Search Results for fossil fuel

The primary fossil fuels are generally defined as coal, oil, natural gas, tar sands, and shale oil. This article discusses the characteristics and the types of fuels used in fossil and fuel industries. It describes the energy conversion in fuels and outlines the efficiency of a heat engine with the help of the Carnot equation.

This article describes the corrosion mechanisms, challenges, and control methods in service water distribution systems. It provides a discussion on typical designs and water qualities for distribution systems used in fossil-fueled and nuclear power plants. The article also explains the techniques for controlling corrosion in service water systems.

Metals and ceramics exposed to high-temperature salt solutions are susceptible to a form of corrosion caused by fused salts accumulating on unprotected surfaces. This article examines the electrochemistry of such hot corrosion processes, focusing on sodium sulfate systems generated by the combustion of fossil fuels. It explains how salt chemistry, including acid/base and oxidizing properties, affects corrosion rates and mechanisms. The article also provides information on electrochemical testing and explains how Pourbaix methods, normally associated with aqueous corrosion, can be used to study fused-salt corrosion.

Stainless steels are iron-base alloys containing minimum of approximately 11% Cr, and owing to its excellent corrosion resistance, are used for wide range of applications. These applications include nuclear reactor vessels, heat exchangers, oil industry tubular, chemical processing components, pulp and paper industries, furnace parts, and boilers used in fossil fuel electric power plants. The article provides a brief introduction on corrosion resistance of wrought stainless steel and its designations. It lists the chemical composition and describes the physical and mechanical properties of five major stainless steel families, of which four are based on the crystallographic structure of the alloys, including martensitic, ferritic, austenitic, or duplex. The fifth is precipitation-hardenable alloys, based on the type of heat treatment used. The article further discusses the factors in the selection of stainless steel, namely corrosion resistance, fabrication characteristics, product forms, thermally induced embrittlement, mechanical properties in specific temperature ranges, and product cost.

Failures in boilers and other equipment taking place in power plants that use steam as the working fluid are discussed in this article. The discussion is mainly concerned with failures in Rankine cycle systems that use fossil fuels as the primary heat source. The general procedure and techniques followed in failure investigation of boilers and related equipment are discussed. The article is framed with an objective to provide systematic information on various damage mechanisms leading to the failure of boiler tubes, headers, and drums, supplemented by representative case studies for a greater understanding of the respective damage mechanism.

This article provides a summary of the concepts discussed in the Section “Corrosion in Specific Industries” in the ASM Handbook, Volume 13C:Corrosion: Environments and Industries. This Section applies the fundamental understanding of corrosion and knowledge of materials of construction to practical applications. The industries addressed are nuclear power, fossil and alternative fuel, land transportation, air transportation, microelectronics, chemical processing, pulp and paper, food and beverage, pharmaceutical and medical technology, petroleum and petrochemical, building, and mining and metal processing.

Low-alloy steels are used in a broad spectrum of applications. In some cases, corrosion resistance is a major factor in alloy selection; in other applications, it is only a minor consideration. This article reviews the applications of alloy steel products in four major industries, namely, oil and gas production, energy conversion systems, marine applications, and chemical processing. Emphasis is placed on the corrosion characteristics of the products, which are used in various applications of each industry.

Ash handling is a major challenge for utilities and industries using coal as a primary fuel. This article discusses the operating problems associated with conventional fly ash/bottom ash handling systems. It describes the two types of fly ash systems, namely, dry and wet fly ash systems. The article presents the ways to minimize operating problems that occur due to corrosion, erosion, scaling, and plugging.

The melting process often includes refining and treating the metal. The choice of which type of melting to use depends on a number of factors: type of alloy being melted, the local cost of electric power, and local environmental regulations. This article discusses the principles, furnace types, charging practices of metal melting methods, namely induction melting, cupola melting, arc melting, crucible melting, reaction melting, and vacuum melting, and the refractories and charging practice of reverberatory furnaces. Molten metal treatment of steels and aluminum also is discussed in the article.

This article describes the control of water chemistry in the steam cycle of a power plant for achieving corrosion control, deposition prevention, and higher cycle efficiency. It discusses the materials requirements of the components exposed to supercritical water in supercritical (SC) and ultrasupercritical (USC) power plants. These components include high-pressure steam piping and headers, superheater and reheater tubing, water wall tubing in the boiler, high-and intermediate-pressure rotors, rotating blades, and bolts in the turbine section. The article reviews the boiler alloys, used in SC and USC boilers, such as ferritic steels, austenitic steels, and nickel-base alloys. It provides information on the materials used in turbine applications such as ferritic rotor steels, turbine blade alloys, and bolting materials. The article explains various factors influencing steamside corrosion in SC power plants. It also deals with the role of overall efficiency in the USC power generation.

This article describes the process of selecting an optimum coating and material system for a specific application. It reviews critical coating functions that influence the coating selection process, and presents some application success stories. The article explores the benefits of thermal spray coatings and functions they provide. It also presents key references from various National Thermal Spray Conference, United Thermal Spray Conference, and International Thermal Spray Conference Proceedings from 2006 through 2012.

Dew-point corrosion occurs when gas is cooled below the saturation temperature pertinent to the concentration of condensable species contained by a gas. This article discusses dew-point corrosion problems in the susceptible areas of dry flue gas handling systems. The corrosion problems associated with the nitrate stress-corrosion cracking in heat-recovery steam generators are also discussed. The article presents general comments on the materials selection; plant operation; use of neutralizing additives; and maintenance, good housekeeping, and lagging (insulation). It concludes with information on guidance for maintaining specific sections of the plant.

This article first describes the two methods used in the 1998 U.S. corrosion cost study. In the first method, the cost was determined by summing the costs for corrosion control methods and contract services. In the second, the cost of corrosion was first determined for specific industry sectors and then extrapolated to calculate a national total corrosion cost. The article then reports the results and conclusions of the study. It concludes with information on corrosion prevention strategies.

Bitumen for coating usage can best be categorized as two fundamental but very different types: asphalts and coal tars. This article provides a detailed discussion on asphalt and coal tar hot-melt applications; asphalt and coal tar emulsions; asphalt and coal tar cutbacks; and coal tar epoxies. It reviews the similarities between asphaltic and coal tar coatings and discusses the health and environmental concerns of these materials.

Gas porosity is a major factor in the quality and reliability of castings. The major cause of gas porosity in castings is the evolution of dissolved gases from melting and dross or slag containing gas porosity. Degassing is the process of removing these gases. This article describes the methods of degassing aluminum, magnesium, and copper alloys. It provides information on the sources of hydrogen in aluminum and gases in copper.

The presence of certain impurities in coal and oil is responsible for the majority of fireside corrosion experienced in utility boilers. In coal, the primary impurities are sulfur, alkali metals, and chlorine. The most detrimental impurities in fuel oil are vanadium, sodium, sulfur, and chlorine. This article describes the two categories of fireside corrosion based on location in the furnace: waterwall corrosion in the lower furnace and fuel ash corrosion of superheaters and reheaters in the upper furnace. It discusses prevention methods, including changes to operating parameters and application of protective cladding or coatings.

This article describes the various environments affecting corrosion performance, corrosion protection, and corrosion control. These include freshwater environments, marine environments, and underground environments. The article provides information on corrosion in military environments and specialized environments, representing less-well-known environments with more limited applications.

This article addresses the general welding characteristics common to both solid-solution-strengthened and precipitation-hardened nickel-, iron-, and cobalt alloys.

This article includes a collection of color images that aid in the identification and classification of forms of corrosion in industries and environments. It emphasizes the negative aspects of corrosion and examines the cost and the effort to test, evaluate, simulate, and prevent corrosion. The ability of corrosion to undo the best complex engineered systems has been documented.