Synthesis and separation of polymethoxy dihexyl ether
A new kind of oxygenated fuel polymethoxy dihexyl ether(PODHEn)was synthesized from n-hexanol and trioxym-ethylene(TOX)using acid cation exchange resin(SQUPC-4)as catalyst.The synthesis and separation of the reaction were investigated as well.The results show that the yield of PODHE1-3 is more than 84% when the molar ratio n(n-butanol)/n(TOX)is 1∶0.6,the reaction temperature is 100℃,the amount of catalyst(mass fraction)is 4%,and the reaction time is 2.5 h,.The optimal process parameters for the PODHEn rectification process are:reflux ratio is 5,tower top recovery ra-tio is 0.338,and feed position is the fifth block.Under these conditions,the purity of PODHE1-3 could reach 99.9% when the column pressure is 105 kPa,the bottom temperature is 263.5℃,and the top temperature is 106℃.PODHE1-3 has the advantages of high cetane number(more than 75),excellent low temperature performance(freezing point of-52.0℃,and cold filter plugging point of-35.0℃),good safety performance(flash point of 116.0℃),high net calorific value(37.4 MJ/kg),etc.The performance indexes meets or approaches the technical requirements of the national standard of vehicle diesel,and it is a diesel blending component with excellent performance.
n-hexanoltrioxymethylenepolymethoxy dihexyl etherAspen Plus softwarephysical and chemical properties
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