Investigation on Hydrogen-rich Syngas Production of Reforming Biofuel Blended with Aqueous Urea Solution

• Main Authors: Ke-WeiLin, 林克衛
• Other Authors: Horng-Wen Wu
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/w36435

博士 === 國立成功大學 === 系統及船舶機電工程學系 === 107 === Biofuel and urea are all environment-friendly hydrogen carriers; they can product hydrogen-rich syngas by reforming methods for fuel cell to generate the power or for other applications. There is little literature to discuss the hydrogen-rich syngas production of biofuel blended with aqueous urea solution (AUS) by reforming. In this study, different biofuels reforming including biodiesel, bioethanol, biobutanol, and HVO blend with AUS are investigated by a thermodynamic analysis and experiment. There are four parts in this study; the first part is to discuss the reforming of biodiesel blended with AUS by thermodynamics analysis. The second part is to evaluate the hydrogen production of bioethanol blended with AUS. The main concept is to utilize the AUS to replace pure water and use a thermodynamic analysis to compare the characteristics of steam and autothermal reforming of bioethanol with/without AUS. The third part is the discussion of hydrogen-rich syngas production of biobutanol blended with AUS by a thermodynamic analysis. This part includes steam reforming of biobutanol and autothermal reforming of biobutanol feed using pure steam and AUS. Hydrogen-rich syngas production, carbon formation, and hydrogen production cost are analyzed. The fourth part is the discussion of partial reforming of biodiesel (FAME) and hydrogen vegetable oil (HVO) by experimental and thermodynamic analysis. The thermodynamic analysis is used to evaluate the effect of O2/biodiesel and O2/HVO molar ratios on hydrogen-rich syngas production. The results of first part show that at a reaction temperature of 700 oC, urea/biodiesel ratio=3, and O2/biodiesel ratio=9, the highest reforming efficiency is 83.78%, H2 production 30.43 mol, and CO production 12.68 mol. In terms of bioethanol reforming, the results show that hydrogen-rich syngas production under both steam and autothermal reforming of bioethanol with the blended AUS is higher than that under the pure steam. The best operating condition of autothermal reforming is the H2O/EtOH= 5 and the O2/EtOH= 1.2 at 800 oC, and the reforming efficiency of bioethanol with the blended AUS reaches 93.17%. The results of bioethanol reforming show that hydrogen-rich syngas production with the use of AUS is higher than that without AUS whether steam reforming or autothermal reforming. In the third part, when the AUS/butanol molar ratio is 8, and the O2/butanol molar ratio equals 3, the reforming efficiency reaches up to 81.42%. The results of partial reforming of biodiesel and HVO show that under the best operating conditions at 800 oC and an O2/ biodiesel molar ratio of 10, the concentration of the H2 is 21.96%, and the concentration of the syngas is 45.5%; at an O2/HVO molar ratio of 10, the concentration of the syngas is 45.14% with the reforming efficiency of 62.87%. In the biodiesel experimental results, when the O2/biodiesel molar ratio of 10, the H2 concentration is 18.80%, the CO concentration is 22.87%, and the reforming efficiency is 72.8%. Moreover, for HVO reforming under the air to fuel ratio of 6.30, the H2 concentration is 17.65%; the CO concentration is 17.67%, and the reforming efficiency is 62.87%. Because the composition of HVO is more complex than that of biodiesel, the reforming efficiency for HVO is lower than that for biodiesel.