Abstract
Electroenzymatic processes are interesting solutions for the development of new processes based on renewable feedstocks, renewable energies, and green catalysts. High-selectivity and sustainability of these processes are usually assumed. In this contribution, these two aspects were studied in more detail. In a membrane-less electroenzymatic reactor, 97% product selectivity at 80% glucose conversion to gluconic acid was determined. With the help of nuclear magnetic resonance spectroscopy, two main side products were identified. The yields of D-arabinose and formic acid can be controlled by the flow rate and the electroenzymatic reactor mode of operation (fuel cell or ion-pumping). The possible pathways for the side product formation have been discussed. The electroenzymatic cathode was found to be responsible for a decrease in selectivity. The choice of the enzymatic catalyst on the cathode side led to 100% selectivity of gluconic acid at somewhat reduced conversion. Furthermore, sustainability of the electroenzymatic process is estimated based on several sustainability indicators. Although some indicators (like Space Time Yield) are favorable for electroenzymatic process, the E-factor of electroenzymatic process has to improve significantly in order to compete with the fermentation process. This can be achieved by an increase of a cycle time and/or enzyme utilization which is currently low.
Highlights
Gluconic acid is widely used in pharmaceutical, detergent, food, textile, and other industries [1,2].It is a product of partial glucose oxidation
Sustainability of the electroenzymatic process is estimated based on several sustainability indicators
We demonstrated that under our process conditions a very high Space Time Yield (STY) can be achieved compared to similar processes in literature [17,18,19,20]
Summary
Gluconic acid is widely used in pharmaceutical, detergent, food, textile, and other industries [1,2]. It is a product of partial glucose oxidation. Glucose itself belongs to the renewable feedstock for the chemical industry. It is an abundant carbon source with good biodegradability. These aspects make it a platform chemical for different syntheses and a good candidate for replacing the use of fossil raw materials [3,4]. Various routes, including chemical, microbial, enzymatic, and bioelectrochemical, have been employed to convert glucose to gluconic acid. The utilization of noble metal catalysts like Pt and Au increases the production costs due to problems with catalyst deactivation and recovery [6,7]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
