Flue Gas Research Articles

Simulation and optimization for flue gas CO2 capture by energy efficient water-lean ionic liquid solvent

Ionic liquids (IL) are treated as advanced materials for energy-saving carbon dioxide (CO2) capture from flue gas but suffer from serious challenges in energy and mass management. Herein, a water-lean IL-based deep eutectic solvent with 1,8-diazabicyclo [5.4.0] undec-7-ene imidazole ([DBU] [IM]) and ethylene glycol (EG) blends was prepared with a screened proportion of IL:EG=7:3. The CO2 loading and saturated solvent viscosity were 1.89 mol/L and 95 mPa·s, respectively. The foundational properties of the IL-EG solvent were determined by experimental measurements and thermodynamic modeling. The vacuum flashing desorption technology was innovatively adopted for energy-saving solvent regeneration. Industrial-scale process simulation of multistage flashing was used to explore the energy consumption during solvent regeneration. Meanwhile, the segmented cooling paved a route for water separation from water-lean solvent. A comprehensive analysis was performed out to optimize the operating parameters for CO2 absorption and desorption. For the recommended 3-stage flashing configuration, the specific process regeneration energy consumption amounted to only 1.54 GJ/tCO2. Consequently, the total capture cost reduced to 48.1 $/tCO2, marking a decrease of 31.28 %, 16.55 % and 10.25 %, compared with MEA solvent, water-lean solvent and biphasic solvent, respectively. This work offered insights for future endeavors in the development of IL-based CO2 capture process from industrial flue gas.

Hollow fibers with encapsulated ionic liquid for gas dehydration

Membrane technology is a viable alternative for achieving energy savings and sustainability, particularly in dehydration applications. The selective removal of water vapor from gas mixtures by membranes enhances the process efficiency furthermore the industry increasingly prioritizes resource conservation and environmental impact, advancements in membrane technology are crucial for meeting these goals and driving progress toward a sustainable future. Our approach consists of the incorporation of a proline amino acid-based ionic liquid encapsulated in carbon capsules, dispersed in a Pebax®1657 matrix, and coated on polyetherimide hollow fibers. The filled capsules have high sorption capacity for both water vapor and carbon dioxide (CO2) contributing for successful exploration for air dehumidification, as well as flue gas, natural gas and biogas dehydration. The membranes had exceptional water vapor permeance, reaching values up to approximately 10,000 GPU while maintaining an H2O/N2 selectivity of around 124,000. CO2/N2 selectivity as high as 100 and promising results for CH4 purification were demonstrated. Long-term studies using alternative modules to prevent saturation of the encapsulated capsules with water vapor and effective regeneration have been proven.

Effect of the temperature control device on the emission character of condensable particulate matter from industrial heating plant

Condensable particulate matter (CPM) is one of the major emissions of primary particles in coal combustion. The removal efficiency of CPM using the temperature control device (TCD) based on the concept of a heat exchanger application with lower capital cost was investigated in an industrial heating plant. TCD operates without water and flue gas interactions and ensures efficient control of CPM emissions, and it also minimizes the potential ion accumulation in recycled WESP water, which could otherwise hinder the removal of CPM. The total mass and chemical speciation were determined by EPA method 202. The total mass of CPM was removed by 25.7–60.6% after the TCD. The CPM captured by CPM filters (CPMspa) was down to around 15–21% and the FPM also was reduced by around 11–26%. The occurrence of vapor gradient forces and thermophoresis forces could enhance the contact between CPM and water film, which was built up on the surface of the cooling tubes during the process of TCD. Then, part of the CPM was removed with a water film. The low capital and operating cost of TCD can be installed in the industrial heating plant or be set up after the WESP in the coal-fired power plant to enhance the CPM removal efficiency.

Impact of oxide layer on performance and creep life of a superheater tube in a coal-fired power plant

The failure of a superheater tube in a coal-fired power plant, designed to resist creep damage at high temperatures and pressures, was investigated after it ruptured following 115,360 h of operation, which was significantly shorter than its expected 200,000-hour life. An oxide layer measuring 106 µm was discovered on the inner side of the tube, which acted as a thermal insulator, raising the tube’s temperature and reducing its thickness. This led to increased stress, decreased creep resistance, and a shortened tube life. The oxide layer’s growth, tube temperature, and stress were estimated. After 115,360 h, at a flue gas velocity of 22 m/s, the oxide layer reached an estimated thickness of 120 µm. The outer and inner tube surface temperatures were 522 °C and 510 °C, respectively, and the stress was estimated at 79.9 MPa. To extend tube life to the designed 200,000 h, it was determined that reducing the flue gas velocity to 15.8 m/s or lower would be required. At this velocity, the tube’s creep life was estimated at 200,070 h when accounting for tube thinning. Without accounting for the reduction in thickness, the estimated life was 210,650 h, which was approximately 1.2 years longer.

Mechanism of CeO2 modified CO2 adsorbent with SO2 resistance: Experimental and DFT study

The flue gas emitted from coal-fired boilers contains a trace amount of SO2 after desulfurization, resulting in poor performance of CO2 adsorbent. In this paper, CO2 adsorption performance of potassium adsorbent modified by CeO2 doping and the effect of SO2 on CO2 adsorption were investigated by simulated flue gas. Theoretical research on the reaction between SO2 and CO2 with dopant was conducted by Density Functional Theory (DFT) method. The results showed that the cumulative CO2 adsorption capacity of the 4% Ce doped adsorbent without SO2 and with SO2 were 10.2% and 53.6% higher than that of the undoped adsorbent. The oxygen vacancy could cause the f orbital of Ce to exert greater influence, making the surface properties more unstable. The activation energy of the adsorption reaction between SO2 and H2O on Ce doped adsorbent was 266.5 kJ/mol, and there were three transition states in this reaction, with O vacancy formation as the rate-controlling step.

Synthesis of porous hypercrosslinked polymers from waste polystyrene for efficient CO2 separation

A series of porous hypercrosslinked polymers (HCP-x) were synthesized from waste polystyrene foam via Fridel-Crafts alkylation reaction, aiming to optimize the utilization of waste plastics. The impact of various crosslinkers on the structural characteristics and CO2 adsorption properties of HCP-x was investigated. The results indicated that HCP-x polymers possess high specific surface areas spanning 830–1182 m2 g−1, abundant narrow micropores, and exceptional thermal stability. Notably, HCP-2 exhibited the highest CO2 adsorption capacity of 2.77 mmol g−1 at 273 K and 1.0 bar. These hypercrosslinked polymers also demonstrated a favorable CO2/N2 ideal selectivity and robust cyclic adsorption performance. Breakthrough experiments confirmed the selective adsorption of CO2 from simulated flue gas containing CO2/N2 (15/85). Additionally, the mechanism underlying CO2 adsorption on HCP-x was elucidated by analyzing adsorption thermodynamics and diffusion kinetics. This study not only introduces an innovative method for recycling waste polystyrene foam but also underscores the potential of HCP-x as an effective adsorbent for CO2 capture.

Robust online monitoring system for PCDD/Fs in a full-scale MSWI by Deans switch: Efficiently separation and purification

Existing online monitoring system for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), technically named Thermal Desorption-Gas Chromatography-Tunable Laser Ionization-Time of Flight Mass Spectrometry (TD-GC-TLI-TOFMS), has been applied in several incinerators in China. TD-GC-TLI-TOFMS can realize rapid detection of PCDD/Fs emissions from incineration sources. However, the long-term measurement of unclean flue gas will pollute the instruments in TD-GC-TLI-TOFMS, and interfere with the peak output of the target 1,2,4-trichlorobenzene (1,2,4-TrCBz). In this study, Deans switch (DS) was utilized for the first time in an online monitoring system for PCDD/Fs to separate 1,2,4-TrCBz signal from impurity signals, which improved the anti-interference capability of the system. Laboratory standard gas experiments showed that after adding a DS device between GC and TLI pulse valve, when the pressure set in DS was 4 psi and switched before or near the peak output of 1,2,4-TrCBz, the change of 1,2,4-TrCBz signal intensity was minimal. The impurities near the target peak were removed, and TLI-TOFMS was highly stable during continuous measurement. Moreover, the maximum intensity peak time of 1,2,4-TrCBz was stable after using DS in different switching time intervals. When connecting DS to TD-GC-TLI-TOFMS for field validation on the tail flue gas of a municipal solid waste incinerator (MSWI), results showed that a better 1,2,4-TrCBz signal could be obtained with a 69.52 % reduction of impurity peaks at the moments closer to the target peak. Furthermore, DS improved the sensitivity of the system to low concentration variations of 1,2,4-TrCBz in the flue gas. The robust system developed in this study can be better applied to incineration factories with poor combustion or suboptimal purification technology, facilitating online PCDD/Fs monitoring.

The Impact of Hydrogen on Flame Characteristics and Pollutant Emissions in Natural Gas Industrial Combustion Systems

To improve energy savings and emission reduction in industrial heating furnaces, this study investigated the impact of various molar fractions of hydrogen on natural gas combustion and compared the results of the Non-Premixed Combustion Model with the Eddy Dissipation Combustion Model. Initially, natural gas combustion in an industrial heating furnace was investigated experimentally, and these results were used as boundary conditions for CFD simulations. The diffusion flame and combustion characteristics of natural gas were simulated using both the non-premixed combustion model and the Eddy Dissipation Combustion Model. The results indicated that the Non-Premixed Combustion Model provided simulations more consistent with experimental data, within acceptable error margins, thus validating the accuracy of the numerical simulations. Additionally, to analyze the impact of hydrogen doping on the performance of an industrial gas heater, four gas mixtures with varying hydrogen contents (15% H2, 30% H2, 45% H2, and 60% H2) were studied while maintaining constant fuel inlet temperature and flow rate. The results demonstrate that the Non-Premixed Combustion Model more accurately simulates complex flue gas flow and chemical reactions during combustion. Moreover, hydrogen-doped natural gas significantly reduces CO and CO2 emissions compared to pure natural gas combustion. Specifically, at 60% hydrogen content, CO and CO2 levels decrease by 70% and 37.5%, respectively, while NO emissions increase proportionally; at this hydrogen content, NO concentration in the furnace chamber rises by 155%.

Engineering Nanoporous Polyaminal Networks for Superior SO2 Capture and Selectivity.

Designing adsorbent materials with high SO2 adsorption capacities and selectivity remains a significant challenge in flue gas desulfurization. This work focuses on developing two nitrogen-rich nanoporous polyaminal networks (NPANs), which demonstrate promising capabilities for SO2 adsorption and separation. Two nitrogen-rich nanoporous polyaminal networks, NPAN-5 and NPAN-6, were synthesized via a one-pot method using thiophene-2,5-dicarbaldehyde and furan-2,5-dicarbaldehyde with 1,4-bis(2,4-diamino-1,3,5-triazine)-benzene, respectively. The Brunauer-Emmett-Teller (BET) specific surface areas of NPANs range from 838 to 956 m2·g-1. At 298 K and pressures of 0.1 and 1.0 bar, NPAN-5, featuring thiophene units, demonstrates a SO2 adsorption uptake of 5.14 and 9.63 mmol·g-1, respectively, surpassing many previously reported materials. Furthermore, at room temperature, NPAN-6, containing furan moieties, exhibits unprecedented selectivity for SO2 over CO2 and N2, with ratios reaching up to 78 and 9321, respectively. Dynamic breakthrough experiments reveal that NPANs effectively separate SO2 from a ternary gas mixture comprising SO2, CO2, and N2 at concentrations of 0.2, 10, and 89.8%, respectively. Notably, NPAN-6 achieves a prolonged SO2 retention time of 218 min·g-1 and a saturation adsorption uptake of 0.42 mmol·g-1. The remarkable SO2 adsorption capacities and selectivities demonstrated by these nitrogen-rich nanoporous polyaminal networks underscore their potential to revolutionize industrial flue gas desulfurization.

Unraveling a novel biphasic CO2 capture process through rigorous modeling

Modification of the chemical absorbent is a crucial aspect in the field of CO2 capture. Nevertheless, the consequences arising from the utilization of modified solvents have not been thoroughly examined on a process scale. This study investigates a biphasic chemical absorption process for CO2 capture using a blended solvent composed of 2-ethylamino ethanol (EAE), diethylene glycol diethyl ether (DEGDEE), and water. The design was based on rigorous consideration of the physical properties of the pure components and the solution, as well as chemical equilibrium. Our results indicate that the proposed biphasic process reduces specific regeneration energy by 6.45 % compared to the conventional method using monoethanolamine (MEA) solution as a solvent (biphasic: 3.41 GJ/Ton; conventional: 3.63 GJ/Ton). Furthermore, it presents the advantage of utilizing low-temperature waste heat for solvent stripping, resulting in a notable 56 % decrease in indirect emissions (biphasic process: 0.119 Ton/Ton, conventional: 0.274 Ton/Ton). When processing flue gases that are more diluted in CO2, the CO2-e of the biphasic process was only slightly increased. Finally, the techno-economic analysis demonstrated that the biphasic process exhibits minimum required treatment prices (MRTPs) comparable to those of conventional methods for treating flue gases with CO2 concentrations ranging from 10 to 19 mol% (biphasic: 0.755 to 1.452 USD/kg, conventional: 0.756 to 1.455 USD/kg). This finding highlights the economic potential of the biphasic process. Overall, this investigation sheds light on the potential of intensifying the CO2 capture process in a biphasic environment.

Cu-trimesate and mesoporous silica composite as adsorbent showing enhanced CO2/CH4 and CO2/N2 selectivity for biogas and flue gas separation

Due to their diverse structure, high porosity, and tunable functionality, Metal-Organic Frameworks (MOFs) hold great potential as materials for diverse applications, including gas separation. Material science researchers are focusing on creating flexible materials that have special properties. Most of the latest research mainly concentrates on fabricating composite materials of MOFs and other functional materials. These MOF-based composites can mitigate the limitations of pure MOFs and may even perform better than the individual components. Here, we present a systematic study on the effect of solvent in synthesising a composite (Cu-BTC@SBA-15) of Cu-trimesate MOF (aka CuBTC) and ordered mesoporous silica SBA-15, showing considerable improvement in selectivity for CO2 adsorption from the flue gas and biogas. The pristine Cu-BTC, SBA-15 and the composites with different content of Cu-BTC were characterized by PXRD, BET, FT-IR, SEM, TEM and TGA techniques. The pure gas adsorption isotherms were measured for CO2, CH4, and N2 gases. Ideal Adsorbed Solution Theory (IAST) is used for the binary selectivity calculations for gas systems such as CO2/CH4 and CO2/N2 in the context of biogas and flue gas separation. The composite exhibited an increase in CO2/CH4 selectivity by 39 % compared to pure Cu-BTC and 85 % compared to pure SBA-15. For the CO2/N2 system, the composite showed 38 % higher selectivity than Cu-BTC. The work has significance in the design of effective MOF-based composites for CO2 separation. Our work might open up a new route to design multifunctional materials for worldwide applications through an adsorptive and or mixed matrix membrane route.

Towards sustainable hydrogen production: Integrating electrified and convective steam reformer with carbon capture and storage

This work reports the design of a process for hydrogen production based on electrified steam methane reforming (e-SMR) coupled with a convective reforming (convective SMR) and carbon capture and storage (CCS) as an alternative to conventional fuel-fired reforming to reduce natural gas (NG) consumption as well as carbon dioxide emissions. The energy required by the reforming reaction is supplied by direct electric heating instead of burning fossil fuel in the radiant section of a furnace, saving 35 % NG and reducing CO2 emission by 29 %. Implementing convective SMR reduces the electric load of the main e-SMR reactor and ensures a slightly higher thermal efficiency (80.2 %) compared to conventional fuel-fired reforming (78.9 %). Further CO2 emissions (85 %) and NG consumption reduction (50 %) are possible by adopting amine-based CO2 capture. If coupled with an energy integration scheme, it is possible to capture 75 % of the CO2 produced, preserving high energy efficiency (79.4 %). This requires only a 14 % increase in capital costs, which is strongly beneficial compared to applying CO2 capture to flue gases of the fuel-fired reforming (69.8 % efficiency and 80 % more capital costs).The process based on e-SMR coupled with convective SMR and CO2 capture ensures a levelized cost of hydrogen (LCOH) of 0.281 € Nm−3 H2, which is much lower than the conventional fuel-fired reforming with CO2 capture applied to flue gases (0.309 € Nm−3 H2). Moreover, it has comparable CO2 emissions (1.59 vs 0.99 kg CO2 emitted kg−1 H2) but produces lower CO2 (6.39 vs 9.88 CO2 produced kg−1 H2) compared to fuel-fired reforming due to using renewable electricity as energy source for the SMR. Compared to conventional fuel-fired reforming, the same process provides similar LCOH (0.283 vs 0.282 € Nm−3 H2) but with drastically lower CO2 emissions (1.59 vs 8.99 kg CO2 emitted kg−1 H2).

Mechanism of enhancing the SO2-resistance and gaseous arsenic removal performance of Iron-modified pyrolusite

Arsenic pollution in the atmosphere caused by smelting flue gas is a huge environmental challenge, and the removal of gaseous arsenic (As2O3(g)) from smelting flue gas is a matter of urgency. Adsorption has been shown to be an effective method for the removal of As2O3(g) from high temperature smelting flue gas. However, due to the high concentration of SO2 in smelting flue gas, the capture of As2O3(g) by adsorbents is inhibited. In previous studies, the mechanism by which SO2 affects the adsorption of As2O3(g) by pyrolusite (PY) has been clearly elucidated. Therefore, this study proposes a method to improve PY’s resistance to SO2 and its As2O3(g) removal efficiency through Fe modification. Under optimal preparation conditions, the 10Fe/PY adsorbent exhibited an adsorption capacity for As2O3(g) that was nearly uninhibited by SO2. The 10Fe/PY achieving an adsorption capacity of 20.90 mg/g under 7.5 v/v% SO2, which is 1.4 times that of PY. The doped Fe increased the active sites on the 10Fe/PY surface for As2O3(g) adsorption, while preferentially reacting with SO2 to form Fe2(SO4)3, thereby reducing the competition between SO2 and As2O3(g) for the active sites on the adsorbent. The findings provide a theoretical basis for the adsorption and removal of As2O3(g) from high-SO2 smelting flue gas.

Simultaneous Desulfurization and Denitrification by H2O2/FeSO4 Preoxidation Combined with Wet Flue Gas Desulfurization Postabsorption: Experimental Investigation and Process Simulation

Simultaneous Desulfurization and Denitrification by H₂O₂/FeSO₄ Preoxidation Combined with Wet Flue Gas Desulfurization Postabsorption: Experimental Investigation and Process Simulation

Study on Mechanism and Effect of Different Viscosity Reducing Methods on Offshore Heavy Oil

Abstract Bohai is rich in heavy oil. And its efficient development is significant. In this essay, ordinary heavy oil and extra one were selected, and the viscosity characteristics was also investigated referring to its internal composition. And so as the reducing viscosity effects of steam, oil-soluble viscosity reducer, diesel, emulsifier, flue gas and carbon dioxide. The experimental results show that resin and asphaltene content have positive effect on the viscosity of heavy oil. Compared with ordinary heavy oil, the drop is significantly greater when the temperature increases by 10°C. For ordinary heavy oil, the inflection point temperature is from 50°C to 70°C, and for extra-heavy oil, it is above 100°C. For ordinary heavy oil, its flow effect can be better improved without too high temperature, while it’s totally different for super heavy oil. For which, higher temperature and other auxiliary viscosity reduction methods are needed to achieve better flow performance. Diesel oil reduce viscosity of heavy oil by similar solubility principle, but the demand for diesel oil is large. At 50°C, the viscosity of super heavy oil with 0.5% emulsion viscosity reducer added is 36 mPa·s, but the water content needs to reach above 30%.Oil-soluble viscosity reducer reduces viscosity by dissolving asphaltenes and resins and dismantling aggregate structure of heavy oil aromatic flakes.However, the dosage should reach about 20 %, so that the viscosity of super heavy oil can be reduced to the level of dilute oil. Overall, for developing super heavy oil, steam compound with oil soluble viscosity reducer can be taken into account at the early production stage, and the emulsion viscosity reducer can be used in the middle development stage and wellbore viscosity reduction and lifting process. Finally, for ordinary heavy oil, flue gas’s viscosity reduction effects, nitrogen and carbon dioxide are investigated. It is found that the viscosity reduction effect of carbon dioxide is the best, followed by flue gas and nitrogen. Considering the offshore gas source, cost and carbon emission requirements, it is recommended to use flue gas in the field. The research provides theoretical guidance and technical reference for development of different types of offshore heavy oil.

Pore-scale study of [formula omitted] desublimation in a contact liquid

Cryogenic carbon capture (CCC) designed to operate in a contact liquid is an innovative technology for capturing CO2 from industrial flue gases, helping mitigate climate change. Understanding CO2 desublimation properties in a contact liquid is crucial to optimizing CCC, but is challenging due to the complex physics involved. In this work, a multiphysics lattice Boltzmann (LB) model is developed to investigate CO2 desublimation in a contact liquid for various operating conditions, with the multiple and fully-coupled physics being incorporated (i.e., two-phase flow, heat transfer across three phases, CO2 transport between the gas and liquid, homogeneous and heterogeneous desublimation of CO2, and solid CO2 generation). The CO2 desublimation process in a contact liquid is well reproduced. Moreover, parametric studies and quantitative analyses are set out to identify optimal conditions for CCC. The decreasing liquid temperature (Tl) and flue gas temperature (T0) are found to accelerate the CO2 desublimation rate and enhance the CO2 capture velocity (vc). However, excessively low Tl and T0 values should be avoided. These conditions increase the energy consumption of cooling while only marginally improving vc, due to the limited CO2 supply. The CCC system performs effectively when purifying flue gases with high CO2 content (Y0). This is because the large Y0 accelerates the CO2 desublimation rate and enhances the overall CO2 capture efficiency. A high gas injection velocity (or Pe) is beneficial for amplifying vc by increasing the gas–liquid interfaces and enhancing the CO2 supply. Nevertheless, too high a Pe should be avoided, as it hinders the transport of CO2 to the liquid or solid CO2 surfaces, ultimately restricting the amount of CO2 available for desublimation and inhibiting the enhancement of vc. This study develops a viable LB model to investigate CO2 desublimation in a contact liquid for varying conditions, which advances the knowledge base of CCC and facilitates its industrial applications.

Synergistic effects of multi-walled carbon nanotubes and Mn0.4Cu0.6Fe2O4 on mercury removal with high efficiency and sulfur resistance

Although ferrite-based adsorbents are the potential mercury removal materials for the high thermal stability, they usually suffer from a low efficiency in flue gas environment, especially under SO2 condition. In the present paper, the multi-walled carbon nanotubes (MWCNTs) are utilized to improve the adsorption capacity of the Mn0.4Cu0.6Fe2O4 adsorbents as well as inhibit the influence of flue gas composition. The influences of temperature, adsorbent type and the flue gas composition on Hg0 removal efficiency are evaluated by experiments. The physical adsorption property of MWCNTs provides a platform for Hg0 oxidation by Mn0.4Cu0.6Fe2O4. The synergistic effect between MWCNTs and Mn0.4Cu0.6Fe2O4 enhances the mercury removal efficiency as well we the sulfur resistance. The results find that the adsorbent of Mn0.4Cu0.6Fe2O4 containing 14 % MWCNTs has a high mercury removal efficiency of 95.6 % at 120 °C even under 1000 ppm SO2 concentration. The kinetic behaviors of adsorbent adsorption are analyzed by theoretical models. The mechanisms of porous carbon-containing modifier to improve the mercury removal performance of Mn0.4Cu0.6Fe2O4 are explored carefully. The present ferrite-based adsorbent exhibits promising prospects for the practical industrial applications of the low temperature mercury removal from coal-fired flue gas.

Effective abatement of naphthalene from flue gas by V-W/Ti catalyst: Study of vanadium species and reaction mechanism

The removal of naphthalene is important but deficient, so that the available V-W/Ti catalysts (1.0 wt% V2O5/TiO2) were prepared for its efficient abatement in this work. Especially, influences of different existence status of vanadium species on naphthalene elimination were investigated via changing the pH value of precursor solution. With the increase of precursor solution acidity, more highly polymeric vanadium species were formed on the catalyst surface. The redox capability was enhanced markedly as a consequence of the stronger electron transfer between V/W and Ti that induced more surface active oxygen and V5+, whereas the catalytic activity was obviously boosted and almost 90 % conversion of naphthalene was achieved at 293 °C. Moreover, the weaker chemisorption between naphthalene and V-W/Ti catalyst allowed the deeper conversion to COx. GC–MS manifested that naphthalene seemed to be an organic component that was difficult to be totally degraded. Naphthalene oxidation was in the following pathway of naphthalene → 1,4-naphthoquinone → phthalic anhydride → phthalates → benzene → benzoquinone → maleic anhydride → COx/H2O. The opening of aromatic ring in phthalic anhydride and benzene ring in benzene were proven to be the rate-controlling step based on in-situ DRIFTS results. The key of naphthalene oxidation was the complete degradation of various intermediates.

Monitoring of GFRP pipelines in Power Plants using acoustic emission testing

In coal-fired power plants, the flue gas is transported through fibreglassreinforced pipelines to cooling towers during the combustion of the respective raw material, which often serve as a marker for a power plant in the landscape. These glass-fibre reinforced pipelines are located at great heights and can have very large diameters. Up to now, testing has been carried out as part of inspections during planned shutdowns and is associated with corresponding costs. The article discusses the use of acoustic measurement methods based on a 4-month installation at the Niederaußem power plant. Measurement results based on the acoustic emission analysis were shown. For the acoustic emission measurements, a repaired site was instrumented and different parameters like hit/event rates, acoustic energies as well as weighted peak frequencies of the acoustic signals were recorded over the monitoring period of 4 months at power plant Niederaußem. In a second power plant Neurath a 5-month AE monitoring were carried out. This measurement results were discussed as well.

Analysis of the Influence of Variation in Medical Waste Heating Value on the Electrical Energy Output of Generator in Medical Waste Cogeneration Incinerator System using Gatecycle Solver

Abstract Medical waste incinerator is a technology capable of processing and exterminating hazardous medical waste through combustion at temperatures exceeding 800°C. Medical waste exhibits a range of heating values depending on its material composition. The heating value represents the potential heat energy released when a substance undergoes complete combustion. A cogeneration incinerator is designed to treat medical waste while also harnessing the heat of the flue gas that emanates from the combustion process. The flue gas acts as a hot fluid that transfers its heat, causing the water temperature inside the boiler to increase and transform into high-temperature steam. This steam drives a steam turbine connected to a generator to generate electrical energy. The amount of electrical energy generated is influenced by the steam quality produced through the boiler’s water-heating process. This study aims to investigate the influence of variation in the heating value in medical waste on the electrical energy output of the generator in a medical waste cogeneration incinerator system. The range of heating value variations used in the testing varies from 25 MJ/kg to 35 MJ/kg. The variation is tested through thorough simulations using GateCycle software to obtain data on the electrical energy generated. To achieve a maximum electrical energy output of 200 kW, fuel with a total heating value of 32.25 MJ/kg is required. This study is beneficial to be implemented as renewable energy sources based on biomass powerplant systems.