Catalytic Conversions of Biomass-Derived Furaldehydes Toward Biofuels

Upgrading of biomass resources toward high-energy compounds (biofuel) is a crucial technology for sustainable development because utilizations of biomass resources can contribute to the low CO2 emission on the basis of carbon neutral concept. In this chapter, recent advances on catalytic hydrogenation and hydrogenolysis of biomass-derived furaldehydes, dehydration products of saccharides, for example, called as hydroxymethylfuran (HMF) and furfural, toward biofuels over heterogeneous catalytic system are introduced. Some approaches on mechanistic study and reactor design are also mentioned in this chapter

Performance of compact fast pyrolysis reactor with Auger-type modules for the continuous liquid biofuel production

Development of a compact fast pyrolysis reactor constructed using Auger-type technology to afford liquid biofuel with high yield has been an interesting concept in support of local production for local consumption. To establish a widely useable module package, details of the performance of the developing compact module reactor were investigated. This study surveyed the properties of as-produced pyrolysis oil as a function of operation time, and clarified the recent performance of the developing compact fast pyrolysis reactor. Results show that after condensation in the scrubber collector, e.g. approx. 10 h for a 25 kg/h feedstock rate, static performance of pyrolysis oil with approximately 20 MJ/kg (4.8 kcal/g) calorific values were constantly obtained after an additional 14 h. The feeding speed of cedar chips strongly influenced the time for oil condensation process: i.e. 1.6 times higher feeding speed decreased the condensation period by half (approx. 5 h in the case of 40 kg/h). Increasing the reactor throughput capacity is an important goal for the next stage in the development of a compact fast pyrolysis reactor with Auger-type modules

Properties of bio-oil generated by a pyrolysis of forest cedar residuals with the movable Auger-type reactor

Our research project has developed the new movable reactor for bio-oil production in 2013 on the basis of Auger-type system. This package would be a great impact due to the concept of local production for local consumption in the hilly and mountainous area in not only Japan but also in the world. Herein, we would like to report the properties of the bio-oil generated by the developing Auger-type movable reactor. The synthesized bio-oil possessed C: 46.2 wt%, H: 6.5 wt%, N: wt%, S: C-NMR and FT-ICR MS supported that the bio-oil was composed by the fine mixtures of methoxy phenols and variety of alcohol or carboxylic acid functional groups. Thus, it is suggested that the bio-oil generated by the new movable Auger-type reactor has a significant potential as well as the existing bio-oil reported previously

Selective aerobic oxidation of 1,3-propanediol to 3-hydroxypropanoic acid using hydrotalcite supported bimetallic gold nanoparticle catalyst in water

Selective oxidation of 1,3-propanediol (1,3-PD) to 3-hydroxypropanoic acid (3-HPA), an important industrialbuilding block, was successfully achieved using hydrotalcite-supported bimetallic Au nanoparticle catalysts in water at 343 K under aerobic and base-free conditions. The highest yield of 42% with 73% selectivity towards 3-HPA was afforded by 1wt%Au_0.8Pd_0.2-PVP/HT catalyst

Direct Hydroxymethylation of Furaldehydes with Aqueous Formaldehyde over a Reusable Sulfuric Functionalized Resin Catalyst

Transformation of C5 furaldehydes to the corresponding C6 furaldehydes over a heterogeneous catalyst is a versatile but demanding reaction process. This report describes our discovery that Amberlyst-15, a conventional sulfuric functionalized resin, affords a 43.1% yield for 5-hydroxymethyl-2-furaldehyde (HMF) production with 57.5% selectivity via direct hydroxymethylation of 2-furaldehyde (furfural) with an aqueous formaldehyde reagent. This report is the first to describe an important achievement on the heterogeneous acid catalyst-assisted HMF production from furfural via direct hydroxymethylation in a batch reactor system. The Amberlyst-15 was also reusable and applicable for C5 furaldehyde upgrading of various types: furfuryl alcohol, furfurylamine, and furoic acid toward the corresponding C6 furaldehydes. Results show that a liquid flow system becomes an advanced tool for the continuous production of upgrading furaldehydes through a fixed Amberlyst-15 catalyst bed. Accordingly, the sulfuric functionalized resin-catalyzed direct hydroxymethylation of furaldehydes with aqueous formaldehyde in both batch and flow reactor systems is worthwhile and opens up new avenues for biomass transformations in particles, an important area of inedible biomass utilization

Fine Crystallized LDHs Prepared with SiO 2 Sphere as Highly Active Solid Base Catalyst

Fine-crystallized layered double hydroxides were prepared by co-precipitation method with coexistence of SiO2 sphere (SiO2@LDH), and these base catalysis and structural properties were investigated. As-prepared SiO2@LDHs exhibited higher base catalysis for the Knoevenagel condensation than conventional LDHs prepared by co-precipitation method in absence of co-existence of SiO2 sphere. Such increase in activity for base catalysis was also observed in various types of SiO2@LDHs with different metal compositions (M2+: Mg2+ or Ni2+, M3+: Al3+ or Ga3+, M2+/M3+: 1 or 3). X-ray diffraction (XRD) measurement suggested that addition of SiO2 induced the decrease in LDH crystallite size. The results of transmission electron microscopy – energy dispersive X-ray spectroscopy (TEM-EDS) and 29Si cross polarization magic angle spinning nuclear magnetic resonance (29Si CP-MAS NMR) on SiO2@Mg-Al LDH suggested that the crystal of Mg-Al LDH is immobilized on SiO2 surface through the Si-O-Al and Si-O-Mg covalent bonds. According to these results, we concluded that the co-precipitation method in the presence of colloidal spherical SiO2 seeds, especially possessing 40 nm diameter, composed the highly-dispersed points of LDH crystal growth on SiO2 surface, and which lead the generation of fine-crystallized highly active LDH nanocrystals

Tailored Design of Palladium Species Grafted on Amino Functionalized Organozinc Coordination Polymer as Highly-Pertinent Heterogeneous Catalyst

The design of highly active and stable heterogeneous palladium catalyst is gaining a lot of attention because of its increasing importance in organic syntheses of commodity chemicals. Herein, we report the tailored synthesis of palladium species grafted on highly stable amino functionalized organozinc coordination polymer (denoted as Pd/AZC) and its extraordinary catalytic performances on Suzuki-Miyaura coupling (SMC) reaction. It achieved the highest turnover number of 2,106,720 (>99% yield) in air among the most reported palladium catalysts for the SMC reaction of bromobenzene. As-prepared Pd/AZC composite is also successfully applied for the catalysis of the Mizoroki-Heck coupling, hydrogenation of nitro, and –C=C– functional groups. Since the developed AZC support has the thermal stability at least up to 573 K, it posesses high potentials for grafting various metal species as catalytically active centers for wide range of metal-catalyzed reactions

Characterization, Synthesis and Catalysis of Hydrotalcite-related Materials for Highly Efficient Materials Transformations

This review is intended to introduce recent progresses in characterization, syntheses and catalysis of hydrotalcite (HT) and HT-related materials. NMR, in situ neutron diffraction and TG-DTA techniques have been used to determine local structure and structural changes of HT. Various synthetic methods to control morphology of HT are introduced together with the crystal formation mechanism. Preparation methods of magnetic HTs are also included. The HT acts as heterogeneous base catalyst for efficient transformations of organic compounds such as synthesis of glycerol carbonate, transesterification of oils (biodiesel production) and carbon-carbon bond formations. The HT has been also used as a support for immobilizing various metal species (Ru, Pd, Ag, Au, Pt, Cu, V, Mn…) which enables highly selective organic reactions such as dehydrogenation of alcohols and deoxygenation of epoxides. Cooperative actions between basic sites of the HT surface and supported metal species are introduced. It is also shown that the HT can work together with other solid acid and metal catalysts to promote sequential reactions in one-pot manner, which gives us very important methodology for environmentally-benign synthesis of value-added chemicals especially from biomass-derived compounds