Beneficial Byproducts of Coal Combustion and Gasification was the Hot Topic Yesterday

A good discussion yesterday, April 28, 2011, covered flyash and FGD byproducts. One of the conclusions is that depending on the fuel and the proximity to byproduct users, there are attractive alternatives to limestone scrubbing. Another conclusion is that the disposal of any solids from power plants will be under greater scrutiny in the future.

Eric Erickson of Haldor Topsoe updated participants on the Haldor Topsoe SNOX technology, an exothermic, catalytic process for the removal of SO₂ and NO_x from flue gas.  SNOX generates additional heat recovery and merchant grade sulfuric acid.  It is ideal for high sulfur coal and petcoke applications as it becomes more efficient and cost effective as the sulfur content of the fuel increases. In the discussion period it was agreed that this process can easily be adapted to the new toxic regulations by using sodium additives ahead of the particulate device to remove the HCl (without injecting enough to remove SO₂).

Richard (Rich) Staehle, Vice-president of Business Development at Marsulex Environmental Technologies, related the evidence to show how high efficiency FGD using ammonia instead of limestone (AS-FGD) has been commercially demonstrated in full-scale systems for well over a decade. This process uses the SO₂ as a feedstock in the production of ammonium sulfate, a valuable crop fertilizer. In addition to significant revenue potential from the fertilizer sales, this technology minimizes or eliminates the solid and liquid waste costs and liabilities associated with conventional FGD systems. Experience at Dakota Gasification is that this granular fertilizer is preferred over alternatives. Therefore a big storage dome supplied because of assumed seasonal demand has not been needed. As soon as it is produced the ammonium sulfate is sold.

Lisa JN Bradley, Ph.D., DABT, Senior Toxicologist and Vice President Environment at AECOM, discussed “Perspectives on Health Risks Associated with Beneficial Re‐Use of Byproducts of Coal Combustion.” EPA stated in their June 2010 proposed rule for the disposal of coal combustion residuals (CCRs) that their intention was to preserve the Bevill exemption for the beneficial use of CCRs.  However, the preamble to the proposal was essentially an advanced notice of proposed rulemaking for the regulation of these uses.  This contradiction was evident in testimony given by EPA at the recent hearing of the House subcommittee on Environment and the Economy on the McKinley bill (HR 1391). EPA’s Office of the Inspector General has also recently issued a report titled “EPA Promoted the Use of Coal Ash Products with Incomplete Risk Information.”  Her talk provided encouraging results for risk assessments and risk-based evaluations for the beneficial uses of CCRs, and how EPA’s own CCR risk assessment can help inform the issue.

Duane Abbott of Beltran Technologies, Inc. covered process gas cleanup from coal and municipal waste gasification. Sulfur and other contaminants in the feed to gasifiers used for power generation can lead to corrosion and high stack emissions if the contaminants are not removed.

The Bios, Abstracts and Photos are linked below.

BIOS, PHOTOS, ABSTRACTS - APRIL 28, 2011.htm