我国的商品燃油虽已经过加氢脱硫处理,但汽油的总硫含量仍有数百mg/L,柴油更高达1000~2000 mg/L,使车辆尾气成为我国城区空气的主要污染源。鉴于加氢精制后残存的硫化物以噻吩及其衍生物为主,本文采用介孔中发生的在强酸催化下与甲醛的缩合反应作为增强吸附的机理,使噻吩类硫化物得以脱除。与氧化/吸附法配合,可使市售燃油的总硫含量降到15 mg/L以下。
Commercial gasoline contains several hundreds mg/L sulfur and diesel contains 1000—2000 mg/L sulfur in China,though the fuels have been treated by hydrodesulfurization.The high level of sulfur content in fuels makes vehicles emission the major pollution source of urban areas.Considering the sulfur compounds are mainly thiophene and its derivatives after hydrodesulfurization,we made a test,in which a characteristic reaction of thiophenic compounds with formaldehyde under catalysis of strong acid occurred in mesoporous adsorbents,and the adsorption of this kind of sulfur compounds was considerably enhanced.Coupled with an oxidation/adsorption treatment,the total sulfur content of commercial fuels dropped to below 15 mg/L.