JPS6087898A - Methane fermentation device - Google Patents

Abstract

PURPOSE:To make piping easy and to enable installation in a place where the climate is extremely cold by passing successively fermentation gas to a fermentation gas cooler, active carbon filter and high polymer membrane filter connected successively and hermetically to the gas take-out port of a methane fermentation tank. CONSTITUTION:The gas generated in a methane fermentation tank 10 is the fermentation gas having the same temp. as the temp. of the digester liquid in the tank and 100% RH humidity. The gas is conducted to the inside of a fermentation gas cooler 12, where the gas is cooled to the external air temp. and thereafter the gas flows through an active carbon filter 14 to an inlet 16 of a high polymer film filter. The fermentation gas past the filter 14 flows into the inside of a membrane filter medium 17 and faces the dry air on the outside of the medium 17 and therefore the moisture in the fermentation gas diffuses into the dry air through the medium 17. While the moisture is diffused, the moisture in the fermentation gas is removed at the outlet 19 of the high polymer membrane filter and the gas is supplied to other gas apparatus through a connecting port 20 of the gas piping.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a methane fermentation device for treating organic waste.

Conventional structure and its problems Traditionally, methane fermentation equipment has been widely used for processing organic waste, from household use to commercial use for processing cafeteria kitchen waste, agricultural waste, etc. It's here. However, this device had the disadvantage that condensed water caused pipe blockage. In other words, the fermented gas generated from the methane fermentation tank contains moisture at the saturated vapor pressure of the methane fermentation tank temperature, and if the moisture condenses in the piping section where the temperature is low and accumulates in the piping, the gas flow will be reduced. It had the disadvantage of blocking the road.

In order to prevent the above-mentioned shortage, a method has been adopted in which the fermentation gas piping is sloped and a water supply device is installed at the bottom of the piping to remove condensed water. However, with this method, all the gas piping in the methane fermentation equipment is slanted piping, which not only makes the piping work complicated and inconvenient in terms of appearance, but also because the gas piping crosses three-dimensionally between each device in the equipment. However, there was a problem in that it became an obstacle during maintenance.

Furthermore, when using a methane fermentation tank in a cold region, even if the above-mentioned inclined piping is installed, water that condenses in the piping may freeze and block the piping.Methane fermentation can be carried out even in cold regions. The device was desired.

OBJECTS OF THE INVENTION The present invention eliminates such conventional drawbacks, and provides a methane fermentation device that has easy piping and can be installed even in cold regions.

Structure of the Invention The methane fermentation apparatus of the present invention connects a fermentation gas cooler, an activated carbon filter, and a polymer membrane filter in sequence to a gas outlet of a methane fermentation tank in an airtight manner, and collects fermentation gas from the methane fermentation tank. The outside air is passed sequentially through the above three types of equipment, and the outside air is supplied to the cooler and the polymer membrane filter. With this configuration, moisture in the fermentation gas can be efficiently removed.

Description of examples An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, 1 is a gas outlet provided at the top of the methane fermentation tank 2, 3 is a fermentation gas cooler connected to the gas outlet 1, 4 is an activated carbon filter connected to the fermentation gas cooler 3, and 5 is a fermentation gas cooler connected to the fermentation gas cooler 3. 6 is an activated carbon layer in the activated carbon filter 4, and 6 is a polymer membrane filter in which two resin membranes 7 are pasted on both sides of a frame-shaped spacer to supply fermentation gas between them. I am in touch with you. The connections between the above-mentioned devices are made with good airtightness. 8 is a gas pipe connection port, which is connected to a fermentation gas consuming device such as a gas tank or gas boiler.

As the polymer material for the polymer membrane filter 6 and the resin membrane 7 that remove the moisture mentioned above, in consideration of chemical resistance etc. A copolymer (hereinafter referred to as PFS) was used. This P F
S IJ', the water permeability is significantly higher than the methane gas permeability, which is 100 to 1000 times higher at room temperature.

Next, the operation of the apparatus of this embodiment will be explained. The fermentation gas generated in the methane fermentation tank 2 enters the fermentation gas cooler 3 as shown by the arrow and is cooled down to the outside temperature. The fermentation gas, which has a temperature of 100% R,H at the digestive fluid temperature of about 35°C in the methane fermentation tank 2, has a temperature of 100% R,H of the outside temperature at the exit of the fermentation gas cooler 3.

Excess moisture condenses on the inner wall of the fermentation gas cooler 3. The condensed water flows down from the inner wall of the fermentation gas cooler 3 through the gas outlet 1 and returns to the methane fermentation tank 2. The fermentation gas that enters the activated carbon filter 4 from the outlet of the fermentation gas cooler 3 passes through an activated carbon layer 5 to remove trace amounts of harmful components. The fermentation gas that has passed through the activated carbon filter 4 enters the polymer membrane filter 6, and moisture is released to the outside through the resin membrane 7. A fan (
(not shown) is provided.

The dried fermentation gas discharged from the gas pipe connection port 8 at the outlet of the polymer membrane filter 6 is sent to gas consuming equipment such as a gas tank and a gas boiler via a gas pipe.

Next, another embodiment of the present invention will be described based on FIG. In the figure, 9 is a dry pressurized air generating device consisting of a compressor, an air tank, an aftercooler, a drain separator, a pressure regulator, and the like. 10 is a methane fermentation tank, 11 is a gas outlet attached to the upper lid of the methane fermenter 10, 12 is a fermentation gas cooler connected to the gas outlet 11, and 13 is a heat exchanger in the fermentation gas cooler 12. , 14 is an activated carbon filter connected to the fermentation gas cooler 12, and an activated carbon layer 21 is provided inside. 15 is a polymer membrane filter, one end of which is connected to the inlet of the polymer membrane filter. The structure consists of a double tube including a de-furnacing material 17 made of a PF3 membrane processed into a chive shape, and an outer covering tube 18 made of cheap material such as polypropylene. 19 is a polymer membrane filter outlet. 2o is a gas pipe connection port, and 23 is a pipe that guides the dry pressurized air that has passed through the heat exchanger 13 to the gap 22 between the P material 17 and the covering tube 18 of the polymer membrane filter 15.

Next, the operation of the apparatus of this embodiment will be explained. The gas generated in the methane fermentation tank 10 is at the same temperature as the digestive fluid temperature in the tank.
Fermentation gas cooler 12 with fermentation gas at a temperature of 0% R, H.
After being guided into the interior and cooled to outside temperature, it passes through an activated carbon filter 14 and reaches a polymer membrane filter inlet 16.

Meanwhile, the outside air is compressed to about 7 kcrf/c
After being compressed to about ri and cooled to about the outside temperature using an aftercooler, dry air is created through a drain separator, the pressure is adjusted, and then introduced to the heat exchanger 13 in the fermentation gas cooler 12 (arrow). The air whose temperature has increased through heat exchange with the temperature of the fermentation gas and whose relative humidity has further decreased is sent to the polymer membrane filter outlet 19.
is introduced between the membrane p-material 17 and the sheathing chip 18.

The fermented gas that has passed through the activated carbon filter 14 flows into the membrane p material 17 and faces the dry air outside the de-furnacing material 17, so that the moisture in the fermented gas passes through the de-furnacing material 17 into the dry air. spread to. While the moisture is being diffused, the moisture in the fermentation gas is removed at the polymer membrane filter outlet 19, and the fermented gas is supplied to other gas equipment through the gas piping connection port 20. On the other hand, the dry air flowing from the polymer membrane filter outlet 19 to the outside of the demolding material 17 enters the polymer membrane filter 1 while containing moisture.
16 to the outside air.

Effects of the Invention As mentioned above, the present invention can reduce and remove moisture contained in fermentation gas without using large amounts of external energy other than the energy required for air flow to diffuse moisture. There is no condensation water inside.

Therefore, there is no need to make the gas piping an inclined pipe, which simplifies the piping work, which not only makes it possible to reduce construction costs, construction period, and construction materials, but also simplifies maintenance while the methane fermentation equipment is in operation. Features include that piping does not become an obstacle to work. Furthermore, by drying the fermentation gas, freezing does not occur in the gas pipes, so the methane fermentation tank can be easily constructed and operated even in cold regions, and has great industrial value.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of an apparatus according to one embodiment of the present invention, and FIG. 2 is a partial sectional view of another embodiment of the apparatus. 3.12...Fermentation gas cooler, 4,14...Activated carbon filter, 6,15...Polymer membrane filter. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Scope of Claims] (1) A fermentation gas cooler, an activated carbon filter, and a polymer membrane filter are sequentially and airtightly connected to the gas outlet of the methane fermentation tank, and the fermentation gas exiting from the methane fermentation tank is A methane fermentation device in which gas is sequentially passed through the three types of equipment described above, and outside air is supplied to a cooler and a polymer membrane filter. (2) The methane fermentation apparatus according to claim 1, which uses a perfluorosulfonic acid resin membrane as the polymer membrane filter. (3) The methane fermentation apparatus according to claim 1 or 2, wherein the polymer membrane filter is constituted by two perfluorosulfonic acid resin membranes. (4) The methane fermentation apparatus according to claim 1, 2 or 3, wherein a fan is provided as means for supplying outside air to the fermentation gas cooler and the polymer membrane filter. (6) The methane fermentation apparatus according to claim 1 or 2, wherein the polymer membrane filter is in the shape of a chive. (6) The methane fermentation apparatus according to claim 1, 2, or 5, wherein the polymer membrane filter is a double tube, and outside air is circulated between both tubes.