Municipal Solid Waste Power Plant Research Articles

Insights into the composition and properties of fly ash emissions from a municipal solid waste power plant

This study examines the fly ash from Soc Son municipal waste power plant (SMPP) and suggests ways to repurpose it to reduce its environmental impact. Fly ash from the Soc Son waste power plant has a gray color, spherical particles with a 5–103 μm diameter, and a high carbon and heavy metal content. Bermorite crystals can absorb and release heavy metals, making monitoring secondary pollutants during incineration crucial. The EDX analysis of fly ash from the Soc Son waste power plant revealed that it was predominantly contaminated with metal elements, with the highest percentage of calcium. The EDX was able to detect heavy metals in incinerator fly ash. The concentration of Zn in the fly ash exceeded QCVN 07:2009/BTNMT standards, indicating the high amounts of some elements that may be hazardous to the environment and human health. Using the SEM/EDX and XRF, the fly ash from the Soc Son landfill power plant was analyzed and discovered that it exceeds permissible limits for dangerous heavy elements. The most common inorganic elements are Ca, followed by Zn, Pb, Cd, and Ag. Fly ash is classed as hazardous waste due to its high concentration of heavy metals, which results from the combustion of municipal solid waste that has not been separated. Vietnam fights municipal solid waste incinerator fly ash production. Some nations stabilize fly ash to remove harmful components and use it in buildings. Stabilized fly ash makes unfired construction bricks and cement manufacturing components and combining fly ash with inorganic trash protects the environment.

Thermal modelling and analysis of a novel solar integrated waste-to-energy plant for sustainable society

Waste-to-energy incineration is an effective and sustainable solution to reduce produced waste and simultaneously generates electricity utilizing thermal energy. The waste-to-electrical efficiency of conventional incineration plants is limited to 20–25% due to the higher amount of moisture content in the feedstock and flue gas heat losses. In addition, tubes of the incineration boiler are subjected to corrosion problems at elevated temperatures. In the present research, a parabolic trough solar-integrated municipal solid waste power plant is proposed and thermodynamically evaluated for different useful outputs. The solar energy is harvested through parabolic trough collectors to reheat the working fluid of the incineration plant to increase the steam temperature before it is fed to the low-pressure turbine. Meanwhile, a single-effect absorption chiller is integrated to utilize the thermal energy of the trough collectors for cooling purposes. In addition, the thermal energy of flue gas is used to power an organic Rankine cycle that further drives a proton exchange membrane and reverse osmosis desalination unit for hydrogen and freshwater production, respectively. In this way, the steam temperature for reheating the low-pressure turbine is increased to further improve the performance of the proposed solar-integrated waste-to-energy plant without causing any corrosion problems to the incineration boiler. The integrated facility is thermodynamically analyzed based on a 560-tons/day incineration plant using the engineering equation solver (EES) software. The results indicate that the overall energy and exergy efficiencies of the proposed plant are 32.51% and 23.7%, respectively, while the coefficient of performance of the absorption chiller is 0.849. Moreover, it is concluded that the produced desalinated water and hydrogen rates are 23.96 kg/s and 0.000857 kg/s, respectively.

Evaluating two-phase fluid flow and heat transfer in pillow-plate heat exchangers with nanofluids for organic Rankine cycle in municipal solid waste power plant: A numerical simulation study

One of the key considerations in the design and operation of process industries nowadays is reducing energy waste. The purpose of this research is to assess fluid flow and heat transfer in pillow-plate heat exchangers (PPHEs) using nanofluids for the Organic Rankine Cycle (ORC) in Municipal Solid Waste (MSW) power plants. The thermal performance and hydraulic features of the PPHE were investigated using a two-phase numerical modeling approach. three nanoparticles of Cu, TiO2, and Al2O3 were examined. To precisely determine the temperature distribution within the heat exchanger, various boundary conditions were used. The results demonstrate a strong correlation between the velocity field and temperature, underlining the importance of boundary conditions in determining the temperature profile. Furthermore, the two-phase model illustrates that nanofluids are extremely reliant on inlet velocity and volume fraction. such that at a 2 m/s inlet velocity, increasing the volume percentage to 12.8% contributes to heat transfer coefficient improvements of 7.57%, 12.15%, and 2.71% for water_TiO2, water_Al2O3, and water_Cu, respectively. These findings give significant insight into the fluid flow and heat transfer properties of PPHEs, as well as prospective pathways for increasing thermal performance and decreasing pump power in ORC systems using nanofluids in MSW-generating plants.

System design and thermo-economic analysis of municipal solid waste power system integrated with steam dryer

High moisture content of municipal solid waste (MSW) decreases the efficiency of power plant firing MSW directly. The MSW power system integrated with an external steam dryer and waste heat recovery system (WHRS) is proposed to enhance the MSW power plant (MSWP) efficiency. A reference case study with a 12 MW MSWP is carried out. The efficiency of MSWP integrated with a steam dryer can be enhanced by 1.07 percentage points (%-pts) and 0.36%-pts with 0.21 and 1.13 MPa steam extraction, respectively, as dryer heating source at a dryness degree of 0.25. Furthermore, when the WHRS is integrated, the power plant efficiency is enhanced by 1.79%-pts and 1.08%-pts. Then, economic analysis is carried out, and results show that the MSWP can bring profits with the integration of a steam dryer with steam 1.13 MPa steam as heat source at rated degree of dryness.

Economic analysis on sewage sludge drying and its co-combustion in municipal solid waste power plant

Co-treatment in municipal solid waste power plant has been deemed to one of the most suitable ways to handle sewage sludge. Economy of the co-treatment process is very concerned in the waste incineration plant. Thermal calculation of sewage sludge co-combustion was done. Four common sludge drying schemes was compared: flue gas drying, steam drying, electric heating drying in the waste incineration plant and in situ electric heating drying in the sewage treatment plant. Sensitivity analysis was also performed. When the water content was 30–40% and the absolute-dry sludge ratio was 2–3%, the boiler efficiency was reduced by 0.56–1.12% compared with the case without mixing sludge, and the power generation decreased by 0.2568–0.3767 MW in steam drying scheme and by 0.0037–0.0094 MW in other schemes. Net present value (NPV) of flue gas drying was the highest among the four sludge drying schemes, which was more than 20 ¥ million, while the scheme of electric heating drying in the waste incineration plant had the lowest NPV, which can't recoup the initial investment. Sensitivity coefficient of flue gas drying was smallest among different schemes, showing that the risk of this program was the smallest. Absolute-dry sludge ratio and unit subsidy for sludge treatment were sensitive factors for NPV in flue gas scheme, which had a sensitivity coefficient of 1.123–1.171 and 1.232, respectively. Operating parameters optimization of co-combustion of sludge was done and ways to improve economic efficiency was discussed.

Determination of Residual Heavy Metals in an Incinerator Bottom Ash from Municipal Solid Waste Power Plant

Bottom ash is a part of by-product from the municipal solid waste power plants which is always a wider problem for the urban and rural communities due to its disposal plants may cause serious environmental pollution. This work was focused on the residual heavy metal in an incinerator bottom ash from the municipal waste power plant placed in Nongkham district, Bangkok. Four bottom ash samples were obtained in 2017. After drying and grounding, the bottom ash samples were prepared to clear solution with the microwave digestion technique using nitric, hydrochloric and hydrofluoric acid under the heating program. The total residual heavy metals in the incinerator bottom ashes, such as lead, copper, zinc, and cadmium were determined by using flame atomic absorption spectrophotometer (FAAS) with deuterium background correction. The total concentration of lead, copper, zinc and cadmium were found in the range of 280.40-354.22mg kg-1, 365.35-524.45 mg kg-1, 1,527.25-2,074.34 mg kg-1, and 0.48-1.02 mg kg-1, respectively. The recovery of all metals was found in the range of 89.4-101.2% and the relative standard deviation (RSD) was to be 2.15-3.55 % (n=7). The concentration of zinc, copper, and lead was found high levels, while cadmium was low concentration. Heavy metals in solid waste material occur in different chemical forms and phases. The sample preparation based on the microwave digestion was successfully developed for the waste samples with a good reliability.

Optimization of an adapted Kalina cycle to an actual municipal solid waste power plant by using NSGA-II method

In this paper thermodynamic and thermoeconomic analyses and even optimization of a Kalina cycle (KC) which is adapted to an actual solid waste power plant with a 5.66 MW installed capacity are presented as an alternative solution which is utilized to produce additional power from the exhaust gas of the plant. Up to now there is almost no study related with an adapted KC to a typical municipal solid waste power plant, and also no study based on an optimization, thermodynamic and thermoeconomic analyses of such a system together. All these facts show the novelty of this study. Herein the waste heat with a temperature of 566 °C is utilized by the adapted KC. According to the analyses of the first and second law of thermodynamics on the system, it is deduced that the electricity of 954.6 kW can be produced with the exergy efficiency of 24.15%. Furthermore, this power production can be improved by using non-dominated sorting genetic algorithm method (NSGA-II) in MATLAB software program. According to the optimization study, the deviations of the net power output and the total cost rate are found to be +3.62% and −1.47 $/h, respectively for the cycle.

Thermoeconomic multi-objective optimization of an organic Rankine cycle (ORC) adapted to an existing solid waste power plant

In this paper, thermodynamic and thermoeconomic analyses, and also optimization of an organic Rankine cycle (ORC) were performed. The system was adapted to an existing solid waste power plant with a 5.66 MW installed power capacity in order to produce additional power from the exhaust gas. The actual operating data of the plant were utilized during all stages of the analyses. The originality of this paper is based on the analysis of the possibility of the energy conversion of an exhaust gas with a temperature of 566 °C into the electricity by utilizing an ORC system in the concept of waste-to-energy. Four different working fluids: toluene, octamethyltrisiloxane (MDM), octamethyl cyclotetrasiloxane (D4) and n-decane were considered and analyzed for the current system. This is also another novelty of this study due to lack of such a study, in the open literature, that deals with an ORC utilized for a typical municipal solid waste power plant. According to the thermoeconomic analyses, toluene was found to be the optimum working fluid with the maximum power output of 584.6 kW and the exergy efficiency of 15.69%. The optimization of the cycle was performed by using the non-dominated sorting genetic algorithm method (NSGA-II) in MATLAB software environment. The optimization results were compared and the deviations of the net power output and the total cost rate were evaluated as −5.89%, −3.51 $/h for toluene; 0.96%, −3.60 $/h for MDM; 8.45%, −2.04 $/h for D4 and 2.00%, −5.54 $/h for n-decane, respectively.

Thermoeconomic analysis and optimization of a Re-compression supercritical CO2 cycle using waste heat of Gaziantep Municipal Solid Waste Power Plant

This paper presents thermodynamic and thermoeconomic analyses as well as optimization of a re-compression supercritical CO2 cycle. A gas turbine cycle (GT) is adapted as a model to an existing plant to generate additional power in Gaziantep Municipal Solid Waste Power Plant (GMSWPP). The total capital cost rate and total cost rate of the GT cycle are found to be 20.47 $/h and 77.14 $/h, respectively utilizing SPECO by using the exhaust gas of 16 kg/s with 1.9 bar and 566.7 °c. The net power, the energy and exergy efficiencies, the total cost and the total capital cost rates of the GT cycle are optimized by +1.73%, +3.21%, +2.45%, −1.11% and −1.64%, respectively using NSGA-II in MATLAB in the range of 2.5≤PR≤4, 200≤P6≤216, 16≤T0≤23 and 9.1≤LMTD≤12.9. This paper provides an originality such that optimization as well as thermodynamic and thermoeconomic analyses is performed simultaneously for an existing MSW power plant, which can be stressed that there are scarce amounts of studies related on this field. Moreover, as another novelty, it can be emphasized that net power output of such like plants which have similar capacity can be improved using the developed model and NSGA-II optimization method.

Thermodynamic Performance Assessment of Different Fluids in a Typical Organic Rankine Cycle for Usage in Municipal Solid Waste Power Plant

Thermodynamic Performance Assessment of Different Fluids in a Typical Organic Rankine Cycle for Usage in Municipal Solid Waste Power Plant

Simulation of MSW Pyrolysis/Gasification Processes for Power Production

With the rapid expansion of industry, urbanization and increasing population in Thailand, many cities face the problem of municipal solid waste (MSW) disposal. The great majority of a plant for MSW, which are in operation around the world, are based on mass burn incineration systems. There are, however, a number of novel, thermal processing technologies for MSW, based on pyrolysis and/or gasification of the waste, which may provide significant technical and environmental advantages over conventional incineration. The objective of this article is to investigate the effect of operational parameters to electricity produced efficiency. The processes consist of drying unit, thermal waste treatment unit which is comprised of pyrolysis, gasification and combustion units, heat recovery steam generation unit, power generation unit and gas cleaning unit. The article are applied to the performance analysis of a MSW power plant in case of after passing through drying unit pyrolysis unit was operated at constant MSW feed rate of 28 tonnes/hr with varied moisture content. At lower moisture content which led higher energy content and more excess air required, the efficiencies of system were increased.

Source Fingerprints of Volatile Organic Compounds Emitted from A Municipal Solid Waste Incineration Power Plant in Guangzhou, China

Air samples of a municipal solid waste power plant were collected for the investigation from chimney, discharge workshop, boundary site and downwind receptor sites during regular operational period as well as overhaul period. In the regular operational period, 29 VOC species were detected from the discharge workshop and 25 VOC species from the plume of chimney. Average total VOC concentration at the discharge workshop site was 57.70±19.55 μg/m3 which was primarily composed of aromatic compounds and alkanes, but it was up to 270.63±2.84 μg/m3 in the plume of chimney which mainly included aromatic compounds and halohydrocarbons. In the overhaul period, average total VOC concentration was 59.70±0.91 μg/m3 in the discharge workshop and 326.35±151.68 μg/m3 in the chimney. Aromatics, halohydrocarbons and alkanes were indentified as the significant VOC fingerprints among which chlorobenzene and tetrachloroethylene were two unique VOC molecular markers of the power plant. Moreover, the VOC emission inventory of Chinese MSWI power plant was estimated approximately, it indicated that annual emission amount of the VOCs from the nationwide MSWI power plants reached 38.6tons in 2005 and would rise to 81.80 tons in the end of 2010.

Thermally driven cooling coupled with municipal solid waste-fired power plant: Application of combined heat, cooling and power in tropical urban areas

Energy recovery from flue gases in thermal treatment plants is an integral part of municipal solid waste (MSW) management for many industrialized nations. Often cogeneration can be employed for both enhancing the plant profitability and increasing the overall energy yield. However, it is normally difficult to justify traditional cogeneration in tropical locations since there is little need for the heat produced. The main objective of this article is to investigate the opportunities and potentials for various types of absorption technologies driven by MSW power plants for providing both electricity and cooling. Results show that cogeneration coupling with thermally driven cooling is sustainably and economically attractive for both electricity and cooling production. The thermally driven cooling provides significant potential to replace electrically driven cooling: such systems are capable of providing cooling output and simultaneously increasing electricity yield (41%). The systems are also capable of reducing the fuel consumption per unit of cooling in comparison with conventional cooling technology: a reduction of more than 1 MW fuel/MW cooling can be met in a small unit. MSW power plant coupled with thermally driven cooling can further reduce CO 2 emissions per unit of cooling of around 60% as compared to conventional compression chiller and has short payback period (less than 5 years).

Municipal Solid Waste Fueled Power Generation in China: A Case Study of Waste-to-Energy in Changchun City

With rapid economic growth and massive urbanization in China, many cities face the problem of municipal solid waste (MSW) disposal. With the lack of space for new landfills, waste-to-energy incineration is playing an increasingly important role in waste management. Incineration of MSW from Chinese cities presents some unique challenges because of its low calorific value (3000-6700 kJ/kg) and high water content (approximately 50%). This study reports a novel waste-to-energy incineration technology based on co-firing of MSW with coal in a grate-circulating fluidized bed (CFB) incinerator, which was implemented in the Changchun MSW power plant. In 2006, two 260 ton/day incinerators incinerated 137,325 tons, or approximately one/sixth of the MSW generated in Changchun, saving more than 0.2 million m3 landfill space. A total of 46.2 million kWh electricity was generated (38,473 tons lignite was also burned as supplementary fuel), with an overall fuel-to-electricity efficiency of 14.6%. Emission of air pollutants including particulate matters, acidic gases, heavy metals, and dioxins was low and met the emission standards for incinerators. As compared to imported incineration systems, this new technology has much lower capital and operating costs and is expected to play a role in meeting China's demands for MSW disposal and alternative energy.