Abstract: The present invention provides a submerged type membrane separation device and a membrane separation method which allow long-term stable filtration. In the submerged type membrane separation device including a membrane module having membrane units stacked on top of each other in stages, in each of which flat sheet membrane element each having a separation membrane are arranged, the membrane module is constructed of various membrane units differing in sludge-filtration resistance or pure-water permeation resistance, whereby it becomes possible to extend a device operation period of time lapsing before transmembrane plugging occurs, or equivalently, the necessity to clean membranes arises. Further, it also becomes possible to design to synchronize timings with which a plurality of membrane units require cleaning.

Abstract: The present invention provides a submerged type membrane separation device and a membrane separation method that can deal with a temporary increase of a treatment flow rate by taking advantage of the filterability of the constituent separation membranes of the device. In submerged type separation device including a membrane module having stacked therein membrane units in which flat sheet membrane elements having a separation membrane are arranged, a membrane unit having the highest filtration resistance or the highest pure-water permeation resistance is placed at the lowermost stage of the membrane module, thereby setting a high temporary filtration flux for the membrane module as a whole. This makes it possible to deal with a short-term flow rate increase.

Abstract: A method produces a chemical through continuous fermentation including: (a) culturing a cell in a culture medium in a fermentor to ferment a feedstock to produce a chemical; (b) conducting filtration of the culture medium with a separation membrane module; (c) separating a permeate containing the chemical from the culture medium while retaining a non-permeated liquid in the fermentor, and (d) supplying a gas from at least one of a lower portion of the separation membrane module and a pipe communicating between the fermentor and the separation membrane module to adjust a gas linear velocity in the separation membrane module to 0.15 cm/s to 70 cm/s while supplying the separation membrane module with a liquid.

Abstract: The present invention provides a submerged type membrane separation device and a membrane separation method which allow long-term stable filtration. In the submerged type membrane separation device including a membrane module having membrane units stacked on top of each other in stages, in each of which flat sheet membrane elements each having a separation membrane are arranged, the membrane module is constructed of various membrane units differing in sludge-filtration resistance or pure-water permeation resistance, whereby it becomes possible to extend a device operation period of time lapsing before transmembrane plugging occurs, or equivalently, the necessity to clean membranes arises. Further, it also becomes possible to design to synchronize timings with which a plurality of membrane units require cleaning.

Abstract: A method of producing a chemical by continuous fermentation includes a fermentation step of converting a fermentation feedstock to a fermentation liquid containing a chemical by fermentation on cultivation of a microorganism; a membrane separation step of recovering the chemical as a filtrate by a separation membrane from the fermentation liquid; a concentrating step of obtaining a permeate and a concentrate containing the chemical by a reverse osmosis membrane from the filtrate; and/or a purification step of distilling the filtrate to increase a purity of the chemical, in which, cleaning etc. of the separation membrane in the membrane separation step is preformed by using the permeated liquid from the reverse osmosis membrane in the concentrating step and/or the condensed liquid in the purification step.

Abstract: A method produces a chemical through continuous fermentation including: (a) culturing a cell in a culture medium in a fermentor to ferment a feedstock to produce a chemical; (b) conducting filtration of the culture medium with a separation membrane module; (c) separating a permeate containing the chemical from the culture medium while retaining a non-permeated liquid in the fermentor, and (d) supplying a gas from at least one of a lower portion of the separation membrane module and a pipe communicating between the fermentor and the separation membrane module to adjust a gas linear velocity in the separation membrane module to 0.15 cm/s to 70 cm/s while supplying the separation membrane module with a liquid.

Abstract: A method of producing chemicals through continuous fermentation includes washing a membrane with a washing liquid supplied from a permeate side of a membrane unit in a continuous fermentation; filtering a culture medium containing a fermentation feedstock, a chemical and a microbe or a cultured cell through a separation membrane; collecting the chemical from a filtrate; retaining or refluxing unfiltered remains in the culture medium; and adding a fermentation feedstock to the culture medium, wherein the washing liquid is high-temperature water having a temperature higher than a temperature of the culture medium and of 150° C. or less, and a concentration of the microbe in a fermenter is controlled by supplying the washing liquid.

Abstract: A method of sterilizing a separation membrane module reduces damage of a ceramic separation membrane, a sterilization process device achieves the method of sterilizing, and an apparatus produces chemicals. The method of sterilizing the separation membrane module includes a ceramic-containing separation membrane including a temperature raise step of raising the temperature of the separation membrane module to a predetermined sterilization temperature by feeding sterilization water having a controlled temperature and pressure so that a rate of temperature change of the separation membrane module is 6.0° C. or less per minute, and a sterilization step of sterilizing the separation membrane module at a predetermined temperature for a predetermined time.

Abstract: A method of producing a chemical includes a fermentation step that converts a fermentation feedstock, through fermentation by culturing a microorganism or culture cells, into a fermented liquid containing the chemical, and a membrane separation step that collects the chemical, as a filtrate, from the fermented liquid with the use of two or more separation membrane modules, and returning the non-filtered liquid to the fermented liquid, wherein in the membrane separation step, timing of the filtration-stop treatment for each separation membrane module is controlled when an intermittent filtration operation including alternately repeating a filtration treatment and a filtration-stop treatment is performed with plural separation membrane modules.

Abstract: A hollow fiber membrane module includes a housing, a hollow fiber membrane sealed in the housing and a sealing agent in a space between the hollow fiber membrane and the housing, wherein 1) the hollow fiber membrane is made of a polysulfone based resin; 2) a membrane surface average pore diameter is 5 nm or more and 500 nm or less; 3) a pure water permeability coefficient under 50 kPa at 25° C. is 0.05 m3/m2/hour or more and 5 m3/m2/hour or less; 4) the sealing agent is at least one selected from the group consisting of a polyurethane resin and an epoxy resin; and 5) a decrease in tensile strength after bringing the sealing agent into contact with saturated steam at 121° C. for 24 hours is 25% or less.

Abstract: A method produces a chemical by fermentation including: filtering a liquid containing a feedstock, the chemical, and bacterial, microbial or cultured cells through a membrane to recover the chemical from the filtrate; retaining or refluxing unfiltered liquid in the liquid; and adding the feedstock to the liquid, wherein the membrane is a porous hollow-fiber membrane including a polyvinylidene fluoride resin, the porous hollow-fiber membrane having an average pore size of 0.001 ?m to 10.0 ?m, pure water permeability coefficient at 50 kPa at 25° C. of 0.5 m3/m2/hr to 15 m3/m2/hr, breaking strength of 5 MPa to 20 MPa, elongation at break of 30% to 200%, crimping degree of 1.3 to 2.5, porosity of not less than 40%, and critical surface tension of 45 mN/m to 75 mN/m.

Abstract: A hollow fiber membrane module for use in production of a chemical substance, which is used in continuous fermentation including filtering a fermentation broth of a microorganism or a cultured cell through a hollow fiber membrane, collecting a chemical substance from a filtrate, retaining a concentrated solution in the fermentation broth or refluxing the concentrated solution, and adding a fermentation raw material to the fermentation broth, wherein a large number of hollow fiber membrane bundles are accommodated in a tubular case, at least one end part of each of the bundles is fixed on the tubular case by a hollow fiber membrane bundling member with an end face of each of the hollow fiber membranes open, and the hollow fiber membrane bundling member is made of a synthetic resin having a hardness retention rate after contact with saturated steam at 121° C. for 24 hours of 95% or more.