g pumice stone with a granulation of 0,8 - 3.0 mm one mixes. As already mentioned it is so possible, already with the actual coating procedure, thus mixing the substrate to give i.e. the pumice stone and the mixture an optimal coating on the surface of the pumice stone so that then with the following glowing also really a continuous and sufficiently thick layer on the substrate is present.

Gemäß Manufacturing process of the catalyst it is conceivable and favourable more einoder several times to evacuate the mixture from liquid and substrate. It is reached by brief evacuating that the liquid and/or the mixture penetrates into the substrate and/or penetrates this, so that the desired optimally secured surface already mentioned is reached.

The invention is characterised in particular by it that a procedure and a catalyst as well as a manufacturing process are intended, with which a new catalyst can be used in the range TCund TNb measurement and/or - regulation, optimal results made possible. In particular it is possible with the descriptive catalyst to leave and/or receive the education continuous from nitrogen oxides depending upon substance class, whereby it is guaranteed that the regaining rates of different substances are almost identical. This characteristic is desired, since for the concentration regulation of different N-connections only the DIN-conformal calibration is sufficient. Additionally the new catalyst converts carbon compounds quantitatively to CO2, so that a simultaneous determination of the parameters TC and TNb is made possible. It was shown that for the TC-measuring range between approx. 10 - 750 mg/l carbon and the TNb measuring range between 1 - 100 mg/l pleasing exact results can be attained nitrogen. Examples are farther back specified in addition.

For the explanation of the procedure for the measurement of the TCund of TNb values like also the special arrangement of the new catalyst further explanations were made on the basis the figures. Show:

Figure 1

a burn reactor in side view,

Figure 2

a catalyst grain on average in univalve execution,

Figure 3

the catalyst grain in clam-shell execution form and

Figure 4

a schematic rendition of the experimental assembly for the determination of the TCund of TNb values of water tests.

Figure 1 shows the burn reactor 1 in side view. A plug 2 is intended above, while the gas inlet for the oxygen with 3 is characteristic. With the burn reactor 1 it concerns a reactor, which is suitable for normal operation both for the pilot plant as well as. In the reactor interior farther back still more near described catalyst between a lower Quarzwollschicht 6 and an upper Quarzwollschicht is the 4 surely arranged. A mechanical abrasion is prevented by the gotten jammed building method with injecting the sample or also when flushing with other gases, particularly since the inflammation takes place nearly like an explosion.

In the range of the catalyst 5 a recessing 7 is recognizable, in which a thermocouple can be arranged, in order to be able to supervise the burn process exactly. The catalyst 5 flowing through gas, which results from the burn of oxygen and the water test, leaves the burn reactor 1 within the range of the Reaktorfuß it 8.

Figure 2 and 3 show in vergröß erter rendition the substrate 10, here in the form of 0,8 - 3.0 mm groß EN pumice stone grains, whose surface 10 with an oxide coating 12 is provided. Appropriate clarifies figure 2. during the execution after figure 3 is added a second layer 14 to the first layer 13, whereby both result in together the oxide coating 12, those all around as gleichmä&szlig as possible; industrial union the grain of the substrate 10 coats.

Figure 4 shows an experimental assembly, with that the oxygen over the flow regulating valve 9 into the Glasgefäß 18 one in-leads. The individual water test becomes over the Dosierer 16 by the sealing diaphragm 17 through into the interior of the Glasgefäß it 18 injected. By simultaneous introducing of oxygen this sample burns at short notice and the incineration gases can then far the quartz wool layer 4 and 6 be pulled through, whereby obligatorily the gases flow through the catalyst 5, whereby the catalyst 5 ensures that the carbon compounds are converted quantitatively to CO2, while the nitrogen oxides are continuously formed independently of the substance class, so that anschließ end the chemoluminescence method to be used can.

The gases flow through after leaving the Reaktorfoß it 8 a separator for condensate 19 with a condensate discharge opening 20 and a cooling 21, in order to dry in this way the gases as far as possible. The Nachtrockner 22 planned thereafter can be arranged before the division of the line or as shown within the range of the subordinate converter 24, where the nitrogen oxides are converted to nitrogen monoxide.

The chemoluminescence equipment is marked with 25, whereby the gases can divert over the gas discharge opening 30, while over the data line 28 the appropriate information can be transmitted directly to the data processing 26.

With 27 an IR spectrograph is marked and with 31 the discharge opening, where the CO2 leaves the equipment, while the appropriate data are likewise supplied to the data processing 26 by way of the data line 29, in order here fast and to be evaluated surely.

Following examples clarify, within which range and with what high regaining rate that erfindungsgemäß e procedure and with that erfindungsgemäß EN catalyst to be operated can. With TNb Mischstandard and TC-standard, i.e. with the two first tables the determined default values are shown, while the further tables clarify the high regaining rate.

With the following substances the problem of the fast aging of the set Ma&szlig steps; solutions up. Therefore the regaining rates are better in the Cund N-range with freshly set solutions.

With * marked values were not considered with the computations, there it itself either around Ausreiß it acts, or the measuring range is too small for the regulation.