Operation Of Coal-fired Power Plants Research Articles

Features of the Mechanism of Gas-phase Ignition of Wood Biomass Particles

ABSTRACT Use of woody biomass instead of coal as fuel for thermal power plants (TPP) is considered a promising direction for reducing emissions of anthropogenic substances during the operation of coal-fired thermal power plants. But the process of replacing coal with wood in the thermal power industry is happening very slowly due to objective reasons. The main one is the deposition of particles that have not fully passed the pyrolysis stage (in this case, a layer of substance in a resinous state is retained in the wood particle) on heating surfaces (for example, superheaters) and a decrease in the efficiency of using the heat of combustion of fuel as a result of contamination of the heating surfaces. Therefore, when developing technologies for burning dispersed wood in the furnaces of boiler units, reliable experimental data are required on the characteristic times of ignition and combustion of woody biomass particles, taking into account the time of transition from local (focal) gas-phase ignition to the combustion of volatiles in the entire vicinity of the particle (tsf). The article presents the results of experimental studies of flame propagation processes in the small vicinity of a particle during the ignition period. The experiments made it possible to establish that the flame propagation velocity in the small vicinity of the particle significantly depends on the ambient temperature. It is shown that under conditions of low-temperature heating (air temperature Tg = 873 K), the propagation velocity of the combustion (flame) is minimal. An increase in Tg values (from 873 K to 1273 K) leads to a significant (4–5 times) increase in the time of complete flame coverage of the particle. According to the results of the experiments, two heating modes were identified: high-temperature and low-temperature with a conditional interface Tg = 873 K. At Tg = 873 K, the characteristic particle size of wood biomass has no significant effect on the characteristics and conditions of flame propagation in a small vicinity of the particle. An increase in the ambient temperature (up to 1273 K) leads to an increase in the influence of particle size on the characteristics and conditions of flame propagation. A hypothesis describing the process of flame propagation has been developed.

Parameter analysis on SO3 measurement in coal-fired flue gas with controlled condensation method

ABSTRACT The accurate, repeatable, and verifiable measurement of SO3/H2SO4 is significant to the reliability operation of coal-fired power plants, as well as environment protection and human health. Although the amount of SO3 in flue gas is very small, and its chemical property is extremely active, the measurement of SO3/H2SO4 is difficult and problematic. The measurement errors of controlled condensation method for SO3/H2SO4 in flue gas were evaluated with a sampling system based on dilute sulfuric acid heating method. In order to improve the test accuracy of this method, the effects of water bath temperature, flue gas sampling flow rate, and spiral condensing tube structure parameters (inner diameter and length of spiral condensing tube) on the recovery efficiency of SO3/H2SO4 were investigated. The results indicate that the recovery efficiency fluctuates in the range between 84.1% and 91.6%, with the water bath temperature increasing from 40°C to 90°C. As the flue gas sampling flow rate increases from .5 L/min to 4 L/min, the recovery efficiency of SO3/H2SO4 shows a gradual tendency of increasing, and the recovery efficiency can be high up to 98.4%. When the inner diameter of the spiral condensing tube increases from 3 mm to 10 mm, the recovery efficiency of SO3/H2SO4 decreases gradually. The recovery efficiency of SO3/H2SO4 increases gradually with the spiral condensing tube length increasing from 900 mm to 2000 mm.

Joint Modeling and Operational Optimization of a Reverse Osmosis-Mechanical Vapor Recompression System for Coal-Fired Power Plant Wastewater.

The operation of coal-fired power plants generates a large amount of wastewater. With the issuance of increasingly strict drainage standards, the cost of wastewater treatment is increasing, and the need to reduce the cost of wastewater treatment is becoming increasingly urgent. Thus, based on the principles of reverse osmosis (RO) and mechanical vapor recompression (MVR) in wastewater treatment, the operational optimization of an RO-MVR joint system was studied in this work with the consideration of reducing the operating costs of wastewater treatment under given operational conditions. Firstly, based on the basic principles of RO and MVR, corresponding mechanism models were established and their accuracy was verified. Then, an economic model of the RO-MVR joint system was established, with the goal of minimizing the water production unit price and daily operating costs of the joint system for optimization analysis. Finally, we analyzed the cost and water production performance of the RO-MVR joint system before and after optimization under different operating conditions. The results show that this optimization based on the RO-MVR joint system will reduce the unit price of water production to 3.16 CNY/m3, with the daily operating costs being decreased by 22% compared to before optimization. This result helps to reduce the cost of zero-discharge wastewater treatment in coal-fired power plants.

Design of Multi-Input Multi-Output Non-linear Model Predictive Control for Main Steam Temperature of Super Critical Boiler

Flexible operation of coal-fired power plants is becoming increasingly necessary for successful integration of large-scale renewable power generation into the power grid. The maximum ramp rate and the number of load cycles are generally limited by the thermal stress experienced by the boiler pressure parts, turbine metallurgy and creep and fatigue of critical thick-walled components Main steam temperature is a critical operating parameter that must be controlled within acceptable limits for safe operation. Main steam temperature deviation beyond acceptable limit has impact on boiler pressure parts and turbine material of construction due to creep and fatigue effect. Base load operating units do not require steep ramp rate and hence recommended ramping rates are kept low within the safe operating zone in comparison to the flexible operation of the units with wide range load change width. Thermal stresses are caused by the temperature changes inside the thick-walled components and turbine steam admission parameters. Hence, the quality of main steam temperature control plays a vital role in flexible operation of the coal fired units. Conventional cascaded PID temperature control loop architecture performs well at steady state condition within a limited variation of load change at low ramp rate but it acts slowly and performs poorly at transient operating conditions of flexible operation of the boiler turbine with wide range load variation and load cycle with high ramp rate and remains far from rated conditions. In this paper, a Multi-Input Multi-Output (MIMO) Non-linear Model Predictive Control (MPC) design for regulation of the main steam temperature of a Once-Through supercritical Boiler is proposed. The controller is based on a non-linear dynamic model which incorporates dynamics of the variables of interest. It has the capability to operate effectively across a wide load range while maintaining main steam temperature within acceptable limits. A notable advancement in this design of MPC is the incorporation of coal flow demand and feedwater flow demand as additional control inputs alongside primary and secondary spray flows. In simulation test cases, the MPC controller demonstrates satisfactory performance and computational efficiency.

Toxic effects of atmospheric deposition in mining areas on wheat seedlings.

Storage and transportation of coal, as well as operation of coal-fired power plants, produce amounts of metallic exhaust that may lead to different atmospheric environment in the overlapped areas of farmland and coal resource (OAFCR) environment. To investigate the effects of different atmospheric environment in the OAFCR region (north of Xuzhou) on wheat seedlings (AK-58), a box experiment was conducted and compared to an area far from the OAFCR (south of Xuzhou). The study revealed that (1) compared to the southern suburb of Xuzhou, the fresh and dry weight, activities of photosynthetic enzymes and POD of wheat seedlings in the OAFCR reduced obviously. (2) Significantly higher levels of Cr, Cd, Pb, Zn, and Cu were found in the shoots and roots of wheat seedlings in the OAFCR, with lower transfer factor for heavy metals (except Cd and As) in comparison to those in the southern suburb. And the bioconcentration factors of heavy metals (except As) in wheat seedlings in the OAFCR were significantly higher. (3) Nearly 90% of heavy metals (Pb, Cu, Cd, Zn, and Cr) absorbed by wheat were stored in cell walls and soluble fractions, with significantly higher contents of Cu and Cr in wheat seedlings' cell walls and higher contents of Pb, Zn, and Cd in soluble components found in the OAFCR. Our results showed that atmospheric deposition in the mining area has a certain toxic effect on wheat seedlings, and this study provides a theoretical basis for OAFCR crop toxicity management.

Perhitungan Beban Emisi Particulate Matter berdasarkan Data CEMS dari PLTU Batu Bara Milik PT PLN (Persero)

In the Coal-Fired Power Plant (CFPP) operation, various pollutants will be generated, including Particulate Matter (PM), which can be monitored with the Continuous Emission Monitoring System (CEMS). The parameters monitored include PM concentration, volumetric flow rate, % O2, and the operation hours and/or CEMS monitoring hours. Emission load calculation by utilizing CEMS data is a Tier 3 calculation method that uses real operation data from a CFPP unit. Information related to PM emission load from CFPP can be considered for corporate decision making in developing emission control strategies. This research utilizes secondary data from January 2021 to July 2023 period, from 52 PT PLN (Persero)’s CFPP units with various boiler, installed capacity, and types of Air Pollution Control Devices specifications. The largest average/month emission load value is 139,632 kg PM/month for CFPP unit that uses PC boiler, have a capacity of > 600 MW, and use low NOx burners and ESP as its APCD; while the smallest average/month emission load value is 525 kg PM/month for CFPP unit that uses PC boiler, have a capacity of 101-300 MW, and use ESP as its APCD. If the average emission load/month from January 2021 to July 2023 is compared with the maximum emission load/month with a PM quality standard of 100 mg/Nm3, all CFPP units do not exceed it and are generally ready to face the tightening of PM quality standard up to 75 mg/Nm3.

“Waste to energy” as a driver towards a sustainable and circular energy future for the Balkan countries

BackgroundThe main goal of the paper is to review the existing state and propose a model solution for the introduction of the waste-to-energy concept in the Republic of Serbia and Bosnia and Herzegovina, as these Balkan countries are a source of high pollution due to the inefficient use of fossil fuels and the operation of coal-fired power plants. Besides, these countries have very low level of waste management, which results in the uncontrolled disposal of a large amount of waste which consists of plastic and microplastic materials which are difficult to decompose in natural ecosystems.MethodsConsidering the type and objectives of the study, a mixed research method was chosen as a combination of exploratory research, descriptive research, explanatory research, and modeling.ResultsThe main result of the research shows the unfavorable situation in the field of waste management in the Republic of Serbia, as well as in Bosnia and Herzegovina. Both countries have adopted adequate strategies and plans, but waste management is not implemented accordingly, Nevertheless, numerous problems create considerable opportunities for improvement, especially regarding the potential for energy production from waste, which is an important approach to implementing the circular economy model. The study showed that the situation is particularly unfavorable in rural areas. Hence, the research proposes (a) a novel model for waste-to-energy governance and (b) a novel model for waste-to-energy management in rural areas. The research was done, and models were developed based on the examples of the Republic of Serbia, and Bosnia and Herzegovina. However, the results can be used in countries with a similar level of waste management and with a larger share of rural areas.ConclusionsThe paper emphasizes the importance of a holistic and systemic approach to waste management, with emphasis on using waste-to-energy concept as particularly applicable in the transition to circular economy. This study proposes a model for the integration of waste management (with emphasis on plastic and microplastic) and energy efficiency, presenting a model of approach that can be used in countries that are at the beginning of introducing a circular economy.

Japanese Climate Litigation and the Development of Personal Rights

Abstract Since climate change was recognised as a global concern, there has been a growing number of climate-related cases around the world. While the development of climate litigation in Japan is often overlooked in the academic literature, Japanese citizens in fact have instituted four lawsuits that all aim to stop the construction and operation of coal-fired power plants, as the use of coal in the power generation sector is primarily responsible for the total emissions of greenhouse gases in Japan. Accordingly, this article aims to introduce the recent climate-related cases and to show how human rights-based concepts are utilized with the intention of incorporating environmental claims. More specifically, the development of the concept of personal rights (Jinkaku-ken, 人格権) is discussed, primarily by examining the arguments made in the tort law-based climate cases.

Portable digital holographic particle analyzer (DHPA) for pneumatically conveyed fuel monitoring: Design and validation

Efficient, clean, and intelligent operation of coal-fired power plants plays a crucial role in the pursuit of energy conservation and carbon reduction. Online monitoring of pneumatically conveyed fuel is essential to furnish fundamental data for combustion optimization. This paper proposes a digital holographic particle analyzer (DHPA) with a portable design for monitoring pulverized fuel fineness. DHPA consists of a particle sampling and recycling probe, a digital inline holographic system, a controlling module, and software. The probe extracts representative fuel particles from the pipe, which are subsequently measured in a three-dimensional field by pulsed digital inline holography before being returned to the pipe. The performance tests of DHPA for coal fineness measurement encompass investigations into the dispersion of particles within the measurement volume, the minimum particle number necessary for reliable results, a comparison with the laser particle analyzer and sieving method, as well as sensitivity to mill parameter changes. It is recommended to capture at least 4 × 104 particles to ensure a credible outcome. DHPA exhibits comparability with the traditional sieving method, displaying an absolute error of 1.48% for fineness R90 measurement. Moreover, DHPA has been successfully employed for measuring and optimizing the coal fineness at full-scale power plants. On-site measurements have unequivocally confirmed the feasibility and effectiveness of DHPA for monitoring pulverized fuel.

Possible underestimation of the coal-fired power plants to air pollution in China

The Chinese government has imposed strict policies on coal-fired power plants and achieved considerable environmental benefits. However, whether coal-fired power plants still impact air pollution needs further testing. Here, we adopted a Difference-In-Differences model to compare air quality stations less and more impacted by nearby coal-fired power plants’ production activities during the strict lockdowns over the pandemic outbreaks. The less operation of coal-fired power plants during lockdowns, or caused by industrial and transportation sector shutdowns, drives down AQI by up to 2.884 units, NO2 by 1.543 μg/m3, PM10 by 3.727 μg/m3, and PM2.5 by 2.220 μg/m3. Our results support the argument that coal-fired power plants contributed significantly to air pollution. However, such significant influences differ across cities with economic levels, electricity usage, population sizes, and between capital and non-capital cities. The technological upgrades are essential for addressing further emission control issues to improve air quality.

An improved control strategy for a denitrification system using cooperative control of NH3 injection and flue gas temperature for coal-fired power plants

Selective catalytic reduction (SCR) technology is widely applied for flue gas denitrification in coal-fired power plants. Given the high penetration of renewable power, coal-fired power plants should operate flexibly to support power grid peak regulation. However, the flexible operation of coal-fired power plants often causes transient overshoot of the NOx outlet concentration and NH3 slip, and restricting the clean and reliable operation of coal-fired power plants is a difficult issue. In this study, a dynamic model of the coal-fired power plant is developed, and the characteristics of a denitrification system during load cycling transient processes were evaluated. Then, an improved control strategy for the denitrification system using cooperative control of NH3 injection and flue gas temperature is proposed. Moreover, the control targets of NH3 injection and flue gas temperature are analytically derived. The NOx outlet concentration exceeds the standard value by 14.22 and 6.80 mg m−3, respectively, during the loading down processes and loading up processes with the original control strategy. When the improved control strategy is adopted, the NOx outlet concentration can be controlled to be smaller than the standard value, and the NH3 slip can be controlled well.

Investigation of operating differences between wind and photovoltaic assisted by coal-fired power plant

ABSTRACT This paper investigates an integrated energy system combining wind/photovoltaic (PV) power and a coal-fired power plant (CFPP). It is found that there are significant differences in the integrated energy system of wind-coal and PV-coal due to the influence of natural conditions on wind and PV. The integrated energy system is analyzed from two aspects: the grid side and the power supply side. On the grid side, the power supply capacity of the system is evaluated by load evaluation. It is found that the load evaluation qualified rate of the wind-coal and PV-coal integrated energy system is 14.2% and 5.3% lower than the grid side standard, respectively. The greater volatility of wind power increases the regulating difficulty of CFPP. Through optimization, the optimal storage capacities of the wind-coal-storage and PV-coal-storage systems are 5.5MWh and 3.2MWh respectively, enabling the integrated energy system power supply to reach grid-side demand levels. On the supply side, the operating depth of CFPP in wind-coal-storage and PV-coal-storage increased by an average of 3.11% and 4.23% per month, respectively. In both combined modes of operation, CFPP combined with wind power has more frequent load regulation, with an average daily regulation frequency of 10.8% higher, while CFPP combined with PV has a higher operating depth of up to 49.84%. This study reveals different aspects of the operational characteristics of wind/PV when supplying power directly in conjunction with CFPP. The results show that the combined supply with wind/PV places higher demands on the operation of CFPP.

A Study on The Projection of Coal-Fired Thermal Power Plants

In this study, the main countries with high coal-fired power plant installation capacity and Türkiye, which are among the first in the world in electricity production in this field, and Türkiye are discussed, and parameters such as the installed power and capacity developments of the coal-fired power plants in these countries, electrical energy production values and CO2 emissions from fossil fuels have been evaluated over the years. Emissions from fossil fuels have been evaluated over the years. In this study, predictions about the future of coal-fired power plants were tried to be made by making projection studies. Analysis results are indicated and interpreted with figures and tables. When projections are made according to the current situation, it is predicted that in 2030 and 2050, China will be the first in coal-fired power plant installed power development and electricity production, and accordingly in CO2 emissions from fossil fuels. In addition, the capacity utilization rates, which are an important parameter regarding the efficient operation of coal-fired thermal power plants and their age, have been determined for certain countries over the years. In this study, the country with the highest capacity ratio, with a capacity ratio of around 90%, was determined as Japan. Today, in connection with the re-emergence of coal with the emergence of the energy crisis, energy production planning, and projection studies gain strategic importance for each country. In the literature, country-based projection studies for coal-fired power plants are insufficient and limited. Comprehensive projection study in this area contributes to the studies in the literature.

Performance of sCO2 coal-fired power plants at various power capacities

Herein, the effect of the power capacity, Wnet, on the performance of supercritical carbon dioxide (sCO2) coal-fired power plants is investigated, with Wnet in the range of (100–1000) MWe. A comprehensive model was established wherein the sCO2 cycle was coupled with the models of various components. For the sCO2 boiler, the total thermal load was assigned to various heaters, and the pressure drop in each heater was calculated. Owing to the strong penalty effect of the pressure drop, both total flow mode (TFM) and partial flow mode (PFM) were applied to the sCO2 boiler. A fluid network integrating the recuperator units was established for heat recovery in the system. A thermal-hydraulic model was proposed for a single unit and an integration package. Various losses were considered in the prediction of the efficiencies of axial flow turbines and compressors. The thermal efficiency increases, attains a maximum, and then decreases with increase of Wnet. This parabolic distribution results from the tradeoff between the decreased efficiency owing to pressure drops in the heat exchangers and the increased efficiency of the turbomachinery. The maximum thermal efficiency occurred at Wnet of 300 MWe and 200 MWe when using the PFM and TFM, respectively. Based on the results, PFM is found to eliminate the penalty effect of pressure drops. Our study provides guidelines for the design and operation of sCO2 coal-fired power plants.

Investigation on the mechanism of Nb and Si co-doping on low SO3 generation from V-based catalyst during NH3-SCR process

Generally, SO3 tends to be formed in the process of selective catalytic reduction (SCR), and SO3 has negative effects on atmospheric environmental production and the safe operation of coal-fired power plants. In this study, a series of Nb and Si codoped V-based catalysts were prepared via the impregnation method, and Nb and Si species were applied to reduce the SO3 generation ratio from the catalyst. Moreover, the controlled condensation method was used to collect the SO3, which formed during the NH3-SCR reaction process. The results indicated that the Nb and Si codoped catalysts exhibited the best NO reduction performance with the lowest SO3 generation ratio. The SO3 generation ratio and the NO conversion ratio for the VW2NbTi-10Si catalyst were 0.39% and 92%, respectively. The physicochemical properties of the catalysts were analysed by a series of characterization techniques. The X-ray diffraction (XRD) results revealed that the Nb and Si species could inhibit the crystallization of TiO2, and the X-ray photoelectron spectroscopy (XPS) results indicated that Nb and Si could decrease the ratio of Oα and V5+ on the surface of the catalyst. From the CO2 and NH3 temperature programmed desorption (CO2 and NH3-TPD) results, the Nb and Si species could reduce the number of alkaline sites on the catalyst surface, and the Si species could significantly enhance the acidity of weak and strong acid sites over the catalyst. Combined with the results of N2-adsorption and desorption, CO2-TPD, H2 temperature programmed reduction (H2-TPR) and XPS experiments, the addition of Nb and Si species was beneficial to inhibiting the adsorption and oxidation of SO2 on the surface of catalysts, resulting in a significant decrease in SO3 emissions. Therefore, in-situ diffuse reflective infrared Fourier transform spectroscopy (DRIFTS) analysis demonstrated that the Nb and Si species could restrict the reaction between SO2 and V species, decreasing the formation of the intermediate product VOSO4. Furthermore, the enhancement of reaction temperature and NH3 volumetric fraction would significantly promote the formation of SO3. However, the variations in the volumetric fraction of O2 and NO expressed ignorable effects on the SO3 generation ratio.

Co-optimization of decarbonized operation of coal-fired power plants and seasonal storage based on green ammonia co-firing

Coal-fired power plants (CFPP) can provide significant inertia and flexibility support for power systems with a high share of renewable energy (RE). The ammonia–coal co-firing technology can effectively reduce carbon emissions (CE) from CFPP. We propose a low-carbon power supply and multi-timescale energy storage system in combination with this technology. The system consists of batteries, fuel cells and the CFPP equipped with the ammonia–coal co-combustion module. It can also cope with short and long term fluctuations in RE. We use the Mixed Integer Linear Programming method to construct an optimization model for this system. We then set up six sub-cases according to the power systems in Texas, USA. Based on weekly and annual simulations of these cases, we analyze the economic and environmental performances of the proposed system with different RE shares, as well as exploring the characteristics of different energy storage methods. Compared to batteries or fuel cells only scenarios, CFPP configured with green ammonia co-firing can significantly reduce the total operating cost (TOC), CE and RE curtailment. We use the rolling horizon optimization method to simulate and calculate the distribution of ammonia storage levels throughout the year. The ammonia storage levels are high in spring and autumn and low in summer. Finally, the sensitivity and efficiency analysis of the proposed system is carried out. As far as ammonia co-firing technology allows, the higher the maximum ammonia–coal mixing ratio, the lower TOC, CE and RE curtailment. This phenomenon is more significant at a higher RE share. The overall efficiency of green ammonia synthesis and combustion for power generation is around 13.92%. It can work in synergy with batteries and fuel cells to improve efficiency and reduce the marginal cost of long-term energy storage.

Economic evaluation of flexible transformation in coal-fired power plants with multi price links

The effects of links among the carbon price, feed-in tariff (FIT), and peak shaving price on flexible transformation in coal-fired power plants are not well understood. To address this gap in knowledge, we first designed multi price links to advance coal-fired power plant flexible transformation. Second, the effects of multi price links on coal-fired power plant operation were analyzed. Third, an economic evaluation model for coal-fired power plant flexible transformation was constructed based on fuzzy real option considering multi price links. Finally, strategies for encouraging coal-fired power plant flexible transformation were proposed. The results showed that (1) matching of the peak shaving models and peak shaving depth was a key factor influencing profits during coal-fired power plant flexible transformation. (2) The effects that multi price links had on the market value of coal-fired power plants mainly resulted from the transferring rate of the carbon price to the FIT and elastic electricity demand. (3) The positive effects associated with multi price links on the market value of coal-fired power plants can gradually be realized by increasing the peak shaving depth. This study not only provides a quantitative coal-fired power plant flexible transformation investment decision model for investors, but it would be also beneficial for promoting low-carbon policies.

Prediction of NOx emission concentration from coal-fired power plant based on joint knowledge and data driven

Accurate NOx concentration prediction is of great significance for the pollutant emission control and safe operation of coal-fired power plants. The global properties of the research object cannot be adequately described by a single data driven model, which hinders generalization performance. We propose a NOx emission concentration prediction method based on joint knowledge and data driven. First, we introduce a knowledge driven combined feature selection method to provide a global feature basis for data driven modeling. Second, we enable adaptive decomposition of the variational modal decomposition (VMD) using the modal energy difference and sample entropy. The method can extract deep time-frequency information in nonlinear and non-smooth features. Finally, we use the Informer combined with an adaptive time series segmentation method to predict NOx concentration. The experimental results indicate that the proposed method predicts the NOx concentration better than several comparative models.

Tradeoff between the efficiency penalty and load depth in a coal-fired power plant with CO2 capture under partial load conditions

With the penetration of renewable energy increasing rapidly in the power system, flexible operation of coal-fired power plants with CO2 capture is expected to play a key role in grid peak-regulating in China. However, studies on the interactions between power generation and CO2 separation units under partial load are still limited. Accordingly, in this paper, the factors that affect the system performance were investigated based on a 1000-MW post-combustion power plant under partial load. The results indicate that minimizing the difference between the quality of the steam extracted from the turbine and the minimum steam quality required for the reboiler, meanwhile resulting in no extra work losses, is the essential target for system integration. Under the IP-LP-PMV (Pressure Maintaining Valve) scheme, the irreversible loss caused by PMV led to an extra system efficiency penalty of 3.31% points under 30% load. However, for the IP-interstage-PMV scheme, the system efficiency could be improved by 0.7% and 1% points under loads of 30% and 40%, respectively, because the work losses caused by splitting and throttling under low load conditions could be reduced by adjusting the extraction location. Therefore, the system performance could be improved by altering the extraction position under partial load operation. By investigating the optimal extraction location under variable loads, it is disclosed that the IP-interstage-PMV scheme and the IP-LP-PMV scheme are the most efficient steam extraction schemes under 40% or 70% loads respectively. Therefore, the theoretical optimal steam extraction position varied under the different loads, and the extraction position should be selected based on the average operating load from the perspective of all the working conditions. This integration principle provides the highest performance improvement potential of 2% points for partial load operation. This study will be helpful to promoting the further deployment of large-scale post-combustion capture projects.

Feasibility of 10 MW Biomass-Fired Power Plant Used Rice Straw in Cambodia

This study investigates the feasibility of rice straw for energy production in Cambodia. The potential areas for a 10 MW biomass-fired power plant installation are estimated based on rice straw availability displayed in a graphic information system (GIS). The discounted cash flow (DCF) method on the profitability index (PI) was executed by Mathlab software, which was used to determine the period of the power plant profitability. The reduction of CO and CO2 emissions from the proposed rice straw biomass-fired power plant with 10 MW capacity was calculated and compared with the coal-fired power plant and open field burning. Prey Veng, Takeo, and Battambang are potential provinces that have an estimated rice straw source of 804,796 t/annum, 720,040 t/annum, and 603,273 t/annum, respectively. Within a 20-year project, the biomass-fired power plant can reach profitability between six and ten years with the operation of the rice-straw price of 20 USD/t to 40 USD/t. The total energy produced by these potential areas is 1251 GWh/annum, with a CO2 emission avoidance of 1.06 million t/annum compared to the coal-fired power plant operation. Simultaneously, the emission savings of the biomass-fired power plant compared to open-field burning are 0.61 million t/annum of CO2 and 0.02 million t/annum of CO in the study site. The findings are prospectively essential for further designing of a small-scale biomass-fired power plant in Cambodia.