Gas Treatment Research Articles

Geopolymer Materials from Fly Ash-A Sustainable Approach to Hazardous Waste Management.

This study explores the utilisation challenges of fly ash from municipal waste incineration, specifically focusing on ash from a dry desulphurisation plant (DDS), which is categorised as hazardous due to its high heavy metal content. The ash's low silicon and calcium contents restrict its standalone utility. Laboratory investigations initially revealed that geopolymers derived solely from fly ash after flue gas treatment (FGT), in combination with coal combustion fly ash, exhibited low compressive strength (below 0.6 MPa). However, the study demonstrated significant improvements by modifying the FGT ash through water leaching. This process enhanced its performance when mixed with high-silica and -aluminium fly ash, resulting in geopolymers achieving compressive strengths of up to 18 MPa. Comparable strength outcomes were observed when the modified ash was blended with commercial cement. Leachability tests conducted for heavy metals (HMs) such as copper, zinc, lead, cadmium, and nickel indicated that their concentrations fell below the regulatory limits for landfill disposal: 2, 4, 0.5, 0.04, and 0.4 mg/kg, respectively. These results underscore the effectiveness of water-washing FGT ash in conjunction with other materials for producing geopolymers, contributing to sustainable waste management practices.

Purification of Steel Mill Gases under Changing Feed Stock Conditions

AbstractThis paper focuses on the operation and results of the gas treatment pilot plant for the purification and conditioning of steel mill gases, a key element of the Carbon2Chem® Technical Center in Duisburg, Germany. Using highly sensitive analytics, it is demonstrated that steel mill gas impurities which are detrimental to downstream catalytic conversion are reduced to single‐digit ppb levels. Strategies for adapting the gas purification process to take account of the transformation of steelmaking towards direct reduction are also discussed.

Global Trends in the Research and Development of Petrochemical Waste Gas from 1981 to 2022

As a highly energy-intensive and carbon-emitting industry with significant emissions of volatile organic compounds (VOCs), the petroleum and chemical industry is a major contributor to the global greenhouse effect and ozone layer destruction. Improper treatment of petrochemical waste gas (PWG) seriously harms human health and the natural environment. This study uses CiteSpace and VOSviewer to conduct a scientometric analysis of 1384 scholarly works on PWG and carbon sequestration published between 1981 and 2022, revealing the basic characteristics, knowledge base, research topic evolution, and research hotspots of the field. The results show the following: (1) In the early stages of the petrochemical industry, it was processed tail gas, plant leakage waste gas, and combustion flue gas that were investigated in PWG research. (2) Later, green environmental protection technology was widely studied in the field of PWG treatment, such as biotechnology, catalytic oxidation technology, membrane separation technology, etc., in order to achieve efficient, low energy consumption and low emissions of waste gas treatment, and the number of publications related to this topic has increased rapidly. In addition, researchers studied the internet of things and technology integration, such as the introduction of artificial intelligence, big data analysis, and other technologies, to improve the accuracy and efficiency of exhaust gas monitoring, control, and management. (3) The department has focused on how to reduce emissions by optimizing petrochemical process lines or improving energy efficiency. Emission reduction and low-carbon transition in the petrochemical industry will become the main trend in the future. Switching from renewable carbon to feedstock carbon derived from captured carbon dioxide, biomass, or recycled chemicals has become an attractive strategy to help curb emissions from the chemical industry. The results of our analysis can provide funding agencies and research groups with information to better understand the global trends and directions that have emerged in this field from 1981 to 2022 and serve as a reference for future research.

Au-TiO2 nanoparticles enabled catalytic treatment of oil and gas produced water in slurry and vacuum membrane distillation systems

Produced water (PW) treatment and reuse provide a promising alternative to address freshwater scarcity and reduce the environmental impacts associated with PW disposal. Efficient treatment of PW is challenging due to its complex matrix and hypersalinity. This study developed innovative gold-doped titania (Au-TiO2) nanoparticles to enable effective treatment of PW collected from the Permian Basin with salinity of ∼118 g/L. The mechanisms of removing organics and ammonia in PW in slurry and vacuum membrane distillation (VMD) systems were investigated via thermocatalysis, photocatalysis, and photo-thermocatalysis. Photocatalysis and photo-thermocatalysis were found more effective for organic removal than thermocatalysis. A baseline study using glucose as a representative of easily degradable organic carbon showed that thermocatalysis and photocatalysis mineralized 23.2 % and 93.1 % glucose, respectively. However, photo-thermocatalysis and thermocatalysis degraded only 17.4 % and 7.5 % dissolved organic carbon (DOC), and 56.2 % and 49.2 % NH3-N in PW, respectively. Au-TiO2 coating on ceramic membranes improved the distillate flux of photo-thermocatalytic membrane distillation (PMD) compared to no catalysts coating in VMD (7.14 versus 6.75 kg per hour per m2). Both PMD and VMD rejected >99.9 % of salts and >96 % DOC, and PMD had slightly higher DOC and salt removal rates. In contrast, normalized permeate flux using pristine membranes (hydrophobically modified without catalysts coating) decreased to zero after 29 h of operation while normalized flux with TiO2-coated membranes under UV on and UV off were 57.5 % and 53.7 % on average, which is much lower than that with Au-TiO2 coated membranes in both UV on (91.3 %) and UV off (88.1 %) cases, indicating Au-TiO2 coating significantly improved membrane anti-fouling propensity and durability during treatment of complex PW. Targeted analysis of three groups of petroleum hydrocarbons and 70 volatile organic compounds showed that only 2-butanone and acetone were detected in the distillates with removal efficiencies of 80 % for 2-butanone in both PMD and VMD, and acetone was removed by 75.4 % in PMD and 69.2 % in VMD. Au-TiO2 nanoparticles demonstrated excellent catalytic performance for PW treatment in slurry and immobilized PMD systems.

Fischer-Tropsch Synthesis for the Production of Sustainable Aviation Fuel: Formation of Tertiary Amines from Ammonia Contaminants.

Fischer-Tropsch synthesis combined with product workup is a promising route toward synthetic aviation fuel from renewable hydrogen and carbon sources like biomass, CO2, and waste. Cost savings can be achieved by reducing the number of gas treatment steps in new plants, but the consequence of contaminants in the feed needs investigation. While feeding 2.6 ppmV ammonia to a Fischer-Tropsch reactor, it was shown that ammonia was predominantly chemically converted into organic amines, with most nitrogen found in the water phase (89%), followed by heavy wax (7%) and light wax (1%). The concentration difference between water and light wax was shown to be due to the post-condensation separation of amines on polarity. Amines up to a chain length of 120 were detected in the heavy wax with MALDI-FT-ICR-MS, which, in combination with the high nitrogen content, suggests that amines have a similar chain growth probability compared to the main hydrocarbon products. Detailed product analysis with three independent analytical techniques showed that tertiary N,N-dimethylalkylamines were by far the most abundant amine class. This suggests that ammonia is decomposed on the cobalt surface and, potentially as a dimethylamine fragment, incorporated in the growing chain. Further evidence was obtained from the abundance of trimethylamine and from the reconciled nitrogen product analysis up to C100, which showed that the amine product distribution followed from naphtha onward the same ASF kinetics as alkanes and oxygenates while being distinctively different from the alkene distribution. The presented findings provide further avenues for studies of the Fischer-Tropsch reaction mechanism and indicate the opportunity of cost saving on gas treatment, while further validation is required to assess the impact on hydrocracking and product quality.

Optimizing environmental costs and economic benefits in new energy vehicle production: A case study of FAW Hongqi in China

This study focuses on the environmental cost accounting and economic benefit optimization of China’s FAW Hongqi New Energy Vehicle manufacturing enterprise under uncertain conditions, within the context of the emission permit system This study calculates the pollution situation throughout the manufacturing and production process of FAW Hongqi new energy vehicles, and constructs a multi-level environmental cost evaluation system for FAW Hongqi new energy vehicle manufacturing projects. Through the interval fuzzy model of FAW Hongqi new energy vehicle manufacturing projects, the maximum economic benefits of the enterprise are simulated. The research results indicate that the pollution emissions of enterprises are mainly concentrated in the three processes of welding, painting, and final assembly. Enterprises use their own exhaust gas and wastewater treatment devices to meet the standards for pollution emissions. At the same time, solid waste generated during the automobile manufacturing process is handed over to third-party companies for treatment. Secondly, based on the accounting results of enterprise pollution source intensity and a multi-layer environmental cost evaluation system, the environmental costs of enterprises are accounted for, and the environmental costs are represented in interval form to reduce uncertainty in the accounting process. According to the accounting results of enterprise environmental costs, the main environmental costs of enterprises are environmental remediation costs caused by normal pollution discharge and purchase costs of environmental protection facilities. Pollutant emission taxes and routine environmental monitoring costs are relatively low. Enterprises can adopt more scientific solutions from the aspects of environmental remediation and environmental protection facilities to reduce environmental costs. After optimization by the fuzzy interval uncertainty optimization model, the economic benefits of the FAW Hongqi new energy vehicle manufacturing project were [101,254.71, 6278.5413] million yuan. Compared with the interval uncertainty optimization model, the lower bound of economic benefits increased by 57.68%, and the upper bound decreased by 12.08%, shortening the results of the economic benefits interval. Clarify the current environmental pollution situation of FAW Hongqi’s new energy vehicle manufacturing enterprise, provide data support for sustainable development of the enterprise, and provide reasonable decision-making space for enterprise decision-makers.

Regulating the Multiscale Stability of Li‐Rich Cathode through Lewis Acid Gas Treatment

Regulating the Multiscale Stability of Li‐Rich Cathode through Lewis Acid Gas Treatment

Gas Molecule Assisted All-Inorganic Dual-Interface Passivation Strategy for High-Performance Perovskite Solar Cells.

The trap states at both the upper and bottom interfaces of perovskite layers significantly impact non-radiative carrier recombination. The widely used solvent-based passivation methods result in the disordered distribution of surface components, posing challenges for the commercial application of large-area perovskite solar cells (PSCs). To address this issue, a novel NH3 gas-assisted all-inorganic dual-interfaces passivation strategy is proposed. Through the gas treatment of the perovskite surface, NH3 molecules significantly enhanced the iodine vacancy formation energy (1.54eV) and bonded with uncoordinated Pb2+ to achieve non-destructive passivation. Meanwhile, the reduction of the film defect states is accompanied by a decrease in the work function, which promotes carrier transport between the interface. Further, a stable passivation layer is constructed to manage the bottom interfacial defects using inorganic potassium tripolyphosphate (PT), whose ─P═O group effectively mitigated the charged defects and lowered the carrier transport barriers and nucleation barriers of PVK, while the gradient distribution of K+ improved the crystalline quality of PVK film. Based on the dual-interface synergistic effect, the optimal MA-contained PSCs with an effective area of 0.1 cm2 achieved an efficiency of 24.51% and can maintain 90% of the initial value after aging (10-20% RH and 20°C) for 2000h.

Comparative life cycle assessment of organic industrial solid waste co-disposal in a MSW incineration plant

Co-disposal experiments involving industrial solid waste (ISW) are conducted at a municipal solid waste (MSW) incineration plant in this study, investing the environmental impact of co-disposal with different ISW addition proportions using life cycle assessment (LCA). Results show that increasing ISW proportions improves economic indicators, reducing the payback period from 7.92 years (0 % ISW) to 6.58 years (40 % ISW). Environmental impact indicators initially decrease and then increase. The indicator with the greatest environmental impact is Eutrophication Potential (EP), the only major indicator with positive values in all scenarios when considering power output. Its normalization value reaches a minimum at 30 % ISW blending, at 7.85 × 10−12. Contribution analysis reveals that the direct emissions of N-containing gases are the primary cause, while the addition of urea, ammonia water, and quicklime in flue gas treatment, as well as the ash-slag landfill, also have significant effects. Technical optimization of stepwise co-disposal, denitrification system and ash-slag reduction will be the focus. Compared to the existing conventional situation, the co-disposal system exhibits considerable improvements in environmental benefits and carbon reduction potential. Notably, there is a significant reduction in non-CO2 greenhouse gas emissions. This study offers theoretical insights for multi-source waste disposal in MSW incineration plants.

Effects of surface treatments for the adhesion improvement between Cu and SiCN in BEOL interconnect

This study focuses on the enhancement of interfacial reliability between Cu interconnects and silicon carbon nitride (SiCN) capping layers in semiconductor packaging structures through pre-deposition surface treatments. We compare three distinct treatments combined with H2 plasma, NH3 plasma, and SiH4 gas inflow, evaluating their effectiveness through quantitative measurement of interfacial adhesion energy using a double cantilever beam (DCB) fracture mechanics test. The results exhibit a remarkable adhesion energy improvement of over 1150 % with the addition of SiH4 gas treatment. Thorough investigations reveal that the mechanism of the exceptional adhesion enhancement is attributed to unique chemical bonding and fracture behavior. In other words, Si atoms in the SiH4 gas treatment incorporate onto Cu surfaces with specific crystallographic orientations, resulting in significantly stronger Cu–Si bonding in selective regions compared to other bondings. Moreover, the crystallographic-orientation-dependent bonding characteristic induces crack kinking at grain boundaries, dissipating the crack propagation energy. This work will provide crucial insight into enhancing the interfacial reliability and manufacturing yield of semiconductor devices.

Pepper catalase: a broad analysis of its modulation during fruit ripening and by nitric oxide.

Catalase is a major antioxidant enzyme located in plant peroxisomes that catalyzes the decomposition of H2O2. Based on our previous transcriptomic (RNA-Seq) and proteomic (iTRAQ) data at different stages of pepper (Capsicum annuum L.) fruit ripening and after exposure to nitric oxide (NO) enriched atmosphere, a broad analysis has allowed us to characterize the functioning of this enzyme. Three genes were identified, and their expression was differentially modulated during ripening and by NO gas treatment. A dissimilar behavior was observed in the protein expression of the encoded protein catalases (CaCat1-CaCat3). Total catalase activity was down-regulated by 50% in ripe (red) fruits concerning immature green fruits. This was corroborated by non-denaturing polyacrylamide gel electrophoresis, where only a single catalase isozyme was identified. In vitro analyses of the recombinant CaCat3 protein exposed to peroxynitrite (ONOO-) confirmed, by immunoblot assay, that catalase underwent a nitration process. Mass spectrometric analysis identified that Tyr348 and Tyr360 were nitrated by ONOO-, occurring near the active center of catalase. The data indicate the complex regulation at gene and protein levels of catalase during the ripening of pepper fruits, with activity significantly down-regulated in ripe fruits. Nitration seems to play a key role in this down-regulation, favoring an increase in H2O2 content during ripening. This pattern can be reversed by the exogenous NO application. While plant catalases are generally reported to be tetrameric, the analysis of the protein structure supports that pepper catalase has a favored quaternary homodimer nature. Taken together, data show that pepper catalase is down-regulated during fruit ripening, becoming a target of tyrosine nitration, which provokes its inhibition.

Techno-economic assessment of the Synthetic Natural Gas production using different electrolysis technologies and product applications

Power to Methane (PtM) systems are considered an attractive alternative for power generation, renewable sources’ potential harnessing, and atmospheric carbon dioxide (CO2) utilization. This study analyzes the potential use of Synthetic Natural Gas (SNG) for electrical power generation or its direct injection into the currently available Natural Gas Transportation infrastructure. A simulation approach using Aspen Plus v14 software was employed to assess various PtM configurations. Six different systems were analyzed for methanation processes, utilizing three types of electrolysis systems: Alkaline (AE), Proton Exchange Membrane (PEME), and Solid Oxide (SOE). Two primary methane applications were considered: integrated into a combined cycle for power generation and a standalone gas treatment stage for grid injection. As a result, the PEME-based system showed the highest generated-to-fed power ratio, larger than SOE (1.45% higher) and AE (20.66% higher). In addition, PEME technology reports the largest generation of SNG per power supply, exceeding 3.4% and 16.4% of those of SOE and AE, respectively. However, the SOE technology showed a larger efficiency than PEME technology by 8.2% and a PtM efficiency larger than PEME by 12.4%. Fixed capital investment for the PtM systems is around 8.6 and 13.9 million USD$, and their total earnings are between −8.2 and 20.9 thousand USD$ a year, depending on the electrolysis technology, methane application, and carbon credits scenario. According to these results, the PEME-based system is the most suitable option regarding technical and economic criteria.

ENGINEERING OF LIQUID-GAS EJECTOR USING NUMERICAL SIMULATION

The article deals with the development and application of the technology of injection of low-pressure associated petroleum gas (APG) into the reservoir through the reservoir pressure maintenance system (RPMS) in connection with the entry into force of the Russian government decree on the mandatory utilization of 95 % of produced APG. The technology under consideration, the key element of which is a liquid-gas ejector (LGE), makes it possible to achieve this level with minimal investment, in the shortest possible time and to stop flaring APG at flares remote from the central oil and gas treatment facilities of oil and gas production facilities. LGEs have a relatively simple and reliable design due to the absence of moving elements.At present, there are known LGEs of classical designs, in which the level of hydrodynamic losses can reach 40–60 %. High hydrodynamic losses make it inexpedient to use such ejectors at small fields operated at a late stage of development, remote from the central oil and gas treatment facilities, due to the limitations of the existing equipment complex and the allowed operation mode of the injection well stock. To ensure the possibility of including LGE in the RPM system it was required to develop a new design of LGE, allowing to reduce hydrodynamic losses up to 30 %, as well as to ensure the maximum possible percentage of APG utilization. The article is devoted to the development, calculation of geometry and operating mode of LGE using numerical modeling in ANSYS environment.Modeling of the flowing part of the main elements of LGE (confuser nozzle, diffuser throat and gas channel width) at different values of parameters directly affecting the level of hydraulic losses is carried out. The results of calculations of numerical simulation of LGE allowed to optimize the dimensions of the internal geometry of LGE, thus it was possible to develop a new device for the required initial data, which will reduce the level of hydraulic losses up to 30 % and ensure the involvement of the maximum volume of gas in the RPM system.

A comparative study on the solubility of CH3SH and H2S in imidazolium-based ionic liquids: A connectionist approach between free volume and thermodynamics

Sulfur contaminants in industrial gas streams, such as hydrogen sulfide and mercaptans, must be eliminated due to safety and environmental considerations. Ionic liquids, as a new class of chemical compounds, are an alternative to conventional aqueous alkanolamine solutions currently used in absorption gas treatment processes. In this work, the solubilities of methyl mercaptan (CH3SH) and hydrogen sulfide gases in 1-butyl-3-methylimidazolium-based ionic liquids with tetrafluoroborate ([C4mim][BF4]), hexafluorophosphate ([C4mim][PF6]), trifluoromethanesulfonate ([C4mim][OTf]), and bis(trifluoromethylsulfonyl)imide ([C4mim][Tf2N]) anions have been studied using molecular dynamics (MD) simulation and a recently developed OPLS all-atom (OPLS-AA-0.8) force field. A new concept, the induced free volume, has been introduced in this work, which provides a realistic and precise connection between the thermodynamic entropic contributions to the dissolution process of CH3SH and H2S in the ionic liquids, on one hand, and the microscopic free/void volume induced as a result of the entrance of a gas solute molecule into the liquid structure, on the other hand. The thermodynamic energetic contributions were correlated to the CH3SH/H2S interaction with the ionic species of the ionic liquids. Quantum chemical energy decomposition analysis (EDA) was employed to calculate and analyze the binding interaction and nature of CH3SH/H2S interactions with the ionic species of ionic liquids. It was found that the van der Waals contributions to the interaction of CH3SH with ionic liquids are more significant compared to that of H2S, while the opposite conclusion could be deduced for the corresponding electrostatic contributions. Both CH3SH and H2S established equivalent hydrogen bonding interactions with the ionic liquids studied in this work. The diffusion coefficients of the ionic species, as well as the excess chemical potentials and Henry’s constants for the dissolution of CH3SH and H2S in the ionic liquids, were calculated by free energy perturbation technique (FEP) and compared with the MD simulated and experimental data, reported in the literature. It was concluded that the OPLS-AA-0.8 force field yields Henry’s constants and diffusivities that are in better agreement with the reliable experimental data corresponding to other OPLS versions reported to date.

Control of spout deflection in dry and wet spouted beds using vibration

Spout deflection is a common instability phenomenon observed in spouted beds which decreases control over the spouted bed and worsens particle recirculation efficiency. Prior work has mitigated spout deflection using electromagnetic fields, inlet gas treatment, and baffles. Here, we demonstrate experimentally that spout deflection can be mitigated through the use of vertical vibration, which can be applied in circumstances which prior methods may not be possible. Spout deflection was mitigated for cases of non-uniform gas flow in a dry spouted bed and particle agglomeration in a wet spouted bed. Furthermore, the particle recirculation rate was found to increase significantly with increasing vibration strength in a wet spouted bed. Thus, we show that vertical vibration can significantly enhance the spout stability in both dry and wet spouted beds, without compromising recirculation rate.

The treatment of high concentration wastewater in the natural gas processing industry.

The operation of the Cansolv tail gas treatment device in natural gas plants generates acidic and alkaline wastewater from the venturi unit and amine purification unit (APU), respectively. The APU wastewater is complex in composition and contains hard-to-degrade organic matter, which can adversely impact the normal functioning of the water treatment system. This study assesses the efficacy of three ozone-based advanced oxidation processes (ozone (O3), ozone/hydrogen peroxide (O3/H2O2), and ozone/Fenton (O3/Fenton)) for treating Cansolv wastewater, with chemical oxygen demand (COD) and total organic carbon (TOC) serving as indicators of organic degradation. The findings demonstrate that all three processes effectively eliminate coloration and reducible sulfur, with O3/Fenton exhibiting superior performance in removing organic substances. The treated wastewater has a clarified light-yellow appearance with residual COD levels at 43 mg L-1. Under the optimum Fenton oxidation conditions (initial pH 5, H2O2 dosage 97.8 mmol L-1, FeSO4·7H2O dosage 550 mg L-1), average TOC and COD removal rates reached 50% and 97%, respectively. After a treatment duration of 60 minutes, the wastewater demonstrated an enhanced membrane-specific flux, confirming the effectiveness of the O3/Fenton oxidation process in mitigating membrane fouling while ensuring the stable operation of the wastewater treatment system.

Multifunctional nanofibrous membranes for highly efficient harsh environmental air filtration and oil–water separation

With the acceleration of the global industrialization process, the treatment of corrosive waste gas and oily wastewater in pharmaceutical, petrochemical and smelting fields still remains tremendous challenges. Herein, a robust polysulfonamide/polyacrylonitril@silica (PSA/PAN@SiO2) nanofibrous membrane with a hierarchical structure was successfully developed to deal with air filtration and oil–water separation under practical complex environments. In the process of air purification, the synergistic effect of multiple components could effectively surmount the conflict between pollution particle removal efficiency and pressure resistance. The air cleaning efficiency (PM0.3) of the PSA/PAN@SiO2 composite membranes could reach 99.05 ± 0.13 % at a low pressure drop of 30 ± 2 Pa. Due to the outstanding stability of PSA and SiO2, the composite membranes still possessed stable filtration performance in complex environments (strong acid, strong alkali and high temperature). Furthermore, PSA/PAN@SiO2 composite membranes with unique wettability (under oil superhydrophobicity and underwater superoleophobicity) could efficiently separate oil–water mixtures and emulsions. This multifunctional filtration membrane provides enormous application potential for the field of individual protection and environmental governance, even in complex environments.

NIR-light controlled local delivery of nitric oxide based on self-targeting carbon dots

Nitric oxide (NO)-based gas therapy has received ever-increasing attention in treatment of many diseases, especially cancer. However, the selective organelle targeted delivery and controllable release of NO remains highly desirable. In this work, a sequentially targeting delivery nanoplatform has been constructed by encapsulating heat-responsive S-nitrosocysteine (the NO donor, SNC) conjugated mitochondria-targeting carbon dots (MitoCDs) and indocyanine green (ICG) within liposomes which are further modified with aptamer that can specifically bind to nucleolin overexpressed on the surface of several cancer cells. MitoCDs were prepared via one-step hydrothermal reaction using citric acid and m-diethylaminophenol as starting materials and used without any external targeting molecules. ICG molecules were employed as NIR-triggered photothermal agent followed by NO precisely controlled release in mitochondria. By combining gas and photothermal treatment, the nanocarrier produced a synergistic and superior killing effect on several cancer cell lines. And the cell growth inhibition of NCL-CSI@Lip on HEp-2 cells raised up to 72.39 %. Such an ‘all-in-one’ mitochondria-targeted NO nanocarrier may lead to new way for overcoming the problem of multidrug resistance in intracellular drug delivery.

Erosion and intergranular corrosion induced failure of S31254 stainless steel – Case study on Venturi scrubber in a natural gas purification plant

The flue gases such as SO2, SO3, and CO2 generated during the purification process of sulfur-containing natural gas need to be treated to a certain concentration before they can be discharged into the atmosphere. The flue gas unit of a purification plant in Sichuan adopts the new Cansolv flue gas treatment process. After running for a period of time, the Venturi scrubber experienced severe corrosion failure, resulting in equipment shutdown and significant economic losses. This paper utilizes an actual failed device as a case study to analyze the corrosion environment of the Venturi scrubber. It conducts a comprehensive failure analysis, encompassing material mechanical properties, metallographic analysis, and failure microstructure analysis, aiming to elucidate the reasons behind the Venturi scrubber failure. Systematic analysis shows that the manufacturing materials used in this scrubber meet all design requirements. However, flue gas at temperatures reaching 280 °C enters the scrubber tower at a flow rate exceeding 10 m/s. The dissolution of acidic gases leads to a significant drop in the pH of the cooling water to 1, manifesting evident signs of erosion corrosion and intergranular corrosion on the material surface. These observations suggest that erosion and intergranular corrosion in high-temperature acidic environments are the predominant factors contributing to the corrosion failure of the Venturi scrubber.

A high-order, localized-artificial-diffusivity method for Eulerian simulation of multi-material elastic-plastic deformation with strain hardening

A high-order method for Eulerian simulation of material undergoing large elastic–plastic deformation is developed. Thermodynamically consistent hyperelastic constitutive relations are assumed, facilitating the treatment of solids, liquids, and gases in a unified manner. The method enables the simulation of multi-material interactions using a diffuse interface approach. Numerical capturing of material interfaces, shock waves, contact surfaces, and elastic-plastic strain discontinuities using high-order compact-difference schemes is assisted by Localized Artificial Diffusivity (LAD). In the new setting involving elastic–plastic deformation, the previously established terms for the artificial properties are verified to effectively regularize normal shocks. Additional LAD terms are introduced to the elastic and plastic kinematic equations to regularize shear shocks and other strain discontinuities, improving solution stability. Other important features of the method that improve robustness include the numerical treatment of compatibility terms in the kinematic equations, and the treatment of rotation. Particular emphasis is focused toward new advancements of the methods for plastic-deformation integration and the associated strain hardening of the material, including rate-dependent plasticity. The method is demonstrated on a variety of test problems, including 1-D impacts, a variant of the Shu-Osher problem, a Taylor impact, and a Richtmyer-Meshkov instability between two elastic–plastic solids with strain hardening.