From the viewpoint of primary energy diversification and CO₂ reduction, interests of using biomass fuel for transportation fuels are rising. Some kinds of FAME (Fatty Acid Methyl Esters), which are obtained from oil fats like vegetable oil using transesterification reaction with methanol, are getting popular for bio-diesel recently. As FAME has unsaturated carbon–carbon bonds which come from feed materials, its performance such as storage stability is concerned. And there are other points of concern, namely, effects of impurities in FAME on car components. In this current situation, technologies to produce high quality fuels from renewable sources, especially from vegetable oils, using petroleum refinery processes should be promising. In our study of the hydrotreatment of palm oil, what we called "Bio hydro-fined diesel (BHD)," it is possible to obtain from vegetable oil hydrocarbons nearly equal to conventional diesel fuel. BHD consists of alkyl chains derived from fatty acids in vegetable oil. BHD has higher oxidation stability than that of FAME. Evaluation of exhaust gases in engine tests on conventional diesel mixed with 10 % BHD showed same THC (total hydrocarbons), CO, and PM (particulate matter) emission as with base diesel alone. LCA (life cycle assessment) evaluation of BHD, petroleum diesel oil, and FAME produced from palm, although Wheel-to-Tank-CO₂ of hydrogenated and FAME is higher than that of diesel, Well-to-Wheel-CO₂ is lower due to the application of the biomass zero count rule. On the other hand, Well-to-Tank energy efficiency was same as FAME.

View full abstract

In biodiesel fuel (BDF) production, dehydration is an essential process to maintain the quality. The dehydration using a desiccant for BDF is expected to save energy compared to conventional heating treatment. However, dehydration of BDF using desiccant has not been reported. Therefore, the purpose of this study is to verify the possibility of BDF dehydration using desiccant experimentally. Molecular sieve is employed as the desiccant, and its adsorption isotherm is determined. Packed bed is employed to demonstrate that continuous dehydration is possible, and the breakthrough curve is obtained. Furthermore, it is revealed that regeneration of the molecular sieve is possible at least 18 times by washing with the diesel oil and heating.

View full abstract

Properties, chemical compositions and hydrotreatment reactivities of Mongolian crude oils and their distillation fractions were investigated and compared with those of Chinese and Middle East crudes. Mongolian crude oils were highly paraffinic with high pour point (> + 17 &drg;C) and low contents of sulfur (0.09-0.24 %), vanadium (<1 ppm) and carbon residue (<4.6 %), but contained large amounts of atmospheric residue (68-83 %). These features are very similar to Chinese Daqing crude. The middle and heavy distillates included large amounts of saturates (>85 %) and n-paraffins (35-50 %). The nitrogen contents were comparable with the other crude oils or distillation fractions examined. The distillates and atmospheric residues were hydrotreated, and the reactivities of hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) were compared. The HDS rates of low-sulfur feedstocks were much larger than those of high-sulfur feedstocks derived from the Middle East, whereas the HDN rates of the same boiling range fractions were similar. The relative HDS rates of the Mongolian feeds to the corresponding mixed Middle East feed were 6-14 for the middle distillates, 7-12 for the heavy distillates, and 5-6 for the atmospheric residues, and the relative HDN rates were 1-2<, 1-2.3 and 0.6-1, respectively. Polyaromatics were readily hydrogenated to monoaromatics but not to saturates due to the difficulty in further saturation.

View full abstract

Metal-supported active carbon adsorbents were applied to remove the small amount of H₂S contained in biogas CH₄. H₂S adsorption experiments using column type-equipment demonstrated that copper-supported active carbon exhibited high H₂S adsorption ability. From the practical point of view, the width and the rate of the adsorption layer were estimated using copper-supported active carbons. Assuming that the metal ion was initially coordinated with oxygen atoms in H₂O molecules, the energy change in substituting a H₂O molecule by a H₂S molecule was calculated using a calculation program for the ab initio molecular orbital method (Gaussian 09). The results of these energy calculations suggest that Cu⁰ and Cu⁺ species have the highest adsorption affinity with H₂S among various metal and metal ions, in agreement with the present experimental results.

View full abstract

Low-temperature hydrogenation of methyl levulinate was studied over a graphite-supported ruthenium catalyst. Methyl levulinate introduced was completely hydrogenated and 65 % yield of methyl 4-hydroxyvalerate and 35 % yield of γ-valerolactone were obtained at neat condition at 343 K. The yield of γ-valerolactone did not increase with an increase in reaction time. The addition of water and levulinic acid enhanced the initial hydrogenation rate and final γ-valerolactone yield. More than 99 % conversion to γ-valerolactone was obtained over the graphite-supported ruthenium catalyst at 363 K by the addition of water and levulinic acid.

View full abstract

We apologize for the following errors which occurred in Vol. 55, No. 5 (September issue), page 337. Figures 6 and 7 : See PDF Attached.

View full abstract