Coal

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 […]

Safeguarding coal-handling assets;
Giant wind turbine hard to bear

First live superconducting cable / Biggest CO2 storage project / Largest hydrogen-fueled plants / Record run for fuel cell cogen system / Largest PV plant still in Bavaria / Luz returns to U.S. / POWER digest

The O&M staff of AES Westover Station wisely took a holistic approach to optimizing combustion within Unit 8’s boiler in order to reduce its NO_x emissions while maintaining acceptable levels of carbon-in-ash content. The results of major modifications—centered on the addition of a fan-boosted overfire air system—were a 60% reduction in NO_x levels, improved unit reliability, and a project payback period measured in months rather than years. As this project proved, the whole is more than the sum of its parts.

Fuel flexibility isn’t free. Whether you’re equipping a new power plant to burn more than one type of coal or retrofitting an existing plant to handle coal blends, you’ll have to spend time and money to ensure that all three functions performed by its coal-handling system—unloading, stockout, and reclaim—are up to the task. The first half of this article lays out the available options for configuring each subsystem to support blending. The second half describes, in words and pictures, how 12 power plants—both new and old—address the issue.

Slagging and fouling of furnaces and boilers’ convective pass top the list of costly coal plant O&M problems. Although sootblowing is a tried and true solution, running sootblowers too often can erode boiler tubes. Lehigh University’s Energy Research Center has developed an "expert" sootblowing system that has outperformed experienced operators’ "seat of their pants" sootblowing procedures on two head-to-head field tests.

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.

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).

It’s said that pioneers take the arrows. In the case of Springerville Unit 3—a 418-MW (net) expansion of a Tucson Electric Power facility in Arizona and the first pulverized coal–fired unit built in the U.S. in more than a decade—the arrows were many. Although Tri-State (the developer), Tucson Electric (the host), and Bechtel Power (the EPC contractor) were wounded by delayed deliveries of major equipment, bankruptcy of a major supplier, and a labor shortage, the companies showed their pioneering spirit and completed the project ahead of schedule. For ushering in a new generation of clean and desperately needed baseload capacity, Springerville Unit 3 is POWER magazine’s 2006 Plant of the Year.

Point Aconi’s circulating fluidized-bed boiler experienced erosion, corrosion, and fouling problems from the day it went on-line in 1993. After several frustrating years of unreliable operation, in late 1999, Nova Scotia Power discovered the right combination of engineering and fuel modifications. Today, after a switch to 80% petroleum coke and major boiler modifications, Point Aconi’s output exceeds its original nameplate rating. For having the vision and fortitude to plan and execute a multiyear, $20 million project to revitalize North America’s first in-service utility CFB boiler, Nova Scotia Power’s Point Aconi plant is the well-deserved winner of POWER magazine’s 2006 Marmaduke Award for excellence in O&M.

Complying with permitted emissions limits may be the most significant operations risk for a power plant. As limits are slowly ratcheted downward, understanding the accuracy and variation of measured pollutant levels becomes even more important. To avoid misunderstandings, regulators and plant owners should factor measurement uncertainty into air quality permit numbers both as the permit is formulated and preceding any subsequent modifications.

Demand records fall nationwide;
GE’s ABWR to be STP’s edge; Entergy buys Palisades plant; Dithering over desert disposal; Tourist trash-to-energy plant;
Brooklyn says "Yo!" to microturbines; POWER digest

Asheville Power Station’s Unit 1 in Arden, North Carolina, was the first coal-fired unit to be modified with a flue gas desulphurization (FGD) system and placed in service to meet the clean air requirements of the state’s Clean Smokestacks Act. As of November 16, 2005, at least 97% of the sulfur dioxide that had been […]

A coal-fired power plant operating in the western U.S. was experiencing short gearbox life in its coal-pulverizing operation. After an annual gearbox inspection, oil analysis results indicated that the AGMA 6EP (ISO 320) gear oil recommended by the original equipment manufacturer (OEM) had failed to provide adequate lubrication and protection. This conclusion was based on […]

The Gasification Technologies Council (GTC, www.gasification.org) was created in 1995 with a straightforward mission: to promote the greater use of gasification as an environmentally and economically preferred alternative for the production of power, fuels, and chemicals from low-value energy sources. Those energy sources include high-sulfur coal, petroleum coke, and wastes. Since that time the GTC […]

Reliant Energy Commits $350 Million for Environmental Upgrades at Two Key Facilities Reliant Energy has announced plans to install state-of-the-art emission control systems at two Pennsylvania power plants, a major step in the company’s strategy for maximizing the long-term value of its power generation assets while reducing air emissions. The utility, Reliant Energy, estimated it […]

In order to promote coal-based technologies, the U.S. Department of Energy will be assisting the Internal Revenue Service (IRS) in the selection of projects to receive tax credits. According to the DOE’s Office of Fossil Energy, recent legislation has been designed to advance cleaner coal-based power generation and gasification technologies. The Energy Policy Act of […]

In early 2003 the United States announced its plans to build a zero-emission prototype of the fossil fuel power plant of the future called FutureGen. It is one of the boldest steps toward a pollution-free energy future ever taken by the U.S. It has the potential to be one of the most important advances in […]

Utility customers depend on and expect reliable, affordable electricity for virtually every aspect of their lives. At the same time, electricity producers in the United States are faced with finding cost-effective methods to meet ever-increasing demand and more stringent environmental regulations. Though it’s not a new trend, the frequency with which new regulatory air quality […]

New flue gas desulfurization (FGD) units are being installed at utilities in many parts of the U.S. and a large percentage of the new scrubbers are of the wet limestone type. Although wet limestone scrubbing is a well-developed technology, it may be unfamiliar to employees at plants that have previously not required scrubbers. This article […]

Design techniques and operating experience with Powder River Basin (PRB) coals have advanced significantly over the past 35 years for boilers that were originally designed for this fuel. Today, boiler installations looking to effectively utilize PRB coals fall into two primary categories: units that were initially designed for bituminous or other coals and units that […]

The University of Iowa (UI) Biomass Fuel Project has produced significant reductions in greenhouse gas emissions, regulated boiler stack emissions, and purchased energy costs. The project utilizes a renewable, biomass fuel source and provides an opportunity for UI to partner with a local industry. UI was approached by Quaker Oats Co., Cedar Rapids Facility in […]

A great location, a fish-friendly cooling system, and the extent of environmental remediation needed to permit it distinguish this repowering project on the Hudson River just south of the New York State capital.

Commercial operation of PacifiCorp’s first new power plant in more than 20 years coincided with the company’s acquisition by MidAmerican Energy Holdings Company this past March. Currant Creek treads lightly on the environment, provides needed power to PacifiCorp’s eastern control area, and has demonstrated its commitment to be a good corporate citizen of the local community. By any account, Currant Creek is a model for how to develop a power project.

Why does Monticello, a 30-year-old plant, deserve recognition as one of POWER’s Top Plants of 2006? Because TXU has been blending Powder River Basin (PRB) coal with local lignite at the plant for the past decade, and steady reductions in air-pollutant emission rates have been the result. That positive experience has made the company confident enough to propose building nearly 9,100 MW of new coal- or lignite-fired capacity in Texas by 2010 at a cost of $10 billion. Read on to share some of the lessons that TXU has learned about handling PRB coal safely.

In April 2005, U.S. Secretary of Energy Samuel W. Bodman asked the National Coal Council to develop a “report identifying the challenges and opportunities of more fully exploring our domestic coal resources to meet the nation’s future energy needs.” The council has responded with eight specific recommendations for developing and implementing advanced coal processing and combustion technologies to satisfy our unquenchable thirst for energy.

Participants in the CEO Roundtable at Electric Power 2006 raised a plethora of issues affecting decisions on future electric power generation. Representing a cross section of power producers, the industry leaders made clear that, although globalization has lost its luster in the power generation sector, its impact on the domestic industry remains profound. Ten years […]

If coal is to be “America’s energy future” (see p. 42), the work of the Powder River Basin Coal Users’ Group (PRBCUG) will have a lot to do with making it so. Since 1999, the PRBCUG (see sidebar) has fostered the safe, efficient, and cost-effective use of the fuel as it watched its membership swell […]

In the U.S. electric power industry, coal is making a comeback as a fuel of choice for new generation projects. During the construction boom that occurred from 1999 to 2003 about 90% of new electric generation utilized natural gas – fired combustion turbines. Unfortunately, over the past few years natural gas supplies have tightened and […]

Is the U.S. supply of coal sufficient to meet the increased demand for coal-fired generation? With the increasing demand for coal to generate electricity, the big question is, How reliable is the supply and transportation of the fuel? Currently, Industrial Info Resources (IIR) is tracking 185 new coal-fired power projects, and if all were to […]