NR2076

NEWS RELEASE                                                                                        MARCH 2015

A Multitude of Hot Gas Filter Decisions Needed Due To Regulatory and Technology Developments

Operators of power plants, industrial boilers, cement kilns and waste incinerators have been challenged by both regulatory and technology developments which increase the number of decisions which have to be made regarding hot gas filtration.

New regulations applying to combustion sources in the U.S., China and other countries require removal of particles to levels 90 percent lower than required a decade ago. Older precipitators are not capable of compliance with the new standards. New alternative technologies may create water and solid waste problems. In fact, a number of different decision trees have to be viewed in order to make the best decisions.

tree2Air Regulations

Discrete   particles, condensibles, mercury and acid gases.

tree2Water and Solid Waste

Regulations   which change the air pollution control options.

tree2Economic Decisions

Including plant   retirement or fuel switching.

tree2Process Options

Including   heat recovery, flyash sale, reducing load, new fan.

tree2Multiple Function

Pollution   control devices which remove more than one pollutant.

tree2Technology Upgrades

New   filter media, scrubber approaches, improved ESPs.

Many older plants are candidates for retirement or fuel switching. The costs of this approach have to be compared to the cost of upgrades to meet the new rules.  This is not a sequential process. Discoveries in one decision tree lead the analyst back to the previous tree.  A new direct sorbent injection approach will greatly lessen the capital cost but will make flyash unsalable. If this ash has to be sent to a hazardous waste landfill, the costs would be enormous. However, some technology upgrades could provide a salable mix of reaction products and ash.

New filter media allows consideration of replacing just precipitator internals. But, if the required pressure increase is more than the existing fan can handle, then the analyst needs to look carefully at the whole process decision tree. A new catalytic filter with direct sorbent injection offers the potential to remove three pollutants in one device. The biggest advantage may be the creation of clean gas at 850oF. This provides some very important energy recovery alternatives but requires retracing the analysis of the water and solid waste, process and technology decision trees.

McIlvaine offers services for both the combustion plant operator and the supplier.

The Hot Gas Filtration Global Decisions Positioning System™ (GdPS)provides a road map for all the participants.

Power Plant Systems and Components  provides a free decision system for operators.

44I Power Plant Air Quality Decisions  provides the decision system for suppliers.