Abstract: Provided is a method for detecting ammonia nitrogen content by using a nitrification biological reaction. In the present disclosure, the nitrifying microorganisms have high specificity for ammonia nitrogen, a metabolism and oxygen consumption capacity closely related to the ammonia nitrogen concentration, high accuracy and high sensitivity of ammonia nitrogen detection, and are not easily disturbed by water body chromaticity, suspended matters, and the like. In addition, the activity of the nitrification microorganism membrane reactor can be kept stable for a long term, and the stability of a sensor is good for long-term use. In the present disclosure, with a mono-component or multi-component solution containing inorganic nitrogen and inorganic carbon as a nitrification nutrient solution, a nitrification microorganism membrane with strong adaptability to the environment, a stable structure, a high selectivity for ammonia nitrogen, and an ability of efficiently degrading ammonia nitrogen can be obtained.

Abstract: A process and a device for continuous flow side-chain alkylation which relate to the technical field of organic synthesis. In this process and the device for continuous flow side-chain alkylation, an ibuprofen raw material is prepared with alkylbenzene as a raw material. This raw material alkylbenzene is easily available and has a low cost, and is suitable for scale-up production. Moreover, an entire preparation process adopts continuous chemical synthesis, and a reaction time of each stage can be precisely controlled, which is beneficial to control a total reaction time and reduce an amount of impurities produced. In this way, a purity and a yield of the ibuprofen raw material are improved. In summary, a continuous synthesis method for side-chain alkylation of alkylbenzene provided by the present disclosure shows a low cost and a high yield.

Abstract: The present disclosure belongs to the technical field of chemical separation and purification, and in particular relates to a purification method and device for continuous distillation and separation of an ibuprofen intermediate raw material. The purification method comprises the following steps: carrying out a primary distillation on synthetic liquid to obtain a primary material and recovered 4-methyl-1-pentene, then carrying out a second-stage distillation on the primary material to obtain a second-stage material and a recovered crude toluene product; and carrying out a third-stage distillation on the second-stage material to obtain isobutyl benzene and a recovered crude n-butylbenzene product. Embodiment results show that the purification method provided by the present disclosure is high in product recovery rate and high in product purity, the purity of isobutyl benzene is up to 99.99 wt %, the recovery rate is up to 99.9 wt %, the impurity content is not higher than 50 ppm.

Abstract: The present disclosure provides an active zinc-based catalyst and a preparation method thereof, and use in catalyzing a rearrangement reaction of ibuprofen. The active zinc-based catalyst includes a carbon-based fiber material and nano-zinc oxide supported on a fiber surface of the carbon-based fiber material. The active zinc-based catalyst is introduced with the carbon-based fiber material, and the carbon-based fiber material is capable of increasing a specific surface area of the catalyst, thereby improving a dispersion degree of zinc oxide, increasing the number of catalytic active sites, and significantly improving a catalytic activity. Meanwhile, due to a certain mechanical strength, the carbon-based fiber material is capable of improving a mechanical strength of the catalyst, making the catalyst exist stably in ketal fluid, maintaining a stable morphology of the catalyst, and avoiding or inhibiting reduction of the catalytic active sites, thereby ensuring a catalytic stability.

Abstract: The present disclosure belongs to the technical field of chemical separation and purification, and in particular relates to a purification method and device for continuous distillation and separation of an ibuprofen intermediate raw material. The purification method comprises the following steps: carrying out a primary distillation on synthetic liquid to obtain a primary material and recovered 4-methyl-1-pentene, then carrying out a second-stage distillation on the primary material to obtain a second-stage material and a recovered crude toluene product; and carrying out a third-stage distillation on the second-stage material to obtain isobutyl benzene and a recovered crude n-butylbenzene product. Embodiment results show that the purification method provided by the present disclosure is high in product recovery rate and high in product purity, the purity of isobutyl benzene is up to 99.99 wt %, the recovery rate is up to 99.9 wt %, the impurity content is not higher than 50 ppm.

Abstract: The present disclosure provides an active zinc-based catalyst and a preparation method thereof, and use in catalyzing a rearrangement reaction of ibuprofen. The active zinc-based catalyst includes a carbon-based fiber material and nano-zinc oxide supported on a fiber surface of the carbon-based fiber material. The active zinc-based catalyst is introduced with the carbon-based fiber material, and the carbon-based fiber material is capable of increasing a specific surface area of the catalyst, thereby improving a dispersion degree of zinc oxide, increasing the number of catalytic active sites, and significantly improving a catalytic activity. Meanwhile, due to a certain mechanical strength, the carbon-based fiber material is capable of improving a mechanical strength of the catalyst, making the catalyst exist stably in ketal fluid, maintaining a stable morphology of the catalyst, and avoiding or inhibiting reduction of the catalytic active sites, thereby ensuring a catalytic stability.