This paper introduced briefly developing trend of propylene rectification technology in gas separating unit and analyzed theoretically the middle reboiler used in propylene rectification column.是什么意思_This paper introduced briefly developing trend of propylene rectification technology in gas separating unit and analyzed theoretically the middle reboiler used in propylene rectification column.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句