3:02 PM Saturday Dec 11, 2010

Still waiting for the hydrogen economy to ignite and save us from the oil squeeze and environmentally unsustainable fossil fuels?

New Zealand engineer John Fleming is part of an effort to bypass the hydrogen era and go directly to the nitrogen-hydrogen economy.

Pure hydrogen has long been touted as a potentially carbon-free alternative to burning fossil fuels for energy, with former US President George W. Bush the most notable cheerleader. It came with the lure of carbon-free energy and virtually limitless supply. But issues of safety, storage, transportation and production costs have to date proved insurmountable and car makers have focused on methanol, plant-derived fuels and electric power.

Those can take more energy to produce than is viable or fail on environmental or performance grounds such as distance in the case of plug-ins. None has emerged as a realistic mass-scale replacement for oil and - as petrol price rises remind us - the clock is ticking.

Texas-based Fleming, 65, is responsible for a string of inventions that produced more efficient, cleaner-burning heating appliances and holds a number of patents. He rose to prominence in New Zealand with Kent Heating, then with its parent Shell Oil. Now a consulting engineer, he has turned his attention to cutting the big issues raised by hydrogen down to size.

The Auckland University engineering graduate is helping researchers at Texas Tech University look at the potential to power vehicles using liquid ammonia, produced by combining hydrogen and nitrogen.

Fleming's most tangible contribution has been a small, cheap processing plant that converts hydrogen and nitrogen into ammonia using a compression and decompression system. It promises on-site production of hydrogen-carrying liquid fuel, solving the problem of storing and distributing (with considerable energy loss) a highly explosive gas from large and expensive centralised plants. "Ammonium can be liquefied, produces no carbon or solid deposits and can burn in internal combustion engines carrying a reasonable amount of hydrogen."

Based on an electrolyser he devised for potential use in gas fireplaces, the processor offers huge cost savings in the production of hydrogen using electricity. The processor costs US$200 ($267) (compared with around $130,000 using large-scale conventional models) and is predicted to produce fuel for about US27c a litre (36c) before taxes.

"Something so cheap and simple turns things on its ears," he says. "The whole hydrogen economy thing has been problematic because of infrastructure and storage. Suddenly we've got a cheap means of making hydrogen in liquid form on the forecourt. It gives you the controlled distribution and storage element that has been missing."

He says it is only one piece of the puzzle in the race to develop hydrogen fuels as a realistic option for powering vehicles. Researchers at Texas Tech and elsewhere are working on the other missing pieces. Those include making the fuel safe to use and consumer friendly, developing high-pressure storage tanks to replace petrol tanks in vehicles, and using renewable electricity sources to produce the fuel. Fleming describes himself as a catalyst for that broad-brush approach.

The processor uses water as the hydrogen source, nitrogen from air and electricity. Because the plants can store electricity, they can make use of renewable sources such as wind, wave, solar and hydro-electric plants at off-peak times, making them more efficient and viable. He says several investors are vying for the rights to commercialise the process.

Perhaps the biggest hurdle will be persuading motorists to use something as toxic and foul smelling as ammonia. "People don't want to get a whiff of it and spillages on skin or in the eyes are to be avoided." But he points out it is already widely used in industry, safety codes are in place and, unlike hydrocarbons and hydrogen gas, it won't blow up. "If you have a car accident, as long as you're not trapped in the vehicle and exposed to high concentrations of ammonia over a long period, you're going to be okay."

We may have little choice. Given the problems with alternative fuel development to date, most observers predict the vehicle fleet will remain largely dependent on oil for at least 15 years. Fleming says we don't have that much time, citing a General Motors estimate that, with greater vehicle use in China and other emerging economies, the world could face a "Saudi Arabia-sized" oil gap within five years. "This is virtually the only game in town which can deal with [declining] Arab oil and carbon emissions. There's no other comprehensive solution capable of being rolled out for existing engines with total use of renewable energy."

Fleming is in New Zealand to garner support and identify opportunities for Auckland University's engineering department to collaborate. He graduated from Auckland in 1968 and credits the engineering school's broad-based curriculum for his ability, and other New Zealand engineers, to solve problems outside their discipline - unlike overseas-trained colleagues whose skills are compartmentalised.

Short term, the ammonia fuel would be blended with petrol to run in existing vehicles but, over time, vastly more efficient engines could emerge, because ammonia allows much higher compression ratios.

"If you really want to take advantage of it, you go to much higher compression ratios using rapid injection devices with huge thermal efficiency improvements."

Problem solver

Auckland born and raised, John Fleming worked for ACI Plastics before joining Kent Heating, a Shell subsidiary, becoming its technical director.

His inventions include catalytic gas fireplaces, a quick-recovery electric tube element, differential temperature switches for solar heating and efficiency-measuring methods for woodburners.

With Kent parent Shell, he was involved in negotiating consistent international standards for heating appliances, including emission levels.

He lives in Lubbock, Texas, with his wife, Cid, and has US citizenship. He still regularly sees his two daughters from his first marriage, one based in Auckland and one in London.

By Geoff Cumming | Email Geoff
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