Hydrogen Generation: An Easier to Site and Operate Industrial Applications

Interview conducted by Mychealla RiceMay 11 2017

In this interview, Dave Wolff from Nel Hydrogen talks to AZoM about why industrial facilities use Hydrogen and how PEM Hydrogen can be a better choice for on-site hydrogen.

Why do industrial facilities use hydrogen?

Hydrogen is the most abundant element in the universe, but because of its chemical activity, it is almost never found uncombined – it is usually combined with other substances.

Hydrogen is primarily used for its chemical properties – as a reducing agent.  Enormous volumes of hydrogen are used in oil refining and to make fertilizer.  Other chemical applications include use for edible oil hydrogenation, such as making margarine.

Due to its high heat conductivity and low density, hydrogen is critical to efficient operation of powerplants, to cool the windings in the electric generator.

Hydrogen is widely used in thermal processing of metals, metal powders, glasses and ceramics, to reduce surface oxides and enhance flowability and wetting.

Hydrogen is also used as a process gas for crystal growing, semiconductor manufacturing, and functional and decorative coatings such as crystal growing, epitaxy, and vapor deposition processes.

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What does the use of hydrogen have to do with siting or operations ?

While hydrogen has useful chemical properties and industrial uses, it is also extremely hazardous to store. Due to its extreme flammability, enormous energy content per mass of hydrogen, rapid rate of burning, and tendency to leak from the tiniest openings, hydrogen is classified by the EPA and OSHA as a Highly Hazardous material.

EPA and OSHA, along with guiding agencies such as NFPA, and insurance experts such as FM, make it hard to store appreciable amounts of hydrogen.  If hydrogen is stored, there are rigorous rules that define how much space must be left unused “sterile” around the storage vessels.  For each range of hydrogen storage, NFPA defines the sterile radius required. A 2006 NFPA study concluded that an explosion from a release of just a few cylinders of hydrogen could create a blast radius capable of injuring people up to 27 meters away – a blast area of over half an acre. According to NFPA, one high pressure hydrogen cylinder contains the chemical explosive equivalent energy to 35 lbs. of TNT explosive.

How is hydrogen produced and transported to customers?

Unlike the familiar industrial gases such as nitrogen and oxygen, hydrogen is not made from air.  While supplies of nitrogen and oxygen can be made anywhere there is air to process, more than 95% of the hydrogen used worldwide is made by hydrocarbon reforming – releasing significant quantities of carbon dioxide in the process.

As the lightest element, hydrogen is very difficult to distribute efficiently to remote customers.  An average industrial gas cylinder weighs 175 lbs., and contains just over one pound of hydrogen.  An entire tube trailer that weighs nearly 40,000 lbs. can transport only 600 lbs. of hydrogen.  And to make matters worse, the relatively few places where hydrogen is made means that tube trailers that leave full to distribute hydrogen to customers weigh nearly as much on the return trip for a new load as when they left – meaning high fuel costs.

Liquid hydrogen, developed primarily for the space program, enables the density of hydrogen to be increased through liquefaction, but at high energy and equipment costs.  Liquid hydrogen storage at customer locations is highly regulated because of the enormous energy content of the hydrogen stored – two gallons of liquid hydrogen contain the same 35 lbs. of TNT chemical explosive energy equivalent as a cylinder of hydrogen gas – and the average liquid hydrogen storage tank is in the range of 6000 gallons.

What are the alternatives to stored hydrogen?

In many processes, users seek safer alternatives if the primary approach used is hazardous. Unfortunately, there are few alternatives to hydrogen in most processes, and in some cases, they are more dangerous, not less.  The development of compact, automated, reliable and competitively-priced Proton Exchange Membrane (PEM) technology, has made it possible for hydrogen users to meet their gas demand, without distribution, delivery or the need for storage.

What’s different about PEM hydrogen generation?

While it’s long been practical to make hydrogen industrially using hydrocarbon-reforming technology, that process does not scale well to locations with limited footprint or for customers with smaller gas demands.  Large-scale hydrocarbon reforming is capital-intensive, operates primarily at a defined rate, and is best used to make feedstock for processes such as refining. A single hydrogen reformer, using many trucks and trailers, might serve hundreds or even thousands of diverse customers.

In contrast, PEM water electrolysis equipment is designed to be compatible with various hydrogen requirements and usage patterns. PEM water electrolysis uses electricity to split water into pure hydrogen and byproduct oxygen.

What makes PEM water electrolysis a better choice for on-site hydrogen supply ?

• Scale – PEM water electrolysis functions efficiently at any scale, making it possible to provide on-site hydrogen to even small individual users
• Load-following – Electrochemical operation enables PEM water electrolysis to follow the usage pattern of users as it varies over a very wide range.  Unlike hydrocarbon reformers which have very limited turndown, a  PEM hydrogen generator can vary output from 0-100% continuously.  PEM water electrolysis systems can also be switched on and off to suit customer operating schedule.
• Pressure – Because hydrogen is a tiny, low density and highly flammable molecule, it is very expensive to compress, requiring highly specialized equipment.  Hence the ability of PEM water electrolysis equipment to provide pressurized hydrogen may be highly valued.
• Purity – Unlike hydrocarbon reforming, which makes impure hydrogen and then uses filtering to clean it up, PEM water electrolysis makes hydrogen which is wet but otherwise over 99.9995% pure, and requires only drying to achieve near-electronic grade purity.
• Zero-inventory hydrogen – Most importantly, PEM water electrolysis equipment can be designed to have virtually no on-board hydrogen inventory.  Whereas a gaseous hydrogen storage system may contain 500 pounds of hydrogen (at 35 lbs. of TNT per pound of hydrogen), the largest PEM water electrolysis system for the process industries contains less than 0.03 lbs. of hydrogen – over 16,000 times less hydrogen inventory.
• Standardized – PEM water electrolysis hydrogen systems are standardized for fast delivery, reproducible results, and easy maintenance
• No hazmats – PEM water electrolysis systems contain no hazardous materials, and when they are not operating, they contain no hydrogen at all.
• Green– While delivered hydrogen almost exclusively is made from hydrocarbons and results in greenhouse gas emissions during production and delivery, PEM water electrolysis can be operated from a green grid or locally-sourced electricity – resulting in hydrogen without carbon dioxide emissions.
• Compact – PEM water electrolysis systems are compact, and can be placed in general-purpose indoor locations.  A PEM water electrolysis hydrogen generator is a fraction of the size of the equivalent stored hydrogen system, and requires zero sterile area.
• Rugged, reliable – With 2600+  PEM hydrogen generation systems operating worldwide, this technology has a proven track record and is rugged, reliable, and long-lasting.

Where can our readers go to find out more?

To learn more please visit our website.

About Dave Wolff

Dave Wolff has over 35 years of project engineering, industrial gas generation and application engineering, marketing and sales experience. He has been the Sales and Marketing leader for Nel Hydrogen since 1999, responsible for sales management in the Eastern USA region.

Dave has an extensive background in hydrogen generation at large and small scale, hydrogen distribution, storage and industrial utilization, and has application knowledge across a diverse range of industries.