Modelización de la reacción entre amoniaco atmosférico y los ácidos nítrico y sulfúrico mediante química cuántica computacional

Abstract

The objective of this work was to model the reaction between atmospheric ammonia and nitric and sulfuric acids resulting from the excessive emission of ammonia into the atmosphere. Computational quantum chemistry methods were used with the help of the Gaussian®03W software package and the Gauss View 3.0 graphic module, applying the Hartree-Fock (HF) and DFT (B3LYP) methods and the basis set 6-311 ++ G (d, p). The thermochemical reaction values were predicted, including the enthalpy, entropy, and Gibbs free energies, which allow us to understand and analyse the behaviour of the chemical reaction. With the results of the modelling, the amount of 742.26 Kilotons of ammonium nitrate and 1225.41 Kilotons of ammonium sulphate generated by the chemical reaction between atmospheric ammonia and nitric and sulfuric acids was valued. A bibliographic review offered a viable alternative to reduce the environmental pollution problem by simulating the chemical reaction with the intervention of formaldehyde, which acts as an atmospheric ammonia consumer agent, mitigating the formation of particles of ammonium nitrate and ammonium sulphate by 25%. Therefore, it was possible to model the reaction between atmospheric ammonia and nitric and sulfuric acids in a satisfactory way using computational quantum chemistry methods, also, the problem of production of ammonium nitrate and ammonium sulphate particles was solved in percentage. When using formaldehyde in the atmosphere, it is recommended to study the interactions that formaldehyde or methyleneimine may have with other components that are free in the environment because of anthropogenic and natural activities since there is not much information and evidence that these compounds affect environmental health.