Abstract: The present invention provides a method for allowing a used inert material that has been subjected to a reaction once, which is disposed of in the background art, to be used again as well as a brand-new one. A method of recovering an inert material of the present invention is characterized by in the fixed-bed reactor, the inert material is loaded in an inert material layer provided between a first-stage catalyst layer and a second-stage catalyst layer, the first-stage catalyst layer is loaded with a first-stage catalyst for producing acrolein from propylene, and the second-stage catalyst layer is loaded with a second-stage catalyst for producing acrylic acid from acrolein, the method comprising the steps of: extracting the inert material from the fixed-bed reactor; washing the extracted inert material; and screening the washed inert material.

Abstract: The present invention provides a method for allowing a used inert material that has been subjected to a reaction once, which is disposed of in the background art, to be used again as well as a brand-new one. A method of recovering an inert material of the present invention is characterized by in the fixed-bed reactor, the inert material is loaded in an inert material layer provided between a first-stage catalyst layer and a second-stage catalyst layer, the first-stage catalyst layer is loaded with a first-stage catalyst for producing acrolein from propylene, and the second-stage catalyst layer is loaded with a second-stage catalyst for producing acrylic acid from acrolein, the method comprising the steps of: extracting the inert material from the fixed-bed reactor; washing the extracted inert material; and screening the washed inert material.

Abstract: The present invention provides a process for producing a (meth)acrylic ester which enables to obtain a (meth)acrylic ester in an excellent reaction yield. The process for producing a (meth)acrylic ester uses an alcohol and an acid as raw materials and an ion-exchange resin as a catalyst, and the process is characterized by comprising a dehydration step and an esterification step, wherein the esterification reaction step follows the dehydration step in which water impregnated in the ion-exchange resin is removed by using as a dehydrating solvent at least one member selected from the group consisting of the alcohol, the acid, and the resulting ester.

Abstract: This invention relates to a storage tank for a viscous oil containing easily polymerizable compounds. The storage tank of the present invention for storing viscous oil containing easily polymerizable compounds comprises a bottom plate, a side wall, a draw-off pipe and an inlet pipe. The bottom plate slopes downwardly toward the draw-off pipe, and an angle of downward inclination of the bottom plate is a gradient of at least 1/200. It becomes possible because of the storage tank to effectively prevent polymerization of easily polymerizable compounds contained in waste oil within the storage tank, and clogging of a pipe is suppressed considerably.

Abstract: The present invention provides a process for producing a (meth)acrylic ester which enables to obtain a (meth)acrylic ester in an excellent reaction yield. The process for producing a (meth)acrylic ester uses an alcohol and an acid as raw materials and an ion-exchange resin as a catalyst, and the process is characterized by comprising a dehydration step and an esterification step, wherein the esterification reaction step follows the dehydration step in which water impregnated in the ion-exchange resin is removed by using as a dehydrating solvent at least one member selected from the group consisting of the alcohol, the acid, and the resulting ester.

Abstract: This invention relates to a storage tank for a viscous oil containing easily polymerizable compounds. A storage tank of the present invention for strong viscous oil containing easily polymerizable compounds, comprising a bottom plate 12, a side wall 13, a draw-off pipe 3 and a inlet pipe 2. The bottom plate 12 slopes downward toward the draw-off pipe 3 and an angle of downward inclination of the bottom plate 12 is gradient at least 1/200. It becomes possible by the present inventive storage tank to effectively prevent the polymerization of the easily polymerizable compounds contained in the waste oil within the storage tank and the clogging of a pipe is suppressed considerably.