propanen.丙烷propane ionization chamber丙烷电离室propanediol oxidoreductase丙二醇氧化还原酶propane tricarboxylic acid[化] 丙三羧酸propane-heated drier unit丙烷加热干燥设备propane selective oxidation丙烷选择氧化propane ammoxidation process丙烷氨氧化工艺propane deasphalting process丙烷脱沥青过程propane tetracarboxylic acid丙烷四羧酸propane-propylene fraction丙烷丙烯馏分Propane de.asphalted asphalt丙脱沥青