DK144458B - PROCEDURE FOR SEPARATING GAS POLLUTANTS FROM A GAS MEDIUM - Google Patents

Description

(is) DENMARK IWi, νίΞ * '

fp (12) PUBLICATION <n> 144 ^ 58 B

DIRECTORATE OF THE PATENT-OO TRADE BRAND

(21) Application No. ^ ° 55/75 (51) IntCI.3 B 01 0 53 / 1A

(22) Filing Day 10. S ep. 1975 (24) Race day 10. s ep. 1975 (41) Aim. available Mar 24 1976 (44) Posted 15 May ?. 1982 (86) International Application No. “(86) International Filing Day - (85) Continuation Day - (62) Master Application No.”

(30) Priority 23. s ep. 1974, 2445315t DE

(71) Applicant BIOLOGICAL WASTE MANAGER1NG (BIAV) AB, 190 51 Bridge, SE.

(72) Inventor Franz Xaver Kneer, DE.

(74) Clerk of the Office of Industrial Excellence v. Svend Schønning.

(54) Process for separating gaseous contaminants from a gaseous medium.

The present invention relates to a method for separating gaseous contaminants from a gaseous medium containing those in which the medium, upwardly flowing into a container, is contacted with a biologically high-active product and wherein the medium which has been purified by

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logical reaction of the contaminants with the biologically active D material is taken out at the top of the container.

^ Gaseous contaminants are understood to mean all waste gases, such as originating from animal breeding plants, from animal carcass processing plants, from fermentation and decay processes, as well as from industrial processing plants.

A process of the kind mentioned above is known from US Patent No. 3,828,525. According to this patent, active sludge from a wastewater treatment plant is used to decompose the pollutant gases in the medium to be purified. It has now been found that significant improvements can be achieved compared to the known process if a compost is used as an absorbent material, ie. a solid product obtained by biodegradation (decay) of organic waste and / or sludge from a wastewater treatment plant in the form of a bed. Such a material has been found to be very strongly adsorbing and thus adsorbs the contaminants, whereby the biodegradation can be carried out efficiently and very quickly. The biological reaction results in a loss of storage, which in turn leads to a sinking of the bed. Thus, it becomes very easy to offset the consumption of adsorbent material so that the container can always be filled with the adsorbent material. In the method of the above-mentioned US patent, a slurry of biological material is used. It then becomes theoretically impossible by a continuous one-step process to completely separate the reacted material from unreacted material.

It is the object of the invention to provide a more efficient process for the separation and reaction of gaseous contaminants from gaseous media.

This is achieved by a process of the kind set forth in the preamble of claim 1, characterized in that as a biologically active product, a partially decomposed compost which is able to adsorb contaminants and provide it as a biologically active process of organic waste material and / or clear mud is recovered. biological composition, and that after compulsory migration downwards in the container, the compost is removed from it, such material being optionally mixed with fresh compost and the mixture being returned to the container at the top of it.

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As the adsorption material, an air-controlled decomposition of organic waste materials is obtained by means of air supply, or, as an adsorption material, a decomposition of compost extracted with an organic coal-containing material is used as air-controlled material. It is therefore advantageous for the filtration process if the composting of the compost has not yet been completed.

Such composting methods are described, for example, in German Publication Publication No. 2,252,188 or German Publication Publication No. 2,253,009.

The filter material prepared according to the aforementioned methods is heavily contaminated with microorganisms, the organic gas contaminants to be purified being introduced into the container, the microorganisms present in the filter material are again nourished and activated. In this biologically active filter material, a strong reaction is now taking place, ie a continued decay and biodegradation which causes the filter mass to collapse and must be supplemented with new material. Thereby, the material returned to the container is seeded and changed in its structure, which is extremely advantageous for the filtration process. Thus, in this so-called return goods processing, it is possible to recover the filter material.

In the preferably cylindrical container, the contaminants are separated in such a way that the waste gases contemplated for purification are caused to flow through the adsorbent from below and upwards while the adsorbent passes through the container from top to bottom. The lower zones of the introduced material are subjected to the greatest load. By means of the withdrawal means, preferably a withdrawal mill (dispensing mill), it is possible, as desired, to take out all this material at the lower part of the container and return it by means of the transport means preferably by means of a lift, to the upper part of the container where it can be regenerated. .

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In addition, by means of the process according to the invention, it is possible for the first time to separate and react by the same method to the most different kinds of organic pollutants. In this way, therefore, for the first time, a biological filtration system intended for circulation is provided which is considerably simpler than portion operation.

The filtration process is therefore adjustable by feeding the throughput of the adsorbent material and by changing the amount of new material to be admixed.

According to a further feature of the invention, bentonite flour can be added as an additive to the adsorption material intended for filling the container.

By the addition of bentonite, in the absorption material, storm-molecular compounds of clay-humus complex are formed. Bentonite acts in the pure state as ion exchangers so that the heavy metal ions present in the wastes or the sulfur substances are fixed in water-insoluble form and certain organic gas contaminants are adsorbed by the humus-complex compounds. Thus, the addition of bentonite has the advantage that during the filtration, clay-humus complex is formed such that a fixation, but also a conversion of various gaseous organic compounds can take place by ion exchange or by complex bonds of heavy metal ions.

According to another feature of the invention, the filling height of the adsorbent in the container is selected depending on the volume flow of the waste gas to be purified. Thus, the volume of the adsorption material must be chosen depending on the amount of gas to be purified in the particular situation and the nature and extent of the contaminants, which can easily be ascertained by experiment.

The invention will now be described in more detail with reference to the drawings and by way of example. In the drawing, FIG. 1 shows a cross-section through an apparatus for carrying out the method according to the invention, and FIG. 2 is a plan view of the apparatus.

In a container 1, constructed as a cylindrical, with a metal housing provided with an insulating layer 2, a bed 3 of biologically high active material is found as an adsorbent. This consists either of an air-regulated supply of organic waste 5 144458 extracted from an air supply or of an air-regulated supply of a compost extracted with an organic carbonaceous material mixed with clear air sludge. However, the decay must not be completely completed for the compost to still be biologically active.

Container 1 has a slightly inclined bottom surface towards the center, above which a discharge cutter 5 is arranged to be able to pass around to obtain an even discharge of the filter material. The take-off cutter is driven by a drive element (not shown) which can be moved about an axis 6, so that the cutter cutter, in addition to its own movement, can be rotated clockwise over the bottom of the container. The cutter mill 5 thereby removes the lower layer of the material bed 3 through an opening 8 in the center of the bottom of the container. The withdrawn material falls onto a transport means 10 which leads it in the direction of the arrow to a mixer 11 with associated supply material 12 for new material and an elevator 13. Thereby the withdrawn material is mixed with new material and returned to the upper part of the container 1 from which it using a space distributor 15 is evenly distributed in the container opening.

Over a blower and a piping system 17 not shown, the waste gases or the air to be cleaned in the bottom area of the container are introduced through a number of nozzles 18. The container 1 is open at the top so that the waste gases supplied from the bottom in the direction of the arrow must flow up through the bed sinking in the container. of filter material and purified by adsorption and biological reaction therewith. This adsorption and biological reaction are biological processes, so that in the filter bed there is a decay process leading to a decay loss. This decay loss is manifested by a recess of the bed, which is constantly replaced by the supply of new material through the feeding means 12 so that the container 1 is constantly filled with filter material. Depending on the volume and strength of the waste gas contaminants, the container is slowly or rapidly circulated or circulated, ie the passage of filter material is retarded or accelerated. Since the waste gases always flow from below and upwards, the lower filter layer is always the most heavily loaded.

However, as the filter material is withdrawn at this location and the sampled material is mixed with new material, the sampled filter material on its way through the container allows time to undergo regeneration. After a certain time, of course, the entire filter material must be replaced with new ones. The filter material removed is suitable for soil improvement.

In addition, if the waste gases to be purified require it, the filter material over the feeder 12 is also mixed with bentonite flour, the dosage of which can be determined by simple tests.

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The container 1 holds a volume of approx. The volume is then selected depending on the amount of gas developed and the nature and quantity of the pollutants. This also applies to the size of the extraction and supply of new material, which also depends on the amount of gas to be passed through the filter and the nature and quantity of the pollutants. In principle, it is not possible at all to mix any new material or a small or large quantity. Pilt is the efficiency of the arrangement can be ascertained by means of measuring probes not shown here and the filter process can therefore be regulated by changing the throughput of the filter material and the mixing of new filter material. Via conveyor 10, used material can be discharged at 20.

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Example

This example illustrates purification to remove pollutants from waste gas from the bio dams at a penicillin plant.

This gas contains the following pollutants:

Ammonia 8-10 ppm triethylamine 8 ppm mercaptans 50 ppm hydrogen sulfide 40-50 ppm

The contaminated air was passed through a filter containing 50 m of a filter material consisting of partially decayed compost obtained by composting the drained sludge from a wastewater treatment plant, the composting being carried out in the presence of air in a closed reactor at a rate of 1000 m per hour. The air that had passed through the filter was analyzed for the above contaminants. It was found that the content of each of the contaminants mentioned was reduced to 0 ppm.