Biomass is a renewable resource, and chemical synthesis from biomass contributes to low carbon emissions. However, cellulose and chitin, which are abundant biomass resources, are difficult to decompose because of their strong crystalline structure. Conventional methods using enzymes or sulfuric acid as catalysts have drawbacks in terms of reaction rate and separation. We have investigated biomass conversion of cellulose and chitin using solid catalysts, and found that depolymerization is possible. Furthermore, we succeeded in synthesizing various useful chemicals from monomeric glucose and N-acetylglucosamine.
The slurry-bed hydrocracking process is the ultimate refining process that can crack extra-heavy oils and meet the flexible demands of the petroleum market, such as increased production of petrochemicals as well as transportation fuels. This research will enable you to predict the optimum reaction conditions for the slurry phase reaction of heavy oils with API gravity below 20. In addition, the developed reaction model represents well the complex phenomena occurring in VR hydrocracking, considering various reaction pathways, reaction mechanisms, catalyst deactivation, sludge formation, and other complex factors.
SAF is one of the most effective measures of reducing greenhouse gas emission in aviation sector. This presentation introduces recent SAF trend, problem and IHI's approacth for SAF production with algae.
Most of foods we buy daily are contained in plastic containers or bags. These containers and bags are occupied about 47% of whole waste plastics. Large amount of plastic produced were disposed in large quantities, some of which is spilled into the sea and has a serious impact on the ocean ecosystem. Therefore, waste plastics are now widely recognized as one of the most serious global environmental problems. In my presentation, I will introduce the latest recycling technologies for waste plastics and examine how plastics should be used in a sustainable society.
We have used nitrogen species isomorphically substituted in the frameworks of mesoporous silica and zeolite as a solid base for a catalyst and an adsorbent. Here, such nitrogen species isomorphously substituted in a carbon framework was prepared, and their activity, selectivity, and durability (especially resistance to water) were compared, which are important factors for catalysis, as well as the safety of their preparation. In addition, a method would be proposed for evaluating catalytic activity by infrared spectroscopy using probe molecules.
Cyano-bridged coordination polymers ([MN(H2O)x]y[MC(CN)6]) are used as heterogeneous catalysts for redox and acid-base reactions. Usually, open metal sites acting as catalytic active sites are selectively formed on the MN ions by the liberation of H2O. On the other hand, open metal sites are hardly formed on the MC ions coordinated by six CN- ligands. In this study, we synthesized the coordination polymer by partially replacing the CN- ligands with labile ligands ([MN(H2O)x]y[MC(CN)5(L)], L = H2O or NH3). The contribution of MC on heterogeneous catalysis of the coordination polymers was evaluated for hydrolysis of organophosphates and selective oxidation of aromatic compounds.
To increase of the level of conversion and decrease the reaction temperature of reverse water gas shift, a membrane reactor was developed using ZSM-5 membrane. The effect of membrane reacter, in which Cu/Zn/γ-Al2O3 and ZSM-5 membrane were used as catalyst and dehydration membrane, was investigated.
Aerobic oxidation of 5-hydroxymethylfurfural (HMF), protected as a six-membered ring acetal with 1,3-propanediol (PDO), was examined using a nitrogen-doped carbon-supported cobalt catalyst in a stepwise approach. Usage of acetal-protected HMF (HMF-acetal) enabled the production of 5-formylfuran-2-carboxylic acid in its acetal form (FFCA-acetal) in 97% yield even in a 20 wt% solution with Ca(OH)2. The protective PDO was recovered in 94% through acid-catalyzed hydrolysis of FFCA-acetal using HCl in the second step. FFCA in 10 wt% could then be oxidized to 2,5-furan dicarboxylic acid in 96% yield under conditions optimized for this step, enabled through the flexibility of the stepwise approach.
The reductive amination of 5-formylfuran-2-carboxylic acid (FFCA) and its dimethylacetal form (FFCA-acetal) was studied with a cobalt phosphide nanorod catalyst to yield 5-aminomethylfuran carboxylic acid (AMFCA) which can be potentially used as a monomer for biobased polyamides. Under optimized conditions, i.e. 0.5 mmol of FFCA-acetal, 5 mmol of NH4OAc, substrate to catalyst ratio of 10 mol/mol, under 5 bar H2 at 393 K for 3 hours in methanol/water 2/1 (v/v), AMFCA was obtained in 91% yield. Kinetic studies suggests that the reaction route via the hemiacetal form of FFCA-acetal is the key for efficient AMFCA formation.
Dehydration of glucose produces HMF, an important key intermediate for biorefinery processes. Crystalline and thermally stable mixed metal oxide YNbO4 showed to possess Lewis acid and base sites able to catalyse HMF; however, a too pronounced basic character has a negative impact in HMF selectivity. In this work we investigate the role of the secondary A3+ metal in controlling the acid-base properties of the material. After a screening of several elements in the lanthanide series, YbNbO4 was found to be the most selective to HMF (60% after phosphorylation). Several parameters of the material synthesis were studied; calcination temperature was found to greatly impact the properties of material.
Heavy oils such as crude oil and marine fuel oil contain components with high molecular weight such as asphaltenes. These components can cause troubles in the processes of oil production, refining and storage because they are precipitated from oil and deposited on pipes in the processes; however, no methods evaluating the deposition properties of heavy oil have been established. In this study, the authors manufactured a testing tool with a small pressure chamber, where the temperature can be controlled, and investigated to evaluate the deposition property of heavy oil at pressure conditions using the tool.
The methanation characteristics of CO2 in the coexistence of O2 were evaluated by a spiral structure catalyst system in which Ni-based or Ru-based catalysts were arranged in two stages. By this system, the CO2 conversion rate under high-speed conditions with a contact time of 0.5 seconds or less was 70% or more at room temperature, and 80% under heat insulation without external heating. In addition, it was shown to have excellent practical characteristics from the exergy evaluation.