# Enzyme-Powered CO2 Utilization: A Bifunctional Immobilized Biocatalyst for Intensified CCU of Industrial Feedstocks to High-Value Chemicals

## TL;DR

This paper introduces a new biocatalyst that converts CO2 and industrial waste into valuable chemicals using immobilized enzymes.

## Contribution

A bifunctional immobilized biocatalyst is developed for CO2 utilization and glycerol valorization with high product yields and reusability.

## Key findings

- The biocatalyst achieved the highest reported formate concentration via enzymatic catalysis (50.4 ± 0.3 mM).
- Dihydroxyacetone and glycerol carbonate were successfully produced from crude glycerol under industrial conditions.
- The system showed improved stability and reusability over five reaction cycles with reduced inhibition.

## Abstract

Decarbonizing industry demands a shift from high-energy
fossil
carbon to more sustainable green processes that valorize CO2 as a waste product. In this context, biocatalysis offers a promising
approach for integrating Carbon Capture and Utilization (CCU) with
the conversion of industrial waste into value-added chemicals. To
facilitate the transition from bench-scale experiments to industrial-scale
CCU, enzyme immobilization plays a crucial role by enhancing biocatalyst
stability, reuse, and overall reaction efficiency. This study explores
an industrially relevant multienzyme CCU platform to valorize CO2 and glycerol by developing a bifunctional biocatalyst through
a one-step sequential purification/coimmobilization strategy using
formate dehydrogenase (FDH) and glycerol dehydrogenase (GlyDH) for
the coproduction of formate and dihydroxyacetone (DHA), with in situ cofactor regeneration. The obtained biocatalyst
was optimized for stability and activity, and its performance was
first evaluated using pure substrates, as well as under industrially
relevant conditions with a crude gas mixture mimicking emissions from
iron and steel industry and crude glycerol from biodiesel production.
The results demonstrate the feasibility of this system for sustainable
CO2 conversion, achieving the highest formate concentrations
reported to date via enzymatic catalysis, 50.4 ± 0.3 mM (2.3
g L–1). Similarly, the valorization of crude glycerol
into DHA was achieved, along with glycerol carbonate as a byproduct.
The biocatalyst-enabled reaction intensification with significant
yields for all products improved stability and reusability over five
reaction cycles and reduced inhibition. The successful production
of three high-value molecules was achieved through a CCU approach
aimed at the valorization of industrial waste.