Ab initio screening of metal sorbents for elemental mercury capture in syngas streams

作者：Jain Anubhav; Seyed Reihani S A; Fischer Christopher C; Couling David J; Ceder Gerbrand; Green William H^*

来源：Chemical Engineering Science, 2010, 65(10): 3025-3033.

DOI：10.1016/j.ces.2010.01.024

• Computational chemistry
• Mercury
• Coal gasification
• Thermodynamics process
• Gases
• Energy

Coal gasification provides an opportunity to improve the thermal efficiency of energy extraction from coal over traditional pulverized coal technology, but efficiencies are hindered by low temperature removal of mercury and other pollutants. This work screens via density functional theory (DFT) calculations 22 pure metals as potential high-temperature Hg sorbents for coal gasification plants. The DFT enthalpy of amalgamation and oxidation is evaluated for each metal as indicators of their potential to either sorb Hg or oxidize in the gas stream. Our results predict Pd to be the most promising candidate for Hg removal, as it has the highest amalgamation enthalpy of all metals not expected to oxidize. No metals tested are ideal for Hg capture, as we find that amalgamation enthalpies correlate with oxidization enthalpies; thus, pure metals are either poor Hg adsorbers or strong oxidizers. Other chemical classes may be more promising as Hg sorbents; future work may apply the screening procedure discussed here to more complex compounds, such as binary and ternary alloys, oxides, and sulfides.

• 出版日期2010-5-15