On the regeneration of thermally regenerative ammonia batteries

Abstract

In the past few years, thermally regenerative ammonia battery (TRAB) has been proposed as an effective tool to recover waste heat at temperatures below 130 °C. Most of the literature available is devoted to the power production step, with less attention being given to the regeneration step (e.g. the removal of ammonia from the anolyte). In this paper, the TRAB is analyzed with particular attention to the 15 regeneration step and to the study of various generation of energy-regeneration cycles. It was shown that approximately 90 °C is necessary for the regeneration step due to the fact that ammonia is present in the anolyte mainly as an ammonia complex. Various cycles were performed with success, demonstrating the efficacy of the proposed regeneration step.

Copper Foam Electrodes for Increased Power Generation in Thermally Regenerative Ammonia-Based Batteries for Low-Grade Waste Heat Recovery

“…17 The regeneration process was first investigated at a regeneration temperature above 90 °C, and five successive power generation/regeneration cycles were conducted without the use of fresh anolyte or catholyte. 21 In addition to these experimental works, a two-dimensional stationary and transient model was developed to simulate a single thermally regenerative ammonia-based flow battery using copper plate electrodes under previously reported experimental conditions, 16 and the simulation results were in good agreement with the experimental data. 22 Although several studies have been conducted, the power density of TRAB is still not enough for practical applications.…”

“…It was obvious that the power density (W/ m 2 ) of the TRAB using copper foam and copper plate in this study was lower than that of other studies. 8,20,21,25 This is related to the fact that the increasing of power is not proportionally increased with the increasing electrode area and the power density based on projected surface area shows a tendency of decreasing with an increase in electrode size. 23,30,31 However, with respect to power output, the TRAB with copper foam in this study produced several times more power than TRABs in other studies due to the high specific area of the copper foam.…”

“…A potentially less expensive, highly efficient, and chemically and thermally stable anion exchange membrane was synthesized using poly­(phenylene oxide) backbones with pendant benzyltrimethyl­ammonium cations to improve of TRAB power generation . The regeneration process was first investigated at a regeneration temperature above 90 °C, and five successive power generation/regeneration cycles were conducted without the use of fresh anolyte or catholyte . In addition to these experimental works, a two-dimensional stationary and transient model was developed to simulate a single thermally regenerative ammonia-based flow battery using copper plate electrodes under previously reported experimental conditions, and the simulation results were in good agreement with the experimental data …”

Thermally regenerative copper nanoslurry flow batteries for heat-to-power conversion with low-grade thermal energy

“…21 This issue was also highlighted recently. 22 The Cu(I) solution was heated under nitrogen at 120 1C to induce thermal regeneration. In order to keep a solution after the disproportionation, the solvent is partially composed of propylene carbonate, which remains in the liquid state (b.p.…”

“…Most thermally regenerative batteries are based on copper [20][21][22] or silver 23 complexation with ammonia or acetonitrile 24,25 in aqueous solutions. The removal or addition of the complexing agent is used to change or even inverse the cell voltage, [20][21][22] or to induce disproportionation of a Cu(I) complex to produce Cu and Cu(II) as described below. 24,25 Cu and Cu(II) can then be discharged in a battery to produce electricity.…”