Fundamental Research Of The Effects Of The Molecular Structure Of Alcohols On Methane Thermochemical Fuel Reforming

Natural gas is an important fossil energy in industrial utilization.Compared to traditional fossil fuels,natural gas combustion releases less CO2 and particulate matters,while its higher octane number represents its better anti-knock characteristics.Meanwhile,syngas production by methane reforming arouses wide interests.In particular,techniques that combine natural gas engine with alcohol reforming to produce H2 and CO by controlling the boundary conditions of cylinders obtained wide attentions.This technique stabilizes the operation of the engine and lowered NOx emissions.Therefore,investigating the reaction mechanisms of methane reforming with alcohols addition and establishing trustworthy kinetic models is significant for the design and optimization of natural gas engines.Based on the In-cylinder Thermochemical Fuel Reforming experiments results,3 experimental sets are conducted on a flow reactor apparatus:1.methanol,ethanol and n-propanol;2.ethanol and ethylene glycol;3.n-propanol and iso-propanol.These experimental sets were intended to investigate the effect of molecular structure of carbon chain,polyhydric alcohol and isomerization on methane reforming.Further,the ratio of OH to C,the number of carbon in an alcohol molecule and different location of hydroxyl were observed to analyze their effect on methane reforming.Binary fuels models are established before kinetic analyses were conducted to reveal the promotion mechanisms of methane thermochemical reforming.The results showed that three sets of alcohols all have good effect on methane reforming under the same low to intermediate temperature,as the concentrations of methane decreased obviously and abundant reforming gases were generated accordingly.The reforming effects were strengthened as equivalent ratio gets larger.The reforming effects of alcohols were ranked as methanol>ethanol>n-propanol,EG>ethanol,n-propanol>iso-propanol.This results showed that the reforming effects of monohydric alcohols on thermochemical reforming were intensified as the ratio of OH to C gets larger,as the number of hydroxyls increases and normal molecular alcohols better than isomer alcohols when the number of carbon is from 1 to 3.Chemical calculations make accurate predictions of the experiments results and the effects differences of alcohols.Kinetic analyses reveal that abundant H,OH and H02 brought into the system by alcohols promote the reforming of methane directly and indirectly.Meanwhile,some intermediate species such as formaldehyde,acetaldehyde and propaniondehyde promote reactions.Thus,the effects of alcohols on methane reforming were explained chemically.