Electrolysis and Electrolyzer Pressure Control -

Electrolysis and Electrolyzer Pressure Control

Back pressure regulators for PEM electrolysis

  • electrolyzer diagram

Water electrolysis is an electrochemical process using electricity to split water into hydrogen and oxygen. This reaction occurs in an electrolysis cell or an electrolyzer unit containing an electrolytic medium between an anode and cathode.

Electrolyzer Technology

Current technologies using Polymer Electrolyte Membrane stacks, also called Proton Exchange Membranes or PEM, were designed for higher efficiency water electrolysis than the earlier alkaline solution electrolyzers. These PEM electrolysis systems may be designed as a balanced pressure system, where O2 and H2 operate at the same pressure, or as a differential pressure system where O2 and H2 operate at different pressures. The advantage of high pressure electrolysis of H2 is that it minimizes the need for a second stage mechanical compression to pressurize for storage. In either the differential or balanced pressure designs, pressure regulation of the O2 and H2 gases is extremely important to the efficiency and life of the PEM electrolyzer. Equilibar has a family of back pressure regulators to control the electrolysis process at a range of pressures, high or low, with extreme precision.

Uses for Electrolysis

Energy researchers are optimizing electrolysis for producing hydrogen as an energy source from renewable resources. Wind turbines and PV cells can be used as electricity sources for the electrolyzer to produce hydrogen for hydrogen fuel cells. The goal is to increase the use of renewable energy and decrease carbon emissions.

Oxygen gas produced in the reaction may be used for a variety of applications, including breathable O2 for space travel and submarines.

Equilibar technology used for electrolysis to generate oxygen in space

Flow cell electrolysis, which is used for spaceflight applications, uses a flowing water electrolyzer to generate enough oxygen from water to keep up with the crew’s metabolic requirements. Many of the current electrolyzer designs require a downstream gas-liquid separation process, presenting challenges in a microgravity environment. One complication is two-phase flow caused by bubble generation in the electrolyzer. Researchers at the University of Colorado at Boulder proposed an alternative electrolyzer configuration and built a prototype using an Equilibar® vacuum regulator.

Read the case study in the link to the right.

The Equilibar® back pressure regulator is dome-loaded and, with its novel multiple orifice design, delivers instantaneous reliable control in the most challenging applications. The dome-loaded design means it requires a fluid (typically air or nitrogen) pressure applied to the dome of the back pressure regulator matching the desired inlet pressure. This setpoint pressure can be manually or electronically controlled. Learn how Equilibar back pressure valves work

Our team of experienced engineers offer detailed guidance in choosing the pressure regulation equipment for a specific condition. Contact an Equilibar engineer to discuss your application in more detail.

Schematic of PEM water electrolysis

Precision stainless steel back pressure regulator for electrolysis and electrolyzer applications ( product info)

Equilibar EVR used for electrolysis in space for oxygen generation

Case Study: Prototype electrolyzer for generating oxygen in space



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