Possibilities and limitations of the organization of anticorrosion protection at gas production facilities

Products of several going and promising onshore and offshore hydrocarbon extraction sites both in Russia and foreign countries are known due to elevated level of corrosive СО2. The article analyzes present procedures aimed at rating corrosive hazard of extracted fluids, selection and implementation of measures for protection of equipment and pipelines against of inner corrosion. Onshore and offshore facilities work within specific environment, which affects arrangement of corrosion protection and corrosion monitoring systems. Presence of СО2 in the extracted products together with other factors stimulate intensive growth of corrosion, and require attentive and reasonable attitude to choose engineering solutions providing safe and reliable operation of production facilities.

Efficiency of different types gas heaters for chimney anticorrosion protection systems of boiler plants

The of researches results of exergy efficiency and optimization of parameters of different types gas heaters by used for anticorrosion protection of gas exhaust ducts of heating boiler plants equipped with exhaust gas heat recovery systems are presented. The choice of a complex technique for analyzing the efficiency of gas heaters, which makes it possible to obtain functional dependences of the selected efficiency criteria on the geometric parameters of the heat exchange surface of gas heaters for solving optimization problems is substantiated. Such a technique can be a technique based on exergy methods and statistical methods of experiment planning theory. This technique by an insignificant number of initial parameters required for calculation, and by the simplicity of calculation and analytical methods for obtaining exergy characteristics is characterized. The work considered three types of gas heaters: water-heating (water-gas) and two gas-heating (gas-gas) pipe and plate type. The heat exchange surface of the water-heating gas heater is assembled from transverse-finned bimetallic (steel base and aluminum fins) pipes, gas-heating pipe-type - from steel pipes with circular turbulators flow, and gas-heating plate-type - from smooth steel plates. The general system of balance equations used in this complex technique, and also its the basic stages, are presented. It is noted that the choice of complex criteria for assessing the efficiency of gas heaters is carried out according to the degree of sensitivity of the criteria to changes in the operating and geometric parameters of gas heaters. Using the proposed sensitivity coefficient, the degree of sensitivity of different efficiency criteria has been analyzed and it has been established that one of the most sensitive to changes in the geometric parameters of the heat exchange surface of gas heaters is the heat-exergy criterion. The results of the corresponding calculations for each of the three gas heaters are presented. It has been established the most exergetically effective is a water-heating gas heater, followed by gas-heating gas heaters, of plate and tube types respectively.

CATALYTIC SYN TIC SYNTHESIS OF PYRIDINES BASED ON THE CRO THESIS OF PYRIDINES BASED ON THE CROTON FRACTION

Background. The presence in the molecule of pyridine bases of nitrogen atoms having the properties of the bases determines the specificity of the products of this class and gives ample opportunities for their use in various industries. . The chemistry of pyridine bases is associated with such general theoretical issues as the electronic structure of the cycle, aromaticity, the effect of substituents on the reactivity of heterocycles in nucleophilic substitution reactions, and tautomerism. At the same time, systematic data on the reactions of alkylation with dihalo-alkanes, acylation under low-temperature poly-condensation, and complexation were not available to create a complete picture of the reactivity of pyridine bases. Materials and methods. The aim of the work is to develop cheap and convenient methods for the preparation of pyridine bases, to search for effective and selective process catalysts, and to determine the degree of anticorrosion protection of metals of the obtained products.

Steel Reinforcement Corrosion - Its Impact on Features of Steel PSC Strand

Steel reinforcement made of refined maraging steel in the form of wires and strands has been for a long time used commonly for reinforcement of prestressed concrete structures. Defects on some of them and unfortunately even accidents of some cases of bridge objects, mainly recently published by media, related to corrosion of prestressed reinforcement awoke interest of both professional and wide non-professional public related to its durability. This issue also opens up a question of durability and liability of prestressed structures. In majority of existing prestressed structures the anticorrosion protection of reinforcement was traditionally secured mainly by alkalinity of the environment, i.e. concreting and/or grouting of prestressed elements in ducts. The abstract presents information related mainly to mechanical characteristics of corrosion-affected prestressed elements.

Surface Modification of Aluminium Alloy by a Silver Nanoparticle-Doped Coating and Examination of Anticorrosion Protection

Aluminium alloys are among the metals that can be easily passivated, demonstrating notable anticorrosion properties. Under aggressive environments, like in seawater, corrosion may appear though due to presence of chloride ions (pH>8.5) leading to pitting failures. The objectives of the presented research were to examine the possibility of functionalizing the surface of an aluminium alloy through a polydopamine (PDA) layer with homogeneously dispersed silver nanoparticles (AgNPs) and examine the corrosion behaviour of the nanostructured coating. The development of a PDA coating provides a promising approach for immobilization of silver nanoparticles onto AA6061 substrate. Exposure to salt spray for 60 h and assessment of the corrosion status through various methods were applied. Depending on the process parameters for the fabrication of the PDA-AgNPs layer, an enhanced corrosion protection was achieved compared to the undoped with AgNPs film and the uncoated Aluminium alloy.