(Industrial Electrochemistry & Electrochemical Engineering Division New Electrochemical Technology (NET) Award) Development of Large Scale Commercial PEM Electrolysis

Abstract

Proton Energy Systems (d/b/a Proton OnSite) was founded in 1996, based on the premise that hydrogen generation from proton exchange membrane (PEM)-based electrolysis cells could be made cost competitive versus existing solutions. From small scale laboratory generators, Proton has successfully scaled up products over several design generations. A key advance has been the development of Proton’s C Series, a 30 Nm3/hr or 65 kg/day hydrogen generator based on PEM technology. A building block of this size is more suited for many applications, including common industrial markets and fueling infrastructure for small fleets of cars. This presentation will describe the evolution of Proton’s electrolyzer technology, including improvements in cell stack technology, balance-of-plant scale up, and the strong product platform we have built leading to our next product scale-up effort, for megawatt scale electrolysis applications. Market drivers and applications for various unit capacities, especially the C Series, will also be discussed. Electrolysis based on PEM technology was initially used in space and underwater for life support applications. Reliability is therefore a key characteristic of these systems. Proton has demonstrated over 50,000 hours of continuous operation in house, and has over 2000 systems fielded across product lines, with excellent reliability and up time. An advantage of the PEM systems in general is the ability to generate and electrochemically compress hydrogen at differential pressure, enabling low pressure on the oxygen side of the cell and inexpensive plastic components. The non-corrosive electrolyte also enables low maintenance cost and simpler balance-of-plant. Commercial applications for on-site hydrogen generation are driven by factors such as the desire for low hydrogen inventory, high purity hydrogen requirements, and lack of easily accessible hydrogen delivery infrastructure. Proton’s initial systems were designed to replace helium as the carrier gas in gas chromatographs, or as the lifting gas in weather balloons. The H Series, the precursor to the C Series, was developed specifically to address the electric generator cooling market. Hydrogen is utilized as a cooling fluid for the windings of over 16,000 power plant generators worldwide due to its high heat capacity and low density. Many of these plants are in areas with no reliable hydrogen delivery infrastructure. By 2006, Proton had established a robust cell design leveraging many of the design principles used today. The C Series was developed to serve larger power plants as well as the next level of fueling demonstrations, including small fleets of fuel cell vehicles and fuel cell buses. In addition, it is an appropriate size for heat treating and semiconductor applications. The cell stack, the core technology for the electrochemical system, was originally developed as a replacement for the existing electrolysis stack design for oxygen generation on board submarines. Proton was selected as the preferred developer based on our water electrolysis cell technology knowledge and expertise, leading to the development of a new, larger active area cell stack, including new flow field materials for the hydrogen side of the cell and a thinner cell configuration. This design effort was completed in 18 months, from early 2008 to 2009. Proton is currently under contract to manufacture cell stacks for several submarine platforms. This new cell architecture was then modified for the commercial application, and used as the basis for designing the new C Series system configuration. On the systems side, funding from the U.S. Army / TARDEC led to the development of key balance-of-plant subsystems, such as the implementation of a new gas/water management system, as well as a new high efficiency power supply configuration to drive the cell stacks. Internal investment from Proton paid for the development of system controls, manufacturing processes, and all of the quality documentation and third party agency certification testing required to release this platform as a commercial product. This development effort also spanned about 18 months, from 2009 to early 2011. Currently, Proton is working to translate many of the material advancements from PEM fuel cells to PEM electrolysis cells. While some changes will require modification, there are significant cost savings and efficiency improvements still possible, which Proton has demonstrated to have feasibility. In addition, Proton is performing another scale up effort to launch a megawatt scale product, representing another order of magnitude increase in hydrogen output. These systems will be designed based on requirements for emerging energy markets such as renewable energy capture and biogas methanization, and will also be discussed in this talk. Figure 1