Take the sulfur and burn it with oxygen to make SO2. Then, direct the stream of SO2 gas into a reactor bed with some vanadium pentoxide catalyst and extra oxygen gas to make sulfur trioxide gas which is the acid anhydride of sulfuric acid. vanadium pentoxide is added to in the contact phase of making of sulfuric acid. V2O5 acts as a catalyst at 450�¢?? where SO2 is made to react with the left over O2 in the first step. Vanadium pentoxide series of sulfuric acid catalysts can be used in the process of sulfuric acid production, to be more specific, is the process of SO2+I/2O2---SO3. With the help of Vanadium Catalyst, the rate of conversion can be improved greatly. It can guarantee the air speed of operation to add 10-20% more when using type star ring catalysts or ring catalysts. Vanadium catalyst can be applied in many fields, such as, sulfur-based acid production, pyrite-based acid production, nonferrous smelting gas-based acid production, gypsum-based acid production etc. Type S101 Catalyst is a medium broad temperature vanadium catalyst which promotes the oxidation from SO2 to SO3, and it is developed by China. With 20 years of manufacturing S101 catalyst, it has reached the international advanced level. Due to its high-quality and steady performance, The advantages of S101 are as listed. Wide applicability, broad range of temperature, high conversion, and high mechanical strength etc. Ring or plum blossom shaped catalysts have solved some problems that cylinder-shaped catalyst encountered; namely, they are small pellets, high pressure drop and high energy consumption, bad resistance of dust accumulation. Type S101 series are broad temperature catalysts which suit for every bed of converter. Type S108 Series sulfuric acid catalysts are invented in early 80 s by China. The advantages of them are outstanding. In general, they are low ignition temperature, high activity in low temperature, high-resistant crushed strength etc. If can be used together with medium temperature type catalyst, such as, S101, you can make more profits; for instance, high conversion, and lowering environmental pollution. Type S108 is low temperature catalysts which suit for 1/3 top of the first bed to decrease inlet operating temperature, and 4th bed, 5th bed to improve equilibrium conversion and decrease gas emission.