Stoichiometric analysis and heat balance analysis of wood pyrolysis were conducted to improve a pyrolytic gasification system. Heat balance around a pyrolysis furnace was estimated by calculating heat of pyrolysis, sensible and latent heats of products and heat loss of a furnace. Using literature data, macromolecules were expressed by mean compositional formulas, and the heat of pyrolysis was obtained by the stoichiometric approach including the overall equation of pyrolysis. Pyrolysis was exothermic reaction at the range of 773 – 1373 K. Despite the exothermic nature of pyrolysis, heat balance calculation around a pyrolysis furnace showed that external heat was required to compensate heat consumption of the sensible and latent heats of products and heat loss of a pyrolysis furnace. When a feed contains moisture, additional external heat was required. To use charcoal as fuel for the external heating to a furnace, the required amount of charcoal was calculated.
Biodiesel fuel (Fatty acid methyl ester: FAME) shows high boiling temperature, so that it allows to accumulate in the engine oil, causing the premature engine wear. Recently, it was reported that the boiling behavior of biodiesel is adjusted to that of petro-diesel fuel by the cross-metathesis reaction with GrubbsII catalyst. In this study, the changes of molecule and fuel properties of PME, JME, RME, SME, and WME by cross-metathesis reaction was experimentally investigated. The cross-metathesis reaction of FAME and 1-hexene with Umicore M51 catalyst was carried out at 40 degree-C. From the experimental result, it is found that the long-chain length unsaturated fatty acid methyl esters components; C18:1, C18:2, C18:3, were converted to low & middle chain length fatty acid methyl esters, and the cold flow property of fuel is improved, but the oxidation stability is decreased.
Recently, biomass from a variety of sources including corn, various trees and sugarcane has been explored as an effective alternative fossil fuel resource. The direct liquefaction of wood biomass has been researched extensively. Herein is proposed a simple process for the direct liquefaction of wood biomass without a diesel oil blending process, instead using diesel oil as a solvent. However, when Japanese cedar was liquefied with a diesel oil solvent, there was more residue compared to using a polar solvent. Thus, the mechanism of formation of the residue was investigated in an effort to increase the amount of liquefied oil. It was discovered that the residue was generated via condensation of thermal degradation fragments derived from the Japanese cedar. For this reason, the effect of tetralin or plastic added as a hydrogen donor was examined. These experiments suggest that residue generation is suppressed by the action of these added hydrogen donors. Furthermore, the amount of liquefied oil obtained increased. This research suggests a new approach to the efficient generation of liquefied oil from biomass in the presence of a readily-available hydrogen donor using diesel oil as a solvent.
Furan compounds such as 5-hydroxymethylfurfural and furfural are valuable platform chemicals produced from lignocellulosics that can be used to produce polymers or liquid biofuels. In recent years, formation of furan compounds from glucose or xylose in ionic liquids has been studied. In this study, production of furan compounds from rice straw in various ionic liquids was conducted. 1-Methylimidazolium hydrogensulfate ([MIM]HSO4) was found to be the most effective ionic liquid. Yields of 7.9 wt% of 5-hydroxymethylfurfural and 4.3 wt% of furfural were achieved at 160 °C and 1 wt% rice straw loading in [MIM]HSO4. It is also found that pretreatment with an ionic liquid, 1-ethyl-3-methylimidazolium acetate effectively enhanced the yield of furan compounds from rice straw by [MIM]HSO4 treatment .
The degradation of current density by impurities in bioethanol from lignocellulosic biomass for use in a direct ethanol fuel cell was evaluated. The degradation experiment of using a single cell was conducted by adding nine impurities, i.e., methanol, acetaldehyde, acetic acid, 1-propanol, allyl alcohol, ethyl acetate, 3-methyl-1-butanol, acetal (acetaldehyde diethyl acetal), and benzaldehyde, to a 2 M ethanol aqueous solution. The current density of the single cell was degraded by the quasi bioethanol including the nine impurities. To clarify the principal poisoning impurity, we performed the cell measurement by only adding each single impurity. As a result, allyl alcohol turned out to be the main catalyst poison under the estimated condition. The negative effects by the other impurities were almost negligible.
In regards to the energy use of water rich herbs, raw materials storage technology is important. Therefore, we carried out an open air storage examination of Erianthus to develop a low-cost storage technology. The Erianthus that was comprised of 492 g/kg water were cut into 15 mm, and were piled up into an original cone with a radius and height of 5 m using a conveyor belt. From the storage starting time, the top sank to 3.5 m in height by the next day. The density of this time was 259 kg/m3 in raw basis and 132 kg/m3 in dry basis. During the storage period, temperature at the surface was about 10 ℃ higher than the lowest air temperature. Those at the center and bottom were 20℃ higher, but they were not affected by the air temperature. The pH at the end of storage became less than 5 in the center, but other positions were neutral levels. The organic acids were mainly observed at the center where pH values were low. The total carbohydrates and HHV contents and recovery after the storage were high in the center part, and were decreased fell to the surface. Under the above conditions, the recovery of total carbohydrates was approximately 70% while the recovery of HHV was 75%.
Ni-CeO2 nano-composite particle was applied to electrode catalyst for anode of a single cell, and anode deterioration by trace tar in fuel gas was evaluated in this paper. CeO2 addition to Ni was effective to suppress carbon deposition. When fuel gas was contaminated by toluene, the voltage drop and recovery cycle was observed several times during the power generation experiments, and then Ni content at the surface of the anode decreased. However, to increase CeO2 content in electrode catalyst was effective to suppress the frequency of the cycle and the decrease of Ni content from the surface. This implies that CeO2 controls anode deterioration by trace tar since steam reforming of toluene is enhanced by the synergetic effect of Ni and CeO2. In the case of toluene content: 20 g/Nm3 in the model fuel gas and CeO2 content: 20 mol.% in the electrode catalyst, the voltage between the anode and the reference electrode was stable for ten hours and the decrease of Ni content from the surface was not observed. Therefore, Ni-CeO2 nano-composite electrode catalyst has potential to be electrode catalyst for solid oxide fuel cell fueled by biomass gasification gas.
Enzymatic hydrolysis by cellulase has potential as an environment-friendly technology for producing bioethanol from lignocelluloses, but its production cost remains expensive. Therefore, several studies have examined methods in reducing the cost of enzymatic hydrolysis, and one of the most effective ways is to reuse enzymes. In this study, we developed a method for evaluating the cellulase activity in enzymatic hydrolysis residues for efficient enzyme reuse. Approximately 70% the of cellulase activity remained in the solid residue after 70% of the glucan was hydrolyzed, and 22% of cellulase activity still remained in the solid residue after 99% of glucan was hydrolyzed. Other experiments were performed in order to examine the application of our proposed method for practical reuse of enzymes. The results indicate that enzymes were recovered from the residues as we estimated by our method. Thus our method is efficient for evaluating cellulase activity in enzymatic hydrolysis residues.