Energy Of SO2 Research Articles

Simultaneous SO2 removal and CO2 reduction in a nano-BiVO4|Cu-In nanoalloy photoelectrochemical cell

SO2 and CO2 emitted from using of fossil fuels are causing serious environmental issues. Herein we put forward a promising strategy to realize CO2 reduction and SO2 removal simultaneously through a photoelectrochemical (PEC) process based on nanoelectrodes. In the present work, SO2 was oxidized to SO42− on BiVO4 photoanode after being absorbed by NaHCO3 solutions. At the same time, CO2 reduction occurred on nanoflower-like copper-indium alloy cathode. The absorption efficiency of SO2 was greater than 95%, and SO32− was oxidized to SO42− with oxidation efficiency about 50% in 3 h. Moreover, the energy of SO2 was recycled to assist the CO2 reduction on the cathode, consequently, the photocurrent densities were increased at least 3 times after introducing SO2. CO2 reduction with CO and HCOOH as main products was improved significantly when SO2 removal was conducted simultaneously. In-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments were also performed to study the adsorption and conversion of SO2 on BiVO4 nanoparticles. The proposed approach could efficiently remove SO2 and recycle the energy of it to reduce CO2 into useful chemicals. This work provides a sustainable strategy for dealing with CO2 and SO2 in the flue gas by combining desulfurization and CO2 reduction in one PEC cell using nanoelectrodes.

Studies on the potential energy curves of hydride diatomic molecules using energy consistent method

By using QCISD/6-311G（d）method, the ground state of SO-2, and its energy, harmonic frequencies, force constants have been calculated. The calculated results are in good agreement with the experimental ones. The analytical potential energy function of SO-2 has been derived based on the many-body expansion theory. The structure and energy of SO-2 can correctly reappear on the potential surface.

Long-term stability of sulfur dioxide permeation tube standard reference materials

A series of NIST (National Institute of Standards and Technology) sulfur dioxide permeation tubes from several Standard Reference Materials (SRMs 1625 and 1627) were studied for their long-term permeation characteristics at temperatures of 20, 25 and 30°C. It was found that contrary to previous reports the steady-state permeation rate was not constant, but showed a very slight downward trend with time. During the day-to-day use of such devices the downward trend in permeation rate is small enough to go unnoticed. In addition, the permeability at 30°C and permeability activation energy of SO2 in FEP-Teflon are also evaluated for tubes that were part of the National Institute of Standards and Technology permeation tube SRM inventory from 1982 to 1989.

Multiple d-type basis functions for molecules containing second row atoms

The importance of multiple sets of d functions on the energy of SO2 and other molecules of Si, P, S, and Cl has been tested by comparing total energies from the SWPS set (supplementation by five sets of d functions as recommended by Strömberg, Wahlgren, Pettersson, and Siegbahn) with those obtained with one or two sets of d functions. The energy improvement due to supplementation is very sensitive to the nature of the attached atoms and to valence shell expansion but the optimum d function exponents are not appreciably affected by either of these factors. When used in conjunction with Dunning–Hay basis sets for second row atoms, supplementation by a single set of d functions provides about 80% of the self-consistent field (SCF) energy lowering obtained with five sets; use of a second set generates about 15% more. These results are compared with the results of adding f or replacing nuclear-centered functions with bond functions. Varying d function exponents about the optimum values produces an energy surface with the same general shape for all ten molecules studied. Based on this uniformity within a limited sample of molecules containing second row elements, recommendations are presented for the inclusion of supplementary sets of d functions in basis sets and the level of energy improvement to be achieved by using them is estimated.

A shock-tube study of the kinetics of decomposition of sulphur dioxide

The rate of increase in strength of absorption bands of SO has been measured in shock-heated mixtures of sulphur dioxide and argon. Arrhenius-type plots indicate a unimolecular first step of the order d [SO]/d t = k [SO 2 ] [ M ], where [SO], [SO 2 ] and [ M ] are concentrations of [SO], [SO 2 ] and total gas. The apparent activation energy at around 3500 °K is 56 kcal/mole. It is shown that on unimolecular reaction theory, if four harmonic modes of oscillation in the SO 2 molecules contribute to the energy available for transformation, the true activation energy is 74 kcal/mole. This agrees with the energy of excitation to a known triplet state of SO 2 , and on this basis it is suggested that the first steps in the decomposition are SO 2 + M = SO* 2 + M — 73.6 kcal/mole (1) and SO* 2 + SO 2 = SO 3 + SO + 25.6 kcal/mole. (2) Step (2) is spin-allowed, whereas the more direct reaction SO 2 + SO 2 = SO 3 + SO —48 kcal/ mole is spin-forbidden. This is an unusual type of decomposition mechanism and occurs because of the high dissociation energy of SO 2 , because the direct step of low-energy is spinforbidden, and because there is a favourably situated triplet state of the molecule.