Anode-Boosted Electrolysis in Electrochemical Upgrading of Bio-oils and in the Production of H₂

Abstract

Oxidizing an organic solute at the anode of an electrolysis cell can enhance the overall cell current, I, by supplementing the applied cell potential by an amount, E boost, the difference in potential required to achieve the observed rate in the presence and absence of the organic. We have found that, when the organic solute is methanol at concentrations, C, corresponding to a chemical oxygen demand of <25 g/L (in the range of that of wastewater or process water from hydrothermal liquefaction), then the effect of the anode-boosting becomes a strong function of the product of C and the cell current, I. Empirically, the boosting follows Hill–Langmuir kinetics, consistent with the cooperativity in the transport of the organic into the double layer of the anode or adsorption on the oxidation site.

Electrocatalysts for Using Renewably-Sourced, Organic Electrolytes for Redox Flow Batteries

“…The kinetics of the electrocatalytic reactions may be complex functions of the composition of the electrolyte, even for substrates that are infinitely miscible with the supporting electrolyte. For example, we found [29] that the kinetics of the oxidation of methanol and water followed Hill-Langmuir kinetics, which prevented high extents of conversion because water displaced the methanol from the vicinity of the electroactive site when the methanol concentration fell below about 0.5 M. Organics such as those in Table 1 could be expected to segregate from the polar media [30] needed to stabilize the polarized, likely charged, current carriers, leading to a complex dependence of the redox reaction rates on the concentration of the substrates.…”

“…Regardless, deconvoluting the complexities noted above for the oxidation and reductions of substrates, such as those in Table 1, will require access to intrinsic kinetics, preferably differential kinetics over wide ranges of substrate concentration [29]. It will also require access to well normalized reaction rates, preferably using a site-counting method that can be used under conditions close to those of the relevant reactions.…”

On the evolution and application of the concept of electrochemical polarization

“…Somewhat differently from the above listed papers, "charge depolarization" was used to indicate that the surface charge of a semiconductor electrode could be reduced in the presence of a suitable adsorbate [50]. Some authors attempt to make their findings understood in terms of depolarization and depolarizer, noting at the same time that these concepts are not only old but "obsolete" [51].…”

Second International Symposium on Biomass/Wastes Energy and Environment (BEE 2019), Tianjin, China, May 23–26, 2019

“…Three of the papers − deal with synergies between industries that benefit the production of renewable fuels. The next entries in the table exemplify depolymerization processes that convert the renewable feedstock into more valuable streams, − including cleaner water . The last four entries explore characteristics of the fuels: their physical properties and their combustion. − …”

“…The next entries in the table exemplify depolymerization processes that convert the renewable feedstock into more valuable streams, 5−8 including cleaner water. 9 The last four entries explore characteristics of the fuels: their physical properties 10 and their combustion. 11−13 Guanyi Chen Robert S. Weber orcid.org/0000-0003-3731-8461…”