正丁醇作为生物燃料在生产和应用方面的进展

作为车用替代燃料,丁醇的热值比乙醇高30%左右,挥发性只有乙醇的1/6左右,吸湿性远小于甲醇、乙醇和丙醇,具有适度的水溶性,腐蚀性低,安全性更高。但丁醇直接应用到发动机上也存在一些问题,如其热值比传统汽油或柴油低,使得燃料消耗量增加;燃烧效率低于甲醇、乙醇;当应用于点燃式发动机时,丁醇较高的黏度将产生潜在的沉积或腐蚀等问题。目前许多研究者将正丁醇作为替代生物燃料进行研究,现有的研究主要是将丁醇与汽油或柴油混合应用在发动机上,或是应用在一些基本的燃烧反应器中。综合各方面的研究成果,正丁醇在混合燃料中体积分数小于20%时,无需调整发动机就可获得与汽油燃料相同的发动机功率;当达到30%时,发动机最大功率开始下降;随着正丁醇体积的增加,燃料消耗量增加。CO、THC、NOx排放的减少或增加取决于具体的发动机、操作条件、丁醇-汽油的混合比等。混合燃料与纯汽油相比,未燃烧醇的排放增加,而且丁醇的比例越高,未燃烧醇的排放越高。

Advances in Production and Application of n-butanol as Biofuel

As an alternative auto fuel ,butanol has a heat value about 30% higher than that of ethanol,only about one sixth of the volatility of ethanol ,dramatically lower moisture absorption than methanol,ethanol and propanol, appropriate water solubility, low corrosivity, and higher safety.However, there are also some drawbacks if butanol is directly used in engines.The heat value of butanol is lower than that of conventional gasoline or diesel fuel,resultlng in higher consumption of fuel.Its combustion efficiency is lower than that of methanol and ethanol.When used in spark-ignition engines,butanol tends to produce deposition or corrosion due to its high viscosity.Many researchers are currently studying n-butanol as an alternative biofuel.Current studies are primarily focused on applying butanol blended in gasoline or diesel fuel in engines or in some basic burning reactors.A comprehensive study of various research results shows that when the volume fraction of n-butanol in a blended fuel is less than 20% ,no modification to the engine is needed to achieve the same engine power with an engine using gasoline.When the volume fraction of n-butanol is 30% ,the peak power of en- gine begins to decline and as the volume fraction of n-butanol THC and NOx emissions will decline or increase depends on mixing ratio of butanol to gasoline.Compared with pure gasoline fuel will increase and the higher the percentage of butanol is, increases,fuel consumption rises.Whether CO, specific engines,operating conditions and the ,the emission of unburned alcohol of blended the higher emission of unburned alcohol there will be.