Comprehensive evaluation and sensitivity analysis of regeneration energy for acid gas removal plant using single and activated-methyl diethanolamine solvents

The absorption of acid gas using reactive amines is among the most widely used types of capturing technologies.However,the absorption process requires intensive energy expenditure majorly in the solvent regeneration process.This study simultaneously evaluated the regeneration energy of MDEA and PZ/MDEA solvents in terms of heat of absorption,sensible heat,and vaporization heat.Aspen Hysys version 8.8 simulation tool is applied to model the full acid gas removal plant for the chemical absorption process.The new energy balance technique presents around the absorption and desorption columns to bring a new perspective of energy distribution in the capturing of acid gas plants.Sensitivity analysis of regeneration energy and its three contributors is performed at several operation parameters such as absorber and stripper pressures,lean amine circulation rate,solvent concentration,reflux ratio,and CO2 and H2 S concentrations.The results show that the heat of absorption of PZ/MDEA system is higher than that for MDEA system for the same operating conditions.The sensible heat is the main contributor in the required regeneration energy of MDEA solvent system.The simulation results have been validated against data taken from real plant and literature.The product specifications of our simulation corroborate with real plant data in an excellent approach;additionally,the profile temperature of the absorber and the stripper columns are in good agreement with literature.The overall results highlight the direction of the effects of each parameter on the heat of absorption,sensible heat,and vaporization heat.

The adsorption of acidic gaseous pollutants on metal and nonmetallic surface studied by first-principles calculation: A review

The acidic gases such as SO2,NOx,H2 S and CO2 are typical harmful pollutants and greenhouse gases in the atmosphere,which are also the main sources of PM2.5.The most widely used method of treating these gas molecules is to capture them with different adsorption materials,i.e.,metal and nonmetallic materials such as MnO2,MoS2 and carbon-based materials.And doping transition metal atoms in adsorption materials are beneficial to the gas adsorption process.The first-principles calculation is a powerful tool for studying the adsorption properties of contaminant molecules on different materials at the molecular and atomic levels to understand surface adsorption reactions,adsorption reactivity,and structureactivity relationships which can provide theoretical guidance for laboratory researches and industrial applications.This review introduces the adsorption models and surface properties of these gas molecules on metal and nonmetallic surfaces by first-principles calculation in recent years.The purpose of this review is to provide the theoretical guidance for experimental research and industrial application,and to inspire scientists to benefit from first-principles calculation for applying similar methods in future work.

Heterogeneous reaction of SO_(2) on CaCO_(3) particles:Different impacts of NO_(2) and acetic acid on the sulfite and sulfate formation

Despite the heterogeneous reaction of sulfur dioxide(SO_(2))on mineral dust particles significantly affects the atmospheric environment,the effect of acidic gases on the formation of sulfite and sulfate from this reaction is not particularly clear.In this work,using the in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)technique,we employed a mineral dust particle model(CaCO_(3))combined with NO_(2)and acetic acid to investigate their effects on the heterogeneous reaction of SO_(2)on CaCO_(3)particles.Itwas found that water vapor can promote the formation of sulfite and simulated radiation can facilitate the oxidation of sulfite to sulfate.The addition of NO_(2)or acetic acid to the reaction system altered the production of sulfate and sulfite accordingly.There was a synergistic effect between NO_(2)and SO_(2)that promoted the oxidation of sulfite to sulfate,and a competitive effect between acetic acid and SO_(2)that inhibited the formation of sulfite.Moreover,light and water vapor can also affect the heterogeneous reaction of SO_(2)with the coexistence ofmultiple gases.These findings improve our understanding of the effects of organic and inorganic gases and environmental factors on the formation of sulfite and sulfate in heterogeneous reactions.