Catalyst – solid sorbent – or support therefor: product or process – Solid sorbent – Free carbon containing
Patent
1988-11-03
1989-11-14
Konopka, Paul E.
Catalyst, solid sorbent, or support therefor: product or process
Solid sorbent
Free carbon containing
55 68, 55 75, 264 295, 423445, 423449, 502420, 502430, 502431, C01B 3110, C01B 3108, B01J 2020
Patent
active
048807656
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a process for producing carbon molecular sieves in accordance with the introductory part of claim 1.
It is known from German Pat. No. 2 119 829 to produce carbon molecular sieves for the separation of small-molecule gases, particularly O.sub.2 and N.sub.2, by treating carbonization products with carbon-splitting hydrocarbons, which in the carbon structure of the carbonization product react by narrowing the already existing pores. Such carbon molecular sieves are produced in rotary kilns. The rotary kiln is indirectly heated and flushed with a nitrogen stream.
The rotary kiln has a relatively large volume with respect to the filling with carbon molecular sieves. This leads necessarily to the fact that large amounts of inert gas are required. During continuous operation, different dwelling periods result for the individual product particles (dwelling time spectrum). A deviation from the product quality results.
It is the object of the invention to create a process making possible the production of carbon molecular sieves with a uniform quality having very good separating characteristics.
According to the invention, this object is attained by passing the carbonization product through a vibrating oven at 800.degree. C. to 900.degree. C. for up to 30 minutes, whereinto a counterflow of inert gas with a steam concentration of 20 to 95% by volume is directed, and the so activated product is again passed through the vibrating oven at 750.degree. C. to 850.degree. C., with a counterflow of inert gas having a benzene vapor concentration of 12% by volume.
The production of the carbon molecular sieves can also be carried out in accordance with the claim 2, in two vibrating ovens, arranged in succession. This process has the advantage that the carbon molecular sieves can be produced in a continuous operation.
For the production of the carbon molecular sieves, a carbonization product is used which has been carbonized in a rotary kiln, in the conditions of an inert-gas atmosphere, at temperatures of 600.degree. to 900.degree. C. Due to the carbonization, cracking products have deposited in the pore system, causing an uneven narrowing, respectively a clogging of the pore system. In order to reverse this effect, according to the invention, the carbonization product is subjected to a light steam activation in a vibrating oven. In this activation, an activation degree of 3 to 6% is reached.
After the activation, in the vibrating oven a treatment with carbon-splitting hydrocarbons, such as benzene, takes place, in order to narrow the pores in a controlled manner.
The carbon molecular sieves produced this way satisfy the following quality test:
An adsorber vessel is filled with 200 ml carbon molecular sieves and an air stream is passed through it for one minute and than evacuated for another minute. After the dynamic balance is established (10 cycles) in the desorption phase a gas amount of 420-500 ml is desorbed and analyzed. The average oxygen concentration of the desorption gas ranges between 43-50% by volume of oxygen in the carbon molecular sieves produced according to the invention.
In the vibrating oven, the reaction space consists of a horizontally arranged channel with a rectangular cross section. This channel is set into oscillations by a vibrator or an eccentric. Due to these swinging motions, the individual carbon molecular sieve particles are transported through the channel.
An advantageous embodiment of the vibrating oven is a round kiln with overlying beds. Thereby, the solid material is guided through the oven in a circular path. At the transition points from one bed to the next underlying bed, the running surface is bevelled in such a manner that the particles, whether they are on the inside or the outside, all have the same dwelling time in each bed. The heating of the oven is done through electric multizone heating.
The heating elements are arranged around the oven like a heating shell and are arranged inside the oven in such a way that the reaction space is located in the focal poin
REFERENCES:
patent: 3801513 (1974-04-01), Munzner et al.
patent: 3960522 (1976-06-01), Munzner et al.
patent: 3960769 (1976-06-01), Munzner et al.
patent: 3979330 (1976-09-01), Munzner et al.
patent: 3996161 (1976-12-01), Chia
patent: 4015956 (1977-04-01), Munzner et al.
patent: 4048472 (1977-09-01), Sauer et al.
patent: 4083810 (1978-04-01), Czerny et al.
patent: 4540678 (1985-09-01), Sutt, Jr.
patent: 4594163 (1986-06-01), Sutt, Jr.
patent: 4615993 (1986-10-01), Schirrmacher et al.
Heimbach Heinrich
Knoblauch Karl
Tarnow Ferdinand
Bergwerksverband GmbH
Dubno Herbert
Konopka Paul E.
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