Provided is a photochemical reaction device wherein two partitions formed from an optically transparent material are arranged apart from each other between a light source and a reaction liquid, and an optically transparent fluid introduction/discharge means for introducing an optically transparent fluid between the partitions and discharging the fluid and a state change detection means for detecting a change in the state of the optically transparent fluid at the discharge side of the optically transparent fluid introduction/discharge means are provided. Also provided are a photochemical reaction method that uses the photochemical reaction device and a lactam production method that uses the photochemical reaction method. The present invention prevents decreases in the performance of the light source even when the optically transparent material in the photochemical reaction device is damaged, and makes it possible to reliably prevent ignition even if the reaction liquid is a flammable liquid.

Provided are a three-phase AC/DC converter disposed between a three-phase AC power supply and a light emitting diode group, the converter including a three-phase full bridge circuit in which pairs of switching elements are connected in parallel between DC buses for the three phases of the three-phase AC power supply; reactors connecting connection portions between the switching elements and corresponding phases of the three-phase AC power supply; a smoothing capacitor on the output side of the three-phase full bridge circuit; a DC voltage detection means; a power supply voltage phase detection means; and a pulse width modulation means for outputting pulse width modulation signals of the switching elements, wherein the pulse width modulation means outputs the pulse width modulation signals based on a power supply voltage phase and an output voltage between the DC buses.

The invention relates to a method for producing cyclododecanone (CDON). During the production, contaminated cyclododecane (CDAN) is produced. This can be separated from CDON by distillation (CDAN-containing fraction). The separation of CDAN and impurities such as 13-oxabicyclo [7.3.1]tridecane occurs by crystallizing out CDAN from the CDAN-containing fraction.

The invention relates to a method for producing cyclododecanone (CDON). During the production, contaminated cyclododecane (CDAN) is produced. This can be separated from CDON by distillation (CDAN-containing fraction). The separation of CDAN and impurities such as 13-oxabicyclo [7.3.1]tridecane occurs by crystallizing out CDAN from the CDAN-containing fraction.

The present invention relates to a laurolactam preparation method and synthesis apparatus, and epoxidation and a rearrangement reaction are performed in the conversion of cyclododecene into cyclododecanone so that the preparation method can synthesize laurolactam having a higher purity with a higher selectivity and in a higher yield than a conventional preparation method.

The present invention relates to a laurolactam preparation method and synthesis apparatus, and epoxidation and a rearrangement reaction are performed in the conversion of cyclododecene into cyclododecanone so that the preparation method can synthesize laurolactam having a higher purity with a higher selectivity and in a higher yield than a conventional preparation method.

The present disclosure discloses a MFI topological structure silicon molecular sieve, a preparation method thereof and a catalyst containing the MFI topological structure silicon molecular sieve, wherein the molecular sieve containing a silicon element, an oxygen element and a metallic element, the ions of said metallic element have a Lewis acid characteristic; the content of the metallic element in the molecular sieve is within a range of 5-100 μg/g based on the total amount of the molecular sieve; the BET specific surface area of the molecular sieve is within a range of 400-500 m.sup.2/g.

The present disclosure discloses a MFI topological structure silicon molecular sieve, a preparation method thereof and a catalyst containing the MFI topological structure silicon molecular sieve, wherein the molecular sieve containing a silicon element, an oxygen element and a metallic element, the ions of said metallic element have a Lewis acid characteristic; the content of the metallic element in the molecular sieve is within a range of 5-100 μg/g based on the total amount of the molecular sieve; the BET specific surface area of the molecular sieve is within a range of 400-500 m.sup.2/g.

The present invention relates to a laurolactam preparation method and synthesis apparatus, and epoxidation and a rearrangement reaction are performed in the conversion of cyclododecene into cyclododecanone so that the preparation method can synthesize laurolactam having a higher purity with a higher selectivity and in a higher yield than a conventional preparation method.

The present invention relates to a laurolactam preparation method and synthesis apparatus, and epoxidation and a rearrangement reaction are performed in the conversion of cyclododecene into cyclododecanone so that the preparation method can synthesize laurolactam having a higher purity with a higher selectivity and in a higher yield than a conventional preparation method.