DE102009006319B3 - Corrosion potential determining method for e.g. coal in fossil-fueled power station, involves analyzing measured process parameters and filling probe, and timely-resolved evaluating corrosion potential of fuel based on analysis - Google Patents

Abstract

The method involves loading an experimental reactor with a sample of a fuel, and guiding a reaction gas from bottom to top through a fuel bed. The fuel is ignited, and filling probes are brought into an exhaust gas path of the experimental reactor. Measured process parameters and the filling probe are analyzed, and corrosion potential of the fuel is evaluated based on the analysis in a time-resolved manner. The filling probes are brought at three measurement points in a combustion chamber (7) of the experimental reactor and/or in a chimney (20) at an outlet of the combustion chamber.

Description

The The present invention relates to a method for fuel corrosion diagnosis and the use of pad probes in fuel corrosion diagnostics.

The Electricity and heat generation by burning fossil fuels such as gas and coal in power plants has been operating for a long time and is currently in spite of the knowledge about not replace the limited resources.

conditioned through this knowledge are in the search for alternative sources of energy In recent years, increasingly wind and solar energy as well other alternative sources of energy moved into the spotlight of interest. To these alternatives fuels belong on the one hand biomass, which is either dried and burned directly or can be converted into biogas, which in turn serves as a fuel serves. For another thing More and more garbage in our society, also as energetic high-quality substitute fuel can be used, which is already in the numerous waste incineration plants in operation happens.

As a "substitute fuel" or short "EBS" is doing generally a for the energy recovery of processed and ready-to-use, quality-monitored fuel from waste designated. Basically different one between substitute fuels made from liquid waste such as waste oil or solvents and those made from solid waste, which are usually made non-recyclable plastics, paper, textiles, composite packaging or similar be prepared specifically.

Thus, while incinerators are not new developments and many of the technical and environmental issues associated with them have already been addressed, such as flue gas cleaning, desulphurisation, etc., the substitution of fossil fuels with CO ₂ -neutral fuels is becoming increasingly interesting for plant operators. However, there have been new problems with the introduction of the above-mentioned new fuels.

From ecological, but also for economic reasons Point of view, it is imperative that power plants have a high energy efficiency exhibit the limited available To use fuels optimally.

the faces the problem that in combustion power plants the components that are directly connected to the Fuel or the exhaust gases come into contact, of course, a increased Corrosion are subject, since these materials the z. T. corrosive Combustion products at high temperatures and extreme conditions are exposed.

By increased Deposit formation on the heat exchanger surfaces and by the resulting corrosion on steam generator tubes the efficiency of the plants is reduced because of the heat transfer coefficient of these materials is significantly lower than that of the original used Metals and alloys. The dynamics of corrosion thereby achieved orders of magnitude up to 1.0 mm / 1 000 h, which requires regular maintenance of the equipment, the travel times of the facilities are shortened and significantly reduces the cost-effectiveness of the systems.

The Corrosion reduction, or ideally prevention, is thus a central task in the planning and operation of a combustion power plant and can be made more resistant both by the use of protective layers Materials such. B. job-welded or thermally sprayed Nickel-based alloys or ceramic materials are made as also through predictive maintenance.

• • wenn die Druckstufe deutlich über 40 bar gewählt wird,
• • wenn die Endüberhitzung des Frischdampfes deutlich über 400°C gewählt wird,
• • wenn der Brennstoff hohe Frachten an chlorhaltigen Stoffen und/oder geringe Frachten an schwefelhaltigen Stoffen aufweist,
• • wenn die Brennstoffmerkmale – Chemie, Feuchte, Heizwert – stark schwanken.

In order to estimate the corrosion potential prevailing in a plant, some empirical correlations have emerged in the past as generally true, but they also T. preclude an increase in efficiency. Accordingly, the corrosion increases,

• • if the pressure level is chosen well above 40 bar,
• • if the final superheat of the live steam is clearly above 400 ° C,
• • if the fuel has high loads of substances containing chlorine and / or low loads of substances containing sulfur,
• • if the fuel characteristics - chemistry, humidity, calorific value - fluctuate greatly.

One An essential element of corrosion reduction is therefore also the Assessment of the fuels themselves, taking appropriate measures can be taken for corrosion protection.

While the Evaluation of conventional fossil fuels is known, so that the corrosion of the equipment minimized during operation by suitable measures and on experience with regard to possible travel times, firing conditions and the like resorted to Biomas se fuels and substitute fuels have different characteristics in terms of pollution and corrosion as "difficult To estimate fuels. This is all the more so than the fuel quality of biomass and EBS strong Batch fluctuations may be subject.

The target of the plant operators Substitution of fossil fuels by biomass and EBS is therefore not readily possible.

The Evaluation of the fuels to be used with regard to the formation of deposits and corrosion potential - before the use - in the respective incinerator is an important prerequisite for plant designers in the planning of new plants, but also for plant operators, which fossil Substitute fuels with biomass fuels and / or EBS want.

It is necessary to limit corrosion risks in advance and estimate since by the avoidance / reduction of corrosion an increase of Energy efficiency and plant availability can be achieved.

The Determination of the corrosion potential in incinerators currently by identifying various parameters before, during and after the use of fuel in the respective plant.

• • Diagnose am Brennstoff,
• • Diagnose im Betrieb und
• • Diagnose durch Begutachtung bei Stillständen.

One differentiates thereby the

• • diagnosis of fuel,
• • Diagnosis during operation and
• • Diagnosis by inspection at standstill.

Already before the use of the fuel there is the possibility of an analysis of the fuel-technical properties of the operating materials, in addition to physical and chemical also the caloric and reactionary Properties are recorded.

The Fuel-technical properties thus include both the determination combustible / non-combustible part of fuels, content on fleeting Components and an elementary and trace analysis, as well as the Determination of kinetic data, eg. B. to release the volatile Components of the ignition and burnout behavior.

in this connection is taken into account, that the ignition and burnout behavior in addition to the actual kinetic data of a number of parameters such as the content of volatile constituents, the particle size distribution, the thermal conductivity and other firing parameters.

So was used in investigations on the ash melting behavior of mixtures from lignite and substitute fuels found that the temperature difference tends to be from the softening point to the pour point of Brown coal over the blends with EBS down to the individual EBS ever smaller but not proportional to each other as expected. The hemisphere temperature For example, the mixtures can also have larger values assume as the two starting fuels. Also for the formation of and corrosion potential are not reliable predictions about the S / Cl ratio alone possible, as in the ash melting behavior tests of mixtures, where a simple mixture calculation of ash melting points is not possible, too here the fuel chemistry and the process conditions for release of chlorine play a crucial role.

adversely is thus that the corrosion potential of the fuel is not by one size alone, z. B. by the chlorine content, express, but as a sum parameter to understand that over the fuel-technical properties goes out and also by the process engineering conditions are influenced.

Also while of the operation other parameters that influence the corrosion potential of the fuel, be determined, where z. B. Temperature, Heat Flow, Ash-Salt Proportion (ASP) and deposit formation with a pad monitor or a pad probe be measured. The difficulty of these measurements is to one in poor accessibility the measuring points in the combustion chamber and the online evaluation of the measuring parameters.

Furthermore can These measurements only after combustion to determine the corrosion potential of the fuel are used, so that preventive, corrosion-preventing or corrosion-reducing measures can not be applied or only with a time delay.

The third possibility for determining the corrosion potential of a fuel is also the the simplest but also the most accurate way of to evaluate the formation and corrosion potential. It is Inspection and sampling of the plant during downtime. However, you can in this type of data acquisition only conclusions about already occurred damage to parts of the system like evaporators and heat exchangers to be pulled. Early detection from negative influences to the plant or the suitability of the fuel for the respective plant is with the help of this method not or only after already collected positive or negative experiences with the fuel possible.

Further can when feeding the plant with different fuels only hard conclusions on the corrosion potential of individual fuels are drawn.

In summary can Although individual properties of a new fuel, the corrosion potential influence, be determined in advance, the determination of an actual Corrosion potential in use, however, is currently with the disposal standing methods are not possible.

It There is therefore a need for a continuous development of the tools for weighting from risks of pollution and corrosion to difficult too Fuels with the highest possible To use energy efficiency in electricity generation without legal thresholds for issue or promotion to exceed alternative energies, not least as possible long travel times of the plants are in the foreground.

• – Beschicken einer Versuchsvorrichtung mit einer Probe des Brennstoffs (Einsprühen über Düse in Vergaser/Verdampferrohr);
• – Vermischen des eingesprühten Brennstoffs mit einem Reaktionsgas (Frischluft vermittels Ventilator);
• – Entzünden des Brennstoffs (Zündelektroden);
• – Bereitstellen einer Prüffläche im Brenn-/Abgasweg der Versuchsvorrichtung, wobei ein Plasma im Bereich der Prüffläche entsteht und die Temperaturen des Brennstoffs und der Prüffläche gemessen werden;
• – Analyse der gemessenen Verfahrensparameter und der Prüffläche; und
• – Bewertung des Korrosionspotentials anhand der Messwerte;
• – wobei ferner eine Prüffläche verwendet wird, die metallen ist und aus einem für den Brennerbau geeigneten Material besteht.

In the EP 1 466 171 B1 A method for determining the corrosion potential of a fuel (low-sulfur fuel oil) is described with the steps

• - Loading a test device with a sample of the fuel (spraying through nozzle in carburetor / evaporator tube);
• - Mixing the sprayed fuel with a reaction gas (fresh air by means of a fan);
• - ignition of the fuel (ignition electrodes);
• - Providing a test area in the combustion / exhaust path of the experimental device, wherein a plasma is formed in the test area and the temperatures of the fuel and the test area are measured;
• - analysis of the measured process parameters and the test area; and
• - evaluation of the corrosion potential on the basis of the measured values;
• - In addition, a test area is used, which is metal and consists of a suitable material for burner construction.

The Object of the present invention is therefore to provide a method for Determination of the corrosion potential of fuels and the use of pad probes in this method, which makes it possible to detailed the combustion process and the exhaust as well as the simultaneously forming coverings dependent on to examine the respective fuel and by means of the measured data of the Coating probe to determine its corrosion potential before this Fuel is burned in a plant.

The Task is solved by the method according to claim 1 and those described in the dependent claims Embodiments, and the use of a lining probe according to claim 11.

at continuously operated grate systems with moving grate, as they usually do industrially used in combustion power plants, run the substeps Drying, degassing and gasification of the fuel and residual burnout of the fuel Solid along the reaction path (rust length) almost simultaneously.

at These rust systems can in particular the oxygen concentration, the temperature and the Residence time independently be controlled from each other along the reaction path. Basic However, studies on a continuous grate system are due to the high duration of the experiment very expensive and not practical.

In contrast, is the experimental reactor is a facility suitable for particulate and granular fuels is and is to simulate real operation on a model scale. In its the simplest form is the experimental reactor, for example a batch reactor, the fuel is added discontinuously and the individual Process steps during this time in a row in a transient operation expire.

Gaseous, liquid and dusty fuels can Of course also burned in model or experimental burning chambers and her Corruption potential can be determined.

In spite of the different reaction conditions and process parameters in real reactors and experimental reactors arising solely on the basis of different size sizing surrendered, surprisingly found that investigations on the corrosion potential of fuels carried out in experimental reactors and the results afterwards can be transferred to continuously operated reactor types.

hereby is enabled the corrosion potential of a fuel taking into account the discussed above complex relationships before his large-scale Use to determine energy production, so that appropriate activities to prevent or reduce corrosion damage Incinerator can be taken. These measures can for example, the injection of excipients, the addition of additives or even the addition of starting fuels.

• – Beschicken eines Versuchsreaktors mit einer Probe des Brennstoffs;
• – Durchströmen der Brennstoffschüttung von unten mit einem Reaktionsgas;
• – Entzünden des Brennstoffs;
• – Einbringen mindestens einer Belagssonde in den Abgasweg des Reaktors;
• – Analyse der gemessenen Verfahrensparameter und der Belagssonde
• – zeitaufgelöste Bewertung des Korrosionspotentials

By using a batch-driven test grid, the experimental effort for determining the corrosion potential can thus be significantly reduced, the method according to the invention thus comprising the steps:

• - loading a pilot reactor with a sample of the fuel;
• - Flowing through the fuel bed from below with a reaction gas;
• - igniting the fuel;
• - introducing at least one lining probe in the exhaust path of the reactor;
• - Analysis of the measured process parameters and the pad probe
• - Time-resolved evaluation of the corrosion potential

Instead of a rust reactor can Of course Other suitable types of reactor such as ignition furnace, downpipe and slagging reactor be used, the reaction gas and air supply and the Fuel input to be adapted to the reactor type. So can for gaseous, liquid and also dusty solid fuels Combustor systems, for granular-solid fuels Fluidized bed systems and for pasty Fuels rotary kiln systems are used.

When Reaction gas is the gas which is fed to the process, wherein in combustion reactions, the reaction gas usually air is. Dependent on However, the reaction conditions and the desired reaction can as reaction gas also oxygen or oxygen / carbon dioxide mixtures, for example, in the oxyfuel process, or for gasification reactions only Steam or carbon dioxide are supplied.

The Ignite of the fuel is preferably carried out by supplying thermal energy over the Reactor walls. Particularly preferably, the reactor walls are already in front of the entry of Fuel preheated, so that the reaction conditions a continuous become more similar to the working reactor and the for the measurements available Period is extended because dead times that arise because of the reactor must first reach the operating temperature minimized become.

Just Otherwise, in small pilot reactors with a small amount of fuel the risk of highly erroneous measurements since during the entire measurement process the necessary reactor and exhaust gas temperature is not achieved. Especially important for the corrosion potential Salts and salt deposits would in such a case not recorded, as the temperatures for their sublimation can not be reached.

at The combustion in the experimental reactor is at least one place in the furnace a lining probe for a period of from 1 second to 300 seconds, preferably from 3 seconds to 45 seconds, brought in.

Around the corrosion potential of the exhaust stream throughout the reactor and If necessary, to determine in the fireplace, pad probes are preferably at least three different measuring points, more preferred at least four measuring points, and more preferably at least five measuring points, brought in.

Further can over the timing of combustion several measurements are made also about the changes the corrosion potential as fuel burns to be able to analyze. Preferably, at least two measurements take place in regular time Distances over the Course of the combustion. To further eliminate measurement errors, be prefers two to five individual measurements at each measurement point at each measurement point carried out. This approach is advantageous because in the present offline measurement the assignment of the probes can not be recognized immediately and the Failure of a single measurement due to poor occupancy would cause significant errors.

By this type of measurement can be the fuel with respect to its Korrorionspotentials both locally as well as temporally dissolved be rated.

When Paddle probe can be any suitable and below those in the reactor existing conditions inert material can be used, wherein the material is chosen that will be the later Analytics not influenced.

When Metal wire meshes have particularly preferably been used as a cover probe It has to be made sure that the probes are not due to of charge or other effects attract the particles, but Only those particles deposit on the probe whose Trajectory hits the probe. The diameter of the wire that the Tissue of the probe forms, preferably between 5 microns and 50 microns, on preferably between 10 microns and 40 μm, and more preferably between 20 microns and 30 μm.

Of the Advantage of this pad probes for determining the depositing corrosive ingredients is that these probes easily can be dimensioned and a complex preservation of the individual samples is not required is.

Next the identification of corrosive deposits by means of the pad probes are advantageously during try also the temperatures and the pressure at different Measuring points of the furnace and / or the fireplace measured, preferably spatially with the temperature measuring points those of the lining probe correlate. In addition, heat flow can and other reactor specific parameters using methods known to those skilled in the art be determined.

• a) Klebrige Salzschmelzen, die sich als Schicht auf der Sondenoberfläche ablagern.
• b) Feine feste bzw. verklebte Partikel und gesprosste Kristalle.
• c) gröbere Partikel wie inerte Aschen, z. B. silikatische Schmelzkügelchen oder sonstige Grobpartikel.

The analysis of the pad probes can with each However, the probes are preferably analyzed by means of SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-Ray Analysis), whereby a distinction is made essentially between three types of coatings:

• a) Sticky salt melts, which deposit as a layer on the probe surface.
• b) Fine solid or sticky particles and spiked crystals.
• c) coarser particles such as inert ashes, e.g. B. silicate melt pellets or other coarse particles.

Of the spatial resolution There are no limits to the REM-EDX, but they are per pad probe preferably 5-50, especially preferred 8-30, and more preferably 10-20 Point analyzes made.

Of the Evaluation of the corrosion potential is based on the assumption that Substantially causal for this Parameters compounds of chlorine are partly responsible, wherein also heavy metals (eg lead, zinc and copper) and alkali metals (Sodium, potassium), as well as calcium are significantly involved. Further is sulfur due to its interactions with the chlorine compounds to take into account. Thus opened From a material point of view, a broad field of corrosion relevant Elements in the fuel. Depending on the cargo, mutual proportions and bonding modes of the elements is the fuel itself from corrosion technology View as more or less difficult to classify.

Further It is assumed that the main responsibility for the corrosion of the system elements From the flue gas deposited deposits are. Because of the process step firing the above freights, proportions and binding types changed in the fuel Freight, proportions and types of bonds are transmitted in the flue gas, the fuel is thus also indirectly responsible for the deposits and their corrosivity.

Vice versa But so can the deposits, which are on the Coarse lining probes from the flue gas, conclusions on the corrosion potential fuel.

One high proportion of chloride-containing salt melts in the lining of the probe thus indicates a high corrosion potential of the fuel, while a low chlorine content or a high sulfate content classifies the fuel is less difficult in terms of expected corrosion damage allow.

In a preferred embodiment are also used to assess the corrosion potential thus determined the data obtained by classical physicochemical analysis considered.

In A final step of the present process may be due to adapted to the corrosion potential determined in this way the fuel is admixed with additives and / or fuel mixtures be mixed with less corrosion potential.

in the Case of high release of corrosive coverings, the first occurs at high temperatures or with advanced combustion, For example, you can adjust the temperature of the system or the Residence time of the fuel in the reactor can be shortened.

The following embodiment is intended to illustrate but not limit the present process.

1 schematically shows an experimental reactor for combustion and analysis of fuels according to claim 1.

2 shows SEM images (MAG = 1.50 KX, EHT = 20.00 kV, Detector = SE1) of pad probes after sampling in the experimental reactor ( 2a ) and in operation in a fluidized bed reactor ( 2 B ).

• • V1-Wirbelschicht, Diagnose im Betrieb 65%/35% (FWL)-Mischung (Feuerungswärmeleistung-Mischung);
• • V2-Wirbelschicht, Diagnose im Betrieb 75%/25% (FWL)-Mischung; und
• • V3-Versuchsreaktor, Diagnose am Brennstoff 50%/50% (FWL)-Mischung.

The 3a and 3b show the comparison of the results of the chemical analysis for magnesium, silicon, chlorine and sodium of the dot and small area measurements of the deposited particles on the paddle probe with:

• • V1 fluidized bed, diagnosis in operation 65% / 35% (FWL) mixture (combustion heat output mix);
• • V2 fluidized bed, diagnosis in operation 75% / 25% (FWL) mixture; and
• • V3 pilot reactor, diagnostic on fuel 50% / 50% (FWL) mixture.

• • Der Brennstoff wird kalt in den Reaktionsraum gegeben, dessen Wände vorher auf eine Temperatur (800°C bis 900°C) aufgeheizt wurden.
• • Die Brennstoffschüttung wird von unten nach oben von einem Reaktionsgas durchströmt.
• • Die für den Kohlenstoffumsatz notwendige hohe Reaktionstemperatur wird durch Strahlungswärmeübertragung von den Wänden auf den Feststoff und das Gas erreicht.
• • Mit steigender Temperatur nehmen die Reaktionsgeschwindigkeit und der Kohlenstoffumsatz zu.
• • Bei einem ausreichend hohem Umsatzstrom werden die Wände weiter aufgeheizt. In diesem Fall wird Wärme vom Brennstoffbett auf die Feuerraumwände übertragen.
• • Mit zunehmendem Kohlenstoffumsatz nimmt die reaktive Oberfläche des Brennstoffes und damit die Freisetzung der chemischen Energie wieder ab.

To determine the corrosion potential of a fuel, it was burned and analyzed in a pilot reactor as follows.

• • The fuel is added cold into the reaction chamber, the walls of which were previously heated to a temperature (800 ° C to 900 ° C).
• • The fuel bed is flowed through from bottom to top by a reaction gas.
• • The high reaction temperature required for carbon conversion is achieved by radiant heat transfer from the walls to the solid and gas.
• • As the temperature increases, the reaction rate and carbon turnover increase.
• • If the flow of electricity is sufficiently high, the walls will continue to heat up. In this case, heat is transferred from the fuel bed to the furnace walls.
• • With increasing carbon turnover, the reactive surface of the fuel and thus the release of the chemical energy decreases again.

Of the the further course of the reaction is from the energy stored in the bed dependent. For a fuel with low storage capacity (low inert content) the temperature of the bed decreases as a result of the cooling effect of the reaction gas quickly, so that the reaction at comparatively high residual carbon contents stops ("cold bubbles").

Has the fuel is a big one Heat storage capacity (high inert content), the cooling is slower. The necessary reaction temperature can longer be maintained so that the embedded in the inert bed carbon can be implemented further. The residual carbon content at the end decreases continue down.

1 shows the construction of the experimental reactor, which consists of a mobile retort ( 6 ) and a fixed firebox ( 7 ). Firebox and retort are lined with refractory material and an insulating layer ( 8th ). The free cross section in the furnace and retort is 415 × 265 mm. Retort and combustion chamber consist of four segments, which are referred to below as segment 1 (rust retort) to segment 4 (uppermost segment of the combustion chamber). The rust retort can be moved on rails under the firebox. At the bottom of the retort is the primary air supply ( 4 ). At the retort, the corresponding pressure loss at five measuring points above the grate or the solid bed and the retort wall temperature can be measured.

The interior of the retort is down through the grate ( 9 ) limited. On the one hand, the grate carries the fuel bed and, on the other hand, it has to realize a low rust rate reduction with a uniform distribution of the primary air. This is aimed at here by a free grate area of about 4%, the free grate area representing the ratio of open gaps on the grate (through which the primary air flows from below) to the entire grate area.

The Column size and number the rust is chosen so that on the one hand reaches a sufficient flow velocity of the primary air and on the other hand ensures a good distribution of the reaction gas becomes.

In dependence From the required test conditions, the rust before the experiment in height be adjusted. The temperature measurement takes place in the fuel bed by means of four thermocouples. On the grate itself is a Measuring point for measuring the temperature of the grate.

The firebox ( 7 ) is formed of the segments 2, 3 and 4, which are bolted together and sealed by flange, and are supported by a anchored in the ground support structure made of section steel. In each segment of the combustion chamber, measuring points for measuring pressure and temperature ( 13 ). Segments 2 and 4 contain additional measuring points for exhaust gas analysis ( 13 ). In segment 3 there are also two nozzles ( 5 ), in which the lances are attached for the secondary air line. At the lower edge of segment 2 is a nozzle with sight glass for visual flame monitoring in the combustion chamber ( 14 ) appropriate.

in the Subsequently, paddle probes were isokinetic in the experimental reactor and in a fluidized bed plant, the real operation of a combustion reactor corresponds, sampled. In addition, paddle probe measurements were carried out in both Plants performed. The Sampling was identical and at similar temperature conditions (about 300 ° C), to the results on the experimental reactor with those of the fluidized bed plant to be able to compare.

Depending on the removal position (measuring opening in the boiler) and the given exhaust gas temperature separates - isokinetic - the freight of the physically (solid, liquid) and material (silicates, oxides, chlorides, sulfates, hydroxides, etc.) different particles of the raw gas. The different particle types (coarse and fine particles, especially salt melts relevant to corrosion) form significant microstructures on the probe.

The mineralogical evaluation of these sedimentary structures and the chemical data from point and small area measurements of the deposited Particles lead to a differentiated condition assessment of the participants in the pavement structure Particles of the raw gas at the sampling position.

2 shows exemplary recordings of the pad probes, which were created with the aid of scanning electron microscopy (SEM). Although visually differences of the deposited on the pad probe particles are recognizable, but the structure of the particles is very similar. In most cases, it is rough to fine, usually solid particles, salt melts are not visible at first glance.

The discernible differences are partly due to the fact that the paddle probe measurement in the experimental reactor with a fuel mixture of 50% hard coal and 50% wood pellets and in the fluidized bed system with a fuel mixture of 65% hard coal and 35% wood pellets or 75% / 25%, in each case based on the rated thermal input (FWL).

outgoing from the sedimentation structure the chemical data from point and small area measurements of the deposited Particles examined.

As in the 3a and 3b can be seen, shows the comparison of measurements - experimental reactor and fluidized bed plant - for magnesium, silicon, chlorine and sodium that in the measurements in operation, ie in the real process and in the measurements on the experimental reactor, ie the simulation of the process control of the real process , similar results are achieved so that they are transferable.

The chemical data from point and small area measurements of the deposited Particles from the paddle probe measurements in the experimental reactor and in the fluidized bed plant are of the same order of magnitude as well so that the pavement formation and Corrosion potential correlate well and with the present method Conclusions on the Corrosion potential of a fuel in large-scale plants based of preliminary tests in the experimental reactor and subsequent evaluation of the plaque sampling can be pulled.

1

fan

2

regulation the air supply

3

orifice

4

Primary air supply

5

Secondary air supply

6

retort with rust

7

firebox

8th

refractory and insulating material

9

rust

10

height adjustment A grate

11

temperature measurement in a solid bed

12

exhaust pipe

13

measuring port for temperature and pressure measurement and exhaust gas analysis

14

sight glass

15

support structure

16

1. quench

17

emission control

18

Second quench

19

exhaust fan

20

fireplace

Claims (14)

Method for determining the corrosion potential of a fuel, characterized in that it comprises the steps of: - charging a pilot reactor with a sample of the fuel; - Flowing through the fuel bed from below with a reaction gas; - igniting the fuel; - introducing at least one lining probe in the exhaust path of the reactor; - Analysis of the measured process parameters and the lining probe: and - Time-resolved assessment of the corrosion potential on the basis of the measured values. Method according to claim 1, characterized in that that pad probes at least three measuring points in the furnace and / or Chimney be introduced at the exit of the combustion chamber of the reactor and the measuring time is between 3 s and 45 s. Method according to claim 1 or 2, characterized that measurements with the pad probes over the time course incineration at regular intervals, whereby at least two measurements take place. Method according to one of the preceding claims, characterized characterized in that the temperature in the fuel bed, in the firebox and / or measured at the entrance and / or exit to the chimney, wherein preferably the temperature measuring points in the vicinity of the measuring points the lining probes lie. Method according to one of the preceding claims, characterized characterized in that the exhaust gas is chemically analyzed. Method according to one of the preceding claims, characterized characterized in that the analysis of the pad probes with a SEM-EDX analysis he follows. Method according to one of the preceding claims, characterized characterized in that in a SEM-EDX analysis per pad probe 5-50, preferably 8-30, and more preferably 10-20 Point analyzes are made. Method according to one of the preceding claims, characterized characterized in that in a SEM-EDX analysis, the measurement results be divided into the group of salt melts, the fine or bonded particles and coarse particles. Method according to claim 8, characterized in that that molten salts, in particular chloride-containing molten salts, Indicator of high corrosion potential. Method according to one of the preceding claims, characterized characterized in that at a high corrosion potential process engineering Sizes adjusted become. Using a pad probe according to a method according to one the claims 1 to 10, characterized in that the lining probe a wire mesh is. Use according to claim 11, characterized that the wires of the wire mesh have a diameter of 20 microns to 30 microns. Use according to claims 11 or 12, characterized that the lining probe is analyzed by means of SEM-EDX. Use according to one of claims 11 to 13, characterized that in a SEM-EDX analysis per pad probe 5-50, preferred 8-30, and more preferably 10-20 Point analyzes are made.