Archive: Coal


Gas turbine "refueling" via IGCC

The jury is still out on the economic and technical feasibility of burning gasified coal to generate electricity. Gasification technology has yet to be proven on a utility scale, especially with Powder River Basin coal as the feedstock. And on the generation side, there are more questions than answers about the capital cost and availability of integrated gasification combined-cycle (IGCC) plants. But with natural gas prices high and rising, it’s definitely worth examining whether it would be economically and technically feasible to convert the existing U.S. fleet of gas-fired combined-cycle plants to burn gasified coal.


Designing wet duct/stack systems for coal-fired plants

A multitude of variables must be accounted for during the design and development of a wet-stack flue gas desulfurization system. The five-phase process detailed below has proven effective on more than 60 wet-stack system design studies. A basic understanding of these concepts will help inform early design decisions and produce a system amenable to wet operation.


Designing HRSG desuperheaters for performance and reliability

Increased cycling of combined-cycle plants has made precise control of attemperator spray water within heat-recovery steam generators more important if damage to their hardware and piping is to be avoided. Complicating the issue is the industry’s still-limited experience with cycling and the fact that demands on the attemperator and turbine bypass of cycled plants are more stringent than those on baseloaded units.


Stressed merchant industry hopes for better days

The U.S. power generation industry is changing at warp speed, via regulatory changes, consolidation, mergers, and sales of assets at yard-sale prices. New players have entered the market and become major players overnight, while several mainstays have gone bankrupt. Though many of the latter blamed high gas prices for their woes, well-diversified merchants enjoyed a record year. Whatever changes are in store for the business of combined-cycle generation, you can be sure that innovations in plant design and O&M such as those described in this special section will keep pace with them.


Constant and sliding-pressure options for new supercritical plants

Sliding-pressure, supercritical plants are all the rage. They generally include certain design features developed for markets and operating environments outside the U.S., where new coal-fired plants have been built in recent decades. U.S. market conditions are different, and considerable capital cost savings—with negligible operating cost differences—are possible if technology options are considered for the next wave of supercritical and ultra-supercritical steam plants.


Estimating SCR installation costs

The EUCG surveyed 72 separate installations of selective catalytic reduction (SCR) systems at coal-fired units totaling 41 GW of capacity to identify the systems’ major cost drivers. The results, summarized in this article, provide excellent first-order estimates and guidance for utilities considering installing the downstream emissions-control technology.


CCPI bears first fruit

In 2002, the Bush administration launched the Clean Coal Power Initiative in the hope that it would develop the missing technology piece of the cleaner energy puzzle. Four years and two rounds later, the U.S. electric power industry is seeing the first usable clean coal technologies emerge before its eyes.


Honduras’ big new oil-fired plant

The 267-MW Pavana III power plant (Figure 1) was officially inaugurated on January 28 by Honduran President Ricardo Maduro. It was built by Helsinki-based Wärtsilä Corp. for Tegucigalpa-based independent power producer (IPP) Luz y Fuerza de San Lorenzo S.A. (Lufussa).     1. From Finland to Central America. The new 267-MW Pavana III power plant […]