简介：Theoxidationbehaviorofthreebiodieselsofdifferentorigins,viz.rapeseedoilderivedbiodiesel,soybeanoilderivedbiodieselandwasteoilbasedbiodiesel,weretestedonanoxidationtester.Thechemicalcompositionsofthebiodieselswerecharacterizedbygaschromatography.Thereafter,thestructuraltransformationoffattyacidmethylester(FAME)ofthebiodieselswasanalyzedbyaninfraredspectrometerandanultravioletabsorptionspectrometer.TheresultsdemonstratedthattheoxidationbehaviorofbiodieselsofdifferentoriginswascloselyrelatedtothecompositionanddistributionofFAMEs.HigherconcentrationofunsaturatedFAMEwithmulti-doublebondsexhibitedpooreroxidationresistance.Furthermore,cis-transisomerizationtransformationoccurredintheunsaturatedFAMEmoleculesandconjugateddouble-bondproducedduringtheoxidationprocessofbiodiesel.Greatercis-transvariationscorrespondedtodeeperoxidationdegree.ThehigherthecontentofunsaturatedFAMEwithmulti-doublebondsinabiodiesel,themoretheconjugateddoublebondswasformed.

简介：Threenewcatalystsbasedonthesilicagelsupportedpolyetherionicliquids(ILs),i.e.,[HO-PECH-MIM]Cl-Si,[H2N-PECH-MIM]Cl-Si,and[HOOC-PECH-MIM]Cl-Si,wereprepared,andtheirchemicalstructureswerecharacterizedbyinfrared(IR)spectroscopyandnuclearmagneticresonance(NMR)spectroscopy.Thermogravimetricanalyzer(TG),X-raydiffractometer(XRD)andscanningelectronmicroscope(SEM)wereusedtoevaluatetheirthermalstability,crystallinestructureandapparentmorphology,respectively.SurfaceareasofthepreparedcatalystswerecalculatedbytheBrunauer-Emmett-Teller(BET)method.Thecatalyticreactionforthesynthesisofpropylenecarbonate(PC)usingCO2andpropyleneoxide(PO)inthepresenceofthepreparedcatalystswasstudied.Theinfluencesoftimesofrecyclingandcatalyststructureoncatalyticperformancewerealsoinvestigated.TheexperimentalresultsshowedthatthesilicagelsupportedpolyetherILscatalystssuccessfullypreparedundermildconditioncouldpossesstheadvantagesofhighactivity,excellentthermalstability,goodselectivityandeasyrecycling,whilethephasetransitionoftheliquidpolyetherILscatalystswasalsoachieved.Whenthereactiontemperaturewas90°C,theCO2pressurewas2.0MPaandthedosageofthecatalystwas2.5%,[HOOC-PECH-MIM]Cl-Siwasfoundtohavethebestcatalyticperformanceinthecatalyticprocess,withtheconversionratereaching100%andtheselectivityequatingto98.2%.Theconversionrateandselectivitystillcouldreachmorethan90%evenafterthecatalystwasreusedfor15times.

简介：<正>TherulesofMIPreactionsforcatalyticcrackingofsulfurcompoundsanditsinfluenceonthesulfurcontentintheMIPnaphthawerestudied.ThemamfactorsinfluencingthesulfurcontentintheMIPnaphthawerethoughttobethesulfurcontentoffeedstockandwerecloselyrelatedwiththeolefincontentofnaphtha.TakingintoaccountthecharacteristicfeaturesofMIPprocess,themethodsforreducingthesulfurcontentintheMIPnaphthawerecomprisedofdecreasingthesulfurcontentoffeedstockbyhydrotreatinganddecreasingtheolefincontentofnaphthathroughpromotinghydrogentransferreactions.Therefore,theEuroⅣcleangasolinewithlowsulfurcontentandlowolefincontentcouldbeobtaineddirectlythroughtheMIPtechnology.