Grantee Research Project Results

2022 Progress Report: UV-LED Photocatalytic Fuel Vapor Emissions Control

EPA Grant Number: SV840016
Title: UV-LED Photocatalytic Fuel Vapor Emissions Control
Investigators: Almquist, Catherine
Institution: Miami University
EPA Project Officer: Aja, Hayley
Phase: II
Project Period: July 1, 2020 through June 30, 2022 (Extended to September 30, 2023)
Project Period Covered by this Report: July 1, 2021 through June 30,2022
Project Amount: $74,663
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2020) Recipients Lists
Research Category: P3 Awards

Objective:

Our ultimate goal is to develop a cost-effective and technologically feasible prototype that would be incorporated into an automobile to reduce evaporative fuel vapor emissions by at least 70% compared to current fuel vapor emission control systems. Three design parameters on which Phase 2 efforts will be focused are: 1) the size and construction of a light weight, low power cylindrical prototype, 2) the durability of the photocatalytic film, and 3) the power, intensity, and distribution of the UV LEDs. Stant Manufacturing suggested that the prototype be lightweight, low power, low cost, and highly effective for inclusion into the existing on-board refueling vapor recovery (ORVR) systems.

The Phase II objectives and strategies are to: 1) Construct a cylindrical UV LED photocatalytic fuel vapor emissions control device that is 3 cm diameter by 10 cm in length, a size that can fit into the current ORVR system; 2) Demonstrate a photocatalytic film that is durable to abrasion and vibrations and when exposed to water vapor; 3) Identify and assess the limitations of this technology for the following experimental variables: the intensity of the UV LEDs at the photocatalytic film, the illuminated area and type of photocatalytic film, residence time, concentration and type of hydrocarbon, UV LED intensity and wavelength, humidity, and the longevity of service life of our device; 4) Demonstrate the operation of the prototype in standard test systems; 5) Conduct an economic analysis for the proposed technology to assess economic attractiveness from multiple perspectives (auto manufacturers, human health, regulations); and 6) Design and develop educational and marketing tools for this technology.

Progress Summary:

Progress toward each of the objectives was made in the first two years of our Phase 2 efforts. Only the progress made in the reporting period is described below:

• Light-weight cylindrical prototypes were constructed and assessed for performance both in lab with selected hydrocarbons and at Stant, Inc in a standard test system for assessing evaporative fuel vapor emissions.
• ZnO/TiO2 composites from sol-gel methods were investigated in an effort to improve upon the durability and photocatalytic activity of the photocatalytic film, but the ZnO/TiO2 composites were found to be less active than pure TiO2.
• UVC LEDs were compared with UVA LEDs as light sources within our test systems. While the wavelengths of the UVC LEDs were shorter than those of UVA LEDs (hence higher energy), the intensity of the UVC LEDs that were purchased was significantly lower than that of the UVA LEDs. Therefore, the performance of the device with UVC LEDs was not as attractive as that with UVA LEDs.
• The longevity of the performance of the prototype devices was assessed for one month, and the performance of the reactor appears to degrade only slightly after one month online with ethanol and hexane vapors. However, aromatic compounds degrade the performance of the devices within a few days.

Future Activities:

Future activities will include the identification of data gaps and completing studies for two future publications. The work will be presented in Phoenix, Az in November, 2022 at the AICHE meeting. Additional focus will be placed on understanding the mechanisms of photocatalytic film deactivation and methods to regenerate the film. In addition, the oxidation of titanium foil will be investigated as a method to create sturdy, water-resistant photocatalytic films. An economic assessment of the device will be conducted from multiple perspectives, and the development of educational tools for the technology will be made.

Journal Articles:

No journal articles submitted with this report: View all 10 publications for this project

Supplemental Keywords:

UV LED, photocatalysis, fuel vapors

Relevant Websites:

US EPA P3: UV LED Photocatalytic Evaporative Fuel Vapor Emission Reduction Device YouTube Video Exit

13th Annual AIChE Midwest Regional Conference Exit

Progress and Final Reports:

Original Abstract

2021 Progress Report

2023 Progress Report

Final Report

P3 Phase I:

UV-LED Photocatalytic Fuel Vapor Emissions Control  | Final Report