Research On Ammonium Chloride Salt Crystal Deposition In Hydrogenation Unit

The oil refining industry in the world,as an important basic industry to measure the national economic level,occupies the lifeline of the national economy.My country's rapid development in recent years has also increased the demand for crude oil year by year.The ammonium chloride crystallization reaction of impurities such as nitrogen and chlorine in crude oil after the hydrogenation process causes local corrosion of equipment,which leads to shutdowns or safety accidents.Therefore,this article is to study the ammonium chloride crystallization and crystal flow deposition law in the hydrogenation system.The crystallization behavior of ammonium chloride was studied,and the mechanism of ammonium salt corrosion in the hydrogenation process was analyed.Conduct actual investigations and process data of a refinery,analyze the hydroprocessing process,material composition,operating temperature,operating pressure,etc.,deduced that the possible location of ammonium chloride crystallization is in the heat exchange system,and use Aspen software to establish process calculations Model,calculate the phase change,the physical property parameters of oil and gas,calculate the reaction temperature of ammonium chloride crystallization and the amount of ammonium chloride crystal crystallization.For the flow and deposition process of ammonium chloride crystals in the heat exchange tube,the Fluent simulation software is used to establish a calculation model,and the flow field,temperature field,and concentration field are combined to realize multi-physics coupling.The discrete phase DPM model is adopted,and the ammonium chloride crystal is the discrete phase.,Oil and gas are used as the continuous phase,working condition parameters are selected,taking into account the influence of temperature on physical parameters,the flow trajectory of ammonium chloride crystal particles is calculated,and the distribution law of ammonium chloride crystal deposition is studied and analyzed.Design the Kp equivalence alternative test model.When ensuring the same Kp value,use low-pressure nitrogen as the medium environment to establish a calculation model compared with the high-pressure oil and gas environment,and compare the flow and deposition of ammonium chloride and ammonium salt particles under different pressure medium environments.The distribution law verifies that low-pressure nitrogen is used to replace high-pressure oil and gas as the medium when the Kp value is unchanged to establish a test platform.Design the test process plan,take the equivalence test as the theoretical basis,realize the test is safe,reliable,and convenient to operate.Choose a low-pressure environment,use nitrogen as the flowing medium,heat the ammonium chloride solid to decompose together with nitrogen into the pipeline,and design the glass tube for experimental observation The device observes the ammonium chloride crystallization and flow deposition behavior along with the gas flow,and measures the amount of ammonium chloride crystallization in the glass tube.