C5 chemicals (isoprene, dicyclopentadiene, piperylene) are co-produced by an extractive distillation process using C5 fraction, by-product of ethylene from naphtha cracker, as a raw material. The authors have developed a new process for producing cyclopentanone and a commercial process for manufacturing cyclopentyl methyl ether using dicyclopentadiene as a starting material for the comprehensive utilization of the C5 chemicals. In this report, we introduce the technical knowledge, especially about catalyst deactivation, obtained in the technical studies for the process development. In addition, we will review recent topics on the development of manufacturing technology for C5 chemicals itself, which is essential to the growth of the C5 chemicals business.
This review paper summarizes the recent advances in the transformation of silyl formate to various organic compounds using one-pot processes. Silyl formate can be synthesized from CO2 and hydrosilane via hydrosilylation. Recently, many catalysts have been developed for CO2 conversion to silyl formate, resulting in the increasing importance of further conversion of silyl formate. A number of conversion reactions of silyl formate are introduced, including hydration, ester formation, amide formation, salt production, carbon–carbon bond formation, and metal carbonyl complex formation. These reactions smoothly proceed because of the high reactivity and electrophilicity of silyl formate. In some cases, the scope of the reaction partners, such as alcohols and amines, will also be discussed.
The use of catalytic steam reforming for direct hydrogen production from biomass-derived ethanol is attracting much attention. Herein, we report a novel electrocatalytic reaction system, catalytic reaction in an electric field, for low-temperature catalytic ethanol steam reforming using low-grade waste heat. Application of an electric field to Pt/CeO2 catalyst enables the reaction to proceed even at 423 K, at which a conventional catalytic reaction only slightly proceeded. Results of activity tests conducted using isotopes indicate that the electric field contributed to activation of the adsorbed OHx species. In-situ DRIFTS measurements revealed that an electric field promoted the formation of reactive adsorbed intermediate acetate species and showed that the steam reforming reaction of the formed acetate species proceeded even at low temperatures. Results show that ethanol steam reforming proceeded efficiently in the electric field at low temperatures. In this electrocatalytic reaction system, hydrogen was produced efficiently from ethanol using less electricity, even at low temperature.
In this study, a core structure estimation method for molecules in heavy petroleum fractions was developed based on Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The mass analysis of molecules in Middle Eastern vacuum residue was performed by a combination of FT-ICR MS with a fractionation technique. In addition, to obtain mass information about the core structures, collision induced dissociation Fourier transform ion cyclotron resonance mass spectrometry (CID FT-ICR MS) was performed for the three or more-ring aromatic fraction (3A+) and asphaltene (As) fractions. The differences in the double bond equivalent (DBE) distribution before and after CID indicate that the dissociation of the internal linkages of the parent ions had occurred, implying that archipelago-type molecules were contained in the 3A+ and As fractions. The proposed method enabled us to assign a core structure to each detected fragment ion successfully. The estimated core structures of the As fraction are similar to the core structures proposed in previous studies. Thus, the proposed method provides reasonable core structures for heavy petroleum fractions.
The catalytic performance of Cu based oxide composites to the dehydrogenation of cyclopentanol was investigated in detail to develop the commercial production process of cyclopentanone (CPN). Among the composites examined in this study, Cu–Zn composite where the ratio of Cu/Zn is 1.12 exhibited high catalytic performance in not only the activity but also the selectivity. Particularly, the Cu–Zn catalyst applying without any pretreatment showed higher catalytic performance to the reaction than the catalyst applying with the pretreatment of H2 reduction, where the performance achieved the target level of the production process. From the result of continuous operation for 300 h, the induction period for 50 h was confirmed. Under the induction period, it was confirmed that the catalyst was activated accompanied with suppressing side reaction, mainly the aldol condensation of CPN. Here, the bench scale operation was also performed with using the Cu–Zn catalyst and the catalyst was confirmed to be applicable to the cyclopentanone production process from cyclopentanol. The active state of the Cu–Zn catalyst was discussed.
Decomposition of methanol into CO and H2 on supported Pd based catalyst was studied for recovery of unused heat at around 473 K. Decomposition of CH3OH into CO and H2 proceeded at lower temperature with greater endothermic heat compared with the CH3OH steam reforming reaction. Effects of additives to Pd were studied and it was found that the addition of Au or Pt was effective for increasing catalytic activity around 473-523 K. In particular, Pd with 30 wt% Au added was the most active for CH3OH decomposition into CO and H2, and H2 yield on Pd–Au(7 : 3)/Al2O3 was 51 % at 523 K. Although high H2 yield was achieved, yield of dimethyl ether (DME) was also high on this catalyst, in particular, at low temperature around 523 K. Formation of DME was significantly suppressed by using BaZrO3 for the support and also mixing BaZrO3 with Al2O3 for support of Pd–Au bimetal catalyst. Therefore, use of BaZrO3 for the support was effective for increasing CO selectivity and Pd–Au(9 : 1)/BaZrO3–Al2O3(1 : 1) was highly active for CH3OH decomposition into CO and H2, and negligible amount of DME was formed around 523 K.
In the super lean burn, the combustion limit (lean limit) is expanded by engine technology with an increased tumble ratio. In order to further expand the lean limit, it is important to combine fuel technology and engine technology. In this study, using two types of engines with different tumble ratios, the influence of fuel composition on the lean limit (the excess air ratio at the IMEP fluctuation rate of 3 %) was investigated. As a result, it was confirmed that it is possible to further expand the lean limit by changing the fuel composition. The lean limit expansion effect by changing fuel composition is almost independent of the two types of engines. It was also confirmed that the laminar burning velocity of the fuel and the lean limit show a good correlation.
Preventing channeling flows during enhanced oil recovery targeting heterogeneous or fracture type reservoirs and leakage flows from saline aquifers containing CO2 remains a challenge. This study evaluated the potential of in-situ gelation as a blocking agent in a heterogeneous reservoir using the reaction between aqueous solution of sodium metasilicate (Na2SiO3 · 9H2O; S–MS) and dissolved carbon dioxide (CO2). Both Raman and scanning electron microscopy/energy dispersive X-ray (SEM-EDS) spectroscopy revealed that the gel was a sodium carbonate type (S–C-gel). Physical characterization of the S–C-gel including the gelation time, gel strength and stability, were investigated in respect of S–MS concentration, temperature, salinity (NaCl), divalent ion concentration (calcium, Ca2+) as well as CO2 injection pressure. Gelation time after CO2 gas injection was around 1 to 24 h depending on temperature and pressure. Gel strength increased with higher S–MS concentration (≤ 10 wt%) and CO2 gas pressure (≤ 5.5 MPa). Threshold pressure gradient (TPG) and gas permeability of the sandstone core filled with in-situ gel increased by 2.6 times and decreased about 1/10, respectively, compared with the water saturated core. These promising findings herein could be extended to CO2 sequestration.
Glycerol is a major by-product of biodiesel production and has attracted great interest as a precursor for the preparation of various valuable chemicals. Conversion of glycerol over α-Fe2O3 catalyst in a fixed-bed flow reactor was investigated to understand the catalytic activity of iron oxide for the selective production of allyl alcohol. Addition of formic acid to the glycerol feed was effective in improving allyl alcohol production because decomposition on the catalyst formed hydrogen atoms, which were consumed in dehydroxylation of glycerol and reduction of α-Fe2O3 to Fe3O4 during glycerol conversion. Moreover, the allyl alcohol yield was further increased using potassium-loaded α-Fe2O3 catalyst, which was attributed to change in the acid sites. The original acid sites of α-Fe2O3, mainly Lewis acid sites, were occupied by potassium, and Brønsted acid sites formed during glycerol conversion. To further enhance the allyl alcohol yield, we attempted to minimize the polymerization reaction by optimizing the potassium loading, Wcat/Fglycerol value (i.e., contact time), and reaction temperature. The highest allyl alcohol yield of 39.8 C-mol% was achieved over 1 mol% potassium-loaded α-Fe2O3 at 623 K and with Wcat/Fglycerol of 1 h.
Renewable hydrocarbons in the composition ranges of gasoline and diesel were prepared from palm oil through hydrolysis and oxidative cleavage followed by decarboxylation. Hydrolysis was carried out with water in a subcritical state to obtain saturated and unsaturated fatty acids from palm oil triglycerides. The hydrolysis product was treated with KMnO4 as an oxidizing agent to convert unsaturated fatty acids into short fatty acids by cleaving C=C double bonds. The obtained product was then decarboxylated with Pd/C catalyst under N2 pressure to produce hydrocarbons including gasoline and diesel fractions. This work demonstrated the potential of palm oil as a source of renewable fuels, providing about 21 wt% gasoline hydrocarbons and 48 wt% diesel hydrocarbons based on palm oil as the feedstock.