Petroquímica União S.A. (PQU)
INNOVA was selected by Petroquímica União S.A. to do the acoustical consulting for their Capuava Ethylene Plant in Santo Andre, Brazil. The Capuava Ethylene Plant produces 500,000 metric tons of ethylene and more than one million metric tons of other petrochemical products.
SCOPE OF WORK
INNOVA was contracted to undertake four separate activities:
- Implement two preliminary acoustic surveys during plant shut-down and start-up
- Confirm noise level targets
- Design noise mitigation solutions to reduce noise from major sources
- Conduct a pre-engineering impact review
INNOVA’s two acoustic surveys included a diagnostic survey identifying noise sources and the measured noise levels of approximately 450 noise sources within the plant. The second survey was undertaken within the neighboring residential neighborhood.
INNOVA’s pre-engineering impact review was conducted as a part of preparation activities for noise mitigation implementation.
Noise level targets were identified for the nearby residential neighborhood, located 492 ft. (150 meters) from the plant. Progressive targets of 65, 60 and 55 dBA were identified, to allow gradual implementation and distribute costs over a number of years.
Approximately 450 noise sources were measured.
The noise sources included:
- Radiator coolers
- Cooling towers
INNOVA proposed a retrofit of the existing compressor building, utilizing the company’s proprietary acoustic assemblies on walls and roof and over boilers. To reduce the significant level of noise breakout from ventilation openings, INNOVA recommended acoustic ventilation and further proposed absorptive barriers around select equipment, such as furnaces and radiator coolers.
UNIQUE PROJECT HURDLES
INNOVA faced to major challenges on this project. More than one design was requested, along with extensive involvement of the plant's Operation and Maintenance staffs in the preliminary design process. Potential scope and complexity of noise mitigation was high. Therefore, the projected cost of mitigation implementation was substantial. For these reasons, the client requested INNOVA provide three designs that would enable the plant to achieve noise targets in a progressive fashion over a lengthy time period.
The plant itself would expand. During the time period in which noise mitigation was to be achieved in a progressive manner, it was expected that the plant itself would be undergo future expansion. Expansion plans included an addition of a power plant-- a major component that would contribute its own set of noise variables.
Therefore, INNOVA’s designs (which guaranteed noise reductions to acceptable levels) would have to be adaptable to incorporate the plant’s modifications and additions.
Finally, the client requested solutions that, if possible, would reduce the existing risks associated with compressing heavier-than-air and highly explosive gasses. The compressor enclosures were required to be designed to allow removal in less than sixty seconds in case of an emergency.
The work was completed within a four month period, between September and December 2003.