Influence of molar ratio of MAI and PbI2 on synthesis of perovskite film

This study explores the influence of molar ratio of the synthetic solution of methylammonium iodide (MAI) and PbI2 on perovskite solar cells. The complete perovskite crystals must be produced in a low-humidity environment. The substrate is spin-coated in the adjusted MAPbI3 synthesis solution and annealed by using a nitrogen furnace tube to form perovskite crystals. During the crystallization of MAPbI3, some of the PbI2 remains, which improves the efficiency of the perovskite solar cell. Therefore, we adjust the molar concentration of MAI to find the appropriate amount of the PbI2 residual. We fix the MAI molar concentration at 1 M and adjust the PbI2 molar concentration from 0.8 M to 1.4 M. The molar ratios of MAI and PbI2 are, then, 1:0.8, 1:1, 1:1.2, and 1:1.4, respectively. Then, we use UV–vis, FE-SEM, and photoelectric conversion efficiency (PCE) measurements for comparing the growth of perovskite crystals and their photoelectric characteristics. The results show that 1.2 M of PbI2 is the most appropriate concentration for perovskite solar cells among the adjusted concentrations.

Effect of Total Pressure and Furnace Tube Material on the Oxidation of T22 in Humidified Air

Oxidation of the Fe-base alloy T22 in humid air at 500 °C was investigated. The samples were exposed for up to 1000 h at 1 bar and 20 bar. The influence of three furnace tube materials, alumina, ET45 and quartz glass, on the oxide scale morphology was investigated. Samples and their cross sections were examined using optical microscopy, scanning electron microscopy, electron probe micro analysis and Raman spectroscopy. Multilayered oxide scales consisting of hematite, magnetite and Fe–Cr spinel were found on all samples. However, the composition and morphology of the oxide scales depend on the furnace tube material and on the system pressure. The system pressure is assumed to change the reaction equilibria and adsorption rates. The tube material changed the initial gas composition by formation of volatile Cr species. This volatilization rate increased at higher system pressures.

Reduction of corrosive activity of operating oil in the benzene department Coke Production of PJSC «ArcelorMittal Kryvyi Rih».

REDUCTION OF CORROSIVE ACTIVITY OF OPERATING OIL IN THE BENZENE DEPARTMENT OF COKE PRODUCTION OF PJSC «ARCELORMITTAL KRYVYI RIH» © I.I. Sikan, R.V. Karenov, N.V. Mukina, S.N. Solonko (Coke production of PJSC «ArcelorMittal Kryvyi Rih», 50095, Dnipropetrovsk region, Kryvyi Rih, Kryvorizhstal str., 1, Ukraine), L.P. Bannikov, PhD in technical sciences (State Enterprise "Ukrainian State Research Coal Chemical Institute (UHIN)", 61023, Kharkov, Vesnina st., 7, Ukraine) This paper analyzes and formulates the optimal technological solutions to reduce the corrosiveness of the absorption oil. The problem of reducing the corrosiveness and the ability of the absorbing oil to form the precipitates becomes especially actual in view of the introduction in the technological scheme of a new tube furnace ThyssenKrupp (Germany) for heating the absorption oil in the benzene section. All major work has now been completed at this facility, and soon the new furnace will be commissioned, which should significantly improve the regeneration of the absorption oil. Research of quality indicators of fresh oil and potentiodynamic testing of its water extracts has been fulfilled. To verify that the tube furnace tube material meets the requirements, a spectral analysis of a sample of the damaged tube was performed. The suspended solids of the circulating oil were observed under a microscope at a magnification of ×250. It was revealed that recycled absorption oil can lose quality as a result of tube furnace wear, frequent stoppages for repairs and watering of oil with coke oven gas condensate in scrubbers. Exit from the state of watering occurs during the operation of the distillation department due to "steaming" in the column. As a result, the concentration of salts in the oil occurs and, as a result, its corrosiveness increases. Oil watering in the distillation column occurs when the heating temperature drops. Before starting a new tube furnace, it is advisable to renew the entire working volume with fresh oil with preliminary flushing of the equipment. This will make it possible not to water it in the future during the smooth operation of the distillation and to maintain the proper quality of the absorption oil. Keywords: capture of benzene hydrocarbons, absorbing oil, distillation column, regeneration, tubular furnace, corrosiveness, survey, watering, suspended particles, aggregation. Corresponding author I.I. Sikan, е-mail: [email protected]

Application of Ultrasonic Guided Wave in LMPH Tube of Ethylene Cracking Furnace

LMPH (Radiation heat exchange tube), the key section of ethylene cracking furnace, has various failure behaviors (e.g., carbonation, vulcanization, oxidation, and deformation) because of its rigorous working conditions and complicated structure [1]. In this paper, the ultrasonic guided wave is applicable to inspect the interior and surface of the LMPH tube. The results demonstrate that large components in the similar structure of the heat exchange bent tube bundle can be inspected effectively, efficiently, conveniently, compared with the traditional inspection method. One inspection example of an ethylene cracking furnace tube bundle is forwarded. The paper also provides an engineering application/case and valuable crafting process for the detection of similar structures by the ultrasonic guided wave method.

ABC-ANFIS-CTF: A Method for Diagnosis and Prediction of Coking Degree of Ethylene Cracking Furnace Tube

The carburizing and coking of ethylene cracking furnace tubes are the important factors that affect the energy efficiency of ethylene production. To realize the diagnosis and prediction of the different coking degrees of cracking furnace tubes, and then take corresponding treatment measures, is of great significance for improving ethylene production and prolonging the service life of the furnace tube. Therefore, a fusion diagnosis and prediction method based on artificial bee colony (ABC) and adaptive neural fuzzy inference system (ANFIS) is proposed, which also introduces a coking-time factor (CTF). The actual data verification shows that the method not only improves the training efficiency and diagnosis accuracy of the coking diagnosis and inference system of the cracking furnace tube, but also realizes the prediction of the development trend of the coking degree of the furnace tube.