Formatted Title
From Contamination to Petroleum Gold: Transforming High-Concentration TPH into Recyclable Resources with the C3 System
Background/Objectives
In the realm of environmental remediation, high concentrations of total petroleum hydrocarbons (TPH) present in non-aqueous phase liquids (NAPLs) have long posed significant challenges. Traditional vapor treatment methods, like granular activated carbon (GAC) and thermal oxidizers, often exhibit inefficiencies under such conditions. GAC's large carbon footprint stems from its origin (coal mining or other organic carbonization), extensive processing, and energy-intensive regeneration. Its treatment efficiency diminishes notably as VOC concentrations rise, rendering it ineffective for a diverse set of chemicals. On the other hand, thermal oxidizers, while moderately effective, pose operational challenges due to supplemental fuel usage, CO2 emissions, and the risk of harmful byproduct formation, alongside escalating operational costs.
Approach/Activities
Enter the cooling-compression-condensing (C3) system – a paradigm shift in addressing high TPH concentrations. Contrary to the norm of relying on chemical reactions, the C3 system harnesses the principle of physical phase change, sidestepping the pitfalls of chemical byproduct generation and the subsequent need for acid scrubbers. This aspect is particularly advantageous as acid production often plagues methods like thermal oxidation, leading to equipment issues such as clogging, corrosion, and fouling.
Furthermore, the C3 system boasts no threshold for VOC concentration, obviating the need for dilution. The resultant NAPL can be recycled, making the C3 approach not just a remediation method but also a conduit for resource conservation. With a recorded removal efficiency exceeding 99.8%, the C3 system emerges as an optimal solution for TPH treatment.
Results/Lessons Learned
Empirical evidence underscores the prowess of the C3 system. In a thermal remediation project in Australia, characterized by soil saturated with TPH as LNAPLs and certain chlorinated solvents as DNAPLs, the use of multi-phase extraction (MPE) coupled with the C3 system led to the recovery of approximately 8,500 pounds of NAPL. In a conventional scenario, this would have equated to the consumption of over 100,000 pounds of GAC.
Similarly, at an oil refinery site in Texas, the C3 system effectively managed soil contamination with hydrocarbon concentrations peaking at 95,597 ppmV, facilitating the recovery of an impressive 2,135,000 pounds of NAPL. Critically, in both projects, the system not only achieved but consistently maintained the stringent air emission permitting.
These instances accentuate the C3 system's duality – a tool for environmental remediation and a mechanism to reclaim valuable petroleum resources from contamination.