Petrochemical FGD, or Flue Gas Desulfurization, is a state-of-the-art technology designed to reduce sulfur dioxide emissions from industrial processes--especially those characteristic of the petrochemical industry. The major function of petrochemical FGD is to clean up flue gases from burning fossil fuels, scrubbing out sulfur dioxide and other pollutants before they get released into the air. The design of the absorber used in petrochemical FGD emphasizes its linearity and customization capability, the oxidizer s reversible flow can be controlled, and separator allows chemical reaction of sulfur dioxide to produce a solid byproduct that has no environmental effect for possible reuse disposal. This kind of systems can be designed on a performance basis to fit a variety of smoothness scales and operating requirements. For one thing, for refineries which use sulfur-containing fuels for instance, chemical plants and other facilities not only need petrochemical FGD to reduce sulfur dioxide emissions but also air-quality control systems such as NOx scrubbers along with new or proposed regulatory limits and standards on emitted pollutants.