The pulverizing and shredding of scrap material leads to the liberation of particulate emissions as well as volatile organic compounds (VOCs), hazardous air pollutants (HAPs) and nuisance odors. In addition, ELVs and appliances which are not completely drained of refrigerant fluids can emit chlorofluorocarbons (CFCs) leading to acid gas emissions.
Air pollution control in metal shredder facilities has historically been focused on the containment of metal shredder residue (MSR) utilizing cyclones, baghouses, scrubbers, and suppression technologies. While these technologies are effective for containing particulate matter (PM), they are not sufficient to control the harmful VOCs which can pass directly through these systems and into the atmosphere. Specifically, end-of-life vehicles (ELVs) and appliances which are not completely drained of gasoline or refrigerant fluids can emit chlorofluorocarbons (CFCs).
The 80,000 SCFM Regenerative Thermal Oxidizer (RTO) will control VOC emissions from the metal shredder process exhaust with 98% destruction rate efficiency (DRE) and a thermal efficiency of 95% allowing the facility to meet compliance goals and reduce operational costs. https://www.recyclingtoday.com/article/general-iron-auto-shredder-voc-emissions-control/
CPI worked closely with the Engineering, Procurement, and Construction (EPC) firm as well as the end user customer to define, select, and engineer the equipment best suited to safely and effectively treat emissions from the metal shredder process exhaust. In this application the process exhaust VOCs contain the elements fluorine and chlorine. These will ultimately oxidize to form gaseous hydrogen fluoride (HF) and gaseous hydrogen chloride (HCl). Condensing moisture can also absorb the HF and HCl to form strong acids. Based on the potential for strong acids and to provide additional corrosion resistance, all “wetted” surfaces which interact with the oxidizer’s flue gas were constructed of Duplex stainless steel.
At the exit of the RTO, a packed tower acid gas scrubber captures and controls the emission of the acids formed during the combustion process. The scrubber operates at 99% removal efficiency.
Thermal treatment of VOCs and other air pollutants works by a simple reaction of the harmful hydrocarbon-based air pollutants with oxygen and heat. In this environment, the VOCs are oxidized to form harmless inert by-products 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.
CPI Regenerative Thermal Oxidizers (RTOs) are engineered to provide exceptional performance and reliability. During operation of the standard two chamber RTO, the VOCs are directed into one of the system’s regenerators, an internally insulated vessel containing specialized ceramic media which allows thermal rate efficiencies up to 97%. The contaminated gases are passed through the first regenerator where energy is transferred from the ceramic media to the gas in order to elevate the temperature. This elevated temperature approaches the ignition level for most solvents and is then directed from the ceramic bed into the combustion chamber. As the stream exits the ceramic bed and travels through the internally lined combustion chamber, minimal heat is added to ensure a proper oxidation temperature and a designed dwell time is maintained providing destruction of the VOCS at greater than 98% efficiency. The resultant clean, oxidized gases are directed to the second regenerator to absorb the heat energy before being released to the atmosphere.
CPI provided a complete turn-key installation, including engineering, design and supply of the RTO and scrubber. The installation of the RTO and related equipment included concrete pad design, ductwork design and sizing, booster fan, and media loading into the RTO and scrubber. CPI provided on-site supervision to ensure coordination with the EPC and their subcontractors as well as the final customer. This approach guaranteed that entire system was installed correctly, returning the customer to fully operational status with minimal downtime.
CPI has been “Enabling Clean Production Since 1969” and continues as a leading supplier of air pollution control equipment. CPI is at the forefront in providing industries including the metal recycling industry with solutions to their air pollution control needs.
Today, CPI partners with its customers as a trusted resource in resolving the most complex air pollution and energy conservation problems. We provide our customers with innovative and cost-conscious solutions to their most complex VOC, NOx, and Odor pollution challenges. Our equipment is also at work meeting energy conservation strategies and minimizing greenhouse gas (GHG) emissions.