Treating high-mercury-containing lamps using full-scale thermal desorption technology

Area of Science:

• Environmental Science
• Chemical Engineering
• Waste Management

Background:

• High-mercury-containing lamps exceed recommended limits for thermal desorption.
• Lamp disposal contributes significantly to mercury pollution.
• Taiwan's industrial waste treatment system processes millions of lamps annually.

Purpose of the Study:

• To establish a full-scale thermal desorption process for mercury recovery from various lamp types.
• To monitor the impact of pre-heating temperatures and desorption times on efficiency.
• To analyze the factors affecting mercury recovery rates.

Main Methods:

• Implementation of a full-scale thermal desorption process.
• Treatment of Super High Pressure Mercury lamps (SHPs), fluorescent tube tailpipes, and fluorescent tubes/CCFLs containing mercury-fluorescent powder.
• Monitoring of varying pre-heating temperatures and desorption durations.

Main Results:

• Achieved 99.95% average thermal desorption efficiency for SHPs and fluorescent tube tailpipes.
• Obtained 97-99% efficiency for fluorescent tubes with mercury-fluorescent powder.
• Reported 69.37-93.39% efficiency for Cold Cathode Fluorescent Lamps (CCFLs) with mercury-fluorescent powder.

Conclusions:

• Thermal desorption is highly effective for mercury recovery from most lamp types.
• Complex mercury compounds in CCFLs reduce thermal desorption efficiency.
• Higher temperatures generally increase thermal desorption efficiency for lamps with mercury-complex compounds.