Industrial waste heat recovery captures and reuses heat generated during industrial processes that would otherwise be lost, improving energy efficiency and cutting costs. Here’s a concise overview:

How It Works

• Sources of Waste Heat: Heat from exhaust gases, cooling systems, or equipment surfaces in industries like manufacturing, steel, cement, or power generation.
• Recovery Methods:
  • Heat Exchangers: Transfer heat from hot gases or liquids to preheat air, water, or other fluids (e.g., shell-and-tube or plate heat exchangers).
  • Organic Rankine Cycle (ORC): Converts low-grade heat into electricity using organic fluids.
  • Heat Pumps: Upgrade low-temperature heat to higher, usable levels.
  • Thermal Storage: Store excess heat for later use (e.g., molten salts or phase-change materials).
  • Direct Use: Redirect heat for space heating, drying, or preheating raw materials.

Benefits

• Energy Savings: Recovering 20-50% of waste heat can reduce energy consumption significantly.
• Cost Reduction: Lower fuel and electricity bills; payback periods often 1-5 years.
• Emissions Reduction: Less energy use means lower CO2 and pollutant emissions.
• Process Efficiency: Enhances overall plant performance.

Applications

• Industries: Steel (blast furnaces), cement (kilns), glass, refineries, and food processing.
• Examples:
  • Preheating combustion air in furnaces.
  • Generating electricity via ORC in chemical plants.
  • District heating using recovered heat.