Chemical Processing and VOC Control

• Organic and Inorganic Chemicals
• Petrochemicals
• Liquid Waste Stream Processing
• Adhesive & Sealants Manufacturing
• Refining Operations
• Plastics and Polyethylene Manufacturing
• Natural Gas Processing, Fractionation, Dehydration

The chemical manufacturing sector covers the transformation of organic and inorganic raw materials by a chemical process and the formation of a variety of solid, liquid, and gaseous products.  Chemical processes such as chemical reactions occur in various types of reaction vessels and the products of these reactions are separated using a variety of techniques including distillation especially fractional distillation, precipitation, crystallization, adsorption, filtration, sublimation, and drying. 

Chemical processing operators have very exacting needs that must consider safety and uptime reliability in any solution design.  Chemical processing often involves corrosive exhaust streams, life hazard compounds, highly explosive concentrations, high pressure solutions, and various compliance requirements.                                                                        

A variety of air pollution control systems are available for the abatement, or control of VOCs in the chemical processing industry, including adsorption, biofiltration, condensation, thermal oxidation, UV light oxidation, and wet scrubbing, as well as combinations of these processes. 

Thermal oxidation and catalytic oxidation are recognized as the most effective and cost-efficient ways to control VOCs from various applications throughout the chemical processing industry.  Oxidation of VOCs and other air pollutants works by simply oxidizing the air pollutants with oxygen and heat.  In this environment the VOCs are converted to harmless inert byproducts like CO2, water vapor (H2O), and usable heat. These harmless by-products are released to the atmosphere or used within primary or secondary energy recovery techniques to further lower the operational costs.

Thermal Oxidation

Thermal oxidation is a process by which the vent gas is raised to 1,400 F, held in a reaction chamber where the hydrocarbons are oxidized to CO2 and water vapor.  Thermal Oxidation provides very high destruction efficiency.  Thermal Oxidation can be segmented into three primary technologies:

• Regenerative Thermal Oxidizer – use specialized ceramic media in the regenerator (heat transfer bed) and switching valves to allow thermal efficiencies up to 97%, and destruction efficiencies that can exceed 99%. RTOs operate by preheating the process air as it passes upward through the first ceramic heat exchange media. This pre-heated air then exits the heat exchange media and enters a combustion chamber where it is heated to the setpoint temperature and oxidization of the VOC’s is completed. Hot, clean air is then passed downward through the second ceramic heat exchange media bed where it is cooled. This regeneration of the heat exchanger allows for much higher thermal efficiencies than traditional recuperative style heat exchangers.

• Recuperative Thermal Oxidizer – uses an air to air heat exchanger to preheat the incoming process air using the clean “hot” air from the oxidizer combustion chamber. This primary heat recovery raises the temperature of the process gas before entering the combustion chamber, resulting in lower fuel requirements for the oxidizer burner system.  Thermal recuperative oxidizers which utilize plate or shell and tube type heat exchangers provide +99.9 percent VOC removal, very low CO and NOx emissions, and low natural gas cost. 
• Direct Fired Thermal Oxidizer (DFTO) – commonly called an afterburner or combustor, this system does not employ heat recovery and are used on applications where primary air to air heat exchangers are not necessary These systems quickly meet EPA requirements but can consume substantial amounts of fuel.

Catalytic Oxidation

• Recuperative Catalytic Oxidizer, for control of VOCs and other air pollutants works by utilizing a specially designed precious metal catalyst where VOCs proceed through the combustion reaction and are converted to CO2, water vapor (H2O), and usable heat.  Catalytic systems typically utilize primary heat recovery.  The heat exchanger utilizes the clean exhaust gases post catalyst to preheat the process gases entering the system.  An integral part of the Catalytic Oxidizer’s performance is the high velocity mixing chamber at the burner, which creates the turbulence needed to ensure proper mixing of the air stream.  By designing for the highest mixing, the system can deliver the highest temperature uniformity before the catalyst bed.  Temperature uniformity ensures that 100% of the catalyst is efficiently oxidizing the VOC’s.   The CPI VECTOR Catalytic Oxidizer provides a minimum 99% VOC destruction of the emissions from the process.

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Oxidizer Equipment Solutions