A Method for Estimating Mass-Transfer Coefficients in a Biofilter from Membrane Inlet Mass Spectrometer Data

Area of Science:

• Environmental Engineering
• Biotechnology
• Chemical Engineering

Background:

• Biofilters (BFs) are crucial for treating malodorous industrial emissions, particularly from meat rendering facilities.
• Effective management of BFs relies on understanding gas removal mechanisms and operational parameters.
• Previous assessments often attributed incomplete removal to inadequate microbial activity.

Purpose of the Study:

• To investigate and enhance the management of a biofilter treating malodorous air from a meat rendering facility.
• To identify the primary reasons for incomplete removal of sulfur compounds.
• To establish a method for estimating key operational parameters like mass transfer coefficients and air velocity.

Main Methods:

• Utilized membrane inlet mass spectrometry (MIMS) to measure removal efficiencies of sulfur gases and toluene retention.
• Developed a computer model incorporating MIMS data to determine air velocity and mass-transfer coefficients.
• Applied the model to simulate scenarios with effective sulfur-oxidizing bacteria to elucidate removal limitations.

Main Results:

• Determined that insufficient mass transfer, rather than inadequate bacterial activity, was the main cause of incomplete sulfur compound removal.
• Quantified the mass-transfer coefficient of toluene and used it as a reference for sulfur gas mass transfer.
• Established a relationship between mass-transfer coefficients and air velocity for the specific biofilter.

Conclusions:

• The combination of MIMS and computer modeling provides an effective method for estimating mass-transfer coefficients and air velocity in biofilters.
• Understanding the interplay between mass transfer and air velocity is key to optimizing the dimensioning and management of biofilters.
• This research offers a data-driven approach to diagnose and resolve performance issues in industrial biofilters.