file under: Chemicals, Design-Build, Industrial, North America, Sustainability, United States

A Breath of Fresh Air

Innovative Emissions Control Project Saves Time, Money and Stress

A major manufacturer is breathing a little easier these days, thanks to an innovative emissions control system that is keeping its plant operating at critical production levels.

The facility, which produces high-purity solvents, needed to quickly comply with Title V and Maximum Achievable Control Technology standards for capturing and treating volatile organic compounds (VOCs) and designated hazardous air pollutants. Implemented through design-build delivery, CDM Smith’s integrated solution achieved the required emissions reductions without curtailing production—enabling the respected manufacturer to comply with emission limits quickly, cost-effectively and without worry.

Three Streams are Better than One
Applying a typical approach to this challenge would have resulted in a complex and expensive single-point control system. CDM Smith’s comprehensive understanding of the emissions control priorities allowed for an alternative design that separates the plant’s vapor sources into three streams, radically simplifying the process and driving down capital costs. Compared to the inefficient, single treatment process, CDM Smith’s design tailors the capture and treatment for each vapor stream. The approach significantly reduces the size and length of collection duct runs and safety systems, and leverages existing equipment.

For instance, new dual cryogenic condensers use the cooling capacity of the plant’s onsite bulk nitrogen supply to treat low-volume, concentrated VOCs from 34 nitrogen-inerted vessels, storage tanks, and distillation units. Cryogenic vapor removal for emissions control has only been practiced once in the United States, and then on only a single-solvent stream; this manufacturer is treating a mixed vapor stream having 10 possible primary solvents. Operating at -125° F, the process condenses—rather than burns—vapors for eventual offsite disposal, saving energy, eliminating flame hazards, and enabling simpler and less expensive compliance monitoring.

Contaminants collected in a second, high-volume air stream from 17 point sources in a research and development building are destroyed using redundant regenerative thermal oxidizers (RTOs), which burn the vapors at 1,500° F. Finally, a third process captures fugitive emissions at bulk storage tanks using vapor exchange piping, similar to the process used by most commercial gas stations.

Having worked with CDM Smith on previous design-build projects, our client asked us to optimize this project. We collaborated with them to modify the process into something simpler, saving them $12.5 million, shaving implementation to 11 months and reducing risks.

Building a System of Trust
Fabricating and installing several thousand feet of ductwork and piping, more than 50 process tie-ins, RTOs and cryogenic treatment, two supervisory control and data acquisition systems, and associated structures and utilities in a hazardous, compact, and continuously operating facility was no simple task. Once civil and structural work was complete, electrical and mechanical trades moved inside, forcing the project team to co-exist with factory operations. CDM Smith worked proactively, meeting daily with the client’s staff and coordinating with their production schedule to avoid interfering with high-priority production lines during construction.

Highly flammable solvent vapors in work areas meant no onsite welding, so fabrication occurred in an adjacent facility set up by CDM Smith specifically for this project. Laser scanning and 3D modeling, which produced as-built models of the facility’s interior, facilitated isometric spool drawings, precise fabrication, and the quick installation of components. Timing, trust and teamwork were critical. CDM Smith’s approach allowed for ongoing operations during difficult mechanical installation in key, high-hazard buildings.

Safeguarding the Environment and Workers
The design produces other economic and environmental benefits. The condensing process uses the cooling capacity of the plant’s normal liquid nitrogen consumption, rather than burning natural gas and generating greenhouse gas emissions. While natural gas is required for the larger RTOs, their regenerative design reclaims exhaust heat for reduced energy consumption.

Just as important was the project team’s attitude and culture of safety, enabling more than 56,000 hours of site work without a single injury. Detailed safety plans, daily toolbox safety talks and safety lunches addressed hundreds of topics and maximized safety awareness. The project team took safety very seriously, even prequalifying subcontractors who shared CDM Smith’s strong commitment to safety.