but does not reduce the GWP as much as the EP.
If hydrogen production is excluded, the increased yield of ethanol in the AP lowers the GWP per MJ to a value comparable to the GWP for the EP.
However, hydrogen is necessary to convert acetic acid to ethanol and its production increases the GWP relative to biorefineries that use an ethanologen for the fermentation step.
Electricity exported from the AP is also lower than in the EP, resulting in a lower GWP credit for the AP.
Targeting a reduction in natural gas use, hydrogen use, or producing hydrogen in a more environmentally efficient process could help lower the GWP of the AP.