液化石油气脱硫醇装置中水洗工艺用水量探讨

介绍了液化石油气脱硫醇装置中水洗单元的原则工艺流程。分析了碱性物质在烃相特殊的存在形式,在水洗过程中与水交换的数量、特点以及混合过程的非理想性,结合液化石油气脱硫醇装置中水洗单元的工艺控制指标和稀释原理,建立了工艺用水量和水耗计算方法,推导了分别基于液化石油气产品的钠离子控制指标和含碱废水pH值控制指标的工艺用水量和水耗计算公式及两个工艺控制参数之间的数学关联式。在此基础上做了如下工作:讨论了液化石油气中碱液含量的确定方法;应用水在纯烃和混合烃中溶解度经验公式和推导的水耗公式计算了以丙烷和丁烷作为烃组分时,液化石油气在脱硫醇典型工艺控制和操作条件下的水耗值为0.046 0和0.040 6 kg/kg;工业运行值分别为0.006 3和0.046 6 kg/kg,分析了产生偏差的原因。

Study on water consumption for water washing process of LPG sweetening unit

The principle process flow of water washing unit in liquefied petroleum gas （LPG） sweetening plant is introduced. The form of alkali material in hydrocarbon phase and the exchange quantity of alkali material with water during water washing as well as mixing process are analyzed. On the basis of process control indexes and dilution principles of water washing unit in LPG sweetening plant, the calculation methods of process water requirement and water consumption were established. The calculation formula for process water requirement and water consumption as well as mathematic correlations between control indexes were estab- lished and deduced based upon the control index of sodium ions in LPG products and the control index of PH value of waste water containing caustic. In addition, （a） the method for determining caustic solution content in LPG was discussed; （b） the water consumption of saturated LPG under the typical process control and operating conditions was calculated by applying the said deduced experimental formula for solubility of water in hydrocarbons and deduced water consumption calculation formula; （c） the calculation data of water consumption and water consumption data of commercial unit were compared, and the causes of their differences were analyzed.