3 results about "Carbon Chloride" patented technology

This invention discloses a method and system for determining volatile halogenated hydrocarbons in dissolved gases of seawater, belonging to the field of analytical chemistry. The method employs direct gas injection combined with a six-way valve switching injection system, enabling the direct and simultaneous determination of seven volatile halogenated hydrocarbons in seawater: chloroform, carbon tetrachloride, trichloroethylene, bromodichloromethane, tetrachloroethylene, dibromochloromethane, and tribromomethane. This eliminates the need for organic solvents and complex pretreatment, filling a technological gap in this field. Validation shows a detection limit of 0.1–1.1 nmol / mol, a retention time RSD ≤ 0.20%, a concentration RSD ≤ 4.93%, and a relative error between -2.01% and 1.56%. The method exhibits advantages such as high sensitivity, good stability, simple operation, and environmental friendliness, and can be directly applied to fields such as marine environmental monitoring and seabed oil and gas resource exploration.

This invention belongs to the field of organic synthesis technology, specifically relating to a method for preparing 1,1,3,3,3-pentafluoropropylene. This invention designs a perovskite-type catalyst doped with noble metals or synergistically constructs a supported metal catalyst. Through a collaborative mechanism where the support provides strong Lewis acidity and fluorination activity, while the noble metal provides dehydrogenation activity, the interfacial interactions and reaction matching of the catalytic system are precisely controlled. This allows for highly efficient catalysis of the integrated "telomerization-fluorination-dehydrogenation" reaction of vinyl chloride (CHCl=CH2), carbon tetrachloride (CCl4), and hydrogen fluoride (HF). The reaction can be carried out continuously in the same reactor and with the same synergistic catalyst system, without the need to change equipment or catalysts, resulting in outstanding production efficiency. Furthermore, the selectivity and controllability of the reaction conditions are significantly optimized, enabling high-selectivity and high-yield synthesis of the target product under mild conditions. Simultaneously, it achieves the resource utilization of industrial waste carbon tetrachloride, representing a major technological breakthrough in terms of raw material cost, process simplification, and environmental friendliness.

The application provides a preparation method of 5N cesium iodide and belongs to the technical field of inorganic material preparation. A cesium carbonate solution is purified to remove insoluble substances, and then cations such as calcium and magnesium are removed by using a cation exchange resin to obtain a purified cesium carbonate solution; the purified cesium carbonate solution is evaporated and concentrated, cooled and crystallized, and dried to obtain dry cesium carbonate; elemental iodine is added into water, carbon tetrachloride is added, and the carbon tetrachloride solution containing the elemental iodine is distilled to obtain refined elemental iodine; the dry cesium carbonate, the refined elemental iodine and hydrazine hydrate are mixed to obtain a cesium iodide solution, which is evaporated and concentrated, cooled and crystallized, and dried to obtain 5N cesium iodide. The application selects a low-cost and high-yield method to purify raw materials from the perspective of raw materials, and 5N cesium iodide is prepared, so that multiple recrystallizations are avoided, and the method has the characteristics of low cost and high yield.