INFLUENCE OF THE OXIDIZER ON THE FORMATION AND PURIFICATION EFFICIENCY OF ACID GASES PRODUCED DURING ASPHALTENE GASIFICATION

Abstract

Link for citation: Ermolaev D.V., Daminov A.Z. Influence of the oxidizer on the formation and purification efficiency of acid gases produced during asphaltene gasification. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2022, vol. 333, no. 4, рр. 215-223. In Rus. The relevance of the study is determined by the need to understand the influence of the oxidizer on the formation of acid gases (CO2, H2S, COS and CS2) during thermal decomposition of high-viscosity hydrocarbons. This is important for predicting the purification efficiency of the produced gasification products and estimating the economic costs. The aim: using the simulation to study the effect of an oxidizer in the form of steam on the composition and properties of asphaltene gasification products obtained from natural bitumen, as well as to determine the cleaning efficiency depending on the amount of steam and the absorbent based on NaOH water-alkaline solution. Object: asphaltene of natural bitumen of Ashalchinskoe field of the Tatarstan Republic (Russia), oxidizer in the form of steam, the value of which varied from 0,1 to 1 depending on the amount of asphaltene. Methods: simulation of asphaltene gasification and acid gas absorption taking into account influence of an oxidizer in a form of steam with regard for basic chemical kinetics, ultimate analysis and TGA. Simulation results of gasification and absorption showed that steam used as an oxidizer during asphaltene gasification has a significant influence on the composition and properties of gasification products, as well as on the purification of syngas. With the increase of steam, a parabolic dependence of the concentrations of syngas components is observed, which values decrease with time, except for CO2. The calorific value of syngas decreases from 11,3 to 7,2 MJ/m3 and the cold gas efficiency increases from 53,4 to 62,5 % due to growth of syngas yield. As the amount of steam increases, the amount of absorbent decreases and the purification efficiency of acid gases rises. Thus, the amount of absorbed CO2 increases by 20,7 % while the absorbent decreases by 6,7%. At the same time the amount of absorbed H2S increased by 0,39 % with decrease of NaOH by 40,9 %.