两种制氢原料的适用性与经济性分析

Applicability and economic analysis of two kinds of hydrogen-making feedstocks

从原料性质、装置运行参数、产品收率及装置能耗等方面对液化石油气+加氢裂化干气(工况1)、天然气+加氢裂化干气(工况2)两种制氢原料的适用性进行分析比较,指出选用工况2可减小转化剂结炭倾向,降低中变床层最高温度13.7℃,避免床层超温,有利于装置长周期运行,同时可增加氢气收率0.5百分点,每生产1 000 m^3纯氢降低能耗99.83 MJ。比较两种原料制氢的加工成本,指出在现有价格体系下,选用天然气+加氢裂化干气作为制氢原料,加工成本低,经济效益显著,按年加工量产氢30 kt计算,年增加效益11 073.12万元。只有当液化石油气价格低于2 644.35元/t时,工况1相较工况2才有经济性。同时指出天然气作为制氢原料优于液化石油气。

The applicability of liquefied petroleum gas+hydrocracking dry gas(working condition 1) and natural gas+hydrocracking dry gas(working condition 2) for hydrogen production is analyzed and compared from the aspects of feedstocks properties, unit operation parameters, product yield and unit energy consumption, etc. It is pointed out that the tendency of coke formation on converter can be reduced by choosing working condition 2, and reducing the maximum temperature of the medium-temperature bed by 13.7 C and avoiding overheating of the bed, being beneficial to the long-term operation of the plant. At the same time, the hydrogen yield can be increased by 0.5 percentage point, and the energy consumption can be reduced by 99.83 MJ/km^3 pure hydrogen production. Comparing the cost of hydrogen production with that of the two feedstocks, it is pointed out that under the current price system, natural gas+hydrocracking dry gas is selected as the feedstocks for hydrogen production, which has low processing cost and remarkable economic benefits. According to the calculation of 30 000 ton hydrogen production per year, the annual increase benefis is 110.7312 million yuan. Only when the price of liquefied petroleum gas is lower than 2644.35 yuan/ton, the economy of working condition 1 is better than that of working condition 2. It is also pointed out that natural gas is superior to liquefied petroleum gas as feedstocks for hydrogen produnction.