Sulfuric Acid and Sulfur Trioxide

Abstract

The article contains sections titled: 1. Introduction 2. Properties 2.1. Physical Properties 2.2. Chemical Properties 3. Development of the Sulfuric Acid Industry 3.1. Early Development 3.2. Further Development of the Nitrogen Oxide Process 3.3. Ascendency of the Contact Process 3.4. Raw Materials Usage 4. Production 4.1. Production by Contact Processes 4.1.1. Reaction Kinetics and Thermodynamics 4.1.2. Catalysts 4.1.3. Process Summary 4.1.3.1. Gas Drying 4.1.3.2. Catalytic Oxidation of Sulfur Dioxide 4.1.3.3. Absorption of Sulfur Trioxide 4.1.3.4. Acid Cooling 4.1.4. Practical Versions of the Contact Process 4.1.4.1. Double‐Absorption Process Based on Sulfur Combustion 4.1.4.2. Double‐Absorption Processes Based on Metallurgical Gases 4.1.4.3. Ordinary Single‐Absorption Processes 4.1.4.4. Wet‐Catalysis Processes 4.1.5. Tail‐Gas Treatment 4.1.6. Economic Factors 4.2. Production by Nitrogen Oxide Processes 4.3. Regeneration of Spent Sulfuric Acid 4.3.1. Introduction 4.3.2. Reconcentration to 70 ‐ 75 % H 2 SO 4 4.3.3. Concentration to 93 ‐ 98 % H 2 SO 4 4.4. Production of Oleum 5. Construction Materials 5.1. Metallic Materials 5.2. Nonmetallic Materials 6. Uses of Sulfuric Acid and Economic Aspects 6.1. Indirect Uses 6.2. Direct Uses 6.3. Economic Aspects 7. Analytical Techniques 7.1. Concentration Measurement 7.2. Measurement of Impurities 7.3. Analysis of Acid‐Plant Gas Streams 8. Sulfur Trioxide 8.1. Properties 8.2. Manufacture 8.3. Handling and Uses 9. Toxicology 9.1. Sulfuric Acid 9.2. Sulfur Trioxide 10. Acknowledgement

Re‐evaluation of sulphuric acid and its sodium, potassium, calcium and ammonium salts (E 513, 514 (i), 514 (ii), 515 (i), 515 (ii), 516 and 517) as food additive

“…Sulphuric acid (H 2 SO 4 ) is generally manufactured by the sulphur trioxide (SO 3 ) contact process from sulphur‐bearing raw materials; different process variants are employed depending on the raw material available (Documentation provided to EFSA No. 1, Müller, , ); in some cases, sulphuric acid is obtained as a by‐product of other processes (non‐ferrous metal smelting). The contact process was introduced in the late 1800s; until the 1960s, it underwent minor changes primarily to reduce the atmospheric emissions of sulphur dioxide (SO 2 ), a key chemical in sulphuric acid production.…”

“…Sulphuric acid and its sodium, potassium and ammonium salts are readily soluble in water (OECD, ; Müller, ): these substances are expected to dissolve in aqueous media into their respective ions. Hydrous or anhydrous calcium sulphate is only slightly soluble in water (0.2−0.3 g/100 mL H 2 O at 25°C) (Lancia et al., ): the solubilised fraction can also be expected to dissociate into calcium (Ca 2+ ) and sulphate (SO 4 2− ) ions.…”

“…Concentrated sulphuric acid is a strong and corrosive dibasic acid that reacts with most metals (Müller, ). The chemical is thermally stable: only at high temperatures, it is partially decomposed into its anhydride (SO 3 ) and water vapour.…”

A Brief History of Chemical Reactor and Reaction Technology

“…The general reaction scheme of a sulfuric acid production plant with oxidizing sulfur and contacting with water did not change very much until today , but equipment improvement was done in intensified contacting and absorption towers. Knietsch, who studied platinum catalysts, was the driving force behind the further development of the sulfuric acid process in the late 19th century, particularly at BASF in Ludwigshafen .…”

“…Knietsch, who studied platinum catalysts, was the driving force behind the further development of the sulfuric acid process in the late 19th century, particularly at BASF in Ludwigshafen . Progress has also been made in the field of purification and separation processes, absorption and filtration .…”