Coal-fired Gas Research Articles

‘New light’: gas and the elementary affect of early melodrama

ABSTRACT The development of coal-fired gas took off very rapidly between 1802 and 1818, used for the illumination of streets and buildings in Britain and Ireland but especially in the metropolis of London. These changes coincided with the emergence of melodrama as a new theatrical sensation, beginning with Thomas Holcroft’s A Tale of Mystery in 1802. At the same time, playgoers were being exposed to a variety of innovations and experiments in visuality such as the phantasmagoria, the panorama, and the ‘aquatic theatre’ of Sadler’s Wells that tested categories of the ‘real’. The London theatres were not only a venue for the marketing of gaslight as a technology but were themselves transformed into palaces of light, both within the auditorium and on stage. Melodrama’s protean qualities as an art form were thus closely bound up with the application of fossil capitalism, for which melodrama acts as a structure of feeling, an elementary affect.

Analysis on development trend of biomass energy distributed utilization

Distributed biomass energy technology has strong adaptability to the types of raw materials, flexible project scale, can meet the needs of special users, better economy in small scale, easier commercial development, in line with the characteristics of biomass resources and China’s national conditions. The distributed utilization of biomass energy mainly includes biomass briquette fuel and biogas. The key technologies include biomass briquette fuel processing and combustion, large and medium-sized biogas engineering technology, biomass gasification pyrolysis and gas utilization. At present, China’s distributed biomass energy technology is mainly in the stage of technological improvement and application demonstration. It is expected that by 2030, most of the key technologies will be basically mature and have the conditions for industrialization. The main development direction of China’s distributed biomass energy industry is the replacement of traditional coal-fired gas, urban/rural clean living energy supply, and rural ecological environmental protection. The pollution caused by burning coal/fuel oil, and at the same time centering on the national new urbanization strategy, provide sustainable clean energy for the construction of new rural areas, and improve the level of rural ecological and environmental protection. At present, the main bottleneck restricting the development of distributed biomass energy industry is economy and reliability. The state should increase investment in technological innovation and policy support, convert the environmental and social benefits of biomass energy into cost benefits, and promote biomass energy. The development of the industry can be distributed and utilized.

Simultaneous Desulfurization and Denitrification Using La-Ce-V-Cu-ZSM-5 Catalysts in an Electrostatic Precipitator.

Different catalysts were loaded onto the collecting plate of an electrostatic precipitator to achieve the simultaneous removal of multiple pollutants from coal-fired gas. The synergistic desulfurization and denitrification effect of the catalyst and the effect of corona discharge on the activity of the catalyst were studied. The La(6%)–Ce(8%)–V(7%)–Cu(8%)–ZSM-5 catalyst prepared by successive impregnation methods had the optimum simultaneous desulfurization and denitrification efficiency at a roasting temperature of 600 °C. The desulfurization and denitrification rates reached 97.09 and 83.30%, respectively. BET and SEM characterization results showed that the loading of active components and additives improved the pore structure of the molecular sieve, which contributed to the high stability of the catalyst’s internal structure and large surface area, as well as better desulfurization and denitrification efficiency. Corona discharge can significantly improve the catalytic effect.

Environmental impact of emissions from incineration plants in comparison to typical heating systems

In recent years, five modern municipal waste incineration plants have been built in Poland. Next ones are being constructed and at the same time building of several others is being considered. Despite positive experience with the operation of the existing installations, each project of building a new incinerator raises a lot of emotions and social protests. The main argument against construction of an incineration plant is the emission of pollutants. The work compares emissions from municipal waste incineration plants with those from typical heating plants: in the first part, for comparison large heating plants equipped with pulverized coal-fired boilers (OP-140), stoker-fired boilers (three OR-32 boilers) or gas blocks with heat output of about 100 MW have been selected, while the second part compares WR-10 and WR-25 stoker-fired boilers most popular in our heating industry with thermal treatment systems for municipal waste or refuse-derived-fuel (RDF) with similar heat output. Both absolute emission and impact - immission of pollutants in vicinity of the plant were analyzed.

Efficiency improvement of organizational-and-technological management of municipal heat-power systems

A new method of efficiency improvement of MHP systems by optimizing the structure and parameters of multilevel organizational and technological management is proposed. The formalization of the method is implemented using the system of mapping of Cartesian products of the ordered sets of input variables and variables of control actions and feedbacks into output variables for each level of the management system. The problem of combination of organizational, technical and technological factors is solved using logical-mathematical functions, and interaction coordination of the MHP subsystems - by selecting the optimal degree of their organizational and functional independence within the limits determined by the above management tools. The possibilities of enhancing regional (city) programs of efficiency improvement of MHP systems by the interaction coordination of their participants taking into the account the size of investment sources received through the program and energy savings achieved are considered. According to scenarios of profit maximization, minimization of losses of fuel and energy resources and minimization of CO 2 emissions, the problem of optimal control of the MHP system consisting of coal-fired boilers, gas-fired boilers, electric boilers, natural gas and biodiesel fuel cogeneration plants is solved. The simulation results, confirming the possibility of efficiency improvement of MHP systems by 20-40 % are presented.

EPA's New Source Review Program: Evidence on Processing Time, 200222014

As the United States moves forward with future energy policy, it must address and resolve issues associated with a shift away from coal and toward natural gas. While natural gas offers a significant opportunity as an abundant and relatively clean fuel source, optimum development and use of this resource requires an efficient and effective permitting process. A long and difficult permit approval process unnecessarily hinders progress toward energy and environmental goals by delaying or even cancelling both additions to new capacity as well as the upgrading of existing capacity. This study provides information on the time required to obtain permits through the Environmental Protection Agency (EPA) New Source Review (NSR) program for refineries and for coal-fired and natural gas–fired electric generating plants. The study finds that processing times for NSR permits for the 2002 to 2014 period varied significantly across EPA regions. They were also significantly longer for coal-fired and combined cycle electric generating units as compared to that for combustion turbines. Finally, processing times were significantly longer over this period for electric generating units and refinery projects as compared to reported permitting times for projects from 1997 to 2001.

Process Optimization Guidance (POG and iPOG) for Mercury Emissions Control

This paper introduces two new tools to quickly identify and assess a broad range of Hg emissions controls for utility gas cleaning systems worldwide. The Process Optimization Guidance (POG) document summarizes the available options for mercury control at most coal-fired power plants, covering everything from efficiency improvements and fuel switching through co-benefit effects (maximizing Hg capture in existing pollution control systems) to Hg-specific sorbent and oxidation technologies. The POG includes a “decision tree” concept that helps the reader determine the potential compliance strategies for particular coal-fired gas cleaning systems. The Interactive Process Optimization Guidance (iPOG) is a user-friendly software package that formalizes the “decision tree” concept in the POG document. It accurately estimates Hg removals and emissions rates for broad ranges of coal quality, the most common configurations for furnace firing and flue gas cleaning, and Hg controls, both inherent and external. Two case studies presented in this paper show its utility in addressing “What if...?” scenarios, in which the impact of adding Hg controls to existing cleaning systems can be quickly and conveniently evaluated. The iPOG supports compliance strategies based on coal cleaning and blending, stronger inherent Hg removal in new air pollution control units for NOx and SOx control, and dedicated external Hg controls, such as activated carbon injection (ACI) and halogen addition. This flexibility is compounded by minimal input data requirements and extremely fast execution times. This makes the iPOG useful for those who are new to the technicalities within the issue of Hg control, such as policy makers or even operators in developed countries or countries with economies in transition. Relative novices can “play” with the iPOG, selecting generic coals and simple plant design options, and then discover just how much simple changes in coal characteristics or plant operation may affect emissions. Being based on statistical regressions of an American Hg field test database and streamlined input data requirements, iPOG cannot possibly resolve differences among different Hg control strategies within the measurement uncertainties or depict the distinctive features of particular gas cleaning systems. Such limitations are especially pronounced whenever SO3 adsorption interferes with Hg removal via ACI and also when distinctive selective catalytic reduction (SCR) design specifications strongly affect Hg0 oxidation along a SCR catalyst monolith. Whereas the Hg removals for such situations are accurately predicted by previously reported reaction mechanisms, they are beyond the current scope of iPOG. However, the iPOG is fully capable of estimating Hg emissions from a preferred control scenario ahead of expert analysis.

Hot-corrosion mechanism of Ni-Cr coatings at 650°C under different simulated corrosion conditions

Abstract The oxidation and lower temperature hot corrosion (LTHC) processes occurring on the surface of Ni-Cr coatings produced by high velocity arc spray (HVAS) were studied. Several different conditions were studied under simulated boiler conditions at 650°C. The protection effect of an Al coating deposited by HVAS onto the Ni-Cr coating was also investigated. Microscope, X-ray diffraction and corrosion rate curves have been used to analyze corrosion mechanisms. The experimental results show that: 1) The oxidation rates are almost superposed in both air (no SO3) and in simulated coal-fired gas (containing SO3) as long as no salt was present on the surface. These rate curves show a logarithmic relationship. 2) When the surface is coated with salt (75%K2SO3 + 25%Na2SO3) the rate curve for LTHC of the Ni-Cr coated surface shows a parabolic shape in the simulated coal-fire flue gas. In air only the oxidation reaction takes place, the second type of LTHC was not seen. And 3) the Al over coating on the Ni-Cr enhances resistance to LTHC because an inter-metallic compound, Al3Ni2, forms at the Al/Ni-Cr interface and because of the increase in coating thickness.

04/00371 Energetic evaluation of brown coal-fired gas and steam turbine processes: Muehlhaus, R. Fortschriftt-Berichte VDI, Reihe 6.: Energietechnik, 2003, 496, (i–x), 1–129. (In German)

04/00371 Energetic evaluation of brown coal-fired gas and steam turbine processes: Muehlhaus, R. Fortschriftt-Berichte VDI, Reihe 6.: Energietechnik, 2003, 496, (i–x), 1–129. (In German)

How green is your plant?

For many years the principal concern of the power generation business has been to provide electricity to consumers with maximum reliability and with considerable concern for efficiency. Move recently two very significant new drivers have appeared in the market place. Environmental concerns associated both with acid rain and greenhouse gases have become more and more pressing, and at the same time deregulation has introduced a new agenda for the power generation business. Forces of environmental and deregulatory pressures do not always pull in the same direction, and this paper looks at the technical developments that have taken place and that are envisaged in the near future to address these matters. The paper discusses coal-fired plants, gas turbines, coal gasification, and carbon dioxide emissions.

96/04202 Coal-fired gas turbine and ash separation system

96/04202 Coal-fired gas turbine and ash separation system

Coal-fired gas turbine and ash separation system

Application of a coal-fired gas turbine for combined-cycle power generation is discussed. A cycle with staged coal treatment, a counterflow combustor and an aerodynamic ash separation cyclone is chosen and its principal components are investigated. Conditions for self-stabilizing char (solid product of coal gasification) combustion are found experimentally and by numerical simulation. It is shown that the obstacle of sticking ash can be obviated by staged combustion of the char and products of mild coal gasification. Experiments carried out with a coal-fired gas turbine at the Technion Combustion Laboratory are described. The main component making it feasible and reliable is an ash separation device, whose performance is analysed experimentally and computationally. Results indicate that the device suffices for the creation of a dynamically stable protective layer on the turbine blades. Efficiency studies indicate good performance of a metal multicyclone with swirl motion of the aerosol initiated by air jets. Simulation of the two-phase flow within the device, explaining its performance, is discussed.

95/06353 Prediction of scattering effect by ash polydispersion on spectral emission from coal-fired MHD combustion gas

95/06353 Prediction of scattering effect by ash polydispersion on spectral emission from coal-fired MHD combustion gas

Erosion-corrosion modelling of gas turbine materials for coal-fired combined cycle power generation

The development of coal-fired combined cycle power generation systems is receiving considerable worldwide interest. The successful development and commercialisation of these new systems require that all the component parts are manufactured from appropriate materials and that these materials give predictable in-service performance. Corrosion and erosion-corrosion, resulting from coal derived particulates, deposition and gaseous species, have been identified as potential life limiting factors for these systems. Models to predict these modes of materials degradation are under active development. This paper outlines the development and testing of models suitable for use in gas turbine environments. The complexity of the corrosion processes means that an empirical approach to model development is required whereas a more mechanistic approach can be applied to erosion processes. For hot corrosion conditions, statistically based corrosion models have been produced using laboratory tests for two coatings and a base alloy at typical type I and type II hot corrosion temperatures (900 and 700°C). These models use the parameters of alkali sulphate deposition flux and SO x partial pressure (at each temperature and for set HCl partial pressures), to predict the rate of the most likely localised damage associated with hot corrosion reactions. For erosion-corrosion modelling, a series of laboratory tests have been carried out to investigate erosion behaviour in corrosive conditions appropriate to coal-fired gas turbines. Materials performance data have been obtained from samples located in the hot gas path of the Grimethorpe PFBC pilot plant, under well characterised conditions, for testing the corrosion and erosion-corrosion models. The models successfully predict the materials damage observed in the pilot plant environments.

Coal Mineral Matter Transformation During Combustion and Its Effects on Gas Turbine Blade Deposition and Erosion

The reaction pathways along which mineral matter is transformed during pulverized coal combustion and the corresponding characteristics of the ash formed are especially important from the standpoint of coal-fired gas turbine operation. Using a novel FT-IR technique and EDX analysis, these mineral matter transformations are investigated when coal is burned in a pulverized coal-dust burner. The mineral transformations of quartz, gypsum, calcite, dolomite, pyrite, and those of the aluminosilicate minerals, kaolinite and montmorillonite, have been evaluated. Discussion of the results focuses on the effect of these mineral transformations on the deposition and erosive characteristics of the resulting combustion-generated ash.

Coal-fired gas turbine and ash separation system

Coal-fired gas turbine and ash separation system

Ash Deposition at Coal-Fired Gas Turbine Conditions: Surface and Combustion Temperature Effects

A study of ash deposition from a cleaned bituminous and conventional bituminous coal is presented. An electrically heated drop tube furnace is used to burn the coal and provide deposition conditions representative of proposed coal-fired gas turbines. Variations in the combustion temperature and deposit surface temperature demonstrate that surface cooling may significantly reduce ash deposition, or may provide little benefit, depending on the combustion conditions. Lower temperature combustion produced larger ash particles, with a greater fraction of ash adhering to the deposition test surface. Although the sticking coefficient was higher at the lower combustion temperature, the deposits were readily removed. A modest numerical simulation suggests that the smallest ash particles can experience significant boundary layer cooling and may account for the reduction in sticking observed at some conditions.

Atypical corrosion from coal-water fuels

Renewed interest in direct coal-fired gas turbines has led to a close examination of the potentially corrosive effects of coal combustion products on turbine blade materials. Short-term tests using a subscale turbine combustor were run with coal-water fuels (CWF) having coal ash levels around 1%. Deposits formed at gas temperatures of 1100°C (2000°F) on the CoCrAIY-coated specimens cooled to a turbine vane surface temperature of 980°C (1800°F). The deposit-coated specimens were subsequently exposed for 1484 h in a furnace-simulated turbine atmosphere at 980°C (1800°F). Examination of the test specimens showed that two atypical forms of corrosion occurred during exposure to combustor products. Accelerated oxidation was observed after the furnace tests. Additional work is recommended to more fully explore the effects of alternative coal feedstock and degree of coal cleaning on corrosion for this application.

A combustion/deposition entrained reactor for high-temperature/pressure studies of coal and coal minerals

The combustion of coal and coal-derived fuels in heat engines poses significant technical challenges in terms of establishing high combustion rates and efficiencies, controlling emissions, and minimizing the impact of fuel contaminants on engine components. An entrained reactor has been designed and constructed to study coal particle combustion, the tendency of coal ash to form deposits on heat engine components, and the effects of fuel additives on residual ash composition. The reactor is designed for high temperature/pressure conditions similar to those of a coal-fired gas turbine. Optical access ports and advanced instrumentation allow the in situ measurement of gas and particle temperatures, and vapor phase alkali concentrations. The reactor has been used to study the deposition potential of several coals as a function of process conditions, and to determine the effects of selected additives on the deposition rate.

Flyash Adhesion in Simulated Coal-Fired Gas Turbine Environment

A rich-quench-lean subscale turbine combustor has been used to expose specimens to the products of combustion from several beneficiated coal-water fuels. An analytical scheme is formulated to extract sticking coefficients from the measured weight gain data, particle size spectrum, and particle density and composition. The inferred sticking coefficients, appropriate for impaction on the pressure surface, range between 0.0003 and 0.11 and are strong functions of the gas and surface temperatures but rather insensitive to the impact angle. The implications of these results on coal-fired gas turbine operation are discussed.