SULFURIC ACID

• Sulfuric acid (H₂SO₄), a colorless, oily liquid, is the world's most produced industrial chemical
• Importance and uses of sulfuric acid

  • Highly versatile: acts as a dehydrating agent and oxidizing agent
  • Majority used in production of phosphate fertilizers, essential for agriculture and food security
  • Widespread applications in production of explosives, other acids, dyes, glues, wood preservatives, lead-acid batteries, petroleum refining, metal processing
• Molecular formula and structure of sulfuric acid

  Consists of one sulfur atom bonded to four oxygen atoms, forming a central SO₃ unit. Two hydroxyl groups (-OH) are connected to the sulfur atom, resulting in the overall structure: HO2S⋅OH
• Physical properties of sulfuric acid

  • Color: Clear, colorless, oily liquid
  • Odor: Odorless
  • Melting point: 10.35°C
  • Boiling point: 315-338°C
  • Density: 1.84 at 15°C
  • Viscosity: High due to intermolecular forces
  • Solubility: Completely soluble in water
• Chemical properties of sulfuric acid

  • Strong acid: Dehydrates water molecules and accepts electrons from other substances
  • Oxidizing agent: Readily loses oxygen to become SO₃
  • Hygroscopic: Absorbs moisture from the atmosphere
  • Corrosiveness: Extremely damaging to human skin and tissues
  • Explosive potential: Violent reactions with water and certain substances at high temperature and pressure
• Contact process for producing sulfuric acid

  1. Preparation of sulfur dioxide

  2. Preparation of sulfur trioxide

  3. Preparation of concentrated sulfuric acid
• Wet sulfuric acid process for producing sulfuric acid

  1. Oxidation of sulfurous feeds

  2. Generation of sulfur dioxide

  3. Catalytic conversion of SO2 to SO3

  4. Cooling and condensation

  5. Formation of sulfuric acid
• Applications of sulfuric acid

  • Chemical manufacturing
  • Metal processing
  • Laboratories
  • Batteries
  • Agriculture & fertilizers
  • Cleaning products
• Sulfuric acid is a highly corrosive substance that can cause severe burns and permanent damage upon contact with skin, eyes, and respiratory system
• Inhaling sulfuric acid mist can irritate and damage the lungs, potentially leading to fluid buildup (pulmonary edema) and respiratory failure
• Long-term exposure to sulfuric acid mist has been linked to respiratory problems, including chronic bronchitis and tooth enamel erosion
• The International Agency for Research on Cancer (IARC) classifies sulfuric acid as possibly carcinogenic to humans based on evidence suggesting an association with laryngeal cancer in workers exposed to strong inorganic acid mists containing sulfuric acid
• Safe handling practices for sulfuric acid

  • Personal Protective Equipment (PPE)
  • Proper ventilation
  • Secondary containment
  • Training
  • Emergency procedures
• Sulfuric acid emissions can contribute to acid rain, harming ecosystems and infrastructure
• Accidental spills or improper disposal of sulfuric acid can contaminate water bodies, impacting aquatic life and water quality
• Strict regulations govern the production, handling, and disposal of sulfuric acid to minimize environmental impact
• The economic importance of sulfuric acid is underscored by its significant global production and consumption statistics, with millions of tons produced and utilized annually across various industries
• Case studies involving sulfuric acid

  • Case 1: Boiler failure due to sulfur dioxide-in-air mixture
  • Case 2: Bhopal tragedy (1984) involving methyl isocyanate gas and sulfuric acid mist
  • Case 3: Tanker rollover causing sulfuric acid spill
  • Case 4: Train derailment causing molten sulfur fire
  • Case 5: Semi-truck rollover carrying sulfuric acid
• Future prospects for sulfuric acid


  • Production sustainability
  • Efficiency improvements
  • Recycling and reuse
  • Emerging markets and new applications
  • High-purity grades
  • Digitalization
  • Circular economy
  • Biomass-based sulfur
• From large-scale applications in fertilizer production, metal processing, and chemical synthesis to its presence in everyday items like batteries and cleaning products, sulfuric acid's versatility fuels its high demand
• Recognizing the negative environmental consequences of sulfuric acid production, researchers are actively exploring ways to make its production more sustainable through advancements in recycling and the development of cleaner manufacturing processes