Regenesys system

The reader, even when reassured by the foreword, may still be reluctant, after reading Chapter 1, to forsake the ingrained notion that irreversible combustion is somehow relevant to equilibrium fuel cells. But here in ESS-RGN are fuel cells, with liquid reactants and products, and without oxygen Combustion cannot be relevant to the Regenesys system, as described below, and in the abb.com reference (Power Conversion Section, 2004) Electricity from the Store . 

Nine Fuel Cells with Central Nafion Membrane - Regenesys System. 

The Regenesys system stores the combined AG of the two half reactions, and releases the same AG for power delivery, with losses of around 25 % due to overvoltages, ohmic power dissipation and ion diffusion. Electron transfer and sodium ion movement are the agents of the process ... 

Note that the muscular motive power of the human body (see the introduction to this book) comes from the isothermal hydrolysis of adenosine tri-phosphate to di-phosphate (Atkins, 1995), a wet reaction in which little power is associated with reactant and product handling. Nature has evolved to a position of elegant fuel economy. Nature also has to undertake a complex chemical manufacturing task to provide automated selfmaintenance of the body. Chemical reactions are isothermal at blood temperature, along the same lines as the Regenesys system of Chapter 2. 

The operating principles of the Regenesys system is shown in Figure 1.17. Two fluids ( fuels ) are involved. When fully charged, a solution of sodium sulphide (NaaSa) in water is fed to the negative electrode, and a sodium tribromide (NaBrs) solution is fed to the positive electrode. The reaction at the negative electrode is... 

RegenOx The trade name for a system for remediating contaminated soils. Two liquids are injected an alkaline solution of sodium percarbonate, and a solution of a catalyst. Claimed to be capable of destroying hydrocarbons, gasoline oxygenates, and chlorinated hydrocarbons. Offered by Regenesis, San Clemente, CA, from 2005. 

New perspectives arising from isothermal oxidation. The next chapter of this book describes the greatly altered perspective of the fuel cell industry, when Grove s ideas are updated. The second chapter describes the detail of Regenesys, or ESS-RGN. This system has changed hands, as noted above, and information is available from http //www.vrbpower.com/. (The initials VRB stand for Vanadium Redox Battery, a low-power alternative to Regenesys.) The new 2005 VRB Power Systems shorthand is ESS-VRB for 2.5 to 10 MW and ESS-RGN for 10 to 100 MW. In Chapter 2 the reader will be acquainted with ESS-RGN, one of the two VRB fuel cell systems (incompressible liquid based) which can be termed complete . The redox battery uses small pumps as circulators. 

Chapter 2 appears on the ESS-RGN of VRB Power Systems, Vancouver, formerly the Regenesys power storage system, both for its own sake and for the thermodynamic points it enables the author to make, reiterate or emphasise in relation to his thermodynamic theories. Here are fuel cells without oxygen, and certainly without combustion, but undoubtedly with charge transfer reactions separated by a potential difference. Moreover, here are fuel cells with incompressible liquid reactants and products. 

The efficiency of such a system is simply the kWh power output divided by the kWh power input (above 50% for Regenesys, a figure not approachable in the proposed hydrogen economy via gaseous hydro-gen/oxygen, as explained in Chapter 1). 

Regenesys uses DuPont s Nafion (Section 6.1.7) as the perm-selective sodium ion transfer membrane, separating the two half cells. Figure 2.1. Diffusion of sodium ions in the concentration difference across the Nafion membrane is one of the irreversibilities of the system. The low-cost plastic (e.g. polyethylene) tanks and pipework are treated with fluorine to provide bromine resistance, and are able to operate with, and contain, both electrolytes at ambient temperature. 

VRB Power Systems http //www.vrbpower.com/ for information on Regenesys. 

A bromine/polysulphide RFB was patented by Remick in 1984 [12], but it was not widely acknowledged until Regenesys Technology commercialized this system in the 1990s [13]. From then on, considerable progress has been made to meet the standards for commercial application several testing and commercial facilities for different series were built [14]. 

As for the polysulfide-bromide system, the studies and commercialization that began seem to have been discontinued Prudent Energy (www.vrbpower.com) has adopted the technology initially developed by the company Regenesys, but does not appear to have relaunched it. 

This type of cell is used to make very large capacity rechargeable batteries and may be used by electricity utilities to balance peaks in supply and demand. There are a number of different chemistries that can be used. Cells based on vanadium have been made (Shibata and Sato, 1999), as have zinc/bromine systems (Lex and Jonshagen, 1999). This type of system is perhaps best exemplified in the so-called Regenesys fuel cell (Zito, 1997 or Price et al., 1999). 

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