JPS58501161A - anaerobic fermentation - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] anaerobic fermentation This invention is aimed at improving the anaerobic fermentation method for organic liquids and the fermentation equipment used therein. related.

Purify the organic waste liquid [e.g. reduce the biochemical oxygen demand (B, O, DJ) of the organic waste liquid. It is well known that organic waste liquids are subjected to anaerobic fermentation (digestion) in order to reduce waste water. like this Anaerobic fermentation produces gases, especially methane. In known digestion methods, the waste liquid retention period The period is generally long, for example about io to 10 days. The fermentation waste liquid is heated to a temperature higher than the environmental temperature. Traditional anaerobic fermentation adds heat energy because it is often necessary to maintain the temperature The overall energy efficiency from the fermentation operation is therefore low.

The purpose of this invention is to carry out anaerobic fermentation of organic waste liquid in a matter of hours, not days. To provide an anaerobic fermentation method for organic waste liquid that can be carried out continuously with a relatively short average residence period of be.

According to this invention, the organic waste liquid is stored in a packed fermentation vessel, that is, by arranging the packing elements and carrying out nine fermentations. The organic effluent is fermented under anaerobic conditions in the vessel, while the organic effluent is passed through an array of packing elements ( 1) The flow rate per unit area passing through a plane perpendicular to the direction of flow of organic waste liquid is substantially uniform. is one: (-) The organic waste fluid flows smoothly on the surface of the packing element array, and rapid changes in flow velocity are relatively less likely to occur. Few; be allowed under certain conditions It is generally preferred that the organic waste liquid flow upwardly through the packing element arrangement. follow In the following description, only this mode of operation will be described. However, other operations For example, an embodiment in which the organic waste liquid flows down the packing element arrangement is suitable. If applicable, this should also be stated.

In the following description, reference will be made to the figure, which is a schematic vertical cross-sectional view of the fermentation apparatus used in this invention. I will explain it.

The fermentation apparatus shown in the figure is sealed and has a valve provided at the upper end of the fermentation vessel 11. Gas discharge-intake conduit with 3, slot with valve S provided at the lower end of the fermentation vessel and a discharge conduit f. A filling element array generally designated 6 is installed within the container l. , are arranged on the perforation support member 7. The waste liquid introduction pipe t is equipped with a valve de, and this waste liquid introduction pipe t is a number of perforated pipes or troughs 1 installed in the container l below the support member. Connected to a liquid dispensing device consisting of 0. Between the tube t and the support member 7 there is a diffusion device or A flow correction device// is provided. The inner peripheral weir is placed on top of the filling element array 6. This is connected to the treated liquid discharge pipe/41, and this treated liquid discharge pipe/41 is connected to the liquid seal top. 13 to keep the gas in the vessel l (or alternatively, to keep the gas in the vessel l For example, a sludge system is used to retain the gas! ).

The first criterion mentioned above, i.e., the flow of organic waste through a plane perpendicular to the direction of flow of organic waste. In order to satisfy the criterion that the flow rate is substantially constant, i.e. the organic waste liquid must be K flows through the fermenter as a flow similar to the extrusion flow, so the organic waste liquid is arranged in a filling element. It is necessary to introduce the packing elements into the array substantially uniformly through the lower surface of the row.

To achieve this, the embodiment shown in the figure requires a set of multi-perforated tubes for directing the organic effluent. to the fermentation vessel, and to further improve the uniformity, a flow straightener// That is, the diffusion device 11 is arranged between the waste liquid inlet pipe t and the filling element array 6. This expansion The scattering device can be used for example on silk fabrics such as perforated plates, grids or silk fabrics made of glass fibres. take form. Thus, as can be seen from the above description, K, the hole passing through the perforated support 7. The flow rate of the machine waste liquid becomes substantially uniform.

The packing element array 6 reduces rapid changes in the organic waste liquid that comes into contact with the surface of the packing element array. should be made possible.

This makes the packing element array a number of arrays of vertical tubes running from the top of the array to the bottom. Theoretically, this arrangement of tubes is best achieved by forming Can be used for invention. , but such a tube arrangement itself does not straighten the flow. Because it does not have the property of Once in, it is contained within the conduit until it exits at the top of the conduit, so that the organic waste is Note that it is necessary to be very well distributed at the beginning. A similar effect is This can also be achieved by a vertical sheet arrangement, but this also suffers from some of the same drawbacks. Motsu. .

Other ways of providing an arrangement of packing elements that approximate a set of tubes are by means of rasppilling, – An array of stacked filling elements, such as single rings or intersecting wall rings. .

If such rings <fil) are packed in different rows that are not close to each other, the flow will be improved to some extent. Although it can be straightened, it is difficult to stack such rings in a large fermentation container. It should be noted that this is very time consuming.

The so-called "throw" packing arrangement consists of simply dumping the packing elements into the reaction vessel. It is only necessary to put a filling element into the reaction vessel, so the container is filled with the thrown filling element. It has the advantage of being extremely simple. However, in this case how to put the filling element Filler elements populated by 1 tend to be somewhat chaotic arrays of 1's. generally speaking Therefore, such a disordered array is often filled with liquid flowing through the packed element array. The velocity of the flow often changes rapidly as it flows across the surface of the element. This is traditionally used Throw-filling element arrays formed from solid pillars or solid cylinders This is especially true in the case of The situation is slightly better than in the previous case, but the same The same holds true for poll-type and saddle-type filling elements. happens. Aspect ratio (length: straight) of conventional straight pilling and ball ring Diameter ratio) When the filling elements are inserted into the metal, the filling elements are oriented randomly or vertically. do. On the other hand, an aspect ratio of less than 1 (e.g. 0.66, preferably O, S-O, co-S) Light* elements with their filling elements are horizontal, i.e. in the case of a simple ring, The walls of the ring form an array of filling elements that tend to be vertical rather than horizontal. . Such a filling element is particularly suitable for use according to the invention and is placed in a container. It is relatively easy to It has been found that this has the advantage that the speed does not change excessively. friend.

Suitability of the filling element for use as a charge filling element for fermenters according to the invention A useful and practical measure for is the pressure drop when air is passed through an array of packing elements. . As is known, the pressure drop due to the shape of the filling element depends, among other things, on its size The smaller filling elements (rings) are larger than the larger filling elements (rings). This results in a large pressure drop and therefore a large resistance to air flow. The reverse is also true It is.

Table 1 lists suitable moths for filling elements of various sizes for use according to the invention. Listing large pressure drop: Table 1 Air flow velocity: /! 00 pounds/hour/square foot Water flow rate: 5ootyytυ / hour / square foot 40 / J / j ,7　oz　t,z −〇　6　j Suitable filling elements that meet the above criteria include side perforations and internal radius ribs or Rings with or without diameter ribs and terraret rings (filling elements formed in parallel lines) are included.

Although we do not wish to be limited by any theoretical reason, we The effectiveness of the fermentation method invented by This is thought to be due to the formation of a film of material containing anaerobic microorganisms that perform decomposition. Furthermore Additionally, by allowing the organic waste to flow relatively smoothly over the surface of the packing element, Not only does this result in a more uniform and wider coverage of the film, but it also provides a more effective film. This is thought to be because it causes a problem.

Thus, the thickness of the film depends on the hydraulic shear rate of the liquid flowing over the film. is limited, thus creating a relatively uniform and smooth flow of liquid over the film. It is possible to provide a substantially uniform film thickness. In other words, filling is required. Effective spreading film on bare surfaces (relatively free of "dead spots") ), the activity per unit surface area becomes more uniform over the horizontal plane of the packing element array. It is thought that it will be one.

Therefore, another measure of the suitability of the shape of the filling element used according to the invention is the film. The free surface area of the packing element array to be covered is preferably at least *0%, more preferably at least 3s should be covered with the film.

Again, without wishing to be limited by any theoretical reasons, in many cases In this case, anaerobic decomposition is thought to occur in stages. In other words, one microorganism is an organic waste liquid. The organic waste inside is decomposed to some extent, and then other microorganisms further advance the decomposition process. it is conceivable that.

Since the flow of liquid through the fermenter is similar to the extrusion flow, this means that e.g. Acid-producing microorganisms are distributed in the stratified layer (stratified film) at the bottom of the fermenter and produce methane. This allows the adult microorganisms to be similarly distributed in the upper part of the fermenter. Furthermore, Since the optimum flow rate on such different films is different, the unit volume ratio is thus It is possible to use packing arrays formed by layers of packing elements with different surface areas. or the flow velocity through one face of the packing element array (which is substantially uniform on that face) Use a tapered fermenter so that the flow rate is different than the flow rate through the other surface. is also possible.

In general, the liquid flow rate through the fermenter according to the invention (in the plane perpendicular to the direction of waste flow) (Considered as the flow velocity passing through the surface) U　O, about 2~j0ψ. For details on the history, see Col. The flow rate is relatively low, such as w7' days. Even at such low flow rates, The low flow rate results in a low residence time compared to prior art residence times, e.g. body time or the like. It provides a low residence time of less than 3 hours, especially 3 to 10 hours.

Depending on the nature of the waste to be treated, heating of the liquid may or may not be necessary for fermentation. However, in any case, fermentation is carried out at temperatures between 0°C and 20°C, preferably between 20°C and 20°C. It is appropriate to use C.

The material flowing up through the packing element array in the fermenter must be at least at the top of the packing element array. also includes gases generated by anaerobic fermentation, such as methane. The filling element is its surface It is desirable to be able to efficiently release debris from the surface, and it is desirable to Packing elements that do not interfere with the formation of anaerobic microbial films on the packing elements To efficiently release gas and facilitate gas flow through the packing element arrangement. is desirable. Is the total flow rate of fluids (liquids and gases) higher at the top of the fermenter? In order to accommodate its increasing flow velocity, the filling element forming the lower part of the filling element array is The filling element has a surface area per unit volume lower than the surface area per unit volume of the filling element. It is desirable to form the entire upper part.

The method and apparatus of this invention can be applied to various organic waste liquids (this organic waste liquid is an aqueous waste of M-machine waste). λ meaning liquid and/or suspension, e.g. domestic sewage, food and beverage manufacturing plants; It can be used to treat wastewater from plants and oil refineries. This fermentation is rich The main functions of (a) waste liquid B, 0. D. Reduce (biochemical oxygen demand) (b) At the same time, it has the function of producing useful substances such as methane from waste. . If desired, the treated effluent can be further purified, for example, by conventional aerobic fermentation methods.

As mentioned above, anaerobic fermentation occurs (it seems) in stages, so the fermentation process according to this invention The fermentation process consists of a number of continuous fermenters, each of which carries out one stage of fermentation. ] It will be held inside The fermentation method and fermentation apparatus according to the present invention can be applied to liquid, organic matter-containing substrates other than waste liquid, e.g. Used for anaerobic fermentation of waste liquids or other substrates to which additional substances or nutrients have been added can. In other words, the method and apparatus according to the present invention can also be used as a mermaid. igenetically altered microorganisms such as bacteria or enzymes, which may be microorganisms that have been It can be used to carry out all anaerobic fermentation in the body.

Engraving (no changes to the content) Procedural amendment Showa 5C 3rd year 4th day Commissioner of the Patent Office ■, Incident display = PCT/GB tco100:1:1g 2. Name of the invention anaerobic development 3. Person who makes corrections゛ Relationship to the incident: Patent applicant name Name: McKeown, Kevin Joseph 5, subject to correction Contents of correction (1) As per attached power of attorney (2) Engraving of the translation of the drawing (no changes to the content) international search report

Claims (1)

[Claims] l organic waste under anaerobic conditions in a packed fermentation vessel (1) with a packing element arrangement (A) In the method of fermenting the liquid, the waste liquid is placed in the packing element array (6) under the following conditions: (1 ) The flow rate per unit area of the waste liquid through a plane perpendicular to the direction of the flow of the waste liquid is substantially uniform. (−) The organic waste liquid has relatively few rapid changes in flow rate and the packing element arrangement table Flows smoothly over the surface; Anaerobic treatment of organic wastewater characterized by fermentation by flowing it under the conditions of Fermentation method. 3 Diffusion device for organic waste liquid, i.e. flow straightening device (II) T-through filling element arrangement (6) The method according to claim 1 or 2, which is introduced in (6). The filling element array ()) consists of an array of input filling elements with an aspect ratio of less than 1. A method according to any one of claims 1 to 3. S The aspect ratio of the filling element is 0.66 or less, preferably θ, S ~ 0.2, as claimed in the patent The method described in Scope No. D.