Non-Thermal Plasma H2, no CO2
Precision H2, a Canadian company, is developing a non-thermal plasma process which disassembles methane (CH4) into hydrogen and carbon black. Note, no CO2!
There are dozens of plasma companies, often focused on medical waste, and some on power (with coal or some waste stream as the feedstock). (See footnote) Usually these are hot plasmas, and tend to be expensive due to the materials problems at high temperature. In a plasma, sometimes called the 4th state of matter, material is very highly ionized by an electrical arc discharge. Lightning is a good example, and many plasma systems are brute force, require a lot of energy, and get very hot.
A so-called “non-thermal” plasma is one in which the electric discharge is controlled and confined. Locally it is extremely hot, but each spark doesn’t last long enough to heat up the surrounding materials. Precision H2 has created a “plasma dissociation reactor”, where the electrical discharge is carefully shaped and especially tailored to the specific job of dismantling methane. The electrical energy goes straight to the molecule, and doesn’t have to get there as heat. (It’s a little bit like cooking with microwaves instead of a conventional oven.)
The methane streaming through the reactor is partly converted to H2, with the carbon dropping out as a nanopowder. The output is then a blend of methane enriched with hydrogen (hythane). In an intriguing twist, this blend can be sent to a fuel cell which will consume the hydrogen, leaving the methane to be cycled back to the reactor. In effect, the fuel cell itself is used to separate out the hydrogen–for its own use. This configuration would produce electricity directly, rather than hydrogen. Pure hydrogen is gotten by using PSA (pressure swing absorption) or membranes to do the separation. Potential partners are already in discussions on both fronts (i.e. fuel cells and purification). Also, hythane can be used directly in engines, to good advantage.
The key is electronics (pulse shaping, and analysis and control of the discharge), and costs for electronics are well understood. Because temperatures remain modest, the reaction chamber can be made inexpensively, and is readily scalable.
There is an energy penalty–not all the “fuel value” of the methane is used, because the carbon itself isn’t oxidized. Instead, since no oxygen is present, no CO2 is produced–think of it as “presequestration”, with resulting GHG and carbon-trading benefits. Also, the carbon is in a valuable form which can be sold, enhancing overall economics. Detailed thermodynamic and financial models have been developed, and the company believes that even today, with “one-off” systems, they can produce hydrogen cost competitively.
The company is raising a round of equity financing.
Contact Dan Fletcher
Montreal, Quebec, Canada
An amazing find can be found at:
“Non-Incineration Medical Waste Treatment Technologies”, an August 2001 report …. explores the environmental and economic impacts, among other considerations, of about 50 specific technologies.
Chapter 4 in particular is an exhaustive review of every technology and nearly every company with a means to destroy hazardous materials. While the focus is on medical waste, most of the technologies also apply to hazardous materials, municipal waste and sludge, biomass, and fossil fuels. Gasification, pyrolysis, plasmas, and many different chemical and electrochemical oxidation and reduction methods are out there, and are being used today at industrial scale. When they can be made to work, the issues are cost, reliability, system longevity, emissions (creation of new hazards, e.g. dioxins), materials handling, feedstock variability, etc. etc. The key is to inject sufficient energy into the material to break the chemical bonds, for example, to get it hot enough for long enough (dwell time).