废旧橡胶低温粉碎中LNG冷能利用的集成分析

为降低废旧橡胶低温粉碎生产精细胶粉的能耗,提出了集成利用液化天然气(LNG)冷能的液氮冷冻粉碎法和低温氮气冷冻粉碎法两种工艺,并对其进行用能分析.研究结果表明:(1)空分装置利用LNG冷能生产液氮,产品能耗可降低60.2%,利用每吨LNG的冷能可节省用电244.3kW · h,冷能利用的效率达到60.7%,精细胶粉的生产能耗可降低126.4kW · h/t;(2)废旧橡胶低温粉碎装置紧邻LNG接收站时,直接利用空分装置副产的氮气和LNG冷能生产低温氮气用于废旧橡胶的冷冻和粉碎,相对于空气冷冻法,精细胶粉的生产能耗可降低437.3kW · h/t,利用1吨 LNG的冷能可节省用电276.3kW · h,冷能利用的效率为70.7%.

Integration Analysis of LNG Cold Energy Utilization in Cryogenic Pulverization of Waste Rubber

In order to reduce energy consumption in the production of fine rubber powders through the cryogenic pulverization of waste rubber, two integration techniques concerning LNG (Liquefied Natural Gas) cold energy utilization, namely the crushing under liquid nitrogen freezing and the cryogenic pulverization with cold nitrogen refri-geration, were proposed and then analyzed in terms of energy utilization. The results show that (1) with the utilization of LNG cold energy in the production of liquid nitrogen, the energy consumption decreases by 60.2%, the power consumption reduces by 244.3kW · h per ton of LNG, the exergy efficiency reaches 60.7%, and the energy consumption of fine rubber powder production reduces by 126.4kW · h/t;and (2) if the cryogenic crushing devices of waste rubber are adjacent to LNG terminals and if the by-produced cold nitrogen recovering LNG cold energy is provided for rubber powder plants to refrigerate and crush waste rubber, the energy consumption reduces by 437.3kW · h/t, as compared with the traditional air freezing method, the power consumption decreases by 276.3kW · h per ton of LNG, and the exergy efficiency of LNG cold energy utilization is up to 70.7%.