In-situ biogas upgrading with H addition in an anaerobic membrane bioreactor (AnMBR) digesting waste activated sludge.

Biological in-situ biogas upgrading is a promising approach for sustainable energy-powered technologies. This method increases the CH content in biogas via hydrogenotrophic methanogenesis with an external H supply. In this study, an anaerobic membrane bioreactor (AnMBR) was employed for in-situ biogas upgrading.

Effect of phosphate compound on the reduction of the pressure drop of laboratory-scale fabric filter.

Fabric filters are generally used to eliminate the particulate matter of flue gas that is generated from waste incinerators. The pressure drop of fabric filter (Δ) is accompanied by the build-up of a dust layer on the fabric filter, and Δ increase leads to an increase in the energy consumption of induced draft fan in an incineration facility. In this study, phosphoric acid (HPO) and monobasic calcium phosphate (Ca(HPO)) are tested as chemicals to reduce Δ in fabric filter using a laboratory-scale equipment.

Effects of phosphoric acid sprayed into an incinerator furnace on the flue gas pressure drop at fabric filters.

Fabric filters are widely used to remove dust from flue gas generated by waste incineration. However, a pressure drop occurs at the filters, caused by growth of a dust layer on the filter fabric despite regular cleaning by pulsed-jet air. The pressure drop at the fabric filters leads to energy consumption at induced draft fan to keep the incinerator on negative pressure, so that its proper control is important to operate incineration facility efficiently.

Decomposition of organochlorine compounds in flue gas from municipal solid waste incinerators using natural and activated acid clays.

High-temperature particle control (HTPC) using a ceramic filter is a dust collection method without inefficient cooling and reheating of flue gas treatment; thus, its use is expected to improve the energy recovery efficiency of municipal solid waste incinerators (MSWIs). However there are concerns regarding de novo synthesis and a decrease in the adsorptive removal efficiency of dioxins (DXNs) at approximately 300 degrees C. In this study, the effect of natural and activated acid clays on the decomposition of monochlorobenzene (MCB), one of the organochlorine compounds in MSW flue gas, was investigated.

Synthesis and redox properties of trinuclear ruthenium-acetylide complexes with tri(ethynylphenyl)amine bridge.

Novel trinuclear ruthenium complexes have been prepared by using tri(4-ethynylphenyl)amine as a bridging ligand. Cyclic voltammetry of the trinuclear ruthenium complexes revealed stepwise quasi-reversible redox behavior of three ruthenium-acetylide species and the central triphenylamine unit, whereas the mononuclear analog showed two sequential quasi-reversible redox waves. The spectroelectrochemical UV-VIS spectral studies suggested that the 1e- oxidized triruthenium species was stable and showed a characteristic absorption at lambda(max) = 505 nm.

Convergent synthesis of platinum-acetylide dendrimers.

An efficient convergent route to the main chain type of organometallic dendrimers, in which platinum moieties are linked by 1,3,5-triethynylbenzene, has been developed. The synthesis of platinum-acetylide dendrons involved the use of two types of trialkylsilyl groups for protection of the terminal acetylene. The platinum-acetylide dendrimers were prepared up to the third generation by reacting dendrons with a triplatinum core and a tetraplatinum core.

Quasi-octahedral complexes of pentamethylcyclopentadienyliridium(III) bearing bis(diphenylphosphinomethyl)phenylphosphine (dpmp).

Reaction of [Cp*IrCl2]2 (1) with dpmp in the presence of KPF6 afforded a binuclear complex [Cp*IrCl(dpmp-P1,P2;P3)IrCl2Cp*](PF6) (2) (dpmp =(Ph2PCH2)2PPh). The mononuclear complex [Cp*IrCl(dpmp-P1,P2)](PF6) (4) was generated by the reaction of [Cp*IrCl2(BDMPP)](BDMPP =PPh[2,6-(MeO)2C6H3]2) with dpmp in the presence of KPF6. These mono- and binuclear complexes have four-membered ring structures with a terminal and a central P atom of the dpmp ligand coordinated to an iridium atom as a bidentate ligand.

Stereoselective ligand-exchange reaction of planar-chiral cyclopentadienyl-ruthenium complexes: thermodynamic control of configuration at a stereogenic metal center.

The reaction of planar-chiral cyclopentadienyl-ruthenium complexes with Bu4NI resulted in the formation of iodo complexes with high diastereoselectivity (up to >99%de). The stereochemistry of the ruthenium center in the starting material did not influence the diastereoselectivity of the products. Epimerization of a diastereomerically pure sample gave a mixture of two diastereomers in the same ratio as with the ligand-exchange reaction, suggesting that the selectivity is determined by the difference in thermodynamic stability between the diastereomeric pair of iodo complexes.

Ruthenium-catalyzed cyclocarbonylation of allenyl alcohols and amines: selective synthesis of lactones and lactams.

Allenyl alcohols such as 4-hydroxybuta-1,2-dienes and 5-hydroxypenta-1,2-dienes having a variety of substituents undergo cyclocarbonylation in the presence of a ruthenium catalyst under mild conditions selectively to give five- and six-membered lactones in a high yield with 100% atom economy. 5-Aminopenta-1,2-dines are also cyclocarbonylated to give gamma-lactams. A possible carbonylation mechanism involving a ruthenium cluster intermediate is proposed on the basis of experimental results.

A divergent approach to the precise synthesis of giant organometallic dendrimers using platinum-acetylides as building blocks.

Giant platinum-acetylides dendrimers were precisely synthesized by a divergent method; the sixth generation dendrimer, the diameter of which is larger than 10 nm, has 189 Pt atoms per molecule, and its molecular weight is as high as 139750.

Metallodendrimers composed of organometallic building blocks.

The incorporation of metallic species into dendritic molecules has been attracting much attention, because the addition of properties characteristic of metallic complexes, such as magnetic, electronic, and photo-optical properties, as well as reactivity, may lead to the realization of new functionalized dendrimers. Organometallic dendrimers offer several advantages in the design of a dendritic molecule with the desired functions due to the diversity of the structure and properties of the organometallic complexes. In the past, the focus was on organometallic dendrimers with metallic species only at specific positions of the molecules, such as the core and the periphery.

Ruthenium-catalyzed carbonylation of allene: direct synthesis of methacrylates and methacrylamides.

Carbonylation reactions of allene in alcohols and amines in the presence of a ruthenium carbonyl catalyst under mild conditions gave methacrylates and methacrylamides, respectively, in good yields with an atom economy of 100%.

New artificial host compounds containing galactose end groups for binding chiral organic amine guests: chiral discrimination and their complex structures.

New linear host (1) and cyclic hosts (2 and 3), which have galactopyranose skeletons as chiral origins and oxyethylenes skeletons as binding sites, were designed based on the structural features extracted from the fructo-oligosaccharide derivatives, having a large chiral discrimination ability, and were then synthesized. These hosts showed chiral discrimination toward chiral organic ammonium salts. For example, the chiral discrimination ability (the ratio of association constants: K(R)/K(S)) of host 1, which has the highest value among them, was K(R)/K(S) = 3 for Trp-O-(i)Pr(+) and K(R)/K(S) = 0.

Helical Chiral Polyisocyanides Possessing Porphyrin Pendants: Determination of Helicity by Exciton-Coupled Circular Dichroism.

Exciton-coupled circular dichroism of the porphyrin Soret band of triblock copolymers prepared from chiral isocyanide monomers and an achiral tetraphenylporphyrin derivative (TPP) provides a novel method for determining the helical sense of poly(aryl isocyanide)s (see the schematic representation of the structure).

Convergent Route to Organometallic Dendrimers Composed of Platinum-Acetylide Units.

The third-generation dendrimer with 45 platinum atoms (shown schematically) was synthesized efficiently by a convergent methodology in which two different trialkylsilyl groups (symbolized by the nodal points) are used to protect the bridging triethynylbenzene derivatives. PT=[Pt(PEt ) ].