Archive: Coal

Coal Plant O&M: Coal Drying Reduces Pulverizer Start-up Costs

If coal leaving a pulverizer isn’t dry, it may plug up the coal pipes leading to the boiler. The coal-drying process in a pulverizer is similar to that used by flash dryers. Certain coals should be preheated to make them more combustible. Generally, preheating is done on higher rank coals — those with a low […]

Speaking of Coal Power: Shedding More Heat Than Light

When Charles Dickens began A Tale of Two Cities with, "It was the best of times, it was the worst of times," he was referring to the French Revolution of the late 18th century. But Dickens’ words apply equally well to the American generation industry of the late 20th century. A decade of overbuilding U.S. […]

Coal Plant O&M: Elemental Analyzer Checks Quality of Delivered Coal in Real Time

When you receive a shipment, you don’t wait weeks to see whether you got what you paid for — do you? J.M. Stuart Generating Station doesn’t, but it used to. Since coming on-line in the early 1970s, the big plant, on the Ohio River near Aberdeen, Ohio, mechanically sampled coal shipments as they reached the […]

PRB Tech Notes: Give Coal Handling the Priority It Deserves

Over the past 17 years — dating back to the 1990 Clean Air Act Amendments and including the introduction of retail competition — coal-fired power plants have become much cleaner and more efficient. Utilities have spent many billions of dollars to install pollution controls for regulatory reasons, and only slightly less to upgrade turbine-generators and […]

The Coal Pile

The February 1907 issue of POWER magazine reported on the construction of a new coal-fired steam engine plant on the Merrimac River outside of Lawrence, Mass. According to the plant’s owner, "the simplest and most flexible means for handling coal… to the furnace is by animal muscle… that brings the coal to the firing floor […]

The Coal Patrol: Looking Back at 2006

To borrow shamelessly from Charles Dickens, one of my favorite authors, for coal in 2006, "It was the best of times, it was the worst of times." No Escape The year began in horror. On January 2, most likely a result of a severe lightning strike, methane gas in the International Coal Group’s Sago Mine […]

Emissions Control: User-Designed Large-Particle Ash Screens Minimize SCR Fouling

Large-particle ash (LPA), also called popcorn ash (Figure 1), is a serious concern for many coal-fired utility boiler operators who have retrofitted their unit(s) with a high-dust selective catalytic reduction (SCR) system. LPA formed in the boiler can easily carry over into the SCR reactor (Figure 2), where it often causes catalyst erosion damage and […]

Technology options for capturing CO2

Concerns about global climate change have prompted interest in reducing or eliminating the carbon dioxide (CO2) emissions of fossil fuel-fired power plants. Here’s a guide to the technology and economics of three CO2 capture methods: postcombustion separation of CO2 from flue gas (applicable to existing plants), and oxygen-fired combustion and precombustion capture (suitable for new coal-fired capacity, including IGCC plants).

Utilities split on readiness of IGCC

For some gencos, the dearth of operating experience for integrated gasification combined-cycle plants adds too much uncertainty to the risk/reward equation for new-capacity technology options. For others, the possibility of being able to comply with air pollution limits as far out as 2018, as well as to meet all-but-certain CO2 caps, makes IGCC well worth investing in—now.