A failed biogas reactor at Bacardi’s largest distillery in Puerto Rico significantly increased the company’s fossil fuel consumption and greenhouse gas emissions, and also hurt production, the company reveals in its latest corporate responsibility report.

Bacardi says the anaerobic reactors – which treat wastewater and convert organic residues into biogas used to produce steam and electricity – are supposed to operate for more than 10 years before they must be refurbished, but at the end of FY2012, a reactor failed prematurely.

This required the company to lower production (by how much, the company did not say) because of reduced wastewater treatment capacity. This in turn reduced energy efficiency.

The site, which accounts for more than a quarter of the company’s energy use and much of its renewable fuel, had to switch mostly to heavy fuel oil for its steam and electricity needs, with company-wide non-renewable fuel use rising from 1,630 TJ in FY12 to 1,660 TJ in FY13.

Its GHG emissions per unit of production rose 11 percent from FY12 to FY13 – to a level not seen for four years (see chart).

And sulfur dioxide, nitrogen oxides and particulate matter also increased by nearly 12 percent.

We’ll have more details on this sustainability report tomorrow.

Takeaway: Bacardi’s experience highlights the risk of anaerobic reactor failures, which can not only increase GHG emissions but hit wastewater treatment and therefore production levels.

Tamar Wilner is Senior Editor at Environmental Leader.