TY - JOUR

T1 - Biocatalysis in Water or in Non-Conventional Media? Adding the CO2 Production for the Debate

AU - Domínguez de María, Pablo

AU - Kara, Selin

AU - Gallou, Fabrice

N1 - Funding Information: P.D.d.M. acknowledges financial support from the European Union’s Horizon 2020 research and innovation programme RADICALZ (Grant number: 101000560) is gratefully acknowledged. S.K. acknowledges Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, Grant number: 391127961) for the financial support. Authors thank Johanna Meyer for the graphical representations.

PY - 2023/9/6

Y1 - 2023/9/6

N2 - Biocatalysis can be applied in aqueous media and in different non-aqueous solutions (non-conventional media). Water is a safe solvent, yet many synthesis-wise interesting substrates cannot be dissolved in aqueous solutions, and thus low concentrations are often applied. Conversely, non-conventional media may enable higher substrate loadings but at the cost of using (fossil-based) organic solvents. This paper determines the CO2 production—expressed as kg CO2·kg product−1—of generic biotransformations in water and non-conventional media, assessing both the upstream and the downstream. The key to reaching a diminished environmental footprint is the type of wastewater treatment to be implemented. If the used chemicals enable a conventional (mild) wastewater treatment, the production of CO2 is limited. If other (pre)treatments for the wastewater are needed to eliminate hazardous chemicals and solvents, higher environmental impacts can be expected (based on CO2 production). Water media for biocatalysis are more sustainable during the upstream unit—the biocatalytic step—than non-conventional systems. However, processes with aqueous media often need to incorporate extractive solvents during the downstream processing. Both strategies result in comparable CO2 production if extractive solvents are recycled at least 1–2 times. Under these conditions, a generic industrial biotransformation at 100 g L−1 loading would produce 15–25 kg CO2·kg product−1 regardless of the applied media.

AB - Biocatalysis can be applied in aqueous media and in different non-aqueous solutions (non-conventional media). Water is a safe solvent, yet many synthesis-wise interesting substrates cannot be dissolved in aqueous solutions, and thus low concentrations are often applied. Conversely, non-conventional media may enable higher substrate loadings but at the cost of using (fossil-based) organic solvents. This paper determines the CO2 production—expressed as kg CO2·kg product−1—of generic biotransformations in water and non-conventional media, assessing both the upstream and the downstream. The key to reaching a diminished environmental footprint is the type of wastewater treatment to be implemented. If the used chemicals enable a conventional (mild) wastewater treatment, the production of CO2 is limited. If other (pre)treatments for the wastewater are needed to eliminate hazardous chemicals and solvents, higher environmental impacts can be expected (based on CO2 production). Water media for biocatalysis are more sustainable during the upstream unit—the biocatalytic step—than non-conventional systems. However, processes with aqueous media often need to incorporate extractive solvents during the downstream processing. Both strategies result in comparable CO2 production if extractive solvents are recycled at least 1–2 times. Under these conditions, a generic industrial biotransformation at 100 g L−1 loading would produce 15–25 kg CO2·kg product−1 regardless of the applied media.

KW - biocatalysis

KW - CO production

KW - green chemistry metrics

KW - wastewater

UR - http://www.scopus.com/inward/record.url?scp=85172787935&partnerID=8YFLogxK

U2 - 10.3390/molecules28186452

DO - 10.3390/molecules28186452

M3 - Article

C2 - 37764228

AN - SCOPUS:85172787935

VL - 28

JO - MOLECULES

JF - MOLECULES

SN - 1420-3049

IS - 18

M1 - 6452

ER -