No serious energy expert for at least the past decade has expected that a single breakthrough would be possible that would easily solve our global energy and climate challenges – and they are still right. There have been hundreds of thousands of excellent engineers from numerous fields optimizing all aspects of practical solutions for renewable energy for decades. It should be clear from some of our comments elsewhere on recent related patents that none of those are of major value.

We saw more than three years ago (from simple theoretical analyses) the possibility of doubling the efficiency of converting CO₂ to hydrocarbons and mid-alcohols, and the potential value of such a process if it could be worked out. We began evaluating in detail all of the relevant engineering of the past three decades and how it could be improved. The discussion of prior mid-alcohols FTS lists the deficiencies we saw in most of the prior mid-alcohols work (even that from a few years ago) which we knew could be done much better – based on our decades of experience in physics, fluid dynamics, turbomachinery, heat transfer, mechanical engineering, electrical engineering, and chemistry. We knew from the beginning that a simple notion and a single breakthrough would not be sufficient, but we had the technical preparation, creativity, and stamina required to chart a new path.

Renewable Fischer Tropsch Synthesis (RFTS™). The significance of the key innovations that have come together at Doty over the past two years can hardly be overstated. We have shown that it will be practical to come within several percent of theoretical limits in a number of key steps and achieve twice the system efficiency that would have been expected from the best works of just three years ago for production of carbon-neutral mid-alcohols, light olefins, and many other hydrocarbons. This, in combination with the rapidly increasing value of the markets of these products, indicates that we have succeeded in bringing together the combination of breakthroughs that are required to make an energy blockbuster possible.

Is it credible that such major advances can be achieved by a small team in such a short period of time? Actually, this is the way breakthroughs usually occur. Large teams with large budgets are good at optimizing, fine tuning, and taking care of all the details essential for executing complex developments once the general path has been laid out. But visionary beginnings are more likely to originate from a single individual with assistance from a few other experts helping with some of the complex details. So it was at Doty.

The claims in our pending energy patents have been carefully crafted to cover every technical approach we can imagine that would achieve efficiency within 20% of what we think will be the practical optimum. It does not matter if someone can circumvent an energy patent with an approach that is even 10% less cost effective, as such an approach will not be practiced on a large scale. Instead, competitors will license our patents, as royalties on large processes are usually only a fraction of a percent of product sales. Big companies try to avoid patent suits. Their experts can recognize a strong patent that will hold up in court, and they would much rather negotiate the license than risk a suit.

Of course, one cannot patent intended or expected results. One can only claim (at least in international patents) specific innovative steps that are clearly supported by the specification. The recent Written Opinions from the International Searching Authority indicate we have done that in our pending energy patents as skillfully as we have in our previous patents.

On Sept 3, 2008, the International Patent Searching Authority concluded that all the pending claims (currently 60 of them) in our primary RFTS patent contain a novel and inventive step. This means we’ll probably get essentially everything we asked for (which was everything we thought was reasonable) covered in our patent claims in most countries. It may still take more than a year of negotiations with the examiners (that is usually the case with important patents) before the patents issue. However, the science, innovations, and practicality in our specifications are clearly presented and undeniable.

While it may not look like it, the Process Flow Diagram below really is severely simplified. A technical-breakthrough-summary of the process and the breakthroughs may be found here. The version simulated and analyzed in the pending RFTS patent is an order of magnitude more detailed, and it is presented in depth here, RFTS-DetailedDesign-1. A copy of the pending Doty-RFTS patent with the Written Opinion is also available, WO2008115933.pdf.

There is always the possibility of someone else developing an alternative that is better than our process. Nobel Laureate George Olah has been working diligently with one of the world’s best teams of hydrocarbon chemists for at least three decades trying to develop better catalysts for direct conversion of CO₂ and H₂ to fuels and other hydrocarbons, but with limited practical success. Olah doesn’t like either FTS (because the process does not achieve high selectivity and thus requires more complex separations) or RWGS (because it’s hard to get the desired efficiency and low methane production). His only possibly competitive process appear to be methanol production – but methanol is quite toxic and it will not be easy for renewable methanol to compete with fossil methanol for at least two decades.

Dimethyl ether (DME, CH₃OCH₃) has also been proposed as an alternative transportation fuel. However, its very low boiling point (-23°C) would bring with it difficulties in handling not unlike those associated with propane. Moreover, its energy density is only 61% that of propane. It is possible that a more direct route to production of DME from CO₂ and H₂ may be developed, but the methanol route to DME is still the best. (The second best option for DME production still requires CO – and thus would be covered by one of our pending patents.) The chances of a breakthrough in catalysis that circumvents the need for first reducing the CO₂ to CO in the RWGS reactor for synthesis of preferred fuels seem extremely remote. CO is an essential component in the syngas for production of mid-alcohols, light olefins, and alkanes. No one has yet made the RWGS reactor work adequately – partly because it cannot be done cost-effectively without our breakthrough in recuperators.

Based on recent Written Opinions from the International Searching Authority, it now appears that the probability that all of our pending patents will be quite valuable is over 99%. Our confidence level will improve even further with time because of a combination of reasons: (1) a longer period of very high prices for oil, ethanol, and light olefins; (2) increasing data on the need to address global warming; (3) validations from more complete and detailed simulations of the WindFuels system; (4) experimental confirmations of our breakthroughs; (5) continued lack of any indications that anyone else will be able to challenge our various priority dates; and (6) continued lack of any indications that a better alternative will be possible for carbon-neutral chemicals and transportation fuels.

To put the Doty pending patents into perspective, it is useful to note that the sales of all the blockbuster drugs (those generating over $1B each in sales annually) have totaled about $200B over the past decade. Sales of our licensed products, WindFuels, could exceed that total in a single year near the end of the life of the pioneering patent. Obviously, we will not directly manage, produce, or control fuel production at that level. We expect to license the process to GE, Siemens, Vestas, BP, ExxonMobil, and dozens of other companies that are interested in being a major part of the best single solution to competitive alternative energy and global warming. It seems reasonable to expect to see several billion-dollar plants in operation or under construction within 7 years, and 1000 such plants around the world should be producing WindFuels worth $300B annually within 18 years.

The recent Written Opinions from the International Searching Authority indicate we can expect to be issued extremely broad and strong claims in our suite of pending patents.

Recuperator Breakthrough. One of the key advances that allows the novel RFTS plant to be more cost effective is a major breakthrough in gas-to-gas recuperators (heat exchangers). Here, we also expect to be awarded a pioneering patent that qualifies as a “super blockbuster”. Heat transfer is central to all power generation, petroleum refining, and most chemical processes. Most of the relevant physics has been well understood since Maxwell formulated it so eloquently in the early 1870’s (about the same time he solved electromagnetic theory, for which both he and Doty are much better known). An enormous number of heat exchangers have been well optimized for many purposes over the past five decades; and the theory and technology have been considered to be fully mature for at least three decades. Nonetheless, we have shown that there is a fundamentally different and much better way to make recuperators for the most demanding applications.

Our pending recuperator patent application is the most significant advance in the field of heat transfer in at least the last half century. It will decimate shell-and-tube recuperators, plate-and-fin recuperators, microtube recuperators, and honeycomb regenerators for all major, clean, non-oxidizing, gas-to-gas applications. There is no question about the validity of our simulations or the novelty of our new approach – this is a field we know very well and have published, patented, and manufactured in for over 25 years. The international search report uncovered nothing even remotely similar. Applications for our novel recuperator will extend well beyond WindFuels. A technical paper was recently presented at the ASME Heat Transfer conference giving an overview of much of the science and engineering. A copy is available here. (Note: The download is presented here with permission from ASME — for reference only. Anyone who wishes to use any part of the article must contact ASME for permission at permission@asme.org.)

Heat Engine Breakthrough. Another of the key advances required for an efficient RFTS™ plant is a more efficient way of converting the waste heat to electricity.

In the most advanced combined-cycle power plants (where gas-turbine inlet temperatures exceed 1000°C), efficiencies approach 80% of theoretical (second law, or Carnot) limits. However, conversion of lower-grade waste heat is much less efficient. For example, some CSP plants operate with turbine inlet temperatures of only 250°C and achieve thermal conversion efficiency of only 16%, or about 45% of second-law limits at this temperature. Most geothermal power plants achieve under 12% conversion efficiency, and they are usually under 45% of theoretical limits.

It was necessary to develop a more efficient heat engine to recover the energy of the low-grade and mid-grade waste heats from the RFTS™ plant, and the results were stunning. We call our innovative heat-engine the DORC (Dual-source Organic Rankine Cycle). Despite the tongue-in-cheek name, the DORC is a huge leap forward in heat engine technology. The DORC permits a 40% to 60% improvement in thermal conversion efficiency when both low-grade and mid-grade heat sources are available simultaneously. And of course, as with all of our advances, the DORC has been validated by detailed simulations using both proprietary and commercial software.

The mid-term potential of our pending DORC patent extends to other renewables. Many existing geothermal power plants are also close to good solar locations. With our DORC, both the low-grade heat from the geothermal source and the higher-grade heat from CSP can be used much more efficiently when they are available simultaneously. Most existing geothermal plants could be upgraded to a Geo-CSP hybrid. The upgrade would require construction of the solar field of concentrating mirrors and replacement of the existing power block, but then the output power can be increased by a factor of 3 during peak hours. Likewise, some existing CSP plants could be upgraded to Geo-CSP hybrids by drilling the wells required to tap the geothermal energy that is available at a depth of a few miles beneath them. New methods of more efficiently tapping this plentiful geothermal energy are currently in development by several major research groups.

While the Geo-CSP hybrid has enormous long-term potential in some areas where wind resources are limited, we do not anticipate it being a common source for RFTS within the next decade, as wind will remain much more competitive in the U.S. for at least the next two decades. However, the DORC will be an essential component of any RFTS plant (whether powered by wind, CSP, or a Geo-CSP hybrid).

References:

1. FD Doty, “Hydrocarbon and Alcohol Fuels from Variable, Renewable Energy At Very High Efficiency“, PCT WO 2008/115933. Priority date, 19 Mar 2007. WO2008115933.pdf

2. FD Doty, pending patent, “High-Temperature Dual-source Organic Rankine Cycle with Gas Separations”, PCT WO 2009/048479. Priority date, 12 Oct 2007.

3. FD Doty, pending patent, “Compact, High-Effectiveness, Gas-to-gas ... Recuperator...”, PCT WO 2009/082504. Priority date, 21 Dec, 2007.

4. FP Incropera and DP Dewitt, “Introduction to Heat Transfer”, Wiley, NY, 2002.

5. R DiPippo, “Geothermal Power Plants: Principles, Applications and Case Studies”, Elsevier Ltd, Oxford U.K., 2005.

6. AP Steynberg and ME Dry, eds. Studies in Surface Science and Catalysis 152, Fischer-Tropsch Technology, Elsevier, 2004.