Emerson Exchange 365

A major manufacturer of cellulose acetate in Latin America was faced with a problem common to many manufacturers trying to establish sound environmental emissions. They lacked confidence in their equipment. The company’s product is derived from natural sources and is, in itself, environmentally friendly. The recovery of acetone during the fiber production process is critical. It consists of passing the process mixture along an activated carbon bed that is meant to absorb most of the acetone and avoid releasing it to the atmosphere. Optimizing acetone adsorption is critical not only for optimizing emissions but also for the reduction of raw material and energy use. In order to assure optimum adsorption, certain variables such as adsorption time and steam flow must be adjusted. Reliable and accurate gas analysis is essential for performing these adjustments.

Unfortunately for the manufacturer, the gas analysis system they had been using failed five times, shutting down the process and inflicting a staggering cost of $10 million USD. The unit’s lack of reliability precluded any further attempt at repairs. The manual inspections the company had been forced to perform were costly, not continuous and, most critical of all, placed personnel in an unsafe area.

The company policy had already established a percent Lower Explosive Limit (LEL) analyzer as critical equipment into the Environmental Critical Equipment List. To avoid a major regulatory Reportable Quantity (RQ) of acetone emissions, the decision was made to install a percent LEL continuous analyzer with Infrared (IR)/Ultraviolet (UV) detectors. The analyzer monitors stack loss and sends the data to a DCS to detect high acetone emission concentrations so that the operator can adjust the adsorption time, steam flow, or even take the equipment out of service to avoid an RQ on the process.

The company decided to perform continuous measurement of acetone concentration at the exhaust line with a Rosemount X-STREAM Enhanced XEGP Gas Analyzer. The technology of the Rosemount X-STREAM Enhanced has given the company the ability to track the recovery rate of the absorber accurately and reliably. The Rosemount X-STREAM Enhanced XEGP continuous gas analyzer features:

• Up to four component gas analysis featuring NDIR/UV/VIS photometer, paramagnetic and electrochemical O2, thermal conductivity and moisture sensors
• Enhanced performance with IntrinzX Technology
• Extended ambient temperature range: 0 to +50 °C (32 to +122 °F)
• Plantweb connectivity and WinControl data acquisition
• Storage of data calibration and event log files
• Large dynamic ranges
• Programmable Logic Controller (PLC) controls, sample handling, and sample lines
• Very low-temperature dependency

The results of the shift to the Rosemount X-STREAM Enhanced XEGP continuous gas analyzer have been extremely positive for this manufacturer, including:

• Reduction in the consumption of raw material
• Reduction on the amount of steam used to clean up the bed when it gets saturated
• Fines caused by high rates of acetone emissions have been eliminated
• Improved safety by removing manual sampling that exposed personnel to dangerous concentrations of acetone
• Reduce acetone emissions to atmosphere from 1,000ppm to 100ppm
• Generate savings by carryover gas consumption on percent LEL analyzers of $5 million USD per year (equivalent to 11 gas tanks)

What a difference reliability makes.

Learn more about the Rosemount X-STREAM Enhanced XEGP Gas Analyzer here.

Do you have questions about how to establish reliable emissions from your plant?