A Few Basics About Hydrogen

Editor’s note: This is the first of a two-part series of Amory B. Lovins’s Hydrogen Primer. This article is a highly condensed version of “Twenty Hydrogen Myths,” a detailed paper from Rocky Mountain Institute (RMI) which aims to address current hydrogen power myths. The full article will be available on www.rmi.org later in June 2003.

RE – Insider, June 23, 2003 The potential cost-effective wind power in the Dakotas could make as much hydrogen as the world now uses — enough, if used in efficient fuel-cell vehicles, to displace all oil now used by U.S. highway vehicles. If there were no oil in Iraq, would we have just fought a war there? The administration cited weapons of mass destruction as the main casus belli, but it cannot be denied that U.S. interest and policies in the region are influenced, and perceived to be influenced, by our interest in oil. Yet, just as our transportation fuels have transitioned from clunky, awkward solids to easy-to-store liquids (coal to oil) during the past two hundred years, they are likely to transition again, from liquids to gases. The most likely candidate to power our transportation devices of the future is the simplest, most abundant gas — clean, efficient hydrogen. The chairs of eight major oil and car companies have said the world is entering the oil endgame and the start of the Hydrogen Era. A Shell planning scenario in 2001 envisaged a radical, China-led leapfrog to hydrogen (now clearly underway), making world oil use stagnate until 2020 and then fall. President Bush’s 2003 State of the Union message further emphasized the commitment to developing hydrogen-fuel-cell cars he’d announced a year earlier (FreedomCAR). Yet many diverse authors have lately criticized hydrogen. Some call it a smokescreen to hide White House opposition to raising car efficiency using conventional technology, or fear that working on hydrogen would divert effort from rather than complement renewable energy deployment/adoption. Some simply presume that if this President believes something, it must not be true. Most reflect errors meriting a tutorial on basic hydrogen facts. But before I discuss the transition to hydrogen, here are four key points about H2 that are not always articulated: 1) Hydrogen makes up about 75 percent of the known universe, but is not an energy source like oil, coal, wind, or sun. Rather, it is an energy carrier — a molecule that, like electricity, can carry useful energy to users. Hydrogen is an especially useful carrier because like oil and gas, but unlike electricity, it can be stored in large amounts. 2) The reason hydrogen isn’t an energy source is that it’s almost never found by itself, the way oil and gas are. Instead, it must first be freed from chemical compounds in which it’s bound, using heat and catalysts to “reform” hydrocarbons or carbohydrates, electricity to “electrolyze” water, or other methods, including experimental processes based on light, plasmas, or microorganisms. All devices that produce hydrogen on a small scale, at or near the customer, are collectively called “hydrogen appliances.” 3) Over two-thirds of the fossil-fuel atoms burned in the world today are hydrogen. The debate is about whether getting rid of the last third (the carbon), and even its combustion (“uninventing fire”), could be more profitable and attractive than burning both the carbon and the hydrogen. 4) Hydrogen is the lightest molecule, eight times lighter than natural gas. Per unit of energy, it weighs 64 percent less than gasoline or 61 percent less than natural gas: 2.2 pounds of hydrogen has (within two percent) the same energy as one U.S. gallon of gasoline, which weighs 6.2 pounds. Conversely, hydrogen is bulky?per unit volume, hydrogen gas contains only 30 percent as much energy as natural gas, and even at 170 times atmospheric pressure (170 bar), only six percent as much energy as gasoline. So much for the basics. Now for the currently prevalent myths: 1. A whole hydrogen industry would need to be developed from scratch. Wrong. Hydrogen manufacture and use is already a large and mature global industry. At least five percent of U.S. natural gas output is currently converted into industrial hydrogen, half of which is used in refineries — mainly to make gasoline and diesel fuel. Globally, about 50 million metric tons of hydrogen is now made for industrial use, about 3-5 times America’s consumption. Nearly all hydrogen is extracted (“reformed”) from fossil fuels, mainly natural gas, because that’s cheaper than electrolysis unless you have extremely cheap electricity (generally well under two cents per kilowatt-hour), or unless the hydrogen is a byproduct (about two percent comes from electrolytic chlorine production). 2. Hydrogen is too volatile and explosive to use as a fuel. Wrong. Although all fuels are hazardous, hydrogen’s hazards are different from and generally more easily managed than those of hydrocarbon fuels. It’s 14.4 times lighter than air, four times more diffusive than natural gas, and 12 times more diffusive than gasoline — so leaking hydrogen rapidly rises away from its source. Also, it needs at least four times the concentration of gasoline fumes to ignite, it burns with a nonluminous flame that can’t scorch you at a distance, and its burning emits no choking smoke or fumes — only water. Hydrogen-air mixtures are hard to make explode. Hydrogen does ignite easily, with only a tenth as much energy as natural gas, which a static spark can ignite. However, unlike natural gas, ignited hydrogen burns at lower concentrations than can explode, and it can’t explode in open air. The 1937 Hindenburg disaster was investigated by NASA scientist Dr. Addison Bain in the late 1990s. He found that probably nobody aboard was killed by a hydrogen fire; the 35 onboard who died as a result of the fire were killed by jumping out or by the burning propeller-engine diesel fuel, flammable furnishings, and dirigible itself, which — coated with a paste containing aluminum powder and chemically similar to rocket fuel — was easily set alight by a spark. The clear hydrogen flames swirled harmlessly above the 62 surviving passengers as they rode the flaming dirigible safely to earth. 3. Making hydrogen uses more energy than it yields, making it impractical. It would violate the laws of physics to convert any kind of energy into a larger amount of another kind of energy. Hydrogen is no exception, and neither are today’s energy forms. Converting gasoline from crude oil is generally 75-90 percent efficient from wellhead to retail pump and electricity from fossil fuel is only about 30-35 percent efficient from coal to retail meter. Hydrogen is typically converted at efficiencies around 72-85 percent in natural-gas reformers (thermochemical devices that separate hydrogen from carbon) or around 70-75 percent in electrolyzers. (These efficiencies are all reduced by 15 percent because a different definition of the hydrogen’s energy content, called “Lower Heating Value,” is appropriate for its use in fuel cells than is used to measure sales of fossil fuels.) But hydrogen’s greater end-use efficiency can more than offset its conversion loss. From wellhead to car tank, oil is typically 88 percent efficient (the lost energy mainly fuels refining and distribution). From car tank to wheels, gasoline is typically 16 percent efficient. The average contemporary vehicle is thus about 14 percent efficient well-to-wheels. A hybrid vehicle like the Toyota Prius nearly doubles the gasoline-to-wheels efficiency to 30 percent and the total to 26 percent. But an advanced fuel-cell car’s 70 percent natural-gas-well-to-hydrogen-in-the-car-tank efficiency, times 60 percent tank-to-wheels efficiency, yields 42 percent — three times higher than the normal gasoline car or one and a half times higher than the gasoline-hybrid-electric car. Thus the energy lost in making hydrogen is more than made up by its extremely efficient use, saving both fuel and money. 4. Delivering hydrogen to users would consume most of the energy it contains. Wrong. Two Swiss scientists recently analyzed the energy needed to compress or liquefy, store, pipe, and truck hydrogen. Their net-energy figures are basically sound — but their widely quoted conclusion that because hydrogen is so light, “its physical properties are incompatible with the requirements of the energy market” is not. In fact, their paper, published by the competing Methanol Institute, simply catalogues certain hydrogen processes that most in the industry have already rejected, except in special niche markets, because they’re too costly, including pipelines many thousands of kilometers long, liquid-hydrogen systems (except for rockets and aircraft), and delivery in steel trucks weighing more than one hundred times as much as the hydrogen carried. The authors also focus almost exclusively on the costliest production method — electrolysis. They admit that reforming fossil fuel is much cheaper, but reject it because, they claim, it releases more CO2 than simply burning the original hydrocarbon. That ignores the hydrogen’s more efficient use: even under conservative assumptions about car design, a good natural-gas reformer making hydrogen for a fuel-cell car releases between forty and sixty-seven percent less CO2 per mile than burning hydrocarbon fuel in an otherwise identical gasoline-engine car, because the fuel cell is 2-3 times more efficient than the engine. Even more fundamentally, the Swiss authors analyzed only costly centralized ways to make hydrogen. Most industry strategists suggest — at least for the next couple of decades — decentralized production at or near the customer, using the excess off-peak capacity of existing gas and electricity distribution systems instead of building the new hydrogen distribution infrastructure whose costs the Swiss analysis finds so excessive. 5. Hydrogen can’t be distributed in existing pipelines, requiring costly new ones. Wrong. If remote, centralized production of hydrogen eventually did prove competitive or necessary, existing gas transmission pipelines could generally be converted by adding polymer-composite liners, similar to those now used to renovate old water and sewer pipes, plus a hydrogen-blocking coating or liner, and by converting the compressors. Even earlier, existing pipelines could carry a mixture of hydrogen, up to a certain level, to “stretch” natural gas; users of fuel cells could separate the two gases with special membranes. Some newer pipelines already have hydrogen-ready alloys and seals, and all future ones should be made hydrogen-compatible, as Japan intends for its big Siberia-China-Japan gas pipeline. As for gas distribution pipes, many older systems are already largely or wholly hydrogen-compatible because they were originally built for “town gas” (synthetic gas that’s up to sixty percent hydrogen by volume), although burner-tips, meters, and other minor components could require retrofit. 6. We don’t have practical ways to use hydrogen to run cars, so we must use liquid fuels. Wrong. Turning wheels with electric motors has well-known advantages of torque, ruggedness, reliability, simplicity, controllability, quietness, and low cost. Heavy and costly batteries have limited battery-electric cars to small niche markets, although the miniature lithium batteries now used in cellphones are severalfold better than those used in battery cars. But California regulators’ initial focus on battery cars had a huge societal value because it greatly advanced electric drivesystems. The question is only where to get the electricity. Hybrid-electric cars now on the market from Honda and Toyota, and soon from virtually all auto-makers, make the electricity with on-board engine-generators, or recover it from braking. This gives the benefits of electric propulsion without the disadvantages of batteries. Still better will be fuel cells — the most efficient (50-70 percent from hydrogen to direct-current electricity), clean, and reliable known way to make fuel into electricity. Fuel cells reverse the high-school chemistry experiment — splitting water with an electric current so hydrogen and oxygen bubble out of the test-tube — by chemically recombining hydrogen and oxygen on a special membrane, at temperatures as low as 160-190degreesF (much higher in some types), to produce electricity, pure water, heat, and nothing else. Invented in 1839, fuel cells have been widely used for decades in aerospace and military applications. Breakthroughs since the early 1990s mean that, even in this decade, they’ll start becoming affordable. As for most other manufactured goods, real cost should fall by about 15-30 percent for each doubling of cumulative production. Used in the right place and manner, even today’s hand-made fuel-cell prototypes can compete in many buildings. Testing of vehicular fuel cells is well advanced. Already, many manufacturers have tens of fuel-cell buses and over a hundred fuel-cell cars on the road; a German website (www.hydrogen.org/h2cars/overview/main00.html) reports 156 different kinds of fuel-cell concept cars and sixty-eight demonstration hydrogen filling stations; Honda and Toyota are leasing fuel-cell cars; six other automakers plan to follow suit during 2003-05; many kinds of military vehicles are demonstrating more advanced fuel cells; ship, boat, scooter, and recreational uses are emerging; and Fedex and UPS reportedly plan to introduce fuel-cell trucks by 2008. A Deutsche Shell director predicted in 2000 that half of all new cars and a fifth of the car fleet will run on hydrogen by 2010, while the German Trans-port Minister forecast ten percent of new German cars. Some automakers formerly assumed that they must extract hydrogen from gasoline (or methanol) aboard cars, using portable reformers, for two reasons: tanks of compressed hydrogen would be too big because hydrogen has so much less energy per unit volume than liquid fuels, and it would be too hard or costly to shift today’s fueling infrastructure from gasoline to hydrogen. Both these problems have now been solved, so few automakers still favor onboard gasoline reformers. That’s good, because they’re very difficult and problematic, and would cut gasoline-to-wheels efficiency to or below that of a good gasoline-engine car. Since almost all automakers now agree that reformers should be at or near the filling station, not aboard the car, there’s no longer any reason to reform gasoline: natural gas is much cheaper, and is easier to reform. Hydrogen will thus displace gasoline altogether, without spending the energy and money to make gasoline first. There is similarly little reason to “bridge” with methanol, except perhaps to run fuel cells in very portable devices like vacuum cleaners, cellphones, computers, and hearing aids. Stay tuned…The final installment of Amory Lovins’s condensed Hydrogen Primer will be available next week as an RE Insider on SolarAccess.com. About the Author Amory Lovins, a MacArthur Fellow and consultant physicist, has advised the energy and other industries for nearly three decades as well as the Departments of Energy and Defense. Published in 28 books and hundreds of papers, his work in about 50 countries — often with L. Hunter Lovins, with whom he co-founded Rocky Mountain Institute (RMI) in 1982 — has been recognized by the “Alternative Nobel,” Onassis, Nissan, Shingo, and Mitchell Prizes, the Happold Medal, eight honorary doctorates, and the Heinz, Lindbergh, Hero for the Planet, and World Technology Awards. He advises industries and governments worldwide, and has briefed 16 heads of state. He serves as CEO of RMI (www.rmi.org), an independent, market-oriented, nonprofit applied research center. Much of its work is synthesized in Natural Capitalism (www.natcap.org). RMI spun off E SOURCE (www.esource.com) in 1992 and Hypercar, Inc. (www.hypercar.com), which he chairs, in 1999. Lovins can be reached at ablovins@rmi.org
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