POWER

News has been emerging from around the world about several projects that seek to turn human sewage — arguably the dirtiest of manmade wastes — into clean energy.

In 2007, Duke Energy’s W.H. Zimmer Station set out to advance the overall performance of its flue gas desulfurization (FGD) dewatering process. The plant implemented a variety of measures, including upgrading water-solids separation, improving polymer program effectiveness and reliability, optimizing treatment costs, reducing solid waste sent to the landfill, decreasing labor requirements, and maintaining septic-free conditions in clarifiers. The changes succeeded in greatly reducing solid waste generation and achieving total annual savings of over half a million dollars per year.

Reducing the minimum load at which a steam turbine can reliably operate is one way to increase revenue for marginal base-loaded units during periods of low electrical demand. For this reason, it is not unusual to see merchant plants operating at "super minimum" load levels that are well below the typical 25% rated full-load limits. However, such units are operating well outside the original equipment manufacturer (OEM) design basis, and owners may experience undesirable damage to their turbines for a number of reasons. That’s why it is important for owners to understand the trade-offs and risks that come with such operation.

If a number of technical, financial, and regulatory hurdles can be overcome, power generated by integrated gasification combined-cycle technology could become an important source for U.S. utilities. Our overview presents diverse perspectives from three industry experts about what it will take to move this technology off the design table and into the field.

Cavitation is defined as the phenomenon of forming and imploding vapor bubbles in a region where the pressure of the liquid falls below its vapor pressure. Cavitation and the resultant damage can occur in any fluid-handling equipment, especially in pumps. Technological advances in industrial protective coatings and composite repair materials have made it possible to repair pumps operating in a cavitating environment rather than simply replacing them after damage occurs. Cavitation-resistant (CR) elastomers have the ability to retain adhesion under long-term immersion, dissipate energy created under high-intensity cavitation, and provide outstanding resistance to corrosion and other forms of erosion.

While many CO₂ removal technologies are being researched through laboratory and pilot-scale testing, an existing technology has a significant operating history at commercial-scale facilities, where it is collecting CO₂ from multiple sources, including low-CO₂ concentration flue gas (<3.1% by volume) with high oxygen concentrations (>13% by volume).

Arkansas-based Baldor Electric Co. launched a new direct drive technology for the cooling tower industry that improves reliability, reduces maintenance, runs quieter, and saves energy. The Adjustable Speed Direct Drive Cooling Tower Motor combines technologies of the field-proven laminated finned frame RPM AC motor with a high-performance permanent magnet salient pole rotor design, and it […]

ASME’s latest revision of its Recommended Practices for the Prevention of Water Damage to Steam Turbines Used for Electric Power Generation: Fossil-Fuel Plants, ASME TDP-1-2006, contains much important design and operating advice that is proven to protect steam turbines. However, many in the industry are not as familiar with the update as they should be. This article provides a concise overview of this critical design standard.

Martin Engineering has introduced an upgraded version of the MARTIN Insertable Dust Collector, which features improved filters and a smaller footprint to control airborne coal dust at belt conveyor loading points and other bulk material-handling operations. Insertable dust collectors are typically installed to reduce problems associated with central baghouse collection systems, including long runs of […]

To supplement domestic natural gas supplies, the U.S. is expected to increase its dependence on offshore liquefied natural gas suppliers in the coming years. However, the composition and hydrocarbon content of imported LNG may significantly vary from those of North American sources. Variation in fuel composition may lead to plants using fuel that violates their combustion turbine fuel specifications and may cause operational problems.

Steve Elonka began chronicling the exploits of Marmaduke Surfaceblow — a six-foot-four marine engineer with a steel brush mustache and a foghorn voice — in POWER in 1948, when he raised the wooden mast of the SS Asia Sun with the help of two cobras and a case of Sandpaper Gin. Marmy’s simple solutions to seemingly intractable plant problems remain timeless. This Classic Marmaduke story, published 50 years ago, takes place during the Cold War at an Air Force Base in northern Greenland, where under-ice tunnels were constructed to move nuclear rockets around the facility unobserved. The miniature nuclear reactor was operated for almost three years before it was shut down and returned to the U.S., ending the Army’s nuclear program. Greenland officially became a separate county within the Kingdom of Denmark in 1953, and home rule was introduced in 1979.

Electro-Chemical Devices’ new plug-and-play Model 2122 Cooling Tower Control System (CTCS) is designed to apply the various chemicals used to prevent corrosion, scaling, and fouling in water-based wet cooling towers. The system also controls acid feed via pH monitoring, blowdown via conductivity, and the inhibitor via a user-selected time basis. Model 2122 CTCS features a […]

In the battle against climate change, most media attention has been paid to "cap-and-trade" schemes, under which countries set upper limits ("caps") on greenhouse gas (GHG) emissions and allow companies to sell ("trade") unused emissions rights to other firms. However, there is a second path to global warming salvation: Carbon offsets.

How would you like to be able to access data on all the power plants in the world and all of their performance metrics, analyze that data, and map it? Those abilities are part of the vision behind the Global Energy Observatory (GEO), an OpenModel website that serves as a wiki for global energy data.

A little more than a year after the Bush administration abruptly withdrew its support for the FutureGen project, the Department of Energy has again announced it will back the proposed Illinois gasified coal power plant and carbon capture initiative. Though the 275-MW project may be different in technical aspects — it will be initially designed for 60% carbon capture, not 90%, and gasify only Illinois Basin Coal (Figure 2) — it is still riddled with many of same funding problems. Making matters worse, it may have been revived too late: Since the DOE withdrew its support, several major carbon capture and storage (CCS) projects and alliances have sprouted in the U.S., and these could give FutureGen a run for its money.

In their recent endangerment finding draft technical support document (TSD), scientists at the U.S. Environmental Protection Agency (EPA) conclude that carbon dioxide emissions are a public health hazard and should be regulated under the Clean Air Act. Federal law requires that regulations be based on scientific information that is "accurate, clear, complete, and unbiased"; the most recent available; and collected by the "best available methods." The EPA’s TSD on carbon emissions violates all of these requirements.

The U.S. Geological Survey (USGS), a federal mapping agency, has of late been propounding the difference between "resources" and "reserves." It says that although the two terms are used interchangeably, the distinction is simple: Reserves are a subset of resources. Coal resources, as an example, include those in-place tonnage estimates determined by summing the volumes for identified and undiscovered deposits of coal, whereas coal reserves are those resources considered "economically producible" at the time of classification, even though extraction facilities are not in place and operative.

This March, Japan’s Mitsubishi Heavy Industries Ltd. (MHI) quietly completed development of the "J-series" gas turbine — a machine that has been extolled in the turbo-machinery world for its ability to produce one of the world’s largest power generation capacities and highest thermal efficiencies.

In early June, as U.S. Energy Secretary Steven Chu confirmed to a House Subcommittee that Yucca Mountain repository was, without doubt, "off the table" and that a blue ribbon panel would further advise the government on what it should do with its high-level nuclear waste, Sweden announced the site of what could be the world’s first permanent spent fuel repository.

I was putting the finishing touches on this month’s editorial when I received an email from a reader who owns a company that serves the power industry. He was very complimentary of an article I recently wrote. "Goes without saying," I was thinking to myself. However, actually saying it goes a long way in my book, and I enjoy hearing from readers — at least most of the time.

Ethiopia, the landlocked nation in East Africa from which key tributaries to the Nile River originate, completed construction of the continent’s highest dam, the 188-meter Tekezé Arch Dam (Figure 3) in February.

News items of interest to power industry professionals.

The gas-rich Persian Gulf state of Qatar in May commenced construction of the region’s largest power and water plant, a massive project comprising eight gas turbine generators, eight heat-recovery steam generators, four steam turbine generators, and 10 desalination units.

Performing regular oil changes on remote generators is far from simple or cost-effective. Here’s how one firm harnessed technology to extend oil change intervals from one week to two months.

Engineers at Purdue University and Sandia National Laboratories have developed a technique that uses sensors and computational software to constantly monitor forces exerted on wind turbine blades. Their achievement could one day improve the efficiency of wind turbines by providing the blades’ "smart" structure with necessary data to adjust to rapidly changing wind conditions.

There has been much excitement about the advent of the "smart grid" recently, especially because of the strong push by the Obama administration. Despite the simple-sounding term, the smart grid is not a simple concept.

The intensifying spotlight on renewable energy seems to be casting a brighter light on the energy storage problem, with lawmakers, researchers, and investors scrambling to seek out the most feasible solution to bridge the intermittent nature of renewable power sources.

The debate over the benefits of using digital bus networks as the communications backbone of new power plants is all but settled. The technology is maturing, and the reliability of digital hardware is superior to that of hardwired systems. Newmont Gold Mining’s 200-MW TS Power Plant is perhaps the power industry’s best example of how a plantwide digital controls architecture can provide exceptional reliability and be significantly less costly to install.

Just as reports emerged earlier this year that NASA had abandoned, for lack of financial resources, its research into space-based solar power that would be harnessed via orbiting solar arrays beaming microwaves to earthly receivers, California’s Pacific Gas & Electric Co. (PG&E) wrote the California Public Utilities Commission (PUC) requesting its approval of a power purchase agreement from a similar technology.

Carbon emissions produced by the combustion of coal may be collected and stored in the future, but a better approach (in the near term at least) is to reduce the carbon produced through efficient combustion technologies. Increasing the efficiency of new plants using ultrasupercritical technology will net less carbon released per megawatt-hour using the world’s abundant coal reserves while producing electricity at the lowest possible cost.