Keywords: clean coal, hydrogen production, clean technology, CO2, carbon dioxide, steam gasification, global warming, climate change, carbon capture, Poland, fixed-bed reactors, calcium oxide
Laboratory scale tests of coal-based hydrogen production with CO2 capture in the aspect of clean coal technologies
In the light of continuously increasing oil prices as well as stronger environmental regulations, an important issue becomes finding an alternative to fossil fuels. Scientists agree that hydrogen seems to be an ideal, price-competitive and environment-friendly future energy carrier. One of the most effective methods of hydrogen production is the process of steam gasification of coal to hydrogen-rich gas. In this paper the results of laboratory tests of steam gasification of coal oriented on hydrogen-rich gas production with CO2 capture are presented. The coal samples used in the experiments were provided by the Polish coal mine Piast. The tests were conducted in a vertical fixed-bed reactor system in a temperature range of 923-1173 K. The idea of the hydrogen-rich gas production process was based on the simultaneous use of iron oxide as an oxygen-transfer compound that enhances the conversion rate of CO to CO2 and use of calcium oxide to ensure an effective CO2 absorption. The addition of Fe2O3 and CaO significantly improved the total yield of hydrogen produced in a 1-h test duration. At a temperature of 923 K, a maximum of 90% of the total hydrogen content was achieved in the produced gas.