Recovering Energy From Ventilation and Process Airstreams

The high cost of energy has prompted industry to look for new ways to reduce operating expenses. Often ignored are the large amounts of recoverable energy present in the ventilation and process airstreams discharged from the plant. The recovery methods available range from fairly simple, well-known devices that have been around for years to new sophisticated equipment that is constantly entering the marketplace. Commonly applied to plant ventilation and process airstreams are these three general energy-recovery methods: 1. Substituting source-capture hoods and high-efficiency air cleaners for exhaust ventilation systems to permit recirculation. 2. Placing heat exchangers in process stacks and general ventilation airstreams, and 3. Collecting hydrocarbon contaminants from process stacks and reusing or selling them. In this paper I will touch on condensation and electrostatic precipitation as methods that can be used to collect and reuse in some form, hydrocarbons from process stacks