The automotive industry is a major air pollution contributor and thus one of the most regulated industries in the world. Of car emissions 60 – 80 % are from tailpipe emissions. However, as tailpipe emissions decrease, more emphasis must be placed on the emissions generated by the vehicle’s materials and production. Therefore, effective emissions testing in automotive industry is required.
The automotive industry could abate 66 percent of emissions from their material production at no extra cost by 2030—if industry participants work together and start now. McKinsey & Company
Several emissions testing techniques are widely used in the automotive industry for measuring vehicle emissions. Typical applications include live on-board exhaust monitoring (CO, CO2, N2O, NOx, formaldehyde, acetaldehyde, oxygen and moisture), analysis of raw and dilute exhaust gas from the engine and tailpipe with gas-bags (CO2, N2O, NOx, CH4, EtOH, THC, H2S, SO2, NH3, formaldehyde and acetaldehyde), diesel Selective Catalytic Reduction (SCR) after-treatment monitoring (NH3) and the Sealed Housing for Evaporative Determination (SHED).
WHAT IS THE SHED (SEALED HOUSING FOR EVAPORATIVE DETERMINATION)?
In the automotive industry, regulatory requirements applying to qualification type testing procedures have been upgraded since the introduction of new gasoline mixes on the market.
According to several industry codes and standards, evaporative losses from gas handling and storage system have to be tested and quantified for vehicle certification.
Sealed Housing for Evaporative Determination (SHED) is used to measure evaporative emissions and it is used by the US Environmental Protection Agency (EPA).
Photoacoustic spectroscopy (PAS) is approved technology by the US EPA as a measurement method for the SHED (regulation 40 CFR Part 1065.269) in emissions testing and monitoring in automotive industry . Vehicle, engine, and fuel testing is an important way for EPA to verify that emission standards are met.
Dr. Jeff Loo explains how he is using GASERA ONE SHED instruments for vehicle evaporative emissions testing in automotive industry.
WHAT TO MEASURE IN EMISSIONS TESTING IN AUTOMOTIVE INDUSTRY ?
In the SHED testing, components of interest are ethanol, methanol and refrigerants (R-134a and HFO-1234yf). For example, when E10 gasoline (10% ethanol) is used, ethanol vapors escape from the tank and permeate through plastic materials (e.g., fuel tanks and fuel hoses). The US EPA prescribes a conservative 1.08 correction factor on conventional FID measurements to account for ethanol emissions. This is unless its vapor fraction is directly measured by advanced instruments. Various methods are approved for the ethanol measurement (e.g. GC-FID or PTR-MS) but PAS is currently the most practical one.
Refrigerants and methanol are measured for additional information. Methanol is leaking from windshield washing liquid container and frigerants from the refrigeration system. Performance of the conventionally used PAS analyzer only marginally meets the requirements. As emission levels drop, high sensitivity and accuracy in effective emissions testing and monitoring in automotive industry is required.
GASERA’S SOLUTION FOR EMISSIONS TESTING IN AUTOMOTIVE INDUSTRY
The GASERA ONE SHED multi-gas analyzer unit is characterized against requirements for the SHED application in laboratory.
The GASERA ONE SHED is an automatic and standalone measurement system that uses an external cavity quantum cascade laser (EC-QCL) as the light source. It meets the current EPA measurement specifications of ethanol and its detection limits are superior to previously used instrumentation:
- EtOH GASERA ONE SHED 23 ppb
- EtOH earlier limits 60 ppb
- The EPA required limit is 36 ppb
Ethanol and methanol can be measured simultaneously and distinguished from each other. The GASERA ONE SHED provides stable and reliable measurement results in emissions testing in automotive industry that are fully pressure and temperature compensated.
REFERENCES
ACEA. Car Emission Testing Facts. https://www.caremissionstestingfacts.eu/
European Automobile Manufaturers Association. Emissions Testing. https://www.acea.be/industry-topics/tag/category/emissions-testing.
McKinsey & Company. The zero carbon car: Abating material emissions is next on the agenda. https://www.mckinsey.com/business-functions/sustainability/our-insights/the-zero-carbon-car-abating-material-emissions-is-next-on-the-agenda#
United States Environmental Protection Agency (EPA) Laws and Regulations. https://www.epa.gov/laws-regulations.
Read also: Gasera’s peer-reviewed research articles.
Matti Tossavainen, Sales and Marketing Manager
