PERFECTION of PREPARATION TECHNOLOGY of the CATALYST CARRIER

Сибунит – носитель для катализатора, использующегося в различных процессах химической промышленности, в том числе и в реакции гидрирования. В настоящее время для его подготовки и проведения технологических операций используется так называемый «сухой» способ, обладающий обширными недостатками, основными из которых являются пыление, а также значительная доля ручного труда на производстве и, как следствие, большая продолжительность отдельных стадий.Предлагается использовать «мокрый» способ с применением аппаратуры роторно-пульсационного типа для подготовки носителя катализатора с целью исключения указанных недостатков.В результате проведённой работы было установлено, что активность образцов катализаторов, полученных с использованием молотковой мельницы и с применением роторно-пульсационного аппарата в реакции гидрогенолиза составила 0,606 моль/мин и 0,642 моль/мин, при выходе целевого продукта 76,15% и 80,00%, соответственно. Также определено, что доля потерь, обусловленная образованием пыли, была снижена более чем в 10 раз по сравнению с действующей технологией. Sibunit is carrying agent for the catalyst used in various processes of the chemical industry, including in hydrogenation reaction. Now for its preparation and conducting of technological operations the so-called "dry" way possessing extensive deficiencies is used, basic of which the fluffing, and also a considerable share of muscle work on manufacture and, as consequence, the big duration of separate stages are.It is offered to use a "wet" way with application of rotor-stator equipment for preparation of a catalyst carrier for the purpose of exclusion of the specified deficiencies.As a result of the spent work it has been established, that activity of the catalysts samples gained with use of the hammer mill and with application rotor-stator system in hydrogenation reaction has made 0,606 gramme-molecules/mines and 0,642 gramme-molecules/mines, at an yield of a target product of 76,15% and 80,00%, accordingly. Also it is defined, that the share of losses caused by a dust generation, it has been lowered more than in 10 times in comparison with acting technology.

Preparation of Cu-BTC Supported Fly Ash-Based Catalyst and Research on Low-Temperature SCR Denitration Performance

The novel Cu-BTC/FA materials were synthesized with Cu-BTC as the active component and solid fly ash as the catalyst carrier. then developed as the NO removing catalysts for low temperature selective catalytic reduction (SCR) with NH3. The physic-chemical properties of catalyst samples were characterized by multiple techniques, such as SEM, XRD, FTIR, XPS, TPR and Raman. The results show that: (1) The active component Cu-BTC loading ratio is 9%, the denitration performance is excellent and has strong stability. Under this condition, the catalyst showed the highest NH3-SCR activity, giving 94% NO conversion. (2) The catalysts show the good cyclic and stability in SCR denitration under 200 ℃. (3) It still shows high NO removal rate and good stability under the condition of SO2, and the denitration rate is as high as 78.36%. (4) There is a certain degree of resource integration for carrier fly ash, which not only treats air pollutants to a certain extent, but also achieves the purpose of solid waste recycling.

Effect of N (N=Fe, Co, Ni, Cu, Ce) Loaded on Blast Furnace Slag in Low-temperature NH3-SCR

Using low-value solid waste blast furnace slag as a catalyst carrier, the active component N (N = Fe, Co, Ni, Cu and Ce) was loaded by impregnation method to study its effect on the denitration and sulfur resistance of the Mn-based blast furnace slag catalyst. BET, XRD, XPS, SEM and FT-IR characterization methods were used to analyze the denitration mechanism. The results show that: (1) Mn-Ce/GGBS catalyst has better denitration and sulfur resistance; (2) Mn-Ce/GGBS catalyst has a significant denitration effect when load ratio is 2:1; (3) The catalyst can reduce the poisoning and deactivation of S and prolong the catalyst service life; (4) MnO, MnO2, Mn2O3, CeO2 and Ce2O3 play an important role; (5) The larger the ratio of Mn4+/Mn3+, Ce4+/Ce3+, Oα/Oβ, the stronger the catalyst activity and the better denitration effect, and the introduction of SO2 will increase the acid sites on the catalyst surface and increase the catalyst activity.

Al-Si@Al(OH)3 Nanosheets Composite for Enhanced Efficient Strategy to Synthesize Al-Si@Al2O3 Core-shell Structure

Owing to the combined advantages of Al-Si alloy and Al2O3, Al-Si@Al2O3 is widely utilized as a heat storage material, catalyst carrier and what adsorption host. Hence, the preparation of Al-Si@Al2O3 and corresponding precursors is of utmost significance. Herein, Al-Si@Al(OH)3 precursor is investigated and Al(OH)3 nanosheets are in-situ formed on the surface of Al-xSi alloy (x = 10, 20 and 30) in the presence of water. The influence of Si content, diameter of Al-Si particles and heating parameters on morphology and thickness of Al(OH)3 nanosheets is systematically explored using X-ray diffraction, electron microscopy, Fourier transform infrared spectroscopy and N2 adsorption/desorption isotherms. The growth mechanism of Al(OH)3 nanosheets is revealed and a pathway to obtain Al-Si@Al2O3 nanosheets with desired structure and thickness is demonstrated.

HETEROGENEOUS CATALYTIC CONVERSIONS OF ACETYLENE

The reactions of interaction of acetylene with water vapor, acetic acid and ammonia in the presence of heterogeneous catalysts have investigated. Depending on the nature of the starting components used, acetaldehyde and acetone, vinyl acetate, pyridine bases and pyrrole synthesized. Heterogeneous catalysts selected for each studied reaction based on some scientific prerequisites for the selection of catalysts. Active catalysts for the investigated reactions were determined, which contain compounds of cadmium, zinc, bismuth, chromium, iron and copper, in general, d-group metals. γ-Al2O3, bentonite and kaolin used as a catalyst carrier. Hydrofluoric acid, acetic acid, ammonium fluoride and others used for peptization. Some hypothetical mechanisms for the formation of target products for each reaction have proposed.

A Modified Scheffe's Simplex Lattice Design Method in Development of Ceramic Carriers for Catalytic Neutralizers of Gas Emissions

A modified Scheffe's simplex lattice design method is proposed to study the properties of multicomponent materials. This modified Scheffe's method allowed determining the optimal compositions of cordierite and corundum based ceramic materials that are used as catalyst carrier for gas purification equipment. The obtained material (0.63-1.25 mm weight fraction of cordierite of 0.35 mass% fraction; < 0.63 mm weight fraction of cordierite of 0.35 mass% fraction; < 0.06 mm weight fraction of corundum of 0.2 mass% fraction; 1.25-2.5 mm weight fraction of cordierite of 0.2 mass% fraction) was used successfully for the manufacturing of catalytic neutralizers of gas emissions.

High-strength porous alumina ceramics prepared from stable wet foams

Porous ceramics have been widely used in heat insulation, filtration, and as a catalyst carrier. Ceramics with high porosity and high strength are desired; however, this high porosity commonly results in low strength materials. In this study, porous alumina with high porosity and high strength was prepared by a popular direct foaming method based on particle-stabilized wet foam that used ammonium polyacrylate (PAA) and dodecyl trimethyl ammonium chloride (DTAC) as the dispersant and hydrophobic modifier, respectively. The effects of the dispersant and surfactant contents on the rheological properties of alumina slurries, stability of wet foams, and microstructure and mechanical properties of sintered ceramics were investigated. The microstructure of porous ceramics was regulated using wet foams to achieve high strength. For a given PAA content, the wet foams exhibited increasing stability with increasing DTAC content. The most stable wet foam was successfully obtained with 0.40 wt% PAA and 0.02 wt% DTAC. The corresponding porous alumina ceramics had a porosity of 82%, an average grain size of 0.7 µm, and a compressive strength of 39 MPa. However, for a given DTAC content, the wet foams had decreasing stability with increasing PAA content. A possible mechanism to explain these results is analyzed.

Modified bamboo-based activated carbon as the catalyst carrier for the gas phase synthesis of vinyl acetate from acetylene and acetic acid

As a significant component of catalyst system, catalyst carrier can impact on coating amount of active component, and in turn catalytic activity. In this work, study of bamboo-based activated carbon as the catalyst carrier for gas phase synthesis of vinyl acetate from acetylene and acetic acid was carried out. Characterization and experimental results showed that bamboo-based activated carbon possessed the conditions and potential of being a catalyst carrier and characterized a greater advantage in structure and properties after modification. After ultrasonic treatment, it was found that the mesoporous distribution of activated carbon increased, which promoted the adsorption to zinc acetate and resulted in 23% increase in productivity of catalyst. Simultaneously, it had a different effect on surface area and pore-size distribution of activated carbon by thermal treatment at high temperatures in N2 and CO2 atmosphere. The productivity of catalyst with bamboo-based activated carbon as catalyst carrier after thermal treatment in N2 and CO2 can be increased by 14 and 20%, respectively. Furthermore, based on the influence of pore size on adsorption and reaction of active components, the necessity of expanding pores of carbon was explained in this paper, which pointed out the direction of activated carbon modification.