This recent study gives some idea about what "clean coal technologies" are all about. The IGCC (Integrated Coal Gasification Combined Cycle) powerplant concept is a major component of the H.R.4 Energy Bill now being debated in Congress. This technology directly interfaces with distributed generation, fuel cells, ultraclean transportation fuels, CO2 sequestration, co-production concepts, GTL/Fischer-Tropsch technologies, hydrocarbon gasification and more. It's surprising that the IGCC concept isn't more widely understood and recognized. If and when H.R.4 passes, however, it will be.
MTR 2001-43
Mitretek Technical Report
COPRODUCTION OF ULTRA CLEAN TRANSPORTATION FUELS, HYDROGEN, AND ELECTRIC POWER FROM COAL SUMMARY REPORT
July 2001
D. Gray G. Tomlinson
Customer: US DOE, NETL Contract No.: DE-AM26-99FT40465
Dept. No.: H050 Project No.: 0601CTC2-C2
Introduction
Coal is our Nation’s most abundant fossil fuel resource and currently is used to produce about 55 percent of our electric power. Coal gasification opens coal to new markets through the concept of coproduction where ultra clean liquid fuels, hydrogen, and other chemicals can be produced in addition to electric power. Transforming coal into a clean synthesis gas (syngas) using advanced gasification technology is a metamorphosis that allows coal to be used more efficiently and cleanly both for the production of electric power and for production of liquid and gaseous fuels and chemicals.
Once the coal is in gaseous form, the high efficiencies associated with gas turbine combined cycle performance now become accessible to coal. This is the rationale behind the Integrated Coal Gasification Combined Cycle (IGCC) concept. However, once the clean syngas has been produced from the coal, it is even more efficient to use this gas to synthesize other products like ultra clean Fischer-Tropsch (F-T) fuels, chemicals, or hydrogen in addition to electric power. This coproduction approach often avoids the inefficiencies of carbon dioxide removal, syngas recycle, and light hydrocarbon reforming that would be necessary in configurations producing just F-T fuels. The clean synthesis gas can also be used to produce chemicals like methanol and dimethyl ether, or can be shifted to produce pure hydrogen.
Gasification allows coal to be used almost as cleanly as natural gas. It allows production of electric power using advanced gas turbines and fuel cell technology at high efficiency. Sulfur is recovered as elemental sulfur rather than being emitted as SOx. NOx is low, and the residual coal ash is transformed into a non-leachable slag. Also coal gasification configurations allow easy production of a concentrated stream of almost pure carbon dioxide that could readily be sequestered once sequestration technology is successfully developed. This report examines performances and costs of using coal to coproduce ultra clean liquid fuels, hydrogen, and electric power. Configurations that produce multiple products are analyzed together with zero emissions facilities that include carbon dioxide sequestration. The performance and economics of these facilities are analyzed and the required selling prices (RSP) of products are estimated.
There are three critically important energy supply issues facing the U.S. in the coming decades. These are adequate electricity supply, adequate natural gas supply, and an adequate supply of clean liquid fuels. The Energy Information Administration (EIA) is forecasting that by 2020 the U.S. will need 200 GW of additional electric power capacity, 10 trillion cubic feet (TCF) of additional natural gas annually, and 5 million barrels per day (MMBPD) of additional oil. Using domestic coal in coproduction configurations addresses all three of these supply issues. Using the concept of coproduction, electricity is generated during the production of the ultra clean fuels and the use of domestic coal feedstock to produce this power will reduce the burgeoning demand for natural gas. Also, most importantly, if we as a nation are committed to limiting our imports of foreign oil then this concept of coproducing clean liquid fuels and power can play a vital role. In combination with increased domestic oil production producing additional clean fuels from our domestic coal resources will allow us to attain the goal of limiting our oil imports.
In the longer term, hydrogen may become the future transportation fuel of choice because of resource limitations of conventional petroleum, the opportunity for high efficiency usage in fuel cell vehicles, and the essentially zero emissions resulting from its usage. Therefore, using domestic coal to coproduce hydrogen in addition to clean liquid fuels and power anticipates the production and use of ultra clean liquid fuels in the shorter term and the gaseous fuel hydrogen in the longer term. Both these liquid and gaseous fuels will be produced from secure domestic resources......
Government Role
In a highly developed and industrialized society like the U.S., the availability of clean, affordable energy is essential for sustaining economic growth, social stability, and public health. A critical and appropriate role for government is to help promote the development of technologies that will provide this nation with such a clean, affordable, and secure energy supply for the 21st century. This government role is an insurance policy designed to protect the U.S. against possible future oil supply disruptions and high oil prices, to limit our dependence on foreign oil imports, and to help ensure an affordable and dependable supply of ultra-clean transportation fuels, hydrogen for future fuels, and electric power from domestic resources. In the long term the production of hydrogen from secure domestic resources will enable us to be free from foreign energy imports and firmly place us on the road to a sustainable energy future. The ability to readily capture a concentrated stream of carbon dioxide from these plants for carbon sequestration will allow these plants to be essentially zero emissions facilities.
The development of advanced technologies that can cleanly and efficiency produce ultra clean transportation fuels, gaseous hydrogen, and electric power from coal with essentially zero emissions is clearly longer-term and higher-risk. Industry by itself is not willing to conduct the necessary research, development, and deployment activities in these areas without significant and direct government involvement and leadership. There are both technical barriers and economic risks associated with the deployment of these advanced technologies that convert coal into ultra-clean transportation fuels, hydrogen and power. However, with the political will, continued R&D, the appropriate incentive mechanisms and government/industrial partnerships these risks and barriers can be overcome. Then, the ability to make clean transportation fuels, hydrogen and power from these domestic resources will be an economically viable option.
Proposed Commercialization Strategy
Because of these technical and economic barriers and risks, government could play a decisive role in assisting the commercial deployment of this coproduction technology. There are many potential strategies that government could use to accomplish this if commercial deployment of this technology is considered to be in the national interest.
One strategy could be to enable the construction and operation of a pioneer, commercial scale demonstration plant. This could be a plant such as is shown in Figure 6. Government could cost share the capital cost with an industrial partnership on a 50:50 basis. Cost to the government would be about $450 million. Other incentives could be used such as Section 29, investment tax credits, accelerated depreciation, price, purchase, or loan guarantees, or excise tax exemptions on the ultra clean fuels. This pioneer plant would produce about 7,000 BPD of ultra clean fuels for the transportation sector and about 475 MW of electric power for sales.
Once constructed this pioneer plant would demonstrate the integrated operation of the various components, clean synthesis gas production, synthesis of ultra clean fuels, and electric-power generation in one facility at commercial scale. Products from this plant would be sold to the transportation fuels and power markets for revenue. It is estimated that this plant would generate over $120 million in net revenue annually. Depending on the financial agreements, a portion of this net revenue could be used to pay back the government investment. Other government income would be generated through payroll and other taxes.
This pioneer facility could also be used as a test bed to demonstrate the performance of emerging technologies. These could include ceramic membranes for oxygen production, advanced gas cleaning processes, catalyst testing, and other novel technologies resulting from a continuing R&D program in clean coal and fuels. In addition, a carbon dioxide removal system could be installed after F-T product separation and the concentrated carbon dioxide stream could be used to test sequestration technologies such as for coal bed methane (CBM) extraction and enhanced oil recovery (EOR). After successful demonstration of the integrated technology with sequestration of carbon, more unit trains could be added to the facility to increase output. |
