Grantee Research Project Results

Final Report: Passive Lean NOx Trap Technology for Mobile Diesel Engines

EPA Contract Number: 68D02070
Title: Passive Lean NOx Trap Technology for Mobile Diesel Engines
Investigators: Nelson, Brian
Small Business: Sorbent Technologies Corporation
EPA Contact: Richards, April
Phase: I
Project Period: October 1, 2002 through July 31, 2003
Project Amount: $100,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2002) RFA Text |  Recipients Lists
Research Category: SBIR - Air Pollution , Small Business Innovation Research (SBIR) , Air Quality and Air Toxics

Description:

Mobile diesel engines, particularly long-haul tractor-trailer trucks, are an increasingly important source of nitrogen oxide (NOx) pollutants, which contribute to the degradation of ambient air quality. The U.S. Environmental Protection Agency (EPA) has implemented a series of increasingly stricter emission limits to better control NOx for such trucks. Presently, there is no satisfactory commercial control technology for meeting the new 2007 diesel truck standards. Sorbent Technologies Corporation has been working to adapt technology developed for controlling NOx emissions from stationary sources to address the mobile engine application. The technology utilizes a specially designed sorbent cartridge that adsorbs the pollutants from the exhaust gas stream and then later releases the pollutants to a NOx reduction system that converts it to diatomic nitrogen and oxygen.

The technical goal of this Phase I research project was to examine the specialized equipment needed to adapt the technology to the mobile application. For a mobile system to be economically practical, the mass and volume of the equipment needs to be minimized and its physical durability extended. Specifically, this project examined ways to optimize the processes of NOx desorption and NOx decomposition, the overall process controls, and the valves needed in the system. An additional goal of this project was to examine the effect of this technology on the tendency of diesel particulate filters to oxidize a portion of the nitric oxide to nitrogen dioxide.

Summary/Accomplishments (Outputs/Outcomes):

The goal of this Phase I research project was met. Based on data from experiments conducted during the research project, a system for reducing the NOx emissions from mobile diesel engines by up to 80 percent has been outlined. Specifically, components for the desorption/regeneration/NOx decomposition process were developed and evaluated. The major components of the system have been specified and, in most cases, commercially available components have been identified.

Conclusions:

These results, coupled with data from stationary engine control-system tests run under other research programs, suggest that the system will operate effectively to significantly reduce NOx emissions from mobile diesel engines. The next step in the commercialization of this technology is to build, test, and verify a prototype mobile NOx control system.

Supplemental Keywords:

air pollution, smog, ozone, passive lean NOx trap, mobile diesel engines, tractor-trailer trucks, nitrogen oxide, NOx, ambient air quality, emissions, mobile sources, sorbent cartridge, exhaust gas stream, diatomic nitrogen, oxygen, small business, SBIR., Air, Scientific Discipline, mobile sources, Environmental Chemistry, Engineering, Chemistry, & Physics, Atmospheric Sciences, air toxics, Environmental Engineering, diesel exhaust, Clean Air Act, emission control strategies, passive lean NOX trap, Nox, automotive emissions, sorbents, NOx reduction, nitrogen oxides (Nox), air pollutants, air pollution, automotive exhaust, air pollution control, sorbent technology