Challenges faced by electrolysis
Polymer electrolyte membrane (PEM) electrolysis is a promising source of green hydrogen for the next generation of fuel cell technology and is expected to increase in use over the next decade as costs of both electricity and renewable energy sources decrease. However, electrolysis and fuel cell process efficiency and lifecycle system reliability are still a concern.
Here, we discuss a current overview of fuel cells & electrolysis, address two major challenges faced by electrolysis, and pose Coriolis mass flow technology as a solution to increase electrolysis viability.
Electrolysis and fuel cells
All across the globe, fuel cell technology has gained attention as people seek out long-term sustainable energy solutions. PEM fuel cell technology has received particular attention, able to generate electricity from hydrogen and oxygen – and the only byproducts are water and heat. This is far more environmentally friendly than the aging combustion processes used in many transport and power system applications. Widespread research and development work is underway to increase their viability for both stationary and portable fuel cell applications.
Sourcing of the hydrogen required for the electrochemical reactions is a major area of focus that is just as important as fuel cell development itself. It is currently estimated that a whopping 96% of hydrogen worldwide is produced through fossil fuel processes involving natural gas, crude oil, and coal. Although a vast majority of some 70 million tons of hydrogen is used annually for industrial applications, the rise of fuel cell technology has demanded a new, cleaner approach to hydrogen generation.
A major source of green hydrogen is water electrolysis, which currently accounts for only 4% of annual hydrogen production but is quickly receiving more attention. While electrolysis methods vary, the basic principle involves the breakdown of water molecules into hydrogen (H2) and oxygen (O2) byproducts. The PEM electrolysis reaction is nearly the reverse of PEM fuel cell reactions.
Primary challenges faced by electrolysis
Electrolysis currently presents two major challenges: cost and efficiency. Research efforts worldwide are attempting to overcome these challenges and improve electrolysis viability.
Economic viability
Since electrolysis requires electricity to break down the water, it can cost over 50% more than hydrogen produced through fossil fuel processes. Still, the incentive remains to push for sustainable energy solutions. Fortunately, electrolysis will become more affordable as other sustainable energy sources such as solar and wind become more efficient. A current estimate predicts the cost of hydrogen production will decrease 30% by 2030.
While those challenges should be minimized with time, some can be more immediately remedied. Capital investment, maintenance, and equipment replacements can account for over 30% of the total lifecycle costs for electrolysis. Choosing reliable pieces of equipment with high lifetime value and wide operating range is critical to reducing the long-term cost of ownership.
Process efficiency
Process efficiency is certainly tied to economic viability: higher efficiency is more cost effective. However, it goes beyond that. The goal of PEM electrolysis is the creation of a clean renewable hydrogen source for fuel cells, so the efficiency must be maximized to increase appeal and incentivize adoption. Various sources place electrolysis efficiency at 70-80% in its current state, but this number needs to keep increasing if it is to compete with fossil fuels.
CODA Coriolis mass flow solution
CODA Coriolis mass flow instruments provide numerous benefits to remedy the cost and efficiency challenges faced by electrolysis setups. Many electrolysis processes require tight regulation of low flow rates and an instrument that can withstand high water temperatures. CODA instruments offer exceptional zero-stability and repeatability to ensure high accuracy measurement and control of ultra-low flows from 0.08 g/h to 100,000 g/h for temperatures up to 70°C.
There is also no required annual calibration for CODA – and since electrolysis and fuel cell systems have lifetimes up to 60,000 hours, this can equate to nearly seven years of annual savings over other mass flow solutions. CODA also presents an opportunity for savings as your process scales, as the available models can cover a wide range of flow rates. Additionally, CODA instruments are inherently resistant to external vibrations and bumps without need for a mass block, protecting your process from costly interruptions while minimizing equipment footprint so you have room for the rest of your setup.