The present invention discloses a method of quickly desorbing phosgene from a catalyst in a phosgene synthesizing tower when the catalyst in the phosgene synthesizing tower is replaced. The method is carried out by first purging out easily-desorbed phosgene from the catalyst activated carbon in the phosgene synthesizing tower with nitrogen gas, then purging with ammonia gas, and the ammonia gas is reacted with the hardly-desorbed phosgene in the catalyst of the phosgene synthesizing tower. Then the phosgene synthesizing tower is rinsed with a water gun and then dried with hot gas. The phosgene content at an outlet of the phosgene synthesizing tower after purging is below 0.5 ppm, which can significantly save the time of the phosgene synthesizing tower for purging the phosgene, greatly reduce the amount of nitrogen gas consumed, and improve the safety of the process operation.

The present invention discloses a method of quickly desorbing phosgene from a catalyst in a phosgene synthesizing tower when the catalyst in the phosgene synthesizing tower is replaced. The method is carried out by first purging out easily-desorbed phosgene from the catalyst activated carbon in the phosgene synthesizing tower with nitrogen gas, then purging with ammonia gas, and the ammonia gas is reacted with the hardly-desorbed phosgene in the catalyst of the phosgene synthesizing tower. Then the phosgene synthesizing tower is rinsed with a water gun and then dried with hot gas. The phosgene content at an outlet of the phosgene synthesizing tower after purging is below 0.5 ppm, which can significantly save the time of the phosgene synthesizing tower for purging the phosgene, greatly reduce the amount of nitrogen gas consumed, and improve the safety of the process operation.

Methods and systems include supplying pulsed microwave radiation through a waveguide, where the microwave radiation propagates in a direction along the waveguide. A pressure within the waveguide is at least 0.1 atmosphere. A supply gas is provided at a first location along a length of the waveguide, a majority of the supply gas flowing in the direction of the microwave radiation propagation. A plasma is generated in the supply gas, and a process gas is added into the waveguide at a second location downstream from the first location. A majority of the process gas flows in the direction of the microwave propagation at a rate greater than 5 slm. An average energy of the plasma is controlled to convert the process gas into separated components, by controlling at least one of a pulsing frequency of the pulsed microwave radiation, and a duty cycle of the pulsed microwave radiation.

The invention relates to a method particularly for reacting phosgene with compounds that contain hydroxyl, thiol, amino and/or formamide groups, comprising the steps of: (I) providing a reactor which has a first reaction chamber (300, 310, 320, 330, 340, 350) and a second reaction chamber (200, 210, 220, 230, 240, 250, 260), the first and the second reaction chambers being separated from one another by means of a porous carbon membrane (100, 110, 120, 130, 140, 150); (II) providing carbon monoxide and chlorine in the first reaction chamber; and simultaneously (III) providing a compound containing hydroxyl, thiol, amino and/or formamide groups in the second reaction chamber. The porous carbon membrane is configured to catalyse the reaction of carbon monoxide and chlorine to obtain phosgene, and to allow this formed phosgene to pass into the second reaction chamber. The invention also relates to a reactor that is suitable for carrying out the claimed method.

A method of reacting a first compound with a second compound, wherein the first compound has a GHS hazard identification of GHS06 and is obtainable from the reaction of at least one first fluid precursor compound and one second fluid precursor compound and wherein the second compound is capable of a chemical reaction with the first compound is provided

Provided in the invention are a catalyst for preparing phosgene and a preparation method therefor, and a method for the preparation of phosgene and the comprehensive utilization of energy thereof. The preparation method comprises the following steps: 1) stirring and soaking activated carbon in a modifying solution, then adding dimethyltin dichloride and chromium oxide powders and carrying out a reaction, and then adding a nickel oxide fine powder and ultrasonically oscillating same to prepare a pre-modified activated carbon; 2) drying the pre-modified activated carbon; and 3) heating and calcinating the dried pre-modified activated carbon from step 2) to prepare the catalyst. Based on the preparation method, thin layers are formed on the surface of the catalyst by bonding chromium tin phosphate and chromium tin silicate with Ni by means of —O—Ni—O—, respectively, which can improve the high-temperature resistance and oxidation resistance of the activated carbon, and improve the safe and stable operation level of a device. The aim of integrated comprehensive utilization of energy is achieved by coupling phosgene production with an evaporation and concentration process of brine and using steam as a heat source for evaporation and concentration of the brine.

Provided in the invention are a catalyst for preparing phosgene and a preparation method therefor, and a method for the preparation of phosgene and the comprehensive utilization of energy thereof. The preparation method comprises the following steps: 1) stirring and soaking activated carbon in a modifying solution, then adding dimethyltin dichloride and chromium oxide powders and carrying out a reaction, and then adding a nickel oxide fine powder and ultrasonically oscillating same to prepare a pre-modified activated carbon; 2) drying the pre-modified activated carbon; and 3) heating and calcinating the dried pre-modified activated carbon from step 2) to prepare the catalyst. Based on the preparation method, thin layers are formed on the surface of the catalyst by bonding chromium tin phosphate and chromium tin silicate with Ni by means of —O—Ni—O—, respectively, which can improve the high-temperature resistance and oxidation resistance of the activated carbon, and improve the safe and stable operation level of a device. The aim of integrated comprehensive utilization of energy is achieved by coupling phosgene production with an evaporation and concentration process of brine and using steam as a heat source for evaporation and concentration of the brine.

The present invention relates to a method for operating a phosgene generator for producing phosgene by reacting carbon monoxide with chlorine in the gas phase on an activated carbon catalyst arranged in a reaction chamber, in which method, after a predefinable operating period, the phosgene production is at least temporarily interrupted by shutting down the phosgene generator over a shutdown period and, after a predefinable downtime, is resumed by starting up the phosgene generator over a start-up period, wherein the method is characterized in that the activated carbon catalyst, before the phosgene generator is started up, is freed of chlorine by adding carbon monoxide so that, during the start-up period, a maximum concentration of chlorine in the gas stream immediately downstream of the reaction chamber of 1000 ppmv is not exceeded. The invention also relates to the use of the phosgene thus obtained in the production of polycarbonate and isocyanates.

The invention relates to an integrated process for conditioning process water (1) from the production (I) of polycarbonate, which process water contains at least catalyst residues and/or organic impurities and sodium chloride, and subsequently utilizing the process water (1) in a subsequent sodium chloride electrolysis (V).

The invention relates to an integrated process for conditioning process water (1) from the production (I) of polycarbonate, which process water contains at least catalyst residues and/or organic impurities and sodium chloride, and subsequently utilizing the process water (1) in a subsequent sodium chloride electrolysis (V).