جستجوی مقالات مرتبط با کلیدواژه "مونواتانول آمین" در نشریات گروه "مهندسی شیمی، نفت و پلیمر"

Using alkanolamine in aqueous and hybrid context is an appropriate method for sweetening natural gas in oil and gas refineries. The environmental effect (aqueous or hybrid) of alkanolamine formulations can be important in the rate of thermal degradation of amine. In this work, the rate of thermal degradation of monoethanolamine (MEA) and methyl diethanolamine (MDEA) in the loaded state (presence of CO2) and in aqueous and hybrid environment (sulfolane + water) and temperature of 145 ◦C using gas chromatography device was investigated. To confirm and justify the products resulting from the thermal degradation of MDEA by the presented mechanisms, the experimental test was repeated in the aqueous environment for a temperature of 160◦C. The thermal degradation of MEA and MDEA in both environments is of the first order. The pseudo-first-order rate constant for a 20 wt.% solution of MEA at a temperature of 145 ◦C in an aqueous medium is (6.28±0.1) × 10-8 and in the hybrid medium, it was obtained (2.26±0.3) × 10-8 per second, and for the degradation of 40 wt.% solution of MDEA in aqueous medium at 145◦C and 160 ◦C, it was equal to 3.19× 10-8 and 2.12 × 10-7 respectively, and for the hybrid medium at 145 ◦C it was 8.09 × 10-8 seconds. Degradation of MDEA at a temperature of 160 ◦C is faster and with more diverse products than at a temperature of 145 ◦C and also the pseudo-first-order rate constant of thermal degradation of MDEA and MDE in the hybrid environment is larger than in the aqueous environment. It is expected that the path of thermal degradation of MDEA takes place through the nucleophilic attack of the amine group and the transfer of the methyl or hydroxy ethyl group from the protonated amine to the attacking nucleophilic molecule.

In recent years, according to the environmental restrictions for greenhouse gases, several solutions have been presented to reduce the emission of carbon dioxide, including improving the efficiency of the process, recovering and reusing it in operational units. In this paper, an optimal structure to reduce the consumption of steam and cooling water utilities in carbon dioxide absorption unit of Amirkabir petrochemical is presented and the simulation results were compared with the current energy supply structure of the petrochemical. The simulation validation showed that the proposed model has less error than 3%. According to the analysis, the energy consumption of the reboiler has been reduced by 49.49% for the proposed process. In addition, the analyzes indicated that the proposed structure is able to reduce the consumption of cooling energy in the condenser of the desorption tower and cooler of solvent by 52.53% and 76.84%, respectively. Accordingly, economic analysis was performed and it was found that the cost of providing steam and cooling water in the proposed process was 50.88% and 53.59% lower and in total has been reduced by 51.05%. Sensitivity analysis also showed that the expansion pressure of the clean solvent flow is directly related to the reboiler duty and the consumed steam cost. In addition, it was found that increasing the feed temperature of the desorption tower is another parameter that reduces the energy consumption of the boiler and cooling water in the cooler of solvent.

Biogas is a sustainable energy source produced from organic waste. Raw biogas can be used to generate electricity, but since the energy content of biogas is directly related to methane concentration, it is necessary to improve the biogas and remove its carbon dioxide and other impurities to inject it into the gas grid. This article represents the biogas-improving process based on low-pressure steam compression, which is optimized with an expansion of the clean solvent exiting from the reboiler of the solvent recovery tower, and sending dense hot steam to the reboiler. Two common and optimal modes have been simulated by Aspan-Hasys software based on pure amine solvents. The obtained results showed an increase in the amount of carbon dioxide recovery, and a decrease in the heat load of the reboiler of the disposal tower to the amount of 3.62 GJ/tCO2, which is a 28.74% reduction compared to the base process.