Process for the production of oleum and sulfuric acid

摘要

In the continuous production of oleum having a concentration of 10 to 45% by weight SO3 and/or sulfuric acid having a concentration of 94 to 100% by weight H2SO4 by burning sulfur with atomospheric oxygen on the principle of overstoichiometric or understoichiometric burning, cooling the resulting SO2-containing gas to 390 DEG -480 DEG C., catalytically reacting the cooled gas to SO3-containing gas on a vanadium-containing catalyst on the principle of single- or double-contact catalysis, absorbing the SO3-containing gas after cooling and, optionally, separating liquid from the gas after absorption, followed by recovering energy, the improvement which comprises effecting the burning of the sulfur with atomospheric oxygen in the presence of a dry SO2-containing gas which contains up to 5,000 ppm (NO)x expressed as NO.