The Propane Education & Research Council (PERC) today released the results of a three-year research effort to demonstrate that propane-fueled forklift engines can meet more strict environmental standards and deliver the work power that has made propane a leading fuel for two classes of forklifts. The PERC study found that existing fuel systems can produce EPA-compliant readings for hydrocarbons (HC) plus nitrogen oxides (NOx) for both steady-state and transient cycles, and increase engine life. The complete report is available online (Final Report: Investigation of Fuel System Technologies and Fuel Composition Effects on Ability of Propane Forklifts tp Meet 2007 EPA Emission Standards).
The research was conducted by the Southwest Research Institute (SwRI) in San Antonio, and was designed to examine the effectiveness of existing propane forklift fuel system technologies to meet 2007 U.S. Environmental Protection Agency (EPA) regulations. The EPA 's 2007 regulations require large spark-ignition (LSI) non-road engines to reduce HC+NOx emissions from 3 g/bhp-hr to 2 g/bhp-hr and demonstrate an increase in useful engine life by 40%.
"It is vital that the propane industry work closely with our customers to help them understand how they can continue to rely on propane-powered forklifts for low emissions and even lower operating costs," said Roy Willis, President & CEO for PERC. "The research found that off-the-shelf electronic engine controls and three-way catalysts were capable of reducing forklifts' emissions and satisfying EPA requirements. This can translate into significant financial savings for companies looking to upgrade their fleet and meet higher environmental performance standards."
As part of the $1.39 million research study, researchers conducted steady-state and transient emissions testing of five different engine control systems with three-way exhaust catalysts from three different manufacturers. They also conducted tests to address the impact of fuel quality on emissions durability, including the effects of heavy ends, propylene content and additives. This included a chemical analysis of fuels, heavy-end residues and engine fuel system deposits. Highlights from the report include:
- Of the systems examined in the study, four existing fuel control systems demonstrated emissions well below the 2007 limit at zero hours under both steady-state and transient cycle conditions. Based on 1,000-hour tests, emissions durability should be sufficient to meet a 5,000-hour useful life requirement.
- Fuel studies found that propylene levels of up to 30 percent had a negligible impact on emissions performance of forklift engines with closed-loop feedback controls and three-way catalysts. The fuel study also found that current vaporizers and mixers can tolerate considerable heavy end deposition without emissions degradation.
- Occasional exposure to high sulfur fuel will not cause long-term degradation of emissions performance, and heavy ends have negligible impact on emissions in the absence of deposits.
The study also found that independent of fuel, proper fuel system component placement and operating conditions have a significant impact on deposit accumulation. Propane, which fuels more than 500,000 forklifts in the United States today.The Propane Education & Research Council (PERC) is a nonprofit 501(c)6 trade organization that is authorized by the Propane Education and Research Act of 1996.