Experimental Research On Catalyst For Hydrous-ethanol Reforming Fuel Engine

Hydrous-ethanol is a renewable energy source and can be used as engine fuel after reformig. The reformed fuel is a low-emission, low-cost and can achieve quasi-homogeneous lean burn, so it has a great prospect. The appropriate catalyst is one of the most important elements which restricts the application of hydrous-ethanol reforming technology on engine.The primary coverage of this paper is to study the reforming catalysts for the hydrous-ethanol reforming fuel engine. The reforming reaction mechanism of hydrous-ethanol is analyzed from the thermodynamic point of view. The components and working principle of the fuel supplying system of hydrous-ethanol reforming fuel engine are presented systematically. Then the influence of chemical composition and catalyst preparation methods on catalytic performance and the characteristics and prospects of Cu-base, Ni-base and Co-base are summarized based on the study of theoretical knowledge and various catalyst with catalyst composition and ethanol reforming preparation methods. Finally, the existing Cu-base, Ni-based and NiMnFe catalysts were studied on the equipment of hydrogen ethanol- reforming catalyst performance-simulated test and engine test. The results are showed that:Cu-base catalyst in simulation test bench performs well in gas selectivity, but badly in reforming rate, and attenuate soon dues to high temperature sinter. When applied to the engine test, emission performance is good, while energy consumption is high. The vector has an great impact on the pulverization phenomenon.Ni-base catalysts in the simulated bench test has high reforming rate and well low-temperature adaptability, but the hydrogen selectivity performance is poor, and carbon distribution serious because of Methanation Vectors. When applied to the engine test, it has the lowest energy consumption, but the emission performances are bad, the NOx emission is higher than Cu-base catalyst, and THC emission is the highest.NiMnFe catalyst is obtained by adding Mn and Fe to Ni-base catalyst. From the simulation bench test, the following changes can be discovered, the temperature at which the catalysts becomes active decreases, reforming ratio decreases slightly, the gas selectivity has hardly been better and the carbon distribution is improved slightly, but the reformer will still stuck. When applied in the engine test, its energy consumption is slightly higher than Ni-base, NOx and THC emissions is in the middle state.The simulation bench test of Ni-base and Cu-based catalysts show that the reforming ratio and the low-temperature activity are improved slightly while the hydrogen selectivity has a great improvement, and requires further study.Overall, the reforming performance of the Cu-base catalyst will attenuate rapidly due to the high temperature sinter, the Ni-base catalyst will lose effectiveness for carbon distribution in a short time, and NiMnFe catalyst did not improve the carbon distribution radically.Therefore, the existing Cu-base, Ni-base and NiMnFe catalysts would not meet the demand of hydrous-ethanol reforming fuel engine. Whereas, it can be found from the study that in order to exploit catalyst for reforming fuel engine the following can be done:first appropriate vector can be used in Cu-base catalyst and agent added to improve the reforming ratio and high-temperature sinter, besides, the methanation vector of Ni-base catalyst and NiMnFe catalyst can be substituted and rare-earth oxide can be added as agent to increase the hydrogen selectivity and reduce the sinter.