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Proposed Canister Durability Test Procedures February 7, 2013 Michael F. Tschantz. Demonstration of Durability. At Type Approval certification In-Use. Considerations for Canister Durability Requirements.
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Proposed Canister Durability Test Procedures February 7, 2013 Michael F. Tschantz
Demonstration of Durability • At Type Approval certification • In-Use
Considerations for Canister Durability Requirements • Goal to establish test method(s) to ensure canister capacity is maintained over vehicle lifetime using ethanol-containing fuels • Test methods should be reliable, repeatable and tied directly to maintaining canister capacity exposed to ethanol fuel • Test methods should avoid unnecessary time, expense, and inconvenience to the vehicle owner and/or manufacturer
Type Approval Recommendation • Provide two certification-level alternative methods to provide automakers with flexibility • Certify vehicle using canister pre-aged to stable working capacity • Annual demonstration that carbon used for certification will maintain <10% degradation
Alternative 1. Proposed Activated Carbon Durability Procedures • Certification-Level Activated Carbon Aging: Demonstration that activated carbon will maintain capacity over lifetime of vehicle by bench aging activated carbon on certification-vehicle canister using repeated gasoline loading cycles prior to certification test. Report at certification and specify carbon used in certified canister. • Nominal Butane Working Capacity of Canister: Establishment of baseline canister butane working capacity for each vehicle model or evaporative family canister per EPA BWC (like US requirements). Report at certification. • Aged Butane Working Capacity of Canister: Establishment of aged canister butane working capacity for each vehicle model or evaporative family canister per EPA BWC (like US requirements). Report at certification.
Alternative 2. Proposed Activated Carbon Durability Procedures • Certification-Level Activated Carbon Testing: Demonstration that activated carbon will maintain >90% capacity over lifetime of vehicle by bench aging-durability testing of activated carbon using repeated gasoline loading cycles – Annual test. Report at certification and specify carbon used in certified canister. • Nominal Butane Working Capacity of Canister: Establishment of baseline canister butane working capacity for each vehicle model or evaporative family canister per EPA BWC (like US requirements). Report at certification.
Recommendations Alternative 1: Certify vehicle using a pre-aged canister Alternative 2: Demonstrate <10% degradation on carbon used for evaporative family
Alternative 1. Proposed Certification Testing Using Pre-Aged Canister • Use canister intended for certification vehicle • Initial EPA Working Capacity: • Average carbon BWC: BWC based on carbon supplier test result (11 samples minimum). • Run 13 test cycles loading vapor through tank port, with vent port open, purge port capped and 10 minute dwell between load and purge. • Load to 20.1 grams breakthrough by FID reading (using a Mini SHED or similar). Load at 15 grams/hour using 50/50 butane/nitrogen by volume. • Purge for 300 bed volumes at a rate of 22.7 liters/minute into the vent port, purge through purge port, tank port capped. • Capacity equals the average of the 12th and the 13th cycle load to 20.1 gram breakthrough • 500 Cycle Gasoline Aging: Load the canister at ambient temperature of 242°C through the tank tube with a 50/50 mixture by volume of air and the specific validation fuel (E10?). Generate the fuel vapor at a fuel temperature of 402°C with a flow rate of 40 grams/hour. Run test until 2 grams breakthrough occurs at the air tube. Let the canister sit for 1 hour. Then purge with air at 24 liters/minute for 400 bed volumes through the purge tube. Begin loading the canister within 1 minute of completing the purge portion of the test cycle. Test two canisters for 500 cycles each. • Final EPA Working Capacity: • Run 13 test cycles loading vapor through tank port, with vent port open, purge port capped and 10 minute dwell between load and purge. • Load to 20.1 grams breakthrough by FID reading (using a Mini SHED or similar). Load at 15 grams/hour using 50/50 butane/nitrogen by volume. • Purge for 300 bed volumes at a rate of 22.7 liters/minute into the vent port, purge through purge port, tank port capped. • Capacity equals the average of the 12th and the 13th cycle load to 20.1 gram breakthrough. • Install Canister onto vehicle prior to Type IV certification tests 1This procedure is similar to those used by multiple automotive manufacturers for internal use and for demonstration purposes to US EPA at certification. It is also similar to that previously proposed by the JRC, except the durability of the activated carbon used is certified (one time or annual test) instead of each model’s or evaporative family’s canister. This change will save a large amount of time and expense relative to that early proposal.
A. Proposed Certification Level Activated Carbon Durability Demonstration • Test shall be run one time annually to certify each carbon type used on certification vehicles. • Use 1 liter, single chamber canister filled with representative, aggregate sample of carbon: • Initial EPA Working Capacity: • Average carbon BWC: BWC based on carbon supplier test result (11 samples minimum). • Run 13 test cycles loading vapor through tank port, with vent port open, purge port capped and 10 minute dwell between load and purge. • Load to 20.1 grams breakthrough by FID reading (using a Mini SHED or similar). Load at 15 grams/hour using 50/50 butane/nitrogen by volume. • Purge for 300 bed volumes at a rate of 22.7 liters/minute into the vent port, purge through purge port, tank port capped. • Capacity equals the average of the 12th and the 13th cycle load to 20.1 gram breakthrough • 500 Cycle Gasoline Aging: Load the canister at ambient temperature of 242°C through the tank tube with a 50/50 mixture by volume of air and the specific validation fuel (E10?). Generate the fuel vapor at a fuel temperature of 402°C with a flow rate of 40 grams/hour. Run test until 2 grams breakthrough occurs at the air tube. Let the canister sit for 1 hour. Then purge with air at 24 liters/minute for 400 bed volumes through the purge tube. Begin loading the canister within 1 minute of completing the purge portion of the test cycle. Test two canisters for 500 cycles each. • Final EPA Working Capacity: • Run 13 test cycles loading vapor through tank port, with vent port open, purge port capped and 10 minute dwell between load and purge. • Load to 20.1 grams breakthrough by FID reading (using a Mini SHED or similar). Load at 15 grams/hour using 50/50 butane/nitrogen by volume. • Purge for 300 bed volumes at a rate of 22.7 liters/minute into the vent port, purge through purge port, tank port capped. • Capacity equals the average of the 12th and the 13th cycle load to 20.1 gram breakthrough. • Final EPA Working Capacity must be ≥90% of the Initial EPA Working Capacity1. • Report at certification. 1This procedure is similar to those used by multiple automotive manufacturers for internal use and for demonstration purposes to US EPA at certification. It is also similar to that previously proposed by the JRC, except the durability of the activated carbon used is certified (one time or annual test) instead of each model’s or evaporative family’s canister. This change will save a large amount of time and expense relative to that early proposal.
Estimated Cost for Aging Canisters • 500 GWC cycles at 40 g/hour onto a 1 liter canister • Test time = 45-55 days • Test cost ~ 11,000 € plus cost of fuel