Experimental And Kinetic Modeling Studies Of N-Propyl Ether Pyrolysis At Various Pressures

The pyrolysis of n-propyl ether（DPE）,as a potential biofuel candidate,was studied for the first time under temperatures of 850-1350K in a flow reactor at low and atmospheric pressures.Synchrotron vacuum ultraviolet photoionization mass spectrometry（SVUV-PIMS）was used for isomeric identification and mole fraction measurements of the pyrolysis products,especially the free radicals.Specific products were observed and measured for the unimolecular decomposition reactions of DPE.A detailed kinetic model of DPE pyrolysis was develop based on the diethyl ether oxidation model.Modeling analyses including the rate of production analysis（ROP）and sensitivity analysis were performed to reveal the consumption pathways of DPE,as well as the formation and consumption pathways of intermediates and products.ROP analysis and sensitivity analysis indicated that the consumption reaction of DPE was mainly controlled by the unimiolecular decomposition reactions and H abstractions at both low and atmospheric pressures.The H abstraction reactions of DPE played crucial roles in DPE consumption.Furtherβ-C–C andβ-C–O scission reactions of three fuel radicals can produce some specific products,including C₁–C₃ aldehydes,alkane,alkene and alkyl radicals,etc.In DPE pyrolysis,a C–O bond fission produced the C₃ carbon chain products.n-Propanol（NC₃H₇OH）was also an intermediate product in DPE pyrolysis.It is interesting to compare the overall behavior in the product distribution between DPE and NC₃H₇OH.The major products of NC₃H₇OH pyrolysis were CO,C₂H₄,CH₂O,CH₃CHO,CH₃OH,and C₃H₆,which were also detected in DPE pyrolysis.Among them,four products,CO,C₂H₄,C₂H₆,and C₂H₅CHO had obviously higher concentrations than those in NC₃H₇OH pyrolysis.Relatively higher mole fractions of C₁–C₃ aldehydes and C₁–C₃ alkanes,alkenes and alkyl radicals were observed in DPE pyrolysis,which demonstrated the structural feature of DPE.