FR2529472A1 - NEW TYPE OF CATALYTIC TEST MICROUNITIS WITH SAMPLE VALVE SAMPLING SYSTEM - Google Patents

Abstract

THE INVENTION RELATES TO AN APPARATUS OF MICROCATATEST TYPE ALLOWING TO DETERMINE IN A FIXED BED THE ACTIVITY OF A CATALYST AT ANY TIME. IT INCLUDES IN COMBINATION A LOAD INJECTION SYSTEM, A TUBULAR REACTOR WITH A FIXED CATALYST BED, A GAS FLOW MEASURING SYSTEM AND A TAKE-OFF VALVE SYSTEM. THE APPLIANCE CAN BE USED IN PARTICULAR FOR REFINING OPERATION ANALYZES.

Description

Several units of the conventional fixed bed microcatatest type have already been

  described in the prior art: the charge generally injected by a pump passes simultaneously with a carrier gas on a fixed bed of catalyst placed in a tubular reactor; at the outlet of the latter, the effluents are recovered in liquid form in a cold trap and in gaseous form in a gas ampoule; an overall mass balance of the operation is obtained by determining the total mass of liquid products and the total volume of gaseous effluents collected, followed by the chromatographic analysis of each of the two phases. This conventional method at the equipment level requires however the separate analysis of two phases, a liquid and another gaseous and allows to perform a single measure of activity by balance sheet; Other types of units have been described in the prior art such as on-line analysis of the effluents by chromatography at the outlet of the reactor; this system has the advantage of studying the activity of the catalyst in the very first moments of its setting in regime, but a long chromatographic analysis prohibits then to obtain several

  points on close measurement times.

  The new apparatus, which is the subject of the present invention, comprises

  Many advantages over previous systems: thanks to the successive hot sampling of effluent by means of a set of chromatographic valves placed in series or in parallel with the reactor outlet, this particular system makes it possible to

  instantaneous analyzes on a very short time; indeed,

  Conventional standards require a much longer injection time in order to

  emulate a sufficient quantity of products for a correct analysis.

  this hot sampling system avoids the separation of two liquid and gaseous phases and their separate analysis. finally, it allows several samples to be taken in a very short time and to store them hot while waiting for their subsequent analysis; this hot storage avoids condensation of products

heavy on the walls of the valve.

  This process is therefore particularly interesting to follow

  rapid deactivation or activation of a catalyst.

  The apparatus, object of the present invention comprises a supply zone (1), a reaction zone (2) with gas flow control (15), a sampling zone (3) with a gas sampling system. Analysis of each of the sampling valves The number of valves can be between 2 and 8, preferably 3 and 6; the originality of the invention comes from the pooling of a conventional microcatatest system (feeding zone

  reaction and flow control) with a sampling system

  effluent analysis and analysis by sampling valves

  cement allows to obtain in a single manipulation several measures of activity, selectivity and therefore stability of a catalyst in

the weather.

  The charge (7) injected by a syringe pump (6) passes through

  line (8) simultaneously with a carrier gas (arriving via

  9) in a preheating zone (11) and then on the bed

  catalytic (12); the preheating and the reaction medium are now

  kept at a constant temperature by a regulated oven (10); the effluent collection system placed at the outlet of the reactor comprises a thermally controlled oven (3) in which is stacked a series of valves (14); during the test, these are closed one by one, thus isolating in a known volume capacity a certain amount of effluent; the principle of closing these valves, operated by means of a key (13) 3., is by the advancement of a conical piston pushing the capacity to a second fixed cone; it has been described in French Patent No. 6910998 filed April 10, 1969 by ELF-ERAP; the non-trapped gas stream continues to circulate around the periphery of the capacitance; the flow rate of the gases (16) can be measured by a mercury-seal volumeter (15) the trapping of the effluents being carried out, the contents of each trap are analyzed by chromatography (5): (transfer carried out by the arrow symbol 4) the The sampling valve (18) is pre-heated on the valve analysis circuit in a furnace (17). On the one hand, the six-way valve eliminates the air present on the perimeter of the capacity by sweeping with a gas. carrier to the outside, on the other hand to connect the trap with the analysis system; the capacity is then open, releasing the effluents to the chromatography column; each valve waiting

  is stored in the thermally controlled sampling furnace (3).

  It should be noted that this system has the advantage of being easily adaptable to other analysis devices (mass spectrometry,

infra-red or ultra-violet).

SCOPE OF THE PRESENT INVENTION.

  This system, object of the present invention can be used for multiple applications at atmospheric pressure or under pressure, in particular A) in refining catalytic cracking hydrocracking reforming hydroisomerization hydrogenation B) in petrochemistry

  aromatic transformation (isomerisation, dismuta-

tion, hydrodealkylation).

  various oxidations (oxidation of toluene to benzaldehyde,

methanol to formol).

  C) in CO + H 2 chemistry (synthesis gas treatment) synthesis of methanol conversion of methanol into hydrocarbons

  conversion of CO + H 2 to higher alcohols.

EXAMPLES.

  The following examples illustrate the invention and relate to catalytic cracking in a fixed bed of cyclohexene over catalyst.

  zeolitic at atmospheric pressure.

  Example 1 relates to a reproducibility test on three cracking tests made under the same conditions, each of the four

  samplings being carried out at identical times.

  Example 2 relates to a volume reproducibility test

  trapped after a fifteen day hot storage.

  Example 3 is the same as before but with

  storage of a cold valve for fifteen days.

EXAMPLE 1

  Three cyclohexene cracking tests are performed in

  the same conditions in the fixed bed reactor under atmospheric pressure.

  at a temperature of 5000 C The reactor is loaded with

  one gram of zeolitic catalyst; from zero time, the cyclo-

  hexene is injected at a constant rate by a syringe pump, is entrained with a carrier gas on the catalytic bed where it is converted; the cracking effluents then pass into the four sampling valves stacked in the furnace heated to 2000 C. A valve is closed every two minutes; at the end

  the catalytic test, the valves are transferred one by one onto the

  chromatography or their content is analyzed.

  The waiting valves remain in the hot oven; Table 1 gives the results obtained for three completely identical tests with

  four samples taken every two minutes; the reproducti-

is less than 1%.

EXAMPLE 2

  Under the same conditions as above, we proceed to the cracking of cyclohexene on equipment equipped with four sampling valves; we take two samples closing each

two times simultaneously.

  One of the two valves of a sample is analyzed immediately

  while the other is kept warm for a fortnight and then analyzed. Table 2 shows that the reproducibility remained 1%, despite the long hot residence time of the valves in the furnace.

sample.

EXAMPLE 3

  The previous test is again carried out, but with the cold storage for fifteen days of one of the two valves of a sample, the results show that the reproducibility is much worse,

  which shows the importance of hot storage of the sample valves

pling.

TABLE 1.

  e = 500 ° C / Atmospheric pressure / VVH = 0 55-1 TEST (1) j TEST (2) TEST (3) Time t 1 t 2 t 3 t 4 t 1 t 2 t 3 t 4 t t t 2 t 3 t 4 sampler = 2 mn 4 min 6 mn 8 nin 2 mn 4 mn E 6 mn8 nin2 mn 4 nin 6 mn 8 mn Conversion 93 5 92 5 91 5 90 5 93 5 92 5 91 5 90 6 93 3 92 5 91 5 90 4

% ME,

  Methyl cycilo-pentenes 43 8 45 45 46 4 44 4 45 7 46 4 43 9 45 1 45 6 46 3 Zmol __ I _ _ Methyl cyci o-II pentane 17 8 16 4 15 6 14 8 117 7 16 5 16148117 7 16 3 15 3 14 7 Zmol _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 5 dd; 5 d; 5 5 5 j; chromaogra x 10 x 105 x 10 x 10 x 10 x x x 10 x x x 105 x 105 x 10

TABLE 2.

  1st pair of valves 2 nd pair of valves t 1 = 2 min t 2 = 4 min valve analyzed valve stored valve analyzed valve stored immediately hot (15 d) immediately hot (15 d, conversion 93 4 93 4 92 6 92 5 Total area of the peaks of 301000 300000 296000 295000 chromatogrdphie

TABLE 3.

  1st pair of valves 2nd pair of valves t 1 = 2 min t 2 = 4 min valve analyzed cooled valve valve analyzed valve cooled immediately (15 days) immediately (15 days) Conversion 93 3 70 92 7 60 Total area 296000 220000 304000 180000 peaks

Claims (3)

  1. Test apparatus operating at atmospheric pressure or under pressure and comprising in combination   a) a system for injecting (1) a load.   b) a fixed catalyst bed reactor (2).   c) a gas flow measurement system.   d) a system (3) of N sampling valves placed in series or in parallel and heated in a furnace between 500 C and 3000 C, at the reactor outlet.   e) an adaptable system schematized by the arrow (4) on a device (5) for analysis-to receive each of   valves for the analysis of their content.   2. Apparatus according to claim 1 wherein said analysis apparatus is selected from the group consisting of a gas chromatograph, a mass spectrometer, an infra-red apparatus or ultraviolet.   3. Use of the apparatus according to claim 1 for analyzes of operations selected in the field of refining,   petrochemicals, synthesis gas treatments and fine chemicals.