Stationary Power Plants Research Articles

Waste biomass gasification char derived activated carbon for pharmaceutical carbamazepine removal from water

Carbamazepine (CBM), a widely occurring pharmaceutical, has been removed from water by upgrading a waste biomass char from a 300 MW biomass gasification power station plant operating in Indonesia. The fuel source is the waste residue palm kernel shell (PKS) after the palm oil extraction process constituting over one million tonnes per year. The resulting waste power station biomass char (CPKS) from the power station gasification process has been converted into high quality activated carbon by carbon dioxide activation as a sequestration opportunity, at different temperatures ranging from 700 to 900°C for 1 or 1.5 hours. The highest BET surface area was 711.5 m2/g and this activated carbon was able to adsorb 1.14 mmol/g or 268.7 mg CBM/g. Equilibrium and kinetic studies have been undertaken.

Recent advances on first-principles modeling for the design of materials in CO2 capture technologies

Novel technologies in consideration of industrial sustainability (IS) are in urgent need to satisfy the increasing demands from the society. IS realizes the production of materials while maintaining environmental and resource sustainability. The chemical materials used in CO2 capture and storage (CCS) technologies play a significant role in the disposal of greenhouse gas emissions coming from large stationary fossil-fired power plants, which breaks the principle of IS and brings severe environmental problems. This study aims at providing a detailed review of first-principles modeling (density functional theory, DFT) of materials in CO2 capture technologies. DFT analysis provides insight into the atomic properties of the studied systems and builds an efficient guidance of the future design of the materials used in CO2 capture technologies. Major materials including oxygen carriers, metal organic frameworks, membranes, zeolites, ionic liquids and some other promising candidates are considered. The computational studies bring the outcomes of the adsorption behaviors, structural characteristics and accurate force fields of the studied materials in short turn-around times at low cost. This review can stimulate the design of novel materials with specific target of CO2 capture and promote the industrial sustainability of fossil fuel combustion technologies.

Predictive Compressor Wash Optimization for Economic Operation of Gas Turbine

Gas turbine engines (GTEs) are widely used for power generation, ranging from stationary power plants to airplane propulsion systems. Compressor fouling is the dominant degradation mode in gas turbines that leads to economic losses due to power deficit and extra fuel consumption. Washing of the compressor removes the fouling matter and retrieves the performance, while causing a variety of costs including loss of production during service time. In this paper, the effect of fouling and washing on the revenue of the power plant is studied, and a general solution for the optimum time between washes of the compressor under variable fouling rates and demand power is presented and analyzed. The framework calculates the savings achievable with optimization of time between washes during a service period. The methodology is utilized to optimize total costs of fouling and washing and analyze the effects and sensitivities to different technical and economic factors. As a case study, it is applied to a sample set of cumulative gas turbine operating data for a time-between-overhauls and the potential saving has been estimated. The results show considerable saving potential through optimization of time between washes.

CALCULATION OF THE INFLUENCE OF THE COMPOSITION OF THE BIOGAS ON THE CHARACTERISTICS OF THE VEHICLE ENGINE

Decrease the consumption of mineral fuels in ICE is considered one of the important goals of reducing the harmful influence of this energy source on the environment. Within this plan, one of the most effective fuels type is biogas obtained from the processing of municipal solid waste and livestock waste. Biogas basically includes methane and carbon dioxide with a wide range of their ratio. The composition of biogas, in relation to the special features of obtaining it, can change, which leads to a change of indicators of the ICE. In connection with, the forecast of these indicators is actual, which is necessary for the development of effective systems for regulating the supply of biogas in the internal combustion engines. This forecast can be executed with the help of mathematical modeling of the working cycle of ICE with using adequate mathematical models. In this research used improved mathematical model of the working cycle of internal combustion engine developed in the department of piston power plant A. Podgorny Institute for Mechanical Engineering Problems NAS of Ukraine. The subject of the research is diesel engine D21A, converted to a gas engine, for which the investigations of possible options biogas composition were carried out with methane and carbon dioxide content in percentage terms: 100/0, 80/20, 60/40, 50/50, 40/60. Influence of the content in biogas of hydrogen, hydrogen sulfide, ammonia and nitrogen oxides in view of their smallness is neglected. The sufficiency of the mathematical model is verified by comparing the effective engine indicators obtained experimentally and by means of a calculation for the rated power mode of 18.5 kW (fuel-methane, n = 1800 min -1 , α = 1, φ = 25°, e = 9.5) . The difference in the comparison of the results didn't be less than 10 %, which proves the fidelity of the model. The influence of control actions on the parameters of an engine working on biogas is presented in the diagrams in X–Y coordinates. Graphical analysis of the results numerical experiment, depending on the changing parameter allows to predict the potential emission of NO, CO, CO 2 , economic indicators (g i , G i ), capacity indicator (p i ), the process quality index of the process inside the cylinder (η i ), to estimate the maximum values of temperature and pressure of the cycle as for the rated power mode (n = 1800 min -1 ) and for the maximum torque capacity (n = 1400 min -1 ), and retrieve additional info for different excess air ratio (α = 1.0, α = 1.1) by external velocity performance and load characteristics for all test parameters of the engine. A numerical experiment based on predict the characteristics of an engine running on biogas with a different ratio of CH 4 / CO 2 made it possible to make a quick, with sufficient accuracy, preliminary analysis indicator indexes of ICE with spark ignition. Inference should be drawn that the use of biogas as a motor fuel for stationary and transport power plants shows positive results, videlicet: improves index toxicity at a significant decrease in the economic index of the engine, decreases the thermal load on the parts of the cylinder-piston group, which contributes to the increase in their motor mileage allowance, the carbon dioxide balance in the environment is observed. The results of mathematical modeling can be useful in optimizing the working cycles of ICE, which are transferred to work with natural gas and biogas. They are also necessary in the development of such complex structures as automatic control systems for the supply of gaseous fuels in the internal combustion engine with the instability of its component composition and the resulting heat of combustion.

Anti-aging treatment of nuclear power plant steel

Duplex stainless steel loses impact toughness quickly during its service at nuclear power plant station as pipe and boiler. Aging induced spinodal decomposition in ferrite phase is the mechanism behind this degradation. This work uses electropulsing to treat the aged steel at the service temperature. The charpy impact toughness and Vickers micro-hardness were recovered significantly. Thermoelectric power is recommended to measure the degree of spinodal decomposition in the aging processing, which was recovered by > 83% by the electropulsing treatment. It was proved that the anti-aging treatment was not due to the Ohm heating. Instead, the electropulsing-induced extra free energy change of − 891 J/mol provided thermodynamic driving force for the regeneration processing. Electropulsing-enhanced diffusivity enables the anti-aging processing to be completed quickly.

Statistical study on distribution of multiple dissolved elements and a water quality assessment around a simulated stackable fly ash

This study reports the leaching and transport behaviors of sixteen elements in fly ash taken from coal-fired power plant stations. A total of 480 water samples were collected from 20 simulative monitoring wells at three different times. Concentrations of elements in water samples were detected to know the spatial variability of substance, contamination level and quality of groundwater around stackable fly ash. The results of the water quality index (WQI) indicate that the water around a stackable fly ash is unsuitable for drinking. Sixteen parameters (Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Mg, Mn, V, Pb, Sb, Ni and Zn) were analyzed using different multivariate statistical approaches to assess the origins of elements in groundwater around stackable fly ash, identified five factor types that accounted for 75.66% of the total variance. Based on drinking water guidelines, As, Sb, Pb, Al and Cd were the dominant contaminants in groundwater around stackable fly ash. The quality of fly ash were considered to contribute much of the Mn, V, Ba and Mg (Cd, Cr and Ni for leaching time; Sb and Pb for leaching intensity; Al and Fe for water depths; B for flow velocity). Co, Cu and Zn had natural and random origins from crustal materials and upper reaches. Cluster analysis (CA) was adopted to classify the 20 simulative monitoring wells into two groups of water pollution, high pollution and low pollution, reflecting influences from leaching solution and upper reaches activities, respectively. The results of Hazard quotient and index (HQ/HI) suggests that As, Sb, Cd, Pb, V and Cr are the largest contributors to health risks in monitoring sites around stackable fly ash.

Modeling, parameterization and damping optimum-based control system design for an airborne wind energy ground station power plant

This paper presents the results of modeling and parameterization of the high-altitude wind energy system ground station power-plant equipped with a generator/motor unit as a primary power source tethered to the airborne module via a winch system, an ultracapacitor energy storage system, and grid inverter connected to the common direct-current link. Consequently, a suitable ground station power plant control strategy is designed, comprising the generator/motor speed control and cable tension control system, direct-current link power flow coordination control, and grid-side inverter control strategy. Control system design is exclusively based on the damping optimum criterion which provides a straightforward way of closed-loop damping tuning. The effectiveness of the proposed ground station control strategy is verified by means of comprehensive computer simulations. These have pointed out to precise coordination of the winch electrical servodrive with the airborne module-related rope force control system and sustained power production during the airborne module ascending phase in the presence of high-altitude wind disturbances, and continuous power delivery to the grid-side inverter, facilitated by the utilization of ultracapacitor energy storage. This indicates rather robust behavior of the overall ground station control system under anticipated external disturbance conditions.

Optimization of the Data Representation Integrated Form in the Viola-Jones Algorithm for a Person’s Face Search

It is shown that the task of a person’s face recognition is one of the most popular at the present time. Its effective solution determines the reliability of many modern systems of personal identification, security, access control, and video surveillance at thermal and nuclear power plant stations. The speed of facial recognition algorithms is one of the key factors that determine the possibility of using for solving specific practical problems. It is shown that one of the methods for increasing the speed of facial recognition algorithms is the use of an integral form of data representation. The Viola-Jones algorithm is identified as one of the classic approaches to solving the problem of face recognition. The main limitations for using the classical integral form of data representation are shown. Rotation of the head is identified as the main factor leading to a significant increase in the error in determining the brightness indicators for the most informative areas of the face. An approach based on the use of modified integrated forms for image frame data representation is proposed. These forms are oriented to the fast processing of information in the presence of a significant rotation of the head. The most important range of possible changes in the angle of rotation of the head is identified. The data structure is considered in case of using the modified integral form. Experimentally confirmed the possibility of using a limited number of modified forms of data representation while maintaining the high reliability of the work of the human face recognition algorithm.

Multi-mode diagnosis of a gas turbine engine using an adaptive neuro-fuzzy system

Gas Turbine Engines (GTEs) are vastly used for generation of mechanical power in a wide range of applications from airplane propulsion systems to stationary power plants. The gas-path components of a GTE are exposed to harsh operating and ambient conditions, leading to several degradation mechanisms. Because GTE components are mostly inaccessible for direct measurements and their degradation levels must be inferred from the measurements of accessible parameters, it is a challenge to acquire reliable information on the degradation conditions of the parts in different fault modes. In this work, a data-driven fault detection and degradation estimation scheme is developed for GTE diagnostics based on an Adaptive Neuro-Fuzzy Inference System (ANFIS). To verify the performance and accuracy of the developed diagnostic framework on GTE data, an ensemble of measurable gas path parameters has been generated by a high-fidelity GTE model under (a) diverse ambient conditions and control settings, (b) every possible combination of degradation symptoms, and (c) a broad range of signal to noise ratios. The results prove the competency of the developed framework in fault diagnostics and reveal the sensitivity of diagnostic results to measurement noise for different degradation symptoms.

The constructal size of a heat exchanger

The architecture of heat exchangers is a classical subject that has been studied extensively in the past. In this paper, we address the fundamental question of what the size of the heat exchanger should be, in addition to what architectural features it should have. The answer to the size question follows from the tradeoff between (1) the useful power lost because of heat transfer and fluid flow and (2) the power destroyed during transportation, manufacturing, and maintenance. Changes in heat exchanger size induce changes in the opposite sign in the power requirements (1) and (2). This fundamental tradeoff regarding size is illustrated by considering one side of a heat exchanger (one flow passage) in laminar flow and in fully rough turbulent flow, with several duct cross sectional shapes and arrays of channels in parallel. The size tradeoff is present in heat exchanger applications across the board, from vehicles to stationary power plants.

DETERMINATION OF DIVERSE ENVIRONMENTAL POLLUTION LEVEL FROM SELECTED AREAS OF RAWALPINDI, PAKISTAN

Anthropogenic contaminants arising from both stationary (power plants, industries and residential heating) and mobile sources (road traffic) can harm ambient air quality in urban areas. Depending upon their physical state, these pollutants are classified as liquid and vapor phases and are subsequently transported to the Earth’s surface through dry and wet deposition. After the deposition of these pollutants onto the surface of earth various health effects caused by these pollutants occurred like cardiovascular diseases and hypertension. In this study four different locations/sites were selected from the Rawalpindi city depending upon the population, traffic rush and industries to examine the noise level, concentration of carbon dioxide and heavy metals. Air sampler was used for the collection of air sample to analyze the heavy metal concentration, Quest electronic sound meter for measuring sound level and SIBATA for CO2 measurement. The study findings revealed that noise level was higher at all selected locations as described by WHO limit (70 dB) being highest at Industrial area due to heavy machinery and lowest at green area. Concentration of all four heavy metals were high as compared with the prescribed limits. CO2 level reaches up to 300 ppm because of coal consumption during the winter season. The threshold values of all these selected parameters well above the prescribed limits defined by the authorities so to combat with this situation we should move towards more energy efficient fuels, proper maintenance of vehicles and machineries, traffic management and installation of noise barriers in industries as well as installation of catalytic convertors in vehicles to stop further air pollution.

Novel process technologies for conversion of carbon dioxide from industrial flue gas streams into methanol

This research aims to develop efficient process technologies that are capable of converting/utilising CO2 streams into energy-rich liquid products (fuels). This would result in better solutions with near-zero-carbon-emissions level. From an energetic and economic point of view, methanol synthesis from CO2 is a competitive alternate to methanol production from biomass. Our work considers the CO2 balance for the technologies proposed, taking into account all CO2 flows from/to the environment. Flue gas CO2 streams released from electric power stations, steel industry, petroleum industry, and cement industry are good candidates for the developed technologies. Three new processes are developed and modelled for converting CO2 streams into liquid methanol. The total cost of equipment and utility for all process scenarios are evaluated and compared. The energy targets as well as the CO2 emissions (balance) are determined. Heat integration is performed on the best selected process technology. The case study employed for the present work is a power station plant burning natural gas for electricity production with a capacity of 112MW, releasing 328t/h flue gases to the atmosphere, of which CO2 gas accounts for 14%; hydrogen required for CO2 conversion comes from the chlor-alkali industry. The optimum process technology reached in this contribution results in methanol production of 0.625t-per-tonne of CO2 waste gas supply, leading to an annual production of 222,507tons methanol with a profit of 56.55M$/y. Thus, the CO2 release to the environment is cut by about 62%.

Fabrication of Metal-Supported Solid Oxide Fuel Cells by Sinter-Joining Method with Silver Bonding Layer

Solid oxide fuel cell (SOFC) is an energy conversion device which generates electricity from hydrogen. SOFC is attracting attentions because of its high energy conversion efficiency and low material cost. For these reasons, SOFC are widely studied to be applied to various power generation systems such as stationary power plant, residential power system, auxiliary power unit (APU), etc. For APU applications, high mechanical strength is required to endure mechanical vibration and external shock during the driving of vehicles, which makes ceramic-based SOFC unsuitable. To overcome this limitation, metal-supported SOFC has been proposed. Metal-supported SOFCs are composed of metal substrate which supports ceramic layers of anode, electrolyte, and cathode. For more than past ten years, various types of metal-supported SOFC have been developed in many organizations. However, conventional metal-supported SOFCs had limitations of high cost thin film coating process such as sputtering, plasma spray, etc, sintering at reducing atmosphere, and unsintered cathode. In our research group, metal-supported SOFCs fabricated by sinter-joining method were developed. To fabricate metal-supported SOFCs by sinter-joining method, metal substrates were bonded to conventional ceramic cells by bonding paste composed of mixture of stainless steel, nickel oxide, yittria-stabilized zirconia (YSZ). Recently, silver has been proposed as bonding materials. By using silver as bonding materials, bonding of ceramic cell can be performed at temperature lower than 950 °C at air atmosphere, which enables full sintering of cathode. This has been rarely reported because conventional metal-supported SOFCs were fabricated by sintering at reducing atmosphere to prevent oxidation of metal substrate during the sintering. Furthermore, it is believed that electrical conductivity, thermal conductivity are improved, leading to lower ohmic resistance and better temperature distribution of metal-supported cells. In this work, 5 x 5 cm2 metal-supported SOFCs with silver bonding layer was successfully fabricated. The microstructure of bonding layer was investigated, which showed good adhesion of silver bonding layer. Electrochemical performance and impedance spectra were studied. Power density of 433 mW/cm2, ohmic resistance of 0.52 Ω cm2, polarization resistance of 0.16 Ω cm2 at 800 °C were obtained, and it is believed that high power density was attributed to low polarization resistance by full sintering of cathode. Metal-supported SOFCs fabricated by sinter-joining method showed 10 times higher mechanical strength than conventional ceramic cells.

Solar power plant station in Fishland

Solar power is the conversion of sunlight into electricity, using photovoltaic (PV) solar panels. This paper introduces the solar power station in Fish Country, in Hungary. The examined solar power station (50 kWp) consists of 200 pieces of polycrystalline silicon Kyocera solar panels. The efficiency of this power station was measured and calculated in order to determine its amortization period and the amount of prevented CO2 emission as a consequence of this technology. The results of the measurement and calculation of the efficiency demonstrate that the facility fulfils the committed requirements. Nowadays, the air pollution is considered as one of the major causes of the global warming. This is reflected by the EU restriction of the emissions. The solar power station, which was built by Aranyponty Halászati Ltd., contributed to reduce the local CO2 emission, but it has impact on the global level as well, because circa 50 tons of carbon dioxide is prevented to be emitted into the atmosphere per year.

Recent development on performance modelling and fault diagnosis of fuel cell systems

This study reviews the latest works on performance modelling and fault diagnosis of fuel cell systems during the past few years. The fuel cell is a promising alternative power source for various applications in stationary power plants, portable power devices and vehicles. Fuel cells provide low operating temperatures and high energy efficiency with zero emissions. A fuel cell is a multiple distinct parts device and has a series of mass, momentum and energy transport through gas channels, electric current transport through membrane electrode assembly and electrochemical reactions at the triple-phase boundaries. These transport processes play crucial roles to determine electrochemical reactions and cell performance so studies on the performance modelling and fault diagnosis have been done deeply. This review shows how these modelling and fault diagnosis studies offer valid findings for transport and performance modelling of fuel cells and recommendations of enhancing transport processes for improving the cell performance. Future directions on the current research topic are also highlighted which will help the researchers to find the challenges ahead.

Method for the Preliminary Fluid Dynamic Design of High-Temperature Mini-Organic Rankine Cycle Turbines

Widespread adoption of renewable energy technologies will arguably benefit from the availability of economically viable distributed thermal power conversion systems. For this reason, considerable efforts have been dedicated in recent years to R&D over mini-organic Rankine cycle (ORC) power plants, thus with a power capacity approximately in the 3–50 kW range. The application of these systems for waste heat recovery from diesel engines of long-haul trucks stands out because of the possibility of achieving economy of production. Many technical challenges need to be solved, as the system must be sufficiently efficient, light, and compact. The design paradigm is therefore completely different from that of conventional stationary ORC power plants of much larger capacity. A high speed turbine is arguably the expander of choice, if high conversion efficiency is targeted, thus high maximum cycle temperature. Given the lack of knowledge on the design of these turbines, which depends on a large number of constraints, a novel optimal design method integrating the preliminary design of the thermodynamic cycle and that of the turbine has been developed. The method is applicable to radial inflow, axial and radial outflow turbines, and to superheated and supercritical cycle configurations. After a limited number of working fluids are selected, the feasible design space is explored by means of thermodynamic cycle design calculations integrated with a simplified turbine design procedure, whereby the isentropic expansion efficiency is prescribed. Starting from the resulting design space, optimal preliminary designs are obtained by combining cycle calculations with a 1D mean-line code, subject to constraints. The application of the procedure is illustrated for a test case: the design of turbines to be tested in a new experimental setup named organic rankine cycle hybrid integrated device (ORCHID) which is being constructed at the Delft University of Technology, Delft, The Netherlands. The first turbine selected for further design and construction employs siloxane MM (hexamethyldisiloxane, C6H18OSi2), supercritical cycle, and the radial inflow configuration. The main preliminary design specifications are power output equal to 11.6 kW, turbine inlet temperature equal to 300 °C, maximum cycle pressure equal to 19.9 bar, expansion ratio equal to 72, rotational speed equal to 90 krpm, inlet diameter equal to 75 mm, minimum blade height equal to 2 mm, degree of reaction equal to 0.44, and estimated total-to-static efficiency equal to 77.3%. Results of the design calculations are affected by considerable uncertainty related to the loss correlations employed for the preliminary turbine design, as they have not been validated yet for this highly unconventional supersonic and transonic mini turbine. Future work will be dedicated to the extension of the method to encompass the preliminary design of heat exchangers and the off-design operation of the system.

Effects of Impurities on CO2 Pipeline Performance

Carbon dioxide (CO2) is a chief constituent of greenhouse gases and should be captured, transported and stored in saline aquifers or used for enhanced oil recovery. This study is focused on pipeline transportation of impure CO2. The major impurities in captured CO2 from power plant stations and gas processing facilities are mainly nitrogen, methane, hydrogen sulphide, and water. Impurities affect the density and viscosity of the CO2 stream thereby impacting on the fluid phase, pressure and temperature of the stream. CO2 pipeline models, however, rarely consider the effects of impurities in the determination of design parameters. Aspen HYSYS (ver.9) is used to model the effect of impurities on the pressure drop, phase envelope and critical pressure and temperature of captured CO2 fluids flowing in pipelines. Cortez, Canyon Reef and Choctaw pipelines in the USA and Weyburn pipeline in Canada were selected as the case studies. The results show that the pressure drop increased in these pipelines due to the impurities with the highest pressure drop occurring in the Canyon Reef pipeline. The impurities increased the pressure drop by about 0.09 bar/km, 0.2 bar/km, 0.10 bar/km and 0.04 bar/km for Cortez, Canyon Reef, Choctaw and Weyburn pipelines respectively. The lower molecular weight gases were found to decrease the mixture density and increase the pressure drop. The results also reveal that the bubble point pressure was increased by impurities in three pipelines but slightly reduced in the Weyburn pipeline and the critical temperature was reduced in all pipelines.

Maximum power for a power plant with two Carnot-like cycles

A stationary power plant with two Carnot-like cycles is optimized. Each cycle has the following irreversibilities: finite rate heat transfer between the working fluid and the external heat sources, internal dissipation of the working fluid, and heat leak between reservoirs. The optimal allocation or effectiveness of the heat exchangers for this power plant is determined by applying, two alternating design rules: fixed internal thermal conductance or fixed areas. The optimal relations obtained are substituted in the power and the maximum power, according to the isentropic ratio of each one of the Carnot-like cycles of the power plant, is calculated. Additionally, the efficiency to maximum power is presented.

Optimal allocation and effectiveness of the heat exchangers for a power plant with two like-Carnot cycles

A stationary power plant with two Carnot-like cycles is optimized. Each cycle has the following irreversibilities: finite rate heat transfer between the working fluid and the external heat sources, internal dissipation of the working fluid, and heat leak between reservoirs; is extended to two or more of this combined model. Using the Bellman’ Principle, we find the optimal recurrence relations for the allocation of the heat exchangers for this power plant. The optimal allocation or effectiveness of the heat exganchers of power plant is determined by two design rules: internal thermal conductance fixed; or areas fixed. The optimal obtained are invariant to the power and efficiency and to the heat transfer law.

A Comprehensive Review on the Properties of Coal Bottom Ash in Concrete as Sound Absorption Material

The government is currently implementing policies to increase the usage of coal as fuel for electricity generation. At the same time, the dependency on gas will be reduced. In addition, coal power plants in Malaysia produce large amounts of industrial waste such as bottom ash which is collected in impoundment ponds (ash pond). However, millions of tons of coal ash (bottom ash) waste are collected in ponds near power plant stations. Since bottom ash has been classified as hazardous material that threatens the health and safety of human life, an innovative and sustainable solution has been introduced to reuse or recycle industrial waste such as coal bottom ash in concrete mixtures to create a greener and more sustainable world. Bottom ash has the potential to be used as concrete material to replace fine aggregates, coarse aggregates or both. Hence, this paper provides an overview of previous research which used bottom ash as fine aggregate replacement in conventional concrete. The workability, compressive strength, flexural strength, and sound absorption of bottom ash in concrete are reviewed.