JPH0669359B2 - Fluidized bed type anaerobic bioreactor- - Google Patents

Abstract

PURPOSE:To improve fermentation efficiency, by pouring a carrier into a fluidized bed type anaerobic bioreactor used for methane fermentation and sticking bacilli thereto. CONSTITUTION:A carrier 13, consisting of a porous substance having about 1.5-3.5 specific gravity and having microbial cells sticking thereto is poured into the interior of a fermenter 1. In normal operation, a raw material solution is fed from a raw material feeding pipe 8 through a pump 9 and an opening and closing valve 7 is opened to discharge an internal solution is discharged from a discharge pipe 6. When the opening and closing valve 7 is closed to drive a pump 4, the internal solution is blown up from the bottom of the fermenter 1 to roll up the carrier 13, then rises, passes from a cavity (10d) through a passes (10e) to the surface above a rotating plate 10, gathers in a dishlike part (10a), overflows therefrom and disperses on a surface above a tilting surface (10b). When the rotating plate 10 is rotated at a high speed, the carrier 13 collides with the inner wall of the fermenter 1 by centrifugal force, drops by the own weight and returns to the fermenter bottom. Water is collected in the peripheral wall 2 and circulated by a pump 4.

Description

Description: TECHNICAL FIELD The present invention relates to a fluidized bed type anaerobic bioreactor used in a subsequent methane fermentation process in a two-phase methane fermentation method, and more particularly to a carrier in a fermenter. It was added to allow the bacilli to adhere and to improve the efficiency of fermentation.

Conventional technology The two-phase methane fermentation method consists of an acid fermentation process and a methane fermentation process.
It is intended to improve the decomposition ability of organic substances by performing a step operation, and in the latter stage of methane fermentation process, it is a requirement to secure the decomposition ability of low-molecular organic acids.

As a bioreactor used in this methane fermentation process, a suspension type device, for example, a continuous complete mixing type reactor has been conventionally used.

Problems to be Solved by the Invention As described above, in the methane fermentation process, the main point is to secure the ability to decompose low-molecular-weight organic acids, but in order to increase the processing capacity, increase the viable cell density. There is a need. However, the growth rate of methane cells is very slow, and it is said that the generation alternation time of cells is 1.5 to 8 days. In the conventional continuous fermentation of the suspension system, the washout of the cells occurs due to a large dilution rate, which causes fermentation. The processing capacity of the tank could not be increased. For this reason, a fluidized bed system in which the bacterial cells are attached to the fermenter has been considered, but it is difficult to directly attach the bacterial cells to the fermenter, and good results cannot be obtained.

Means for Solving the Problems In the fluidized bed system of the present invention, cells are easily attached to the fermenter, that is, a porous carrier having a specific gravity of about 1.5 to 3.5 is added to keep the cells at a high concentration. In this case, since the methane bacterium that easily attaches to the carrier is bacillus, in the present invention, by attaching bacilli having a relatively long generation alternation time to the carrier, In order to increase the microbial cell concentration, increase the microbial cell retention time, and shorten the fermentation liquid retention time, the carrier is allowed to settle at the bottom of the tank when the internal liquid does not flow, and inside the tank when flowing. It is a product of which the efficiency of fermentation is measured by dispersing it in the.

Embodiments of the Invention Referring to the drawings for the embodiments of the present invention, FIG. 1 is a front sectional view showing the overall structure of an example of the bioreactor of the present invention, and FIG. 2 shows the action of the rotating plate portion of the bioreactor. 3 is a perspective view showing the structure of a groove provided on the outer peripheral surface of the rotary plate, and in FIG. 1, 1 is a fermenter, and the upper end portion is outward. It is formed as a stepped cylindrical hermetic container, and a ring-shaped support 2 is attached to the upper part of the inside by a bridge. The bottom of the tray 2 communicates with the bottom of the fermenter 1 via the pipe 3 and the pump 4, and the lower edge of the tray 2 is provided with a hanging edge 5 and one end is opened at a proper position on the inner surface thereof. A discharge pipe 6 communicating with the outside is provided together with an on-off valve 7. The raw material supply pipe 8 is provided on the side surface near the lower end of the fermenter 1.
Are provided together with the pump 9.

Next, 10 is a rotating plate, which is attached to the lower end of a vertical shaft penetrating the upper end of the fermentation tank 1 and rotated at a high speed by a motor 11 provided on the upper surface of the tank body. 12
Is an inverter connected to the motor 11 circuit. The rotating plate 10 is formed on an inclined surface 10b that surrounds the dish-shaped portion 10a and has an upper surface inclined outward, and a plurality of blades 10c ... The central portion of the lower surface is formed as a cavity 10d, and is formed as an integral block provided with a passage 10e that connects the cavity 10d and the inclined surface 10b.
Thus, the vanes 10c ... On the outer surface, a large number of recessed lines 10f are provided radially from the inclined surface 10b to the blades 10c on the peripheral surface, each of which is provided with a plurality of notches 10g, and ribs 10h are provided on the periphery of the inclined surface 10b. Has been formed.

Action, effect The present invention is configured as described above, accommodates the carrier 13 to which the bacterial cells have been attached in advance in the fermenter 1, and normally supplies the raw material liquid from the raw material supply pipe 8 via the pump 9, The on-off valve 7 is used to take out the internal solution to the outside.

Now, when the on-off valve 7 of the discharge pipe 6 is closed, and then the pump 4 is driven, the internal liquid is blown up from the lower part of the fermentation tank 1 as shown by the arrow in FIG. And rises, goes out from the cavity 10d on the lower surface of the rotating plate 10 through the passage 10e to the upper surface of the rotating plate 10, accumulates in the dish-shaped portion 10a, overflows, and is dispersed on the upper surface of the inclined surface 10b. Next, when the motor 11 is driven to rotate the rotating plate 10 at a high speed, the carrier in the liquid is blown off by the centrifugal force and collides with the inner wall 1 of the fermentation tank 1 and falls by its own weight to return to the bottom of the tank. The water in the liquid flows into the ridges 10f, passes through the notches 10g, is laterally skipped from the peripheral surface of the rotary plate 10, and is received by the inner surface 2 of the peripheral wall of the catcher 2.
It is stored in the receiving tray 2 and circulated to the lower portion of the tank via the pump 4. In addition, when the carrier flows down, an orifice 1a is provided on the wall of the fermenter 1 so that the recovered carrier has a negative pressure so that the carrier can be easily returned.

Now, the rotary plate 10 rotates at a high speed to separate the carrier and the water, but since the blades 10c ... Are attached to the lower end of the peripheral surface of the rotary plate 10, the separation efficiency increases too much, In other words, if more water than is necessary is stored in the saucer 2, this blade 10c ...
Acts as a resistance to reduce the rotation of the rotary plate 10, and thus proper separation is always performed.

Moreover, with the above configuration, the carrier is circulated along the inner wall of the tank by centrifugal force, and then flows down along the tank wall by its own weight, and is not subjected to forced circulation by the pump, so that the carrier is not crushed or the adherent cells are dispersed. It can be prevented and extremely efficient processing can be performed.

[Brief description of drawings]

FIG. 1 is a front sectional view of an example of a bioreactor of the present invention, and FIG. 2 is a sectional view for explaining the action of a rotating plate,
FIG. 3 is a perspective view showing the structure of a groove provided on the outer peripheral surface of the rotary plate. 1 ... Fermenter, 2 ... Receptacle, 3 ... Pipe, 4,9 ... Pump, 6 ...
Discharge pipe, 7 ... Open / close valve, 8 ... Raw material supply pipe, 10 ... Rotating plate, 11
… Motor, 10c… Vane, 10f… Recess, 13… Carrier

Claims (1)

[Claims] 1. A fermenter (1) in the form of a closed container, above the inside of
A flat ring-shaped bridge (2) is mounted on a supporting frame, communicates with the upper and lower surfaces slightly above the bridge (2), and a plurality of cutouts are provided from the upper end to the lower end of the peripheral surface ( A rotating plate (10) having a large number of 10f) attached thereto, a blade plate (10c) attached to the lower end of the peripheral surface of the rotating plate (10), which is positioned in the receiving shaft (2), is provided with a hanging shaft. A pipe (3) that connects the inside and the bottom of the fermenter via a pump (4), a discharge pipe (6) that opens at the lower end to receive one end, and the other end communicates to the outside through an open / close valve (7), the lower end A fluidized bed type anaerobic bioreactor in which raw material supply pipes (8) each having one end opening into the tank via a pump (9) are provided.