What other CO2 savings do ethers offer?
The bio-ethers ETBE and TAEE have been shown to offer GHG additional savings compared to the bio-ethanol used in their manufacture. This is because the energy saved when a refiner exploits the high octane and reduced volatility they deliver more than counterbalances the extra processing step involved in converting the bio-ethanol to the bio-ether.
Studies carried out by Hart Energy Consulting and CE Delft, both respected independent consultants, using their own in-house modeling systems showed that ETBE offered an additional CO2 benefit over direct ethanol blending.
The studies support the following conclusions:
- By using ETBE a refiner uses less refinery fuel when producing finished gasoline than when using ethanol instead. This energy efficiency means naturally less CO2 emissions.
- By maximizing ETBE production and ETBE usage a refinery can further reduce its CO2 footprint.
- ETBE typically offers an additional saving of 24kg of CO2-equivalent/GJ of ethanol.
It should be noted that the above mentioned CO2 reduction is small compared to the total refinery footprint. However it is significant when considering the greenhouse gas balance for ETBE.
Hart Energy Consulting has also recently completed a follow-up study on TAEE which shows that this is a general benefit for bio-ethers.