Mass Balance

Challenge

Manufacturing sites have many process units, each with inlet and outlet streams. Many sites do not have insight into the mass balance of these process units. Performing a mass balance on these process units (or the overall plant) is critical for identifying a number of issues, including leaks, faulty sensors, meter calibration issues, process inefficiencies, and more. Unfortunately, the plants that do perform mass balances likely use a method that is difficult to maintain and does not update as new data is available for continuous monitoring.

Solution

Companies using these systems turn to Seeq’s advanced analytics. Using context to separate product batch operation To ensure mass balance calculations are accurate, reliable, and up-to-speed, process manufacturing operations use Seeq to calculate and monitor their plants’ mass balance. This mass balance can run continuously to track changes over time and identify discrepancies between inlet and outlet streams.

Results

The results of the mass balance (acceptable or unacceptable) provide key insights into the operation of the system. If the mass balance results are acceptable (in equals out), this confirms that the process does not have major leaks and that the flow sensors are operating correctly. If the mass balance results are not acceptable (in does not equal out), this may indicate several potential issues, such as a leak, a bottleneck in the process, faulty sensors, meter calibration issues, accumulation, or more.

Calculations & Conditions

• Formula: Convert flow rates to consistent mass units
• Periodic condition: Create a condition for how frequently the mass balance is calculated
• Signal from condition: Calculate totalized flow rates
• Formula: Calculate the difference between the total in and the total out
• Value Search or Deviation Search: Identify when the difference between in and out exceeds a certain value or percentage
• Scorecard: Visualize mass balance in table form

Data Sources

• Process historian

Data Cleansing

Before a mass balance can be performed, all inlet and outlet flow rates must be converted to consistent mass units. This unit conversion is easily accomplished in Seeq using the Formula tool and stream properties. Additional data cleansing, such as filtering of noisy signals, may also be applied, if necessary.

Reporting and Collaboration

Results can be summarized in an organizer topic. An organizer topic can also be used as a dashboard for continuous monitoring of the mass balance