Problem
An East Coast chemical
plant that manufactures phenol, acetone and alphametyl styrene from
cumene planned to install an air pollution control system to
control the volatile organic compounds (VOCs) emitted during their
chemical production process. Phenol is consumed internally as an
intermediate chemical while acetone and alphametyl styrene are sold
off. Once the chemicals are produced, they are shipped to another
plant to make carpet fibers. This plant already had a carbon
recovery system in place, but needed a system to control the low
concentration residual airstream from the carbon recovery
system.
Action
After thorough vendor evaluation, the plant selected and
contracted Anguil Environmental Systems, Inc. to solve their VOC
emission problem. The combination of VOCs in the airstream and
their low concentration made catalytic oxidation the ideal
technical choice. Plant engineers had concerns that an oxidation
system might have an adverse effect on the precise pressure and
volume control required in their production process. Anguil's
experience and success with chemical process applications provided
the plant personnel with the confidence that catalytic oxidation
was a viable solution.
Solution
An Anguil Model 650 forced draft catalytic oxidizer, rated for
65,000 SCFM (102,512 Nm3/Hr), was selected to process the airflow
from up to 25 point sources of emissions. As always, Anguil's
engineering staff worked closely with the customer throughout the
design and manufacturing processes to ensure that the system
precisely met their requirements. The system was sized to provide
99% destruction efficiency and 70% thermal energy recovery. The
reactor section contains two parallel catalyst beds; each bed
oxidizes half of the incoming airflow. The catalyst converts VOCs
into carbon dioxide, water vapor and thermal energy. The thermal
energy is then reclaimed by utilizing a primary heat exchanger,
thus reducing the system operating costs.
In order to address the concern of the precise pressure and
volume control required for the customer's production process, a
four module heat exchanger was manufactured. By using a greater
plate thickness, as well as fabricating "ribs" and "dimples" on the
plates, a pressure differential of 87.5 w.c. was sustained.
The plant's process operates 24 hours a day, 7 days a week. The
oxidation unit is required to run continuously to accomodate the
chemical process. The control system was integrated into the
customer's control system and redundancy was designed into the most
critical control items. A difficult pollution control issue was
solved by Anguil, resulting in another of their more than 800
satisfied customers worldwide.