Assessing the influence of the carbon source on the abatement of industrial N 2 O emissions coupled with the synthesis of added-value bioproducts.

The continuous abatement of a synthetic N2 O emission from a nitric acid plant coupled with the simultaneously production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) copolymer and the coenzyme Q10 (CoQ10 ) in a bubble column reactor (BCR) was tested using methanol, glycerol and a mixture of sodium acetate-acetic acid (Ac-HAc) as a carbon and electron donor source. The BCRs were inoculated with Paracoccus denitrificans and supplied with the carbon/electron donor at a loading rate of 139gCm-3 d-1 . High N2 O removal efficiencies (81-91%) were achieved, with glycerol supporting the highest abatement. The PHBV cell content ranged from 25 to 53%, with highest accumulation in the culture obtained with methanol and Ac-HAc. However, the greatest PHBV productivities were observed in the BCRs operated with glycerol and Ac-HAc (21.7 and 33.5gPHBVm-3 d-1 , respectively). Glycerol supply induced the highest molar ratio (23%) of the homopolymer 3-hydroxyvalerate in the composition of PHBV. In addition, the specific cell content of CoQ10 ranged from 0.4 to 1mgg-1 . This work constitutes, to the best of our knowledge, the first study combining N2 O abatement with the simultaneous production of multiple bioproducts, which pave the way to the development of greenhouse gas biorefineries for climate change mitigation.