Abstract: A perforated tray without downcomer in accordance with the present invention satisfies following conditions: (a) The hole has a diameter of 10 mm to 25 mm. (b) Two adjacent holes are spaced by a distance of 1.2 d to 3 d, measured between the two centers. (c) The tray thickness is 2 mm to 8 mm. (d) The opening ratio is 10% to 30%. A perforated tray tower without downcomer fitted with two or more such perforated trays without downcomer in accordance with the present invention satisfies following conditions: (g) Perforated trays are spaced by a distance of 0.1 D to 0.5 D (D denotes the tower diameter). (h) The levelness of each perforated tray is 8 mm or less. (i) If a plurality of perforated trays are used at the same stage, the two most closely located holes that respectively belong to adjacent perforated trays are spaced by a distance of 50 mm to 150 mm, measured between the two centers.

Abstract: The present invention relates to a pharmaceutical solution containing a physiologically active non-peptide substance, an organic acid and a biocompatible organic solvent, and provides a pharmaceutical solution wherein a physiologically active non-peptide substance is dissolved at a high concentration.

Abstract: A hydrophilic membrane having a low adsorptivity for a protein is disposed, as an interface, on a side to be contacted with a skin, and a drug such as a physiologically active peptide is transdermally delivered by iontophoresis. The membrane has an adsorptivity for a protein of not greater than 10 &mgr;g/cm2. The thickness of the membrane is about 10 to 200 &mgr;m, and the porosity of the membrane is about 60 to 90%. Such membrane includes a hydrophilized fluororesin membrane, a hydrophilized polysulfone membrane and a hydrophilized cellulose derivative membrane.

Abstract: The present invention provides a heat-exchanging method for an easily polymerizable compound which method effectively prevents polymerization in a heat exchanger to enable a long-term stable heat exchange when an easily polymerizable liquid compound (for example, acrylate ester) or an easily polymerizable compound-containing liquid (for example, aqueous acrylic acid solution) is heat-exchanged. A vertical spiral type heat exchanger with a fluid path space of not less than 6 mm is used as a heat exchanger to carry out the heat exchange under conditions where the average liquid flow rate is not less than 0.2 m/sec and where the liquid residence time is not more than 100 seconds.

Abstract: A method is disclosed which produces acrylic acid in a high yield as maintaining the conditions for purifying acrylic acid in constant ranges and preventing the acrylic, acid from polymerization. By using single a single reactor, propylene concentration adjusting in the range of 7-15 vol. % and water concentration adjusting in the range of 0-10 vol. % are introduced thereinto thereby obtaining an acrylic acid-containing gas. Then the gas is introduced to an acrylic acid absorption column to adjust water concentration in the range of 1-45 wt. %, thereby preventing from polymerization.

Abstract: This invention concerns a method for absorbing acrylic acid, characterized by supplying an acrylic acid-containing reaction gas component obtained by the reaction of catalytic gas phase oxidation to an acrylic acid absorption column and advancing a high boiling inert hydrophobic organic liquid into counter-flow contact with said reaction gas in said acrylic acid absorption column with the mass flow rate of the organic liquid fixed in the range of 0.2-4.5 times the mass flow rate of the acrylic acid in the reaction gas thereby absorbing acrylic acid in said organic liquid and obtaining an acrylic acid-containing solution and a method for purifying acrylic acid, comprising a step for purifying the acrylic acid-containing organic liquid obtained by the step mentioned above. By this invention, a product of acrylic acid containing a low boiling substance at a low concentration can be produced.

Abstract: This invention is providing a method for efficient treatment of the waste material from a process for production of acrylic acid and an acrylic ester. This is a method for the disposal of waste material, which at least one waste material selected from the group consisting of waste oil, waste water, and waste gas emitted from a process for production of acrylic acid is/are purified with at least one waste material selected from the group consisting of waste oil, waste water, and waste gas emitted from a process for production of an acrylic ester jointly. The efficiency of the treatment is enhanced by simultaneously treating the waste material from an adjoining process for the productions each other.

Abstract: A method for refining an easily polymerizable matter while preventing an easily polymerizable matter-containing substance from being polymerized and an apparatus for use in the method are disclosed. The method and apparatus for refining and separating the easily polymerizable matter-containing substance by the use of a distillation column provided with a heat exchanger set the linear velocity of a vapor in a connecting line intervening between the distillation column and the heat exchanger at a level of not less than 5 m per second and the retention time of the vapor at a level of not more than 3 seconds.

Abstract: A method for the production of acrylic acid comprises (i) a step for introducing a polymerization inhibitor to a stage other than a stage for supplying a raw material and a stage for supplying a reflux of said distilling column or (ii) a step for supplying the acrylic acid recovered by thermally decomposing said oligomer to said stage for dehydration. Thus, the present invention enjoys effective utilization of acrylic acid and exalts the efficiency of production.

Abstract: A method of manufacturing (meth)acrylic acid includes: a reaction step of carrying out a catalytic gas-phase oxidation reaction; an absorbing step of absorbing (meth)acrylic acid from a (meth)acrylic-acid-containing mixed gas prepared in the reaction step; a refinement step of separating, refining, and recovering (meth)acrylic acid from a (meth)acrylic-acid-containing liquid prepared in the absorbing step; and a recirculation step of recirculating (meth)acrylic acid contained in a vent gas produced in the refinement step to the absorbing step and/or the refinement step.

Abstract: A method for starting up a distilling column destined to handle an easily polymerizing compound-containing solution characterized by supplying at the start of the operation of the distilling column a polymerization inhibitor to the bottom liquid of the distilling column having a temperature of not higher than 80° C. Further, by supplying a reflux liquid through the top of the distilling column or the middle stage of the column prior to the start of the temperature elevation of the distilling column, thereby preventing the polymerization of the easily polymerizing compound more effectively.

Abstract: In distillation of a polymerizable compound such as (meth)acrylic acid or a liquid containing such a polymerizable compound with use of a distillation column equipped with a reboiler, (a) a vertical multi-tube reboiler whose outlet nozzle inside diameter (D1) is 0.2 to 1 time its reboiler shell inside diameter (D2) is used as the reboiler, (b) an outlet of an outlet nozzle of the reboiler to a gas-phase section of the distillation column is provided at a position such that a distance L from the top tubesheet of the reboiler to the lower end of the outlet of the outlet nozzle satisfies L=(0.4 to 3)×D1, and (c) a liquid level in the distillation column is maintained in a range such that a height H of the liquid level from the top tubesheet of the reboiler satisfies H=(0.1 to 0.8)×L.

Abstract: A method for the absorption of (meth)acrylic acid and/or (meth)acrolein and an apparatus thereof which, in an absorption column adapted to cause an (meth)acrylic acid and/or (meth)acrolein-containing gas obtained in consequence of catalytic gas phase oxidation to come into countercurrent contact with a solvent, contemplate using a packing of relatively high efficiency in absorption disposed on the upstream side of the flow of a liquid containing the solvent and a packing and/or trays of relatively low performance of forming polymerization disposed on the downstream side thereof, in the column.

Abstract: For a heat exchanger using a heating medium for the purpose of heating a fluid to be handled during a steady state, this invention provides a method for using relevant devices which enables the heat exchanger to be operated safely and infallibly without suffering the raw material or the reaction product to polymerize in the reactor or the pipes during an unsteady state, suffering the reactor or the pipes to sustain a fracture owing to a rise in the internal pressure of the vessel, and suffering the apparatus for production to sustain serious damage. This invention pertains, mainly in a heat exchanger admitting a heating medium and using it for the purpose of heating a fluid to be handled, to a method for using relevant devices during the unsteady state, characterized by introducing a cooling medium in the place of the heating medium mentioned above.

Abstract: A purifying apparatus characterized by being equipped with a vapor dispersing device possessing in a vapor inlet part owned by the apparatus on the lateral inside thereof an opening part facing downward from the horizontal direction and a horizontal projected cross section area in the range of 10-40% of the cross section area of said apparatus. In consequence of the incorporation of the vapor dispersing device according to this invention, the drift of the gas is repressed, the efficiency of separation is improved, and the possible polymerization of a compound under treatment in the lower part of the column is prevented.

Abstract: A method for producing (meth)acrylic acid of high purity by repressing formation of a polymer possibly generated during the course of production is disclosed. The production is accomplished by returning the waste liquid generated at the step of the addition of aldehyde treating agents (d) to the step of the absorption (b) and/or the step of separation (c).

Abstract: Disclosed is a method of removing heavy metals contained in exhaust gas which has been generated by burning a waste liquid containing the heavy metals discharged in a process of producing organic compounds. The method includes the steps in the order of: (a) a combustion step of burning the waste liquid to produce exhaust gas; (b) a gas-liquid contact step of rendering a liquid containing an alkali compound in contact with the exhaust gas to collect the heavy metals in bottoms of the liquid; and (c) a coagulating step of adding a coagulant to the bottoms to coagulate the heavy metals in the bottoms for removal of the heavy metals. According to this method, the heavy metals contained in the exhaust gas can be efficiently separated and removed.

Abstract: A method for refining an easily polymerizable matter while preventing an easily polymerizable matter-containing substance from being polymerized and an apparatus for use in the method are disclosed. The method and apparatus for refining and separating the easily polymerizable matter-containing substance by the use of a distillation column provided with a heat exchanger set the linear velocity of a vapor in a connecting line intervening between the distillation column and the heat exchanger at a level of not less than 5 m per second and the retention time of the vapor at a level of not more than 3 seconds.

Abstract: A distillation apparatus is provided with a distillation tower, a reboiler, a bottom outflow pipe for drawing a liquid from the bottom of the distillation tower, and a pot provided between the bottom of the distillation tower and the bottom outflow pipe. A part of the drawn liquid is discharged to the outside of the distillation apparatus while the rest is flowed to the reboiler. The pot has a cross-sectional area smaller than a cross-sectional area of the distillation tower and larger than a cross-sectional area of the bottom outflow pipe.

Abstract: A method is provided for preventing an easily polymerizable substance from being polymerized in a thin-film type evaporating device by supplying a solution of the substance to the evaporating heating surface of the device by the centrifugal force of a stirring rotary shaft, characterized by mixing a distilled vapor of the substance with a molecular oxygen-containing gas and supplying the extracted liquid or a solution having lower viscosity than the extracted liquid to a feed raw material inlet thereby adjusting the quantity of a wetting liquid per unit length of the surface in the range of 0.02-2 m3/mHr. In the evaporation of the substance by the use of the device, a method for preventing the substance from polymerization is provided.