Air Permitting of IGCC Plants

Coal gasification, cleaning of the synthesis gas (syngas), and combustion of the clean syngas is currently the upcoming IGCC (Integrated Gasification Combined Cycle) method in the thermal power production and control of several air contaminants and possibly the greenhouse gases. A good number of patented feed-gasifiers are commercially available. Once coal or other feed is gasified, the elemental sulfur is removed from syngas and, then it is possible to remove the carbon-dioxide (a greenhouse gas) as required by the upcoming local, state, and federal environmental regulations. Currently, the syngas with the carbon-dioxide is fired in the stationary combustion turbines (CTs) to produce power. IGCC process is, currently, the preferred choice over conventional thermal power production in regard to cleanup of fuel and significantly reduced contaminant emissions. The air permitting requirements include the review of: feed preparation and PM emissions; feed gasification and contaminant emissions; elemental sulfur recovery and SO₂ emissions; options for carbon-dioxide recovery; syngas characteristics for combustion; CT design and combustion mechanisms; air contaminant emissions of CT; controlled CT emissions of nitrogen-oxides and carbon-monoxide gases using the SCR and oxidation catalysts, respectively; and, emission of volatile organic compounds (VOCs), and hazardous air pollutants (HAPs). However, the IGCC processes are being rigorously reviewed for the system integration and reliability, and significant reduction of air contaminant emissions (including the greenhouse gases). This paper included a review of IGCC air contaminant emission rates, and various applicable regulatory requirements, such as NSR (New Source Review), NSPS (New Source Performance Standards), and MACT (maximum achievable control technology). The IGCC facility's NO_X, CO, SO₂, PM, VOCs, and HAPs emission rates would be significantly low. Thus, effective, construction and installation, and operation air permits would be necessary for IGCC facilities.