Problems of Chemistry and Chemical Technology

Solid-State Synthesis of Stable Substances Li–Mn–O System

By employing thermal, X-ray diffraction and chemical analysis, we study chemical reactions, which occur at heating manganese oxide ( ) with lithium carbonate ( ) on air. We reveal that only three thermodynamically stable substances – manganese (III) oxide ( ), lithium manganate ( ) and mixed oxide with spinel structure – can be formed at 700–900 C temperature ranges. Many other known substances of Li–Mn–O system are unstable under these conditions and cannot be obtained by solid-state methods

Researching and designing of processes adsorption/desorption of nitrogen oxides on the zeolites

The paper under study reports on the research results of the adsorption/desorption process of nitrogen oxides from a gas stream on the synthetic zeolites of X-type. We demonstrate the adsorption ability of the probed zeolites is 100 %, which testifies the complete removal of nitrogen oxides from a gas stream. We present the mathematical model of the probed process, determine the process’ optimum terms and parameters and illustrate the model’s adequacy. The research results demonstrate the mathematical description and appropriateness of practical application of the proposed method.

The choice of the optimal cation exchanger for local water sodium cycle installations

According to the following criteria: purity degree, physical and chemical properties, the comparison of samples of industrial strongly acidic cation exchangers in Na-form is made in this paper to substantiate their efficiency in water softening processes. Furthermore, we compare production costs of sodium cycling process in the course of concurrent regeneration with different consumption of NaCl and speeds of water passing.

The influence of caesium compounds on the properties of the low-temperature catalyst of carbon monoxide converstion. caesium formiate promotion

This paper studies the influence of promoting admixtures of the Cs formiate on the catalyst activity, selectivity, stability, crystal structure and morphology of Cu-Zn-Al catalyst of low-temperature CO conversion. We test two methods of introducing the promoter, notably into the calcinated as well as into the carbonate catalyst mass. On the experimental side, we determine that Cs introduction in the amount of 1 % allows reducing the catalyst activity in a side reaction of methanol formation by 2–2,5 times.

Research into anticorrosion efficiency of vegetable extracts

This study suggests the anticorrosion protection of extracts of various types of vegetable resources. It is a promising source for developing nontoxic corrosion inhibitors, including volatile ones. We show that compositions of volatile corrosion inhibitors based on the aliphatic amine, heterocyclic nitrogen containing сompounds, isopropanol vegetable extracts at their application both from a gas phase as well as by a pin method demonstrate better protective properties than the known nitrite of dicyclohexylamine.