Sodium Metabisulfite is an efficient reductive bleaching agent and bactericide, renowned for its strong sulfur dioxide release characteristics, reductive bleaching capability, and stability under acidic conditions. Its production primarily involves the absorption of sulfur dioxide gas from sulfur combustion by soda ash solution, followed by crystallization and drying, with the mainstream process being the continuous production of "soda ash + sulfur dioxide → sodium metabisulfite".

❋ Aliases: Sodium Pyrosulfite
❋ English Name: Sodium Metabisulfite
❋ Chemical Formula: Na₂S₂O₅
❋ Molecular Weight: 190.11
❋ CAS Number: 7681-57-4

Key Properties: Strong reducibility, controlled SO₂ release, acidic in aqueous solution, decomposes in acid

Frontier Application Scenarios

1. "Color Preservation Expert" in Food Processing

   • Dried Fruit Color Protection: Inhibits enzymatic browning, maintains natural color of fruit and vegetable products, prevents vitamin C oxidation;

   • Winemaking: Serves as bactericide and antioxidant, controls fermentation microorganisms, protects wine flavor stability.

2. "Efficient Reduction Specialist" in Chemical Synthesis

   • Flavor Synthesis Reduction: Acts as selective reducing agent in vanillin and other flavor production, improves product yield;

   • Paper Pulping Aid: Used in pulp cooking process, reduces cellulose degradation, enhances pulp whiteness.

3. "Deoxygenation and Dechlorination Guardian" in Water Treatment and Environmental Protection

   • Industrial Wastewater Treatment: Removes residual chlorine and heavy metal ions from wastewater, reduces environmental toxicity;

   • Oilfield Water Injection: Functions as oxygen scavenger, prevents corrosion in water injection systems, extends equipment life.

4. "Professional Assistant" in Photography and Electronics

   • Film Development Fixing: Component of fixing solutions, promotes dissolution of unexposed silver halide;

   • Circuit Board Etching: Used in electronics industry for etchants formulation, controls etching rate and precision.

Technological Breakthroughs and Sustainable Development

• Food-Grade Process Upgrades: Employs multi-stage absorption and recrystallization technologies, strictly controls arsenic, lead and other heavy metal content, meets FDA and EFSA standards;

• Tail Gas Recovery Innovation: Develops absorption tower tail gas recycling systems, achieves near-zero SO₂ emissions;

• Synergistic Formulation Optimization: Combines with ascorbic acid, citric acid for synergistic use, reduces dosage while enhancing preservation effects;

• Green Application Expansion: Replaces methyl bromide and other fumigants in postharvest fruit and vegetable treatment, reduces ozone-depleting substance usage.