Gas Treatment Process Research Articles

Biowaste to hydrogen or Fischer-Tropsch fuels by gasification – A Gibbs energy minimisation study for finding carbon capture potential and fossil carbon displacement on the road

To reach its greenhouse gas emission reduction goals, Norway needs a shift away from the use of fossil fuels in the transport sector. The production potential and efficiency of Fischer-Tropsch biofuels and hydrogen from gasified wet organic municipal solid waste has been investigated. The carbon capture potential was estimated for both production processes and the number of road vehicles compared, which can be supplied with the fuel. Gibbs free energy minimisation is used to predict the synthesis gas composition. A detailed analysis of the different gas treatment processes that lead to either gasoline and diesel production, along with energy recovery as electricity, or hydrogen in either compressed or liquefied form is conducted. Both processes can utilise all available waste heat and the Fischer-Tropsch biofuel process is even self-sufficient with electrical power. The production of hydrogen has both higher first and second law efficiencies and a greater number of vehicles can be supplied with fuel. Either 2367 tonne H2 or 1497 tonne gasoline, 1279 tonne diesel, and 1.33 MW of net electric power can be produced at 1073 K gasification temperature, where both yield and efficiencies are highest. Hydrogen production also has the larger carbon capture potential during fuel production.

Facilitated Transport Membranes With Ionic Liquids for CO2 Separations.

In recent years, significant development milestones have been reached in the areas of facilitated transport membranes and ionic liquids for CO2 separations, making the combination of these materials an incredibly promising technology platform for gas treatment processes, such as post-combustion and direct CO2 capture from air in buildings, submarines, and spacecraft. The developments in facilitated transport membranes involve consistently surpassing the Robeson upper bound for dense polymer membranes, demonstrating a high CO2 flux across the membrane while maintaining very high selectivity. This mini review focuses on the recent developments of facilitated transport membranes, in particular discussing the challenges and opportunities associated with the incorporation of ionic liquids as fixed and mobile carriers for separations of CO2 at low partial pressures (<1 atm).

Cellulose-based carbon hollow fiber membranes for high-pressure mixed gas separations of CO2/CH4 and CO2/N2

Carbonized cellulose -based hollow fiber membranes were prepared by dry-wet spinning phase inversion method, followed by carbonization and evaluated in terms of gas separation performance for CO2/N2 and CO2/CH4 mixtures, under flow conditions. Permeability and real selectivity were measured for both mentioned mixtures, in a temperature range of 25 °C to 60 °C, a differential pressure range of 8 bar(a) to 20 bar(a) and a CO2 concentration range from 5% v/v to 15% v/v. The highest yielding mixture selectivity values were 42 for CO2/N2 at 10% v/v CO2, 25 °C & 8 bar(a) and around 150 for CO2/CH4 at the same conditions, whereas the respective CO2 permeabilities were 110 and 45 Barrer. Additionally, experiments of varying head pressure, while maintaining differential pressure, transmembrane pressure, at 8 bar(a), have revealed that CO2/N2 separation factor can be further enhanced with real selectivity being raised to 55 and permeability to 180 at 20 bar head pressure. The same approach had negligible effect on CO2/CH4 separation. This is an important finding by taking into consideration that natural gas treatment, i.e. sweetening and purification processes, is energetically and economically convenient if it takes place under the conditions, where the NG stream is extracted from the wells, or after a decompression. Moreover, Process simulation indicates that a two-stage system using the developed carbon membranes is technologically feasible to produce 96% methane with a low methane loss of <4%. Further improving membrane gas permeance can significantly reduce the specific natural gas processing cost which is dominated by the membrane-related capital cost.

An Analysis of the Prospects for Coal-Fired Thermal Power Station Reconstruction on the Basis of Coal Gasification and a Combined-Cycle Unit

Modern trends in technical reequipment of coal-fired thermal power stations (TPS) are analyzed by the example of the Verkhnetagil’skaya District Power Station (GRES), where obsolete coal-fired power units requiring replacement were in operation. This problem is specific for many Russian thermal power stations. Two alternatives of reequipment are considered: replacement of obsolete steam-turbine power units with a natural gas-fired combined cycle unit (CCU) and conversion of coal-fired power units into integrated gasification combined-cycle units (IGCCU) with gas turbines operating on purified synthesis gas. Technical reequipment of the considered TPS was performed by replacing the coal-fired steam-turbine power units of phase I–II with a 420 MW CCU. The CCU core was a 288 MW Siemens SGT5-4000F gas turbine. A CCU on its basis was modelled in the THERMOFLEX code. The calculated results demonstrated high power and environmental effectiveness in replacement of coal-fired power units at TPSs with natural gas-fired CCUs, thereby cutting down coal equivalent consumption by 727 000 t.c.e. (or 24%). For conversion of a TPS to an IGCCU, the fuel saving could be as great as 543 000 t.c.e./year (18%) under comparable conditions. In this case, the atmospheric emissions (of dust and SO2) could be decreased many times (by 99%) due to implementation of an effective gas treatment process in the gasification system. Due to the huge coal reserves in Russia, the conversion of coal-fired TPSs to modern technologies with coal gasification may be a promising alternative for many TPSs during their reconstruction. In addition, it will contribute to improving the country’s energy security. In addition, this will improve the country’s energy security.

New insights on mercury abatement and modeling in a full-scale municipal solid waste incineration flue gas treatment unit

Modeling approaches are generally used to describe mercury transformations in a single step of flue gas treatment processes. However, less attention has been given to the interactions between the different process stages. Accordingly, the mercury removal performance of a full-scale solid waste incineration plant, equipped with a dry flue gas treatment line was investigated using two complementary modeling strategies: a thermochemical equilibrium approach to study the mercury transformation mechanisms and speciation in the flue gas, and a kinetic approach to describe the mercury adsorption process. The modeling observations were then compared to real-operation full-scale data. Considering the typical flue gas composition of waste incineration facilities (high concentrations of HCl compared to Hg), it was found that a process temperature decrease results in better mercury removal efficiencies, associated with a higher oxidation extent of Hg in HgCl2, and the enhancement of the sorbent capacity. Improvements can also be attained by increasing the sorbent injection rate to the process, or the solid/gas separation cycles. An empirical correlation to predict the mercury removal efficiency from the main operating parameters of dry flue gas treatment units was proposed, representing a useful tool for waste incineration facilities. The presented modeling approach proved to be suitable to evaluate the behavior of full-scale gas treatment units, and properly select the most adequate adjustments in operating parameters, in order to respect the increasingly constraining mercury emissions regulations.

Research on VOCs Treatment of Electrophoresis Coating Process

The coating process is the main source of VOCs emissions in the aluminium profile industry. The electrophoretic coating process is a surface processing method widely used by aluminium profile companies. However, the electrophoretic coating process generates a large amount of exhaust gas, and the main component of the exhaust gas is VOCs. This paper combined with the monitoring of the exhaust gas treatment project of an electrophoresis coating workshop of a large aluminium profile company, and found that the main component is xylene. The exhaust gas treatment process uses “activated carbon adsorption + spray absorption” and more than 97% of emissions could be achieved.

Acid(g)/base(g)-controlled reversible Δν1/2 of absorption spectrum of a functional dye film

UV–Vis absorption full width at half maximum (FWHM) plays a significant role not only in describing spectral shapes but also in determining the use of organic dyes for a particular application. For example, organic dyes with a relatively wide absorption FWHM are beneficial with respect to enhancing photon absorption efficiency of solar cells, whereas, for improving color purity in optical filters, narrow FWHM is desirable. Despite such a critical role, studies examining the modulation of absorption FWHM from an organic dye in the solid state are relatively lacking. In this work, we suggest rapid, simple, and effective method to control the absorption FWHM of a squarylium-based dye (SQ) film using an organic solvent vapor. Alternative treatments of base/acid gas to the SQ film (2.0 s for each gas) resulted in reversible absorption FWHM (ΔFWHM: 121 nm). From the systematic optical and morphology characterizations, it was revealed that changes in FWHM originated from reversible molecular arrangements between monomer-type and H-aggregate-type of SQ by efficient base/acid vapor diffusion into the SQ film. Moreover, the modulation exhibited high fatigue resistance against repeated gas treatments, which secures its practical applications. These results suggest that the proposed simple gas-treatment process in this work is beneficial for the efficient modulation of absorption FWHM of various organic dyes.

Unraveling How the H2 Treatment Helps Improve the Performances of Cu and Ag Loaded Y Zeolites for Adsorptive Desulfurization.

This work seeks for a better understanding on how the gas treatment process affected the structure of metal loaded zeolite Y (MY, M = Ag, Cu) adsorbants and how the structural changes affected the performances of the adsorbents for adsorptive desulfurization. A series of characterization tools including solid-state nuclear magnetic resonance were employed. Compared to the N2 treatment, the H2 treatment on the MY adsorbents led to the reduction of the loaded M components to their metallic state and, consequently, brought several structural changes to the zeolitic framework. The structural changes brought by the H2 treatment can be accounted for the decreased Brönsted acidity over the Lewis acidity of the adsorbents and thus helped in improving their adsorption capacity. This paper provides new insights on how the zeolitic framework changes affected the sulfur adsorption capacity of MY, which is helpful for designing better adsorbents for sulfur removal from oil.

The Performance of Low-Pressure Seawater as a CO2 Solvent in Underwater Air-Independent Propulsion Systems

Air-independent propulsion systems have improved the performance and decreased the vulnerability of underwater weapon systems. Reforming systems, however, generates large amounts of water and CO2. The recovery or separation of CO2, a residual gas component generated in vessels, entails considerable cost and energy consumption. It is necessary to understand the characteristics of the interaction between CO2 and seawater under the conditions experienced by underwater weapon systems to design and optimize a CO2 treatment process for dissolving CO2 in seawater. In this study, numerical analysis was conducted using the derived experimental concentration and MATLAB. The diffusion coefficient was derived as a function of temperature according to the CO2 dissolution time. Experiments on CO2 dissolution in seawater were conducted. The concentration of CO2 according to the reaction pressure and experimental temperature was obtained. The diffusion coefficient between CO2 and seawater was found to be 6.3 × 10−5 cm2/s at 25 °C and 7.24 × 10−5 cm2/s at 32 °C. CO2 concentration could be estimated accurately under vessel operating conditions using the derived CO2 diffusion coefficients. Optimal design of the residual gas treatment process will be possible using the derived seawater–CO2 diffusion coefficients under the actual operating conditions experienced by underwater weapon systems.

The in situ redispersion of a PdCu/AC alloy catalyst under a CFCl2CF2Cl/H2 atmosphere: a combination of experimental and DFT study.

A novel CFCl2CF2Cl(R113)/H2 gas treatment process was proposed and successfully applied for the redispersion of a sintered alloy PdCu/AC catalyst. The redispersion process was initiated by the formation of an oxidative PdCuClx intermediate, which can easily migrate to a nearby catalyst surface and then be reduced to smaller PdCu NPs.

Advanced Process Control to Minimize Disturbance in Gas Processing Facility (GPF)

For the gas treatment process, the process that occurs is separating the gas from the components of H2S, CO2, and H2O. The separation of gases from these components uses the aid of Amine fluid and TEG fluid. The unit that important in this process are Amine and TEG Contactor. To be able to separate the three components from the gas, the mass flow rate of Amine and TEG must be controlled so that the processing can work optimally. In reality in the field, the input of this process from the well is not always steady. So, this condition becomes a disturbance from the control process. The solution to minimize the disturbance of process with Advanced Process Control (APC). Therefore, this research will design APC on Amine and TEG Contactor to improve the stability of the mass flow response of Amine and TEG. In designing APC, the plant model is required first. Plant modelling obtained with software HYSYS and validated with MATLAB. The result shows the RMSE value below 5 %. The result proved to be able to make the process more stable from before design proven by slurries settling time, steadystate errors and maximum overshoot.

Neighborhood Variational Bayesian Multivariate Analysis for Distributed Process Monitoring With Missing Data

Conventional methods for distributed monitoring commonly assume that complete process measurements are available. However, the problem of missing data is often encountered in the monitoring of large-scale multiunit processes. This paper proposes an approach based on a neighborhood variational Bayesian principal component analysis (NVBPCA) and canonical correlation analysis (CCA) for the efficient distributed monitoring of multiunit processes in the presence of missing data. Missing observations for a local unit are reconstructed through NVBPCA by considering information from both local and neighboring units. A CCA-based local monitor, which identifies the status of the local unit and the type of a detected fault using information from both the local and neighboring units, is then developed. The NVBPCA–CCA approach has a better performance since its missing data handling and local monitor construction consider information from both the local and neighboring units. The efficiency of the proposed monitoring method is demonstrated through its application in a numerical example and an industrial tail gas treatment process.

Sistema de extraccion y tratamiento de metano

Currently sanitary landfills are considered sources of atmospheric pollutants. Biogas, a product of the biological decomposition of organic waste, incorporates mostly methane (CH4) and carbon dioxide (CO2), which are greenhouse gases. A large number of municipal sanitary landfills do not have control over methane gas emissions to the surface. This project is based on the construction of a portable prototype system for the extraction and treatment of methane gas from landfills. The objective was to manufacture and build a portable prototype system for the extraction and treatment of methane gas from municipal sanitary landfills. That it implements the necessary sections and devices to treat the gas and in this way facilitate its later use as fuel in heating systems, domestic use and / or internal and external combustion thermal machines. Using for this purpose a system of gas extraction, separation of solids, de-humidification and desulphurisation process. In the system variables such as the percentage of methane, temperature and humidity are monitored, in order to give a stability to the gas treatment process.

Experimental and Numerical Simulation Study on Co-Incineration of Solid and Liquid Wastes for Green Production of Pesticides

A large amount of solid and liquid waste is produced in pesticide production. It is necessary to adopt appropriate disposal processes to reduce pollutant emissions. A co-incineration scheme for mixing multi-component wastes in a rotary kiln was proposed for waste disposal from pesticide production. According to the daily output of solid and liquid wastes, the proportion of mixing was determined. An experiment of the co-incineration of solid and liquid wastes was established. Experimental results showed that the mixed waste could be completely disposed at 850 °C, and the residence time in the kiln exceeded 1 h. A model method for mixture and diesel oil-assisted combustion was proposed. Numerical simulation was performed to predict the granular motion and reveal the combustion interactions of the co-incineration of mixed wastes in the rotary kiln. Simulation results reproduced movements, such as rolling and cascading, and obtained the optimum rotational speed and diesel oil flow for the rotary kiln incineration operation. The simulation showed that the temperature in the kiln was maintained at 850 °C, and the mass fraction of CO and O2 at the outlet reached the standard for the complete combustion of the waste. Finally, the rotary kiln incineration and flue gas treatment processes were successfully applied in engineering for green production of pesticides.

Designing Desorber for MEA Regeneration after Associated Petroleum Gas Treatment. Part 2

The paper presents a desorption-based method for treating a waste mono-ethanolamine (MEA) solution to extract hydrogen sulfide. The process is used in the associated petroleum gas (APG) treatment unit to remove hydrogen sulphide together with the MEA solution process of hydrogen sulfide absorption from the APG that comes from the well. Extracted hydrogen sulfide can be used to obtain elemental sulfur. The object of development is a stripper for APG treating to remove hydrogen sulfide.Such a treating system is, as a rule, unavailable separately from the absorber and represents an integrated system to treat APG from hydrogen sulfide. Thus, the work objective was to determine parameters, and develop and design desorption column where mono-ethanolamine purification from hydrogen sulphide occurs.The paper presents calculation of desorption column that allows us to close the treatment process, thereby ensuring the regeneration of the mono-ethanolamine solution through treatment by the desorption process. The waste amine is returned to the gas treatment process, and the extracted hydrogen sulfide goes to the Claus process for elemental sulphur production. The column calculation was performed taking into account chemical and thermal processes. The APG treatment unit option to extract hydrogen sulfide with further elemental sulfur produced through the Claus process has been obtained to solve this problem by using the APG as an industrial and domestic gas.

Unexpected Aldehyde Generation in the Exhaust Gas at Waste Incineration Facilities.

Acid gases generated during the thermal treatment of waste are neutralized using devices, such as bag filters coated with slaked lime. However, residual trace organic substances can react with the highly reactive slaked lime. This study investigates the dynamics of organic substances generated in the bag filter when slaked lime is used in the exhaust gas treatment process. The mechanism of aldehyde generation was clarified using head space gas chromatography mass spectrometer (HS-GC/MS). Results indicated that methanol was converted to formaldehyde at a conversion ratio of 0.097% and ethanol was converted to acetaldehyde at a conversion ratio of 0.260%. In addition, when amines used as emulsifiers during slaked lime production persisted in the matrix, acetaldehyde formed at a maximum concentration of 121 mg/m3. The simulation method developed in this study can be used for the initial evaluation of aldehydes unexpectedly produced in an incineration treatment facility.

Partitioning of arsenic in slurry feed entrained-flow gasifier with wet gas cooling cleaning system

Abstract Slurry feed entrained-flow gasifier has been applied more and more in waste treatment. However, the data on the distribution and emission of arsenic (As) in such gasifiers are very limited. The fate of As in gasification system is closely related to the conditions of gasifier and subsequent gas treatment processes. In this paper, the partitioning of As in slurry feed entrained-flow gasifier with wet gas cooling cleaning system is determined. The influence of feedstock and process water are studied. It is shown that co-gasification waste with coal and the redox condition of process water have little effect on the overall distribution of As. 91.7–94.5% of As is distributed to flash wastewater under water-oxidizing condition and 85.5–99.7% of As partitions into the wastewater under water-reducing condition. Less than 4% of As enters the raw syngas. Under the condition of waste addition and reducing water, As has the risk of being released into the atmosphere with the exhaust gas (8.4–57.0 μg/Nm3). According to the data detected under water-oxidizing condition, the concentration of As in clarified water is 0.367–1.195 ppm, and that in clarifier solid is 34.06–159.84 ppm. Therefore, the reuse of clarified water as process water of wet gas treatment system and clarifier solid as feedstock of gasifier may lead to As recycling in the gasification system.

Evaluating the eco-efficiency of China's industrial sectors: A two-stage network data envelopment analysis

Because the industrial process always results in pollutant emissions, pollution treatment has become necessary for the sustainable development of industry. This paper aims to evaluate the eco-efficiency of China's industrial sectors between 2007 and 2015 by using the directional distance function (DDF) of network data envelopment analysis (DEA), which contains a two-stage structure that divides industrial processes into three linked subprocesses, i.e., the production, wastewater and waste gas treatment processes. The results show that (1) from 2007 to 2015, the eco-efficiency and all process efficiencies of China's industries achieved considerable improvement. This finding indicates that China's industries have already achieved a win-win situation in the development of environmental protection and economic growth over the past few years. (2) During the sampling period, the highest performance was observed during the waste gas treatment process, followed by the wastewater treatment and production processes. During the same period, the performance of wastewater treatment exhibited the fastest growth, followed by the performance of production and waste gas treatment. (3) The eco-efficiencies of China's industrial subsectors exhibited significant industrial differences: the eco-efficiency of the mining industry was the lowest due to a decline in its performance during the waste gas treatment process, while due to the excellent performance during the production wastewater treatment process, the eco-efficiencies of the electricity, gas production and supply industries were the highest.

Temperature Swing Adsorption in Natural Gas Processing: A Concise Overview

AbstractTo enable the technical use of natural gas, efficient gas processing is essential. Various components such as water, sulphur compounds, carbon dioxide, nitrogen, and heavy hydrocarbons must be removed. Temperature swing adsorption (TSA) is a commonly used way of removing some of these components. This paper describes where TSA is used in the natural gas treatment process and outlines the application of commercial adsorbents in TSA plants. The state of research on adsorbents and process control in TSA plants in natural gas processing is discussed.

Environmentally friendly treatment of airpollutants: evaluation of cumulative process for flue gas treatment

This paper proposes the combination of two different domains; the environment and agriculture. Emission of sulfur oxides and nitrogen oxides is associated with global acidification (e.g. acid rain), and it has become a serious environmental problem. Meanwhile, the amount of fertilizer consumed globally in 1996 was over 6 times that consumed in 1960. Electron beam flue gas treatment (a dry process) can simultaneously convert sulfur dioxide, sulfur trioxide and nitrogen oxides into nitrogen fertilizer. This process has been considered costly. An electron beam industrial plant has been built and is currently operating. The data delivered from this industrial plant proves that economic performance of the electron beam process is about the same as that of the conventional wet limestone process.