Efficient new process for the desulfurization of mixtures of air and hydrogen sulfide via a dielectric barrier discharge plasma

S Dahle

doi:10.1063/1.4935102

Abstract

The efficient removal of hydrogen sulfide, H2S, from streams of H2S in air via a dielectric barrier discharge (DBD) plasma has been investigated using a quadrupole mass spectrometer. A suitable plasma device with a reservoir for storing sorbent powder of various kinds within the plasma region was constructed. Plasma treatments of gas streams with high concentrations of hydrogen sulfide in air yielded a removal of more than 98% of the initial hydrogen sulfide and a deposition of sulfur at the surface of the dielectric, while small amounts of sulfur dioxide were generated. The presence of calcium carbonate within the plasma region of the DBD device resulted in the removal of over 99% of the initial hydrogen sulfide content and the removal of 98% of the initial sulfur dioxide impurities from the gas mixture.

Highlights

The presence of hydrogen sulfide usually causes significant problems[1] due to its toxicity and its corrosive behavior
The presence of calcium carbonate within the plasma region of the dielectric barrier discharge (DBD) device resulted in the removal of over 99% of the initial hydrogen sulfide content and the removal of 98% of the initial sulfur dioxide impurities from the gas mixture
A rotary vane pump (RVP) is connected via another dosing valve (V3), being able to control the absolute pressure within the DBD plasma reactor which is indicated by the attached Pirani vacuum gauge

Summary

INTRODUCTION

The presence of hydrogen sulfide usually causes significant problems[1] due to its toxicity and its corrosive behavior. It is able to dissociate H2S,33,34 thereby producing H2,35,36 but has mostly been investigated at low pressures such as 150 Torr.[9] It was found to be more effective at high temperatures,[37] but a sufficient efficiency was gained only in combination with other systems.[38,39,40] DBD discharges have been shown to be able to oxidize H2S towards H2SO4,41 and to induce reactions with surfaces like InP.[42] The use of a packed-bed DBD reactor, only enhanced the dissociation via the gases’ residence time.[43] some catalysts have been employed to enhance the dissociation of H2S towards the production of atomic sulfur.[44,45] The biggest problem employing plasma-based dissociation or oxidation processes for hydrogen sulfide abatement, is the irreversible removal of the sulfur and its reaction products from the gas stream. Calcium carbonate was chosen, due to its ability to bind sulfur via the formation of calcium sulfate that is commonly used in wet gas scrubbers

EXPERIMENTAL

RESULTS AND DISCUSSION

CONCLUSION