Weizmann Institute of Science, Department of Environmental Sciences and Energy Research, Rehovot 76100, Israel
ETH-Swiss Federal Institute of Technology Zurich, Department of Mechanical and Process Engineering, 8092 Zurich, Switzerland
Solar Technology Laboratory, Paul Scherrer Institute, 5232 Villigen, Switzerland
Abstract
The treatment of flue gases from fossil fuel fired power stations by tri-reforming with natural gas or by coal gasification (In other words, you don't need natural gas for this process. Syngas derived from coal gasification will work as well.) could become an attractive approach for converting the CO2, H2O, O2, and N2 contained in these flue gases via syngas processing into useful products, such as methanol, hydrogen, ammonia, or urea. (So, we can get both fuel and fertilizer by treating CO2-containing flue gas with syngas derived from coal gasification.) The present study determines the constraints for achieving such thermochemical reactions under conditions of thermoneutrality, by reacting the flue gases with water, air, and natural gas or coal at 1000–1200 K. (The overall process of reacting CO2 flue gas with coal-derived syngas and water is "thermoneutral" because some of the included reaction steps are exothermic and provide the heat energy needed to drive the rest of the process, as other research we've documented for you confirms.) The implications of such reactions are examined in terms of CO2without the addition of much, if any, of energy from external sources. The process is nearly self-sustaining.) emission avoidance, fuel saving, economic viability, and exergy efficiency.(Again, by "exergy efficiency" we presume them to mean that some steps of the reaction process produce enough heat energy to drive the entire system
M. Halmann and A. Steinfeld
Weizmann Institute of Science, Department of Environmental Sciences and Energy Research, Rehovot 76100, Israel
ETH—Zurich, Department of Mechanical and Process Engineering, 8092 Zurich, Switzerland
Solar Technology Laboratory, Paul Scherrer Institute, 5232 Villigen, Switzerland
Abstract
Flue gases from coal, gas, or oil-fired power stations, as well as from several heavy industries, such as the production of iron, lime and cement, are major anthropogenic sources of global CO2 emissions. The newly proposed process for syngas production based on the tri-reforming of such flue gases with natural gas (As noted above, syngas derived from coal will work as well as natural gas. - JtM) could be an important route for CO2 emission avoidance. In addition, by combining the carbothermic reduction of iron oxide with the partial oxidation of the carbon source, an overall thermoneutral process can be designed for the co-production of iron and syngas rich in CO. (In other words: This process could, as well as producing fuels from Carbon Dioxide by using syngas derived from coal, refine iron from iron ore. Talk about your useful by-products. - JtM) Water-gas shift (WGS) of CO to H2 enables the production of useful syngas. The reaction process heat, or the conditions for thermoneutrality, are derived by thermochemical equilibrium calculations. The thermodynamic constraints are determined for the production of syngas suitable for methanol, hydrogen, or ammonia synthesis. The environmental and economic consequences are assessed for large-scale commercial production of these chemical commodities. Preliminary evaluations with natural gas, coke, or coal as carbon source indicate that such combined processes should be economically competitive, as well as promising significant fuel saving and CO2 emission avoidance. The production of ammonia in the above processes seems particularly attractive, as it consumes the nitrogen in the flue gases."
We'll attempt to summarize the gist of all this, as we understand it: We can, without the addition of much external energy, use Syngas, derived from coal, to convert Carbon Dioxide into liquid fuels and useful chemicals, and, at the same time, refine iron ore, the use of which helps to both chemically reduce the Carbon Dioxide and provide heat energy to drive the entire process, and, by involving the excess Nitrogen contained in the CO2-containing flue gases, we can make some fertilizer, as well.
How much more complete, how much more sensible and profitable, does all of this have to be before we stop whining about liquid fuel shortages and global warming, and just get to work solving the problems - with coal?
Yes, Coal can do that. Coal can do all of that. Heck, it ain't a triple play. It's a Grand Slam home run.