Saturday, August 07, 2010

The Surprising Reality of a Clean, Abundant Coal Future

Other than perhaps methane hydrates, coal seems to be the most abundant and widely dispersed fossil fuel available for human use. While there are roughly 1,000 gigatons of proven world coal reserves, it is estimated that there are roughly 3,000 gigatons of coal under the North Sea alone! It is likely that world coal reserves have been grossly underestimated.

The problem that is set out for humans is how to use the massively abundant coal resource in a clean and responsible manner.
The US DOE has given 36 month research grants to 7 US universities, to spur the development of multiple breakthroughs in achieving cleaner and more responsible coal use.
The selected projects, each 36 months in duration, include:

Georgia Tech Research Corporation, Atlanta, Ga. This project will improve the understanding of turbulent flame propagation characteristics of syngas and HHC fuels at realistic conditions and also in inhomogeneous environments, such as in premixer nozzle boundary layers and core flows—while extending existing data sets to a broader reactant class of HHC fuels, such as mixtures diluted with CO2, H2O, and N2, at realistic pressures, temperatures, and turbulence intensities and other design/operating conditions, including systems with extensive levels of exhaust gas recirculation (EGR).

This research will also develop physics-based models of turbulent burning rates in realistic flows to further assist the gas turbine industry. (DOE share: $404,404; recipient share: $101,212)

Texas A&M University, College Station, Texas. This project will develop a database of turbulent burning velocities, NOx mechanism validation data (including ‘first-of-a-kind’ direct measurements of NNH to NO reaction rates), a comprehensive fuel mechanism with a validated NOx submechanism, and experimental data on the effect of contaminants on laminar flame speed and ignition kinetics.

This scientific research will enable the development of syngas/HHC-fired gas turbines to achieve very low emissions through the design of advanced modeling tools that are carefully validated. (DOE share: $501,711; recipient share: $125,500)

University of Texas at Austin, Austin, Texas. This project seeks to develop integrated film cooling and thermal barrier coatings (TBC) configurations that will mitigate the effects of contaminants that naturally occur when using syngas/HHC fuels. Experimental simulations of optimized cooling designs and detailed aero-thermal measurements will guide the development of improved computational models of these complex designs.
The University of Texas research will focus on film cooling crater and trench configurations on a simulated vane experiencing active deposition of contaminants. Partner Penn State University will focus research on the optimization of film cooling configurations for the contoured endwalls. An optimum cooling configuration for the endwall-vane junction will be developed based on the results of the joint studies at Penn State and University of Texas. (DOE share: $500,000; recipient share: $120,000)

University of North Dakota, Grand Forks, N.D. This research will develop the heat transfer and deposition predictive tools and surface protective cooling technologies which allow for the reliable design of leading edge cooling schemes in a syngas environment. This research is important since it has been found that cooling the leading edge of a first stage of a modern gas turbine offers considerable challenges due to an aggressive heat transfer environment and a very modest pressure difference for cooling.

The University of North Dakota studies will be performed at three different experimental rigs to investigate: the effects of leading edge diameters on stagnation region deposition rates and heat transfer augmentation under a variety of conditions; the effectiveness levels for film cooling geometries on both smooth and rough surfaces; and new internal cooling methods which may be able to accommodate stagnation region heat loads at the aggressive inlet temperatures of modern gas turbines. (DOE share: $500,000; recipient share: $125,000)

Louisiana State University and A&M College, Baton Rouge, La. This project will develop novel molecular dynamics methods to improve the efficiency of novel TBC materials, and demonstrate the new TBC systems under IGCC environments. Because computational materials based TBC design tools are currently not available, this research offers the possibility for completely new efficient TBC computational design tool, making a step change to current advanced TBC design methodology.

In this research project, the most promising TBC compositions will be subject to high performance computing, material characterizations, and oxidation and corrosion tests, including a High Temperature/High Pressure Durability Test Rig to evaluate the durability of the coatings. (DOE share: $504,863; recipient share: $129,808)

University of California-Irvine, Irvine, Calif. This project will investigate degradation mechanisms of hot-turbine hot section component protective oxides and high-temperature TBCs unique to coal-derived syngas and HHC fuel. This research is important because preliminary testing has shown that the chemical composition and growth kinetics of protective thermally grown oxides (TGOs) are substantially altered for turbine systems operating on syngas and HHC fuels. Thus, one key objective of this new research project is to identify the root cause this anomalous oxidation behavior and develop mitigation strategies.

This project will address thermo-chemical and thermo-mechanical mechanisms by correlating results of accelerated coating degradation with the syngas/HHC environment and the impurities characteristics of coal-derived syngas and HHC fuels. This improved mechanistic understanding of the degradation of critical turbine system materials in HHC-fueled systems may also guide the development of more robust materials sets that could be important to the gas turbine industry. (DOE share: $500,000; recipient share: $125,000)

Stony Brook University, Stony Brook, N.Y. This project will explore the science and technology of advanced TBCs in IGCC turbines that use HHC fuels. Recent research data indicate that the current bill of coating materials is not directly translatable to the moisture-rich, ash-laden environment present with syngas/HHC fuels. Thus, the Stony Brook University research focuses on a multi-layer, multifunctional strategy comprising of discretely engineered coating layers to combat the various technical issues through a concerted effort integrating material science, processing science and performance studies, including recent developments in advanced in-situ thermal spray coating property measurement for full-field enhancement of coating and process reliability. _GCC

Massive new coal, gas, and oil fields are likely to be discovered -- mostly offshore, since most of the Earth's surface is covered by water. Massive deposits of methane hydrates will go largely unutilised, until safe and economic methods of retrieving such deposits are developed. From a biologic and microbial standpoint, planet Earth has a limitless potential for growing biomass and producing bio-energy -- and billions of dollars are being spent to perfect various approaches to bioenergy -- which has the advantage that it can be developed virtually anywhere on Earth, and even off-planet, given sunlight and CO2.

And still you have the molten core of Earth, producing massive quantities of usable heat. Sunlight itself is a massive, relatively unused resource which waits mainly for well-designed orbital solar power platforms for best large-scale development and exploitation.

Finally, you have the best baseload power source of all -- safe, advanced, abundant nuclear fission, with hundreds of thousands of years of fuel given responsible fuel recycling, breeding, and inter-locking fuel cycles for various fertile and fissile fuels.

In other words, peak energy is a million years away, unless people get stupid and go for the great human dieoff out of incompetence and suicidal leadership. By then, surely humans will have learned to control fusion, so that peak energy would be further offset in time by hundreds of millions of years.

Of course, if humans stay around this planet for too long, the local star will pay a visit, imparting perhaps more energy to Earth than any humans-still-around might wish. Which brings up the topic of space travel . . . . . .



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