甲醇和甲醛催化合成聚甲氧基二甲醚

聚甲氧基二甲醚作为柴油添加剂,可以提高柴油的十六烷值(CN),提高燃油的利用率,作为甲醇大宗下游产品具有广阔的应用前景。在固定床管式反应器中,以改性大孔阳离子交换树脂为催化剂,在温度40～100℃、液相空速1.32～16.37 h^-1、甲醛/甲醇摩尔比1～4和反应压力0.1～3.0 MPa下,以单因素实验和正交实验相结合的方式,系统地研究了甲醛与甲醇缩醛化工艺条件,获得了较佳的工艺条件,在温度70℃、甲醛/甲醇摩尔比3:1、液相空速1.32 h^-1、反应压力2.0 MPa的条件下,甲醇的转化率为69.72%,DMM_3-8选择性为62.08%。

Catalytic synthesis of polyoxymethylene dimethyl ethers from methanol and formaldehyde

Polyoxymethylene dimethyl ethers as the additive of diesel oil can increase cetane number(CN) and improve fuel efficiency.It will have a broad application prospect as methanol downstream product.In a continuous flow fixed bed tubular reactor,using modified macroporous cation exchange resin as catalyst,the effects of temperature,formaldehyde/methanol molar ratio,pressure and liquid space velocity on the reaction were investigated.The single-factor and orthogonal experimental methods were applied at a broad experiment range(temperature 40—100℃,liquid space velocity 1.32—16.67 h^-1,formaldehyde/methanol molar ratio 1—4 and pressure 0.1—3.0 MPa).The orthogonal experiment design was used to investigate the integral effect of these factors on the reaction.Thus the appropriate operating conditions were obtained.At temperature 70℃,formaldehyde/methanol molar ratio 3:1,liquid space velocity 1.32 h^-1,pressure 2.0 MPa,conversion of methanol and selectivity of DMM_3—8 were 69.72% and 62.08% respectively.