Grantee Research Project Results
Final Report: Metal Organic Frameworks for Low-Cost Radon Mitigation
EPA Contract Number: 68HERC22C0012Title: Metal Organic Frameworks for Low-Cost Radon Mitigation
Investigators: Jayaraman, Ambalavanan
Small Business: TDA Research Inc.
EPA Contact: Richards, April
Phase: I
Project Period: December 1, 2021 through May 31, 2022
Project Amount: $100,000
RFA: Small Business Innovation Research (SBIR) Phase I (2022) RFA Text | Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Air
Description:
Exposure to radon is the second leading cause of lung cancer in the United States, resulting in about 21,000 deaths annually. This exposure is due to accumulation of radon in the soils below homes and its subsequent diffusion or convection into our living spaces. In this SBIR Project, TDA Research, Inc., (TDA) is developing a novel low‐cost radon mitigation system, using a state‐of‐the‐art metal‐organic framework (MOF) sorbent, in conjunction with a HEPA filter. Recent theoretical studies have suggested that certain MOF sorbents have unique radon adsorption characteristics, with high radon to nitrogen selectivities that suggest these materials can concentrate radon by many orders of magnitude.
TDA's system is a simple long-life drop-in device capable of mitigating the exposure to individuals, whether in residential, commercial, or industrial settings; greatly reducing the levels of both radon and its decay progeny. Our device relies the newly developed high capacity sorbent traps that binds the radon long enough (several days) for it to decay into non-gaseous, solids, in the form of radioactive decay chain products, like polonium, bismuth, and lead. The high efficiency particulate air (HEPA) filter used in the sorbent bed is capable of removing the already decayed radon atoms, now in the form of charged progeny attached to dust particles or other particulates. In our system the newly developed sorbent with the HEPA filter is packaged in the form of a long-life replaceable filter-cartridge system.
Summary/Accomplishments (Outputs/Outcomes):
Over the SBIR Phase I project period, we successfully completed all the proposed Phase I technical objectives. The summary of the achievements include:
- Synthesized a total of 40 batches of MOF sorbents and characterized them based on the BET SA, pore size and pore volume
- Screened the sorbents for radon adsorption by measuring the adsorption isotherms of xenon as a surrogate, nitrogen as the balance gas, and water vapor as a contaminant
- Scaled-up the synthesis of select (about 5) MOF sorbents (including pelletization and granulation as needed) for actual radon adsorption testing at Bowser-Morner.
- Performed xenon adsorption breakthrough cycle testing at TDA for our best performing sorbent (the FMOF-Zn, based on Xe/N2 selectivity), and examined the effects of activation and relative humidity.
- Worked with Bowser-Morner (a Nationally accredited radon testing laboratory) to carry out radon adsorption (exposure) tests with our MOF sorbents
- Competed the sizing and the detailed design of a full-scale prototype device. We calculated that we need about 2 L of the sorbent for a full-scale system sized to treat a typical basement (750 ft2) that has a before radon mitigation concentration of 10 pCi/L. The system is expected to consume about 10 W power compared to 91 W for today's regular radon mitigation systems, providing a cost savings of about $105/year.
- We also developed the design of a sub-scale prototype unit that will be fabricated and tested in the Phase II Project to elevate the TRL to 5
- Finally, we carried out an engineering analysis for the shielding and disposal requirements. We found that we can dispose the used cartridge as a regular heavy metal waste. Since the residual radiation in the Pb-210 (the decay product of Rn-222) is very small (~ 0.3 pCi in total over a 20 year life for the sorbent bed).
Conclusions:
In the Phase I of this EPA funded SBIR project, we developed a unique metal organic framework sorbent that has a high capacity and selectivity for Radon adsorption from air. This MOF is highly hydrophobic and adsorbs very little moisture, which allows it to adsorb radon with high capacity, as demonstrated in Radon exposure tests in Phase I. Based on the sorbent's radon uptake (performance), we then designed a low-cost fan and filter-cartridge system that can be deployed in a variety of situations, initially designed for the average basement in the US.
In Phase II we plan to design, build, cost an inexpensive long-life sorbent cartridge‐based radon capture system, composed of an energy efficient fan, HEPA filter, and a proprietary MOF sorbent.
Unlike the current radon mitigation systems that use a blower to evacuate the radon source, TDA's sorbent based deployable cartridge system will provide high separation capabilities with minimal energy usage, with far lower costs of installation and a more modular design (e.g. capable of scaling with multiple systems to adapt to the needs of any space). In the Phase I project Foresight, our TABA service provider, carried out a detailed Technology Niche Analysis for TDA's technology that allowed us to develop the business /commercialization strategy needed to take this technology to market.
Key Aspects of TDA's Commercialization Approach
- Innovation Being Commercialized: The present technology is a radon mitigation device for use in the built environment to reduce exposition to radon. The proposed device consists of a novel sorbent material to trap and bind radon combined with a traditional high efficiency particulate air (HEPA) filter, capable of removing the decayed radon atoms.
- Value Proposition: The present technology offers the following potential core value propositions: ease of retrofit of existing building structures in need of a means of radon mitigation (i.e., through a small, portable, modular system that does not require modification of the building structure). The final result will be to significantly reduce the cost of Radon mitigation compared to conventional alternatives.
- SWOT Summary: TDA's core strengths include the company's technical expertise, favorable market macro trends, and the ease of integration of the proposed product into end-user environments and the lower cost overall both upfront and the saving sin operating cost over its life; weaknesses to address include the fact that the proposed technology is new and unproven, that the IP landscape needs to be studied and the IP position secured for the new sorbent technology through patents and freedom-to-operate analysis; there exist opportunities in additional large and attractive markets for sorbent based separations; and primary threats are concerned with the intense competition in the R&D community and potential developments on the regulatory side.
- Commercialization Strategy: TDA's business strategy is to develop commercially useful materials and technology based on sound scientific principles and to form partnerships with established contractors or leading manufacturers via licensing arrangements to bring those technologies to market. This is a sound approach to addressing the market. We believe TDA's commercialization strategy is best executed through partnership with established incumbents with similar technologies and system solutions that may be interested in extending their platform offerings into radon mitigation; this may include companies that currently offer Radon detection solutions or others who may have a variety of high efficiency particulate air (HEPA) filter offerings but do not have a filter capable of eliminating radon in their portfolio of products.
From a top-down point of view, the market for our radon mitigation system is estimated through the radon measurement instrument market, which was valued at $570 million in 2020 and is expected to reach $1.2 billion by 2030, growing at a compound annual growth rate (CAGR) of 7.5% from during the forecast period. (Allied Market Research 2022)
References:
Allied market research website; "Radon Measurement Instrument Market by Mechanism (Active and Passive), Measurement Duration (Long-Term and Short-Term) and Application (Residential & Commercial, Research Laboratories, and Industrial): Global Opportunity Analysis and Industry Forecast, 2021-2030.". https://www.alliedmarketresearch.com/radon-measurement-instrument-market-A08262 (accessed March 12, 2022).
Darby et al; Br. Med. J. 330 (2004), pp. 223-227.
El-Gamal (2008) Eastern Mediterranean Health Journal, 14, 1257.
USA (1999) Health Effects of Exposure to Radon: BEIR VI. National
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.