卷 52, 编号 6 (2018)

A combination of the syngas generation and methanol synthesis steps by pressure is considered to obtain methanol from oil- and gas-fields flare gases. The combined process is thermodynamically analyzed within 700–1100°C and 2–10 MPa for flare gas conversion into syngas. The features of the synthesis of syngas by steam, steam–oxygen, and steam–air conversion are considered. The combined steam conversion of flare gas at 900–950°C and the synthesis of methanol at 230°C together with a total pressure of 3.5–5 MPa make it possible to produce methanol with a yield of up to 1.1 t_methanol/t_raw and may be recommended for the qualified processing of flare gas into methanol directly on the fields. The synthesis of methanol from syngas with a high amount of CO₂ is experimentally verified on copper–zinc catalysts at 230–270°C and 5–8 MPa.

This paper completes our work on calculation of a chemical-technological complex for coprocessing cracking and pyrolysis gases on the basis of a method developed for optimal design of a chemical-technological complex (CTC) with progressive fulfilment of steps aimed at optimizing the entire complex with consideration of the mutual influence of all its processes. Using the mathematical model of the entire CTC with complete kinetic models of all the selected processes as a basis, its optimization was performed and the optimal regimes with a maximum production capacity for all the target products were selected for these processes. Advisable routes of the motion of byproducts were selected. The resulting closed flowsheet of the chemical-technological complex with notations of all inlet and outlet flows and established couplings of material and recycled flows between all the reactor elements was presented. Using the complete mathematical model and the selected economic criterion and optimization method as a basis, the chemical-technological complex was subjected to global optimization and, as a consequence, the optimally consistent material flows of the entire complex were determined with the resulting maximization of its rate-of-return, i.e., an appreciable increase in the economic efficiency of CTC operation.

The role of the macro- and microdistribution factors in the electrodeposition of metals and alloys on the components of electronic devices has been studied. There are three types of deviation of the deposition rate distribution from uniform distribution caused by differences: (1) in the surface area of ​​the cathode and dielectric sections, (2) in the deposition rate in the individual sections of one group, and (3) between the local deposition rates at different points of the surface of the individual cathode section. Methods for evaluating the microthrowing and leveling ability and predicting the microdistribution from the leveling ability data and the use of the Wagner number for evaluating the role of the macrodistribution factors were considered. Examples were given to illustrate the types of deposition rate distribution from electrolytes with positive, zero, and negative leveling ability.

The hydrothermal carbonization of organic ingredients from municipal solid waste (exemplified by apples, meat, offset paper, newsprint, birch and oak sawdust, cotton cloth, polypropylene, and polyethylene terephthalate) is studied in the temperature range 240–280°C. The yield of the solid hydrothermal carbonization product (excluding plastics) is 0.50–0.62 at 240°C, 0.46–0.54 at 260°C, and 0.37–0.46 at 280°C. The yield of the solid product in the case of polypropylene and polyethylene terephthalate is close to 1. When increasing the temperature, the carbon content of the solid product increases from 45–52% for the initial ingredients to 61–75% for the products obtained at 280°C (excluding plastics). The calorific value of the products of hydrothermal carbonization obtained from organic waste with a calorific value of 15 to 19 MJ/kg (excluding plastics) is 19–26 MJ/kg for 240°C and 21–29 MJ/kg for 280°C. The products of the hydrothermal treatment of apples and sawdust at 280°C have the highest calorific values (28–29 MJ/kg). The calorific value of plastics after hydrothermal treatment remains practically unchanged.

The present investigation illustrates a computational study of the turbulent diffusion flame in a cylindrical burner that is confined by two coaxial jets (methane/hydrogen and air). This is to improve the reactive mixture, the reactants combustion and to reduce the concentration of carbon monoxide as pollutant chemical species. The coupled models LES/PDF are, hereby, used to surmount the turbulence/chemistry interaction in the transport equations of chemical species. The predicted mixture fraction, the progress variable, and the carbon monoxide mass fraction are selected to validate the coupled models with respect to the experimental references data. Furthermore, the same scalar parameters which are considered in the previous numerical validation are evaluated from different fuel compositions of the hydrogen and the methane percentage to supply the combustion chamber. The computed results are carried out by FLUENT-CFD; where, they prove that hydrogen addition reduces the carbon monoxide concentration in the combustion products and improves the reactants combustion caused by the rich mixture.

Troxerutin supported palladium (TXT-Pd) catalyst was prepared readily by using one-step synthetic method. As-fabricated TXT-Pd catalyst was evaluated by means of fourier transform infrared spectrometer (FTIR), atomic absorption spectroscope instrument (AAS), and X-ray photoelectron spectrum (XPS). As-prepared catalyst possessed perfect catalytic properties to the Heck reaction of aryl halide with vinyl compounds in N₂ atmosphere and the yields were up to above 95%. Particularly, the TXT-Pd catalyst could catalyze the Heck reaction of bromobenzene with low reaction activity and acrylic acid even at a low temperature 80°C even with a little amount of the catalyst. The remarkable interest was reusing properties, with which the yield was up to 36.7% after 7 times of the reusable catalyst. Moreover, TXT-Pd catalyst also showed high catalytic activity to the Heck reaction of substituted aryl halides with acrylic acid or styrene.