Method for manufacturing high purity sulfuric acid

A method for manufacturing a high purity sulfuric acid, comprising:

• providing a mixed solution, wherein the mixed solution comprises sulfuric acid, a first solution, hydrogen peroxide, water, oxygen gas, and an insoluble impurity, and a boiling point of the first solution is higher than a boiling point of the sulfuric acid;
• performing sequentially a first preheating step, a second preheating step and a distillation step to the mixed solution to form a second solution, all of the first preheating step, the second preheating step and the distillation step are carried out by a gravity flow at 1 atm, wherein the hydrogen peroxide, a portion of the water, and the oxygen are removed by the first preheating step, an additional portion of the water is removed by the second preheating step and a remaining portion of the water is removed by the distillation step, a temperature of the first preheating step is lower than a temperature of the second preheating step, the temperature of the second preheating step is lower than a temperature of the distillation step, and the second preheating step comprises adding a catalyst into the mixed solution;
• performing an evaporation step to the second solution in a range from 340° C. to 350° C. at 1 atm to remove the insoluble impurity and the first solution, thereby obtaining a first gas, wherein the sulfuric acid of the second solution is partially degraded into water and sulfur trioxide (SO3) during the evaporation step, and the first gas comprises the SO3, sulfuric acid, and water;
• and
• applying a sulfuric acid to absorb the first gas to form a high purity sulfuric acid, wherein a concentration of the sulfuric acid is larger than 96 weight percent, a concentration of the high purity sulfuric acid is at least 96 weight percent, and a molar concentration of an impurity in the high purity sulfuric acid is less than 0.1 ppb molar concentration, wherein the impurity includes silver, aluminum, gold, barium, beryllium, bismuth, calcium, cadmium, cobalt, chromium, copper, iron, gallium, germanium, mercury, potassium, lithium, magnesium, manganese, molybdenum, sodium, niobium, nickel, lead, antimony, tin, strontium, tantalum, titanium, thallium, vanadium, zinc and/or zirconium.