Catalytic co-combustion of biomass and brown coal in a fluidized bed: Economic and environmental benefits.

The work is devoted to the study of combustion of brown coal, pine sawdust, and their mixtures in a fluidized bed of catalyst at 600-750°С. It is shown that an increase in the content of sawdust in a mixture with brown coal leads to an increase in the burnout degree of solid fuel from 94.4% to 99.

High-Loaded Copper-Containing Sol-Gel Catalysts for Furfural Hydroconversion.

In this study, the high-loaded copper-containing catalysts modified with Fe and Al were successfully applied for the hydroconversion of furfural to furfuryl alcohol (FA) or 2-methylfuran (2-MF) in a batch reactor. The synthesized catalysts were studied using a set of characterization techniques to find the correlation between their activity and physicochemical properties. Fine Cu-containing particles distributed in an amorphous SiO matrix, which has a high surface area, provide the conversion of furfural to FA or 2-MF under exposure to high pressure of hydrogen.

Promoting effect of Zn in high-loading Zn/Ni-SiO catalysts for selective hydrogen evolution from methylcyclohexane.

The dehydrogenation of methylcyclohexane to toluene was investigated over high-loading monometallic Ni-SiO and bimetallic Zn/Ni-SiO catalysts. The catalysts were prepared by the impregnation coupled with the advantageous heterophase sol-gel technique. Their performance was tested in a fixed-bed flow reactor at 250-350 °C, 0.

Ni-Cu High-Loaded Sol-Gel Catalysts for Dehydrogenation of Liquid Organic Hydrides: Insights into Structural Features and Relationship with Catalytic Activity.

The heightened interest in liquid organic hydrogen carriers encourages the development of catalysts suitable for multicycle use. To ensure high catalytic activity and selectivity, the structure-reactivity relationship must be extensively investigated. In this study, high-loaded Ni-Cu catalysts were considered for the dehydrogenation of methylcyclohexane.

CuFeAl Nanocomposite Catalysts for Coal Combustion in Fluidized Bed.

A method of oil-drop granulation was suggested for the preparation of spherical CuFeAl nanocomposite catalysts. The catalysts were characterized by a set of physicochemical methods (X-ray diffraction, temperature-programmed reduction by H, low-temperature nitrogen adsorption, crushing strength) and tested in the oxidation of CO and burning of brown coal in a fluidized bed. It was found that the catalysts have high mechanical strength (16.

The Influence of Cu and Al Additives on Reduction of Iron(III) Oxide: In Situ XRD and XANES Study.

The reduction of Fe-based nanocomposite catalysts doped with Al and Cu has been studied using in situ X-ray diffraction (XRD), in situ X-ray absorption near-edge structure (XANES), and temperature-programmed reduction (TPR) techniques. The catalysts have been synthesized by melting of iron, aluminum, and copper salts. According to XRD, the catalysts consist mainly of FeO and AlO phases.

An efficient empirical model for microwave-induced average temperature of liquid cylindrical reactants.

Microwave-assisted chemical reactions have become very popular in preparative chemistry due to many advantages such as accelerated reaction rate, higher chemical yield and lower energy use. In dedicated equipment, however, the microwave units operate as "black boxes" keeping the role of the thermal effects in microwave-assisted chemical processes somewhat obscure. To address this issue, in this paper, we propose a simple mathematical model for computing microwave-induced temperature in a three-media cylindrical structure representing a core element of a typical microwave reactor with the reactant assumed to be stirred by convection flows.

Applicability study of classical and contemporary models for effective complex permittivity of metal powders.

Microwave thermal processing of metal powders has recently been a topic of a substantial interest; however, experimental data on the physical properties of mixtures involving metal particles are often unavailable. In this paper, we perform a systematic analysis of classical and contemporary models of complex permittivity of mixtures and discuss the use of these models for determining effective permittivity of dielectric matrices with metal inclusions. Results from various mixture and core-shell mixture models are compared to experimental data for a titanium/stearic acid mixture and a boron nitride/graphite mixture (both obtained through the original measurements), and for a tungsten/Teflon mixture (from literature).

Practical aspects of complex permittivity reconstruction with neural-network-controlled FDTD modeling of a two-port fixture.

The paper discusses characteristics of a new modeling-based technique for determining dielectric properties of materials. Complex permittivity is found with an optimization algorithm designed to match complex S-parameters obtained from measurements and from 3D FDTD simulation. The method is developed on a two-port (waveguide-type) fixture and deals with complex reflection and transmission characteristics at the frequency of interest.

CAD of efficient TMmn0 single-mode elliptical applicators with coaxial excitation.

This paper suggests computational and engineering approaches to designing single-mode elliptical applicators for thermal processing of cylindrical samples of relatively small diameters. Through a systematic computational experimentation employing a 3D conformal FDTD model, we show that stable and efficient excitation of even and odd TMo modes of elliptical waveguides can be achieved by appropriate placing of two (one active and one passive) coaxial probes extended in the longitudinal direction of the cavity of relatively small height and by choosing the dimensions of the cavity. Effects produced by cylindrical loads inserted in the electric field maxima of the applicators featuring even TM010, TM110, and TM210 modes are studied for materials with different dielectric constants and the loss factors.