Coproducing Value-Added Chemicals and Hydrogen with Electrocatalytic Glycerol Oxidation Technology: Experimental and Techno-Economic Investigations

Abstract

The electrocatalytic oxidation technology of biomass-derived oxygenates such as glycerol presents a promising method of coproducing renewable chemicals and hydrogen in an electrochemical reactor system that uses oxidation chemistry and existing proton exchange membrane technology to electrocatalytically convert oxygenates into value-added chemicals and hydrogen. In this paper, we first demonstrate the techno-economic feasibility of the electrocatalytic glycerol oxidation technology with our experimental investigations. Simple and direct conversion of glycerol into glyceraldehyde (GAD), glyceric acid (GLA), and hydroxypyruvic acid (HPA) by anodic oxidation in an electrocatalytic batch reactor over Pt/C catalysts was performed with only water as a stoichiometric chemical oxidant. We also conducted conventional catalytic (non-electrocatalytic) glycerol oxidation using a catalytic batch reactor with pressurized oxygen as the oxidant to compare conventional catalytic performances to that of the electrocatalytic reactor. The electrocatalytic glycerol oxidation process had a yield for GAD, GLA, and HPA production that was ∼1.7 times higher than that of the nonelectrocatalytic process. The turnover frequency of the electrocatalytic process is comparable to and even higher than that of a non-electrocatalytic system. On the basis of the experimental results, we develop process simulation models for both the electrocatalytic and non-electrocatalytic processes and then analyze the energy efficiency and economics of the process models. The minimum selling price (MSP) of GLA for the electrocatalytic process was $2.30/kg of GLA compared to $4.91/kg of GLA for the non-electrocatalytic process.

Efficient electrochemical production of glucaric acid and H2 via glucose electrolysis

“…The economic feasibility for the electrocatalytic and nonelectrocatalytic glucose oxidation strategies was estimated assuming a production scale of 1000 tons GRA per year 63 .…”

A review of recent developments on kinetics parameters for glycerol electrochemical conversion – A by-product of biodiesel

“…The highest yield of 1,3 propanediol (72%) was achieved from the electro fermentation in the BES which is very close to the 1,3 propanediol yield reported in a mixed microbial culture based glycerol fermentation process. When compared with other conven tional heterogeneous catalytic reactors, the operating cost of glyc erol electrochemical conversion is cheaper due to the simplicity of the reaction process and the reactor design (Kim et al, 2017a). Glycerol electrochemical reforming also saved approximately 2.1 kWh m 3 H 2 of electrical energy and the energy efficiency of glycerol conversion to hydrogen was around 44%.…”

“…Lee et al (2019a) reported high glycolic acid yield (66.1%) with a selectivity of 72% after 6 h of reaction at 80 °C. Besides, the glycerol/catalyst molar ratio is a crucial param eter to attain high glyoerol conversion and products selectivity (Kim et al, 2017a). Glycerol conversion, yield and selectivity of desired products can be calculated using Eqs.…”

A review of recent progress on electrocatalysts toward efficient glycerol electrooxidation

“…Selective electrooxidation technology employs an ion exchange membrane and oxidation chemistry for the electrocatalytic transformation of glycerol to specialty chemicals (Kwon et al 2011b, Simões et al 2012. This process has been successfully used to convert glycerol to glyceric acid (GLA) and glyceraldehyde (GLAD) even without the use of a stoichiometric chemical oxidant such as H 2 O 2 or O 2 in GEOR (Kim et al 2017). When compared to the operating cost of the conventional heterogeneous catalytic reactor, that of a GEOR reactor is less because of the simplicity of the reaction process and the reactor design.…”

“…Meanwhile, the electrons produced by water serve as the stoichiometric oxidant to produce the acid. The protons migrate to the cathode through the electrolyte in the reactor where they are transformed to H 2 by combining with the electrons (Kim et al 2017). Table 1 presents the typical oxidation products and their applications.…”