SBIR Phase II: Single-Stream Reclamation Process for Complex Refrigerant Mixtures

The broader/commercial impact of this Small Business Innovation Research (SBIR) Phase II project is its ability to significantly reduce the atmospheric impacts of refrigerants used in heating, ventilation, air conditioning, and refrigeration (HVACR) applications. Each year in the US, tens of millions of pounds of solar heat trapping refrigerants are released into the atmosphere through inadvertent or illegal venting. This equates to tens of millions of tons of otherwise avoidable CO2 equivalent emissions each year. Millions more pounds of re-usable refrigerants are collected each year but are either stockpiled or destroyed due to a lack of separation technology to process mixed and out-of-specification refrigerants. Such refrigerants are being phased down by 85% by 2036 under the American Innovation and Manufacturing Act. However, existing systems will require servicing using these refrigerants for decades longer. Through the development of an efficient, single-stream process for reclaiming recovered refrigerant mixtures, this project will help minimize the environmental impacts of refrigerants by making recovery and reclamation possible and profitable. By providing a reclaimed, domestically produced source of legacy refrigerants, the project will enable the U.S. to keep air-conditioning, heat pump, and refrigeration systems operational while transitioning to more sustainable alternatives. This project aims to develop a single-stream reclamation process for separating complex azeotropic refrigerant mixtures into 100% reclaimed single-component refrigerants. Refrigerant blends are designed to be azeotropic, meaning the components have essentially the same boiling and cannot be separated using traditional distillation. Extractive distillation with ionic liquids (EDIL) can break azeotropes and separate complex mixtures into single components so they can be reused or repurposed into non-regulated products. This project will seek to develop a multi-stage, continuous separation process capable of separating complex mixtures containing hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), chlorofluorocarbons (CFCs), and hydrocarbons commonly found in recovered refrigerant supply chains into 99.5%+ pure components. Phase II project will transition the EDIL platform from proof-of-concept into a full-scale commercial process capable of meeting demand for a sustainable source of legacy refrigerant throughout the ongoing phase-out and beyond. The project scope includes (1) developing a novel library of thermophysical properties for various ionic liquids and refrigerants, (2) sophisticated rate-based modeling and computational simulation of complex separations, (3) experimental demonstration through actual pilot-scale separations, (4) in-depth technoeconomic analysis and long-term stability studies to validate process economics and (5) a comprehensive refrigerant lifecycle analysis to assess its impact against other end-of-life alternatives. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.