Adsorption Chamber Research Articles

Investigation of performance of potential adsorbents for emissions mitigation in a diesel generator.

Globally, the release of greenhouse gases primarily carbon dioxide (CO2) emissions to our Earth's surface has climbed by about 45% to its present atmospheric concentration rate of 420 parts per million (ppm) during the industrial era. An unprecedented rise in atmospheric CO2 concentration has been claimed to lead to significant factors such as global warming potential (GWP) and climate change effects. An increase in atmospheric CO2 concentrations is a serious threat to the environment. Recent research efforts have focused on mitigating emissionsfrom anthropogenic point sources. Adsorption-based post-combustion CO2 capture using solid adsorbents is the most effective and efficient method for mitigating gas adsorption in the exhaust system. In the current study, activated carbons are obtained from three potential biomass, namely, (i) coconut shell, (ii) rice husk, and (iii) eucalyptus wood, through a - single-stageactivation method. The prepared activated carbon materials are analyzed using proximate and ultimate analyses. Further investigations are performed using different characterization techniques to ensure their adsorption efficiency. Adsorbents are packed one after the other in an in-house fabricated double adsorption chamber and coupled to the exhaust unit of a generator. Test experiments are conducted to examine adsorbents' capture efficiency in emissions mitigation. Adsorbents' adsorption parameters are evaluated in experimental investigations. At 2.5bar and 50°C, a maximum loading capacity of samples is achieved by 4.85mmol/g, 4.58mmol/g, and 5.96mmol/g for coconut shell, rice husk, and eucalyptus wood adsorbents, respectively. With a post-combustion carbon adsorption chamber, CO2 and NO are captured about40-64% and 38-58%, respectively, for all three adsorbents. The thermodynamic parameter of isosteric heat of adsorption value is below 40kJ/mol, ensuring physisorption for all adsorbents.

A heavy-load wall-climbing robot for bridge concrete structures inspection

Purpose The purpose of this paper is to present a wall-climbing robot platform for heavy-load with negative pressure adsorption, which could be equipped with a six-degree of freedom (DOF) collaborative robot (Cobot) and detection device for inspecting the overwater part of concrete bridge towers/piers for large bridges. Design/methodology/approach By analyzing the shortcomings of existing wall-climbing robots in detecting concrete structures, a wall-climbing mobile manipulator (WCMM), which could be compatible with various detection devices, is proposed for detecting the concrete towers/piers of the Hong Kong-Zhuhai-Macao Bridge. The factors affecting the load capacity are obtained by analyzing the antislip and antioverturning conditions of the wall-climbing robot platform on the wall surface. Design strategies for each part of the structure of the wall-climbing robot are provided based on the influencing factors. By deriving the equivalent adsorption force equation, analyzed the influencing factors of equivalent adsorption force and provided schemes that could enhance the load capacity of the wall-climbing robot. Findings The adsorption test verifies the maximum negative pressure that the fan module could provide to the adsorption chamber. The load capacity test verifies it is feasible to achieve the expected bearing requirements of the wall-climbing robot. The motion tests prove that the developed climbing robot vehicle could move freely on the surface of the concrete structure after being equipped with a six-DOF Cobot. Practical implications The development of the heavy-load wall-climbing robot enables the Cobot to be installed and equipped on the wall-climbing robot, forming the WCMM, making them compatible with carrying various devices and expanding the application of the wall-climbing robot. Originality/value A heavy-load wall-climbing robot using negative pressure adsorption has been developed. The wall-climbing robot platform could carry a six-DOF Cobot, making it compatible with various detection devices for the inspection of concrete structures of large bridges. The WCMM could be expanded to detect the concretes with similar structures. The research and development process of the heavy-load wall-climbing robot could inspire the design of other negative-pressure wall-climbing robots.

An Active Compliance Adsorption Method for Climbing Machining Robot on Variable Curvature Surface

This article proposes an active compliance adsorption method for a negative pressure adsorption climbing robot with 3 active compliance suction units which integrate 3 degree of freedom active compliance actuators along with flexible adsorption chambers. This method enables the climbing robot to adsorb and move stably on the surface of large and complex components with variable curvature for machining purposes. The main contribution lies in two aspects. First, an adsorption performance indicator (API) depicting the stretch of the flexible sealing lip is proposed by analyzing the leaked airflow of the climbing robot's suction unit. Second, the pose control method of the suction chamber based on the real-time estimated adsorbed surface is proposed, where the API is used as the optimization target. The experiments have been performed and the results show that a 10 kg-weight climbing robot with three active compliance suction units can keep adsorption force over 1000 N when the surface's curvature radius changes continuously from 1.1 to 14.6 m, with a significant increase in the adsorption force up to 156% compared with only pure passive compliance adsorption method.

Three Dimensional CFD Simulation Model with Experimental Validation of Silica Gel–Water Pair Adsorption Cooling Bed

In this paper, a three-dimensional full simulation model of a solar-driven adsorption cooling system integrated with user-defined functions (UDF) is successfully validated with a manufactured adsorption chamber filled with silica-gel type A. model is validated on the desorption phase with a maximum deviation error of 1.7%. Temperature with adsorption contours are shown for more understanding of the heat flow with adsorption behaviour inside the chamber in all directions. The maximum temperature at the desorption phase is reached after 300 seconds at fins area, and adsorption maximum uptake reached 0.16 kg/kg at fins wall but reached from 0.13 to 0.14 kg/kg around fins area. The average adsorption uptake reached 0.136 at the end of the adsorption process. The resultant uptake between adsorption and desorption is 0.018 kg/kg with a refrigerant mass of 1.8 kg in a complete cycle time.

Experimental investigation on using adsorbent for post‐combustion carbon dioxide capture from CI engine exhaust

AbstractAn unpredictable rise in greenhouse gas (GHG) emissions is a primary concern to the global scientific community. It is directly related to the rapid expansion of the human population and associated with the immense energy demand. The combustion of hydrocarbon fuels in internal combustion (IC) engines releases a large amount of carbon dioxide (CO2), which is one of the causes of GHG emissions. Mitigation of CO2 emissions is a significant challenge to the world. Although several researchers have focused on capturing CO2 from power plants, some researchers have taken initiatives in recent times to capture CO2 in IC engines. This study particularly explored the possibility of using a biomass based‐adsorbent to capture CO2 in the exhaust of a diesel engine. Initially, activated carbon was obtained from palm shells by adopting the preparation methods such as (i) carbonization and (ii) chemical activation. Then, the produced activated carbon was analyzed to examine its physicochemical characteristics and surface textural properties by adopting characterization techniques. The adsorbent sample was loaded in an in‐house fabricated adsorption chamber which was attached to the exhaust of a single‐cylinder, four‐stroke, naturally aspirated, air‐cooled, direct injection (DI), constant speed diesel test engine. The performance of palm shell‐based activated carbon was evaluated as a potential adsorbent for CO2 capture when the engine was operated with two distinct fuels, (i) 100% diesel (D100) and (ii) an optimum biodiesel‐diesel blend (JME20) comprising 80% D100 and 20% Jatropha Methyl Ester (JME). The experimental results showed that an average of about 30% and 37% of CO2 was captured by using palm shell‐based adsorbent in D100 and JME 20 operations, respectively.

Treatment of petroleum refinery wastewater by adsorption using activated carbon fixed bed column with batch recirculation mode

Water pollution and the lack of access to clean water are general global problems that result from the expansion of industrial and agricultural activities. Petroleum refinery wastewaters consider as a major challenge to the environment and their treatment is mandatory. The present work concerns with the removal of chemical oxygen demand (COD) from petroleum refinery wastewater taken from Iraq's Al-Diwaniyah petroleum refinery plant by using an activated carb fixed-bed column operated at a batch recirculation mode. The fixed bed column used in this work was composed of three sections: upper, central, and bottom compartments. The bottom compartment serves as a feeding chamber to the central adsorption chamber while the upper compartment serves as a collecting effluent chamber. By adopting response surface methodology (RSM), in the pacts of various operational parameters such as packing level, pH, and time on the COD removal efficiency were investigated. The optimal conditions were an activated carbon packing level of 80%, pH of 5.7, and adsorption time of 73 min approximately, which resulted in a COD removal efficiency of 96.70%. The results indicated that the packing level of activated carbon had a major effect on COD elimination followed by pH, while time had a minor effect. The model equation's adequacy was demonstrated by its strong R2 value (0.975). The present study demonstrates that the adsorption system by activated carbon is an effective method for removingcondomODom Al-Diwaniyah petroleum refinery wastewaters.

Preparation, characterization, and performance of activated carbon for CO2 adsorption from CI engine exhaust

AbstractMitigation of carbon dioxide (CO2) from various sources is a major challenge in the world today. Apart from attempts to control CO2 emissions from large CO2 emitting sources such as coal‐fired power plants and significant fossil fuel‐consuming industries, there have also been attempts made to control CO2 in internal combustion (IC) engines. Compression ignition (CI) engines find their applications mainly in automotive vehicles, decentralized power generation units, standby power requirements in hospitals and educational institutions. In recent years, there has been a great interest in developing eco‐friendly and low‐cost adsorbents for CO2 capture via the adsorption method. This investigation explores the possibility of using activated carbon obtained from coconut shell for capturing CO2 in a CI engine exhaust. Surface texture characteristics and physicochemical properties of the coconut shell‐based activated carbon are determined for their suitability as a potential adsorbent for CO2 adsorption. Furthermore, an attempt is made to combine a postcombustion carbon capture device in a CI engine. For this purpose, an in‐house fabricated adsorption chamber is packed with activated carbon and attached to a single‐cylinder, four‐stroke, naturally aspirated, direct injection (DI) diesel engine exhaust. The test engine is operated on two different fuels; (i) diesel (D100) and (ii) biodiesel‐diesel blend comprising 20% of Jatropha methyl ester (JME) and 80% of diesel (JME20). The engine performance and CO2 emission without and with the adsorption chamber are evaluated for D100 and JME20 operations. Further, the performance parameters of the adsorption chamber packed with activated carbon are also evaluated in both fuel operations. The results are analyzed, discussed, and presented in this paper. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.

Exergy analysis of vacuum ice production device by solid adsorption

This paper proposes a vacuum ice production device by solid adsorption. An analysis model related to exergy loss and exergy efficiency is established in each component of the vacuum flash ice making system. By comparing the exergy analysis results of adsorption vacuum ice production device and condensing vacuum ice production, this paper has drown an effective method to reduce exergy loss. It has been found that the exergy efficiency of the adsorption vacuum ice production device is 9.64% higher than that of the condensing vacuum ice production device. The exergy efficiency of water vapor adsorption in the adsorption chamber is the highest, while the exergy efficiency of water vapor adsorption in the condensation chamber is the lowest. In order to reduce the energy demand of the device, the heat released by the condenser should be fully utilized to reduce the exergy loss of the condenser. At the same time, the heat and mass transfer of the flash evaporation process should be enhanced when designing the flash chamber, such as optimizing the ice making working fluid to improve the exergy efficiency of the flash chamber.

Experimental Investigation of an Intensified Heat Transfer Adsorption Bed (IHTAB) Reactor Prototype.

The first experience in the operation of intensified heat transfer adsorption bed reactor designed for low-pressure adsorption processes is presented in this paper. This work aims to assess the possibility of fluidizing the porous media bed induced by the pressure difference between the evaporator and the adsorption reactor. The conducted experimental research allowed indicating the type of silica gel recommended to use in fluidized beds of adsorption chiller. The fixed bed of silica gel was observed for the lower pressure differences, while fluidization appeared in the case of the pressure difference between the evaporator and the adsorption chamber higher than 1000 Pa. The most significant differences in the adsorption process between the fixed bed and the fluidized bed are revealed in the changes of sorbent temperatures. The silica gel bed was fluidized with water vapor generated in the evaporator.

Sustainable Water Purification and Energy Generation Over Crystalline Chitosan Grafted Polyaniline Composite

The present research demonstrates the design and development of a dual-compartment water purification proto-plant for microbial degradation of organic waste using microbial fuel cell technology and adsorptive removal of inorganic pollutants present in sewage water using highly crystalline chitosan grafted polyaniline (CHIT-g-PANI) and rice husk derived adsorbent. The materials were characterized by UV–Vis, infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and relevant standard methods. The observed results revealed the highly crystalline, biocompatible, porous nature of CHIT-g-PANI as electrode materials for effective microbial degradation of organic wastes of sewage water for generating electricity and water purification. Thus, observed parameters were power density of 6.496 w/m2, sustainable usability for 20 days, and removal of organic waste by 97% from sewage water. Furthermore, the above partially treated water was passed through an adsorption chamber filled with rice husk-derived adsorbents, which removes the 84.5% inorganic impurities of its original concentrations.

Management of Produced Water from Niger Delta Oilfield with Modified Agricultural Waste

Hydrocarbon reservoirs contain produced water as one of its constituents. Produced water most times contains toxic materials and other impurities that affect the ecosystem. Most of the available treatment techniques have not been very effective in reducing some of the contaminants to an acceptable disposal limits.Banana peels was washed with clean water, dried under the sun for three days, and oven-dried at 105±5o C for 3 hours. It was milled, sieved (150 and 300 microns,), and then treated with 0.4mol/L HNO3 , rinsed with clean water to remove any pigment that might interfere with the result. Sample (produced water) was treated in adsorption chamber for 4 hours using 150 micron size of adsorbent. Treatment was repeated with 300 micron size. Treated sample was analyzed and characterized. For the 150 micron size, the percentage reductions for the metals concentration (Pb, Ni, Cd, Cu, Fe, Mg, Cr, Zn, Mn, Ca, Ar, B, Sn, Ba) were found to be 87.18%, 23.08%, 42.86%, 100%, 80.12%, 34.33%, 28.93%, 45.40%, 47.89%, 97.18%, 33.06%, 43.24%, 62.50%, and 44.44% respectively. Similar reductions in same metals with 300 micron size were equally obtained. The finer adsorbent was more effective. Langmuir model best described the adsorption of lead with isotherm R2 of 0.98, while Freundlich described the adsorption of nickel and iron, with isotherms R2 of 0.85 and 0.93 respectively. Produced water from Niger Delta oil field was effectively treated of contaminants using banana peels with 150 micron size produced the best result.

Preferential SOx Adsorption in Mg-MOF-74 from a Humid Acid Gas Stream.

The preferential adsorption of SOx versus water in Mg-MOF-74 from a humid SOx gas stream has been investigated via materials studies and nuclear magnetic resonance (NMR). Mg-MOF-74 has been synthesized and subsequently loaded simultaneously with water vapor and SOx (62-96 ppm) in an adsorption chamber at room temperature over a time period of 4 days with a sample taken every 24 h. Each sample was analyzed by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA)-mass spectrometry, and scanning electron microscopy-energy-dispersive spectroscopy. The metal-organic framework (MOF) showed retained crystallinity and peak intensity in PXRD, and after 2 days, it showed no obvious degradation to the structure. Use of multiple techniques, including TGA, identified 10% by weight of SOx species, specifically H2S and SO2, within the MOF. 1H solid-state NMR shows a substantial reduction of H2O when SOx is present, which is consistent with SOx preferentially binding to the oxophilic metal site of the framework. After 14 weeks aging, the sulfur remains present in the three-dimensional MOF, with only half being desorbed after 23 weeks in air.

Small Angle X-ray Scattering Test of Hami Coal Sample Nanostructure Parameters with Gas Adsorbed Under Different Pressures.

The complexity and multiscale structure of coal pores significantly influence the gas diffusion and seepage characteristics of coal. To apply small angle X-ray scattering (SAXS) to study the coal pore structure parameters within the scale of 1-100 nm in the methane adsorption process, the X-ray window was optimized and a gas adsorption chamber was designed to interface with the small angle X-ray scattering platform. The fractal dimension and porosity of Hami coal samples under different methane pressures were studied using the small angle X-ray scattering platform and adsorption chamber. The surface and nanopore fractal information of the nanopores in coal were distinguished. The variation trends of the pores and surface fractal dimension with time under the same methane pressure were compared. The results indicate that the surface dimension changes from 2.56 to 2.75, and the extremum point may indicate that the primary nanopore structure is crushed by the adsorbed gas after approximately 15 minutes. This work clarifies that the fractal dimension can characterize the changes in nanopores in the process of gas adsorption by using SAXS. According to the fractal characteristics, the adsorption of gas in coal nanopores is summarized as four steps: expansion from adsorbance, deformation, crushing and recombination. The minimum porosity is 0.95% and the extreme value point is 1.47%. This work also shows that decrease in surface energy affect the porosity changes in nano-size pores. This work is of some significance to coalbed methane permeability improvement and gas extraction.

Prediction of Sorption Processes Using the Deep Learning Methods (Long Short-Term Memory)

The paper introduces the artificial intelligence (AI) approach for modeling fluidized adsorption beds. The idea of fluidized bed application allows a significantly increased heat transfer coefficient between adsorption bed and the surface of a heat exchanger, improving the performance of adsorption cooling and desalination systems. The Long Short-Term Memory (LSTM) network algorithm was used, classified as a deep learning method, to predict the vapor mass quantity in the adsorption bed. The research used an LSTM network with two hidden layers. The network used in the study is composed of seven inputs (absolute pressures in the adsorption chamber and evaporator, the temperatures in adsorption chamber and evaporator, relative pressure, the temperatures in the center of adsorption bed and 25 mm from the bed center, the kind of the solids mixture, the percentage value of the addition) and one output (mass of the sorption bed). The paper presents numerical research concerning mass prediction with the algorithm mentioned above for three sorbents in fixed ad fluidized beds. The results obtained by the developed algorithm of the LSTM network and the experimental tests are in good agreement of the matching the results above 0.95.

The Thermodynamics‐Based Benchmarking Analysis on Energy‐Efficiency Performance of CO2 Capture Technology: Temperature Swing Adsorption as Case Study

Based on the principle of thermodynamics, this study proposes a benchmarking analysis framework for evaluating the energy efficiency of carbon capture technology. First, the boundary and elements for the benchmarking framework are defined. Then, the specific heat consumption, coefficient of CO2 capture performance, and exergy efficiency are calculated as indicators for the benchmarking analysis using a general calculation method. Second, benchmarking analysis is conducted using performance data from the literature for a temperature swing adsorption (TSA) case study. Previous research is used to classify energy consumption into three TSA boundary levels: adsorbent, adsorption chamber, and adsorption system. Third, a more complete benchmarking analysis is presented based on cyclic data from a self‐coded TSA simulation program. The influence of regeneration temperature and regeneration partial pressure on the energy‐efficiency performance is analyzed to demonstrate the viability and fairness of the proposed benchmarking analysis method. Finally, the ways to obtain standard data for the proposed benchmarking analysis via experimental methods are discussed. The proposed method can be used to guide the current design of TSA‐based carbon capture technology toward optimal energy efficiency.

Design of Ammonia Gas Measurement System using TGS-826 Sensor, Arduino Nano Microcontroller, 16x2 LCD, and Micro SD Module

Design of ammonia gas measurement system using TGS-826 sensor, Arduino Nano microcontroller, 16x2 LCD and micro SD module has been successfully carried out. Design was created with the help of SketchUp application. System design that has been made consists of ammonia adsorption chamber and electronic components in the form of a TGS-826 sensor, Arduino Nano microcontroller, 16x2 LCD and micro SD module. Working principle of the system that has been designed begins with the active sensor TGS-826 in detecting ammonia gas. Output from the sensor is then forwarded to the Arduino Nano microcontroller for processing. Processed data is then displayed by 16x2 LCD and the ammonia gas measurement data will automatically be stored in the micro SD module. Results of this design will make it easier in making the system.

Experimental investigation of multilayered graphene systems for hydrogen storage

The present work provides a comprehensive study of hydrogen uptake and storage in multilayered graphene systems, namely graphene nanoplatelets (GNP), supported by quantitative experimental investigations. For this purpose, a customized Sievert’s Apparatus is fabricated to handle the cryogenic temperatures and pressures up to 5 bar. GNP was characterized using high resolution transmission electron microscopy, x-ray diffraction and Raman spectroscopy to determine the number of layers and presence of defects. Adsorption studies of molecular hydrogen on GNP have been conducted at three different temperatures of 298 K, 243 K and 99 K, all cases explored up to 2 bar pressure in the adsorption chamber. The maximum gravimetric density of 2.47 wt% have been observed at temperature of 99 K and 2 bar pressure. The nature of hydrogen storage between the GNP layers at different experimental conditions, its bearing on the quantity and stability is analyzed by developing a modified version of the expanded graphite model. Further, the improvement in the performance of the multi-layered graphene system is discussed and correlated experimentally to possible aiding of hydrogen storage through formation of physisorption channel.

Evaluation of on-stream industrial CO 2 adsorbent in air pretreatment for cryogenic production of oxygen

Abstract This study devises a laboratory testing methodology for commercial CO2 adsorbents to mimic their adsorption behaviors in industrial adsorption chamber. The methodology proposes to use “dense loading procedure” for adsorbent packing, concentrated CO2 feed such as 0.2 vol% CO2, and curve fitting of breakthrough curve using Boltzmann function. Application of the testing methodology for process study including regeneration protocol and dual bed adsorbent ratio of an industrial adsorption chamber has been demonstrated. The loss of breakthrough CO2 capacity is attributed to the weakening of adsorption strength of the processing adsorbent over long on-stream operation.

Numerical investigations and mathematical models of carbon capture by adsorption-A review

The concentration of CO2 in the atmosphere, which causes a serious impact on the climate, provided a development space for the carbon capture technology. The adsorption technology for carbon dioxide capture has been extensively studied because of its low energy consumption. The experimental study on carbon dioxide capture adsorption technology, which commonly require enough time-consuming and funding, determines the significance of numerical investigation. In this paper, the progress on numerical investigation and mathematical model of heat transfer and mass transfer in the adsorption chamber is reviewed. The simplified method of the adsorption process is analyzed in the following aspects: the mass transfer process is commonly simplified as the adsorption kinetic model and the adsorption equilibrium model, the pressure loss is expressed by the bed pressure drop, and the heat transfer process is analyzed by the temperature distribution in the adsorption chamber. The construction and application of various researchers’ models are finally summarized in this paper.

Interfacial Growth of TiO2-rGO Composite by Pickering Emulsion for Photocatalytic Degradation.

A 2D sandwich-like TiO2-rGO composite was fabricated by the Pickering emulsion approach to improve the photocatalytic efficiency. Through an in situ growth of antase-TiO2 nanoparticles on the interface of O/W type GO Pickering emulsion, TiO2 nanoparticles were closely and densely packed on the surface of well-exfoliated rGO sheets; meanwhile, many mesoporous voids acting as the adsorption chamber and microreactor were produced. Evaluated by methylene blue (MB) degradation, its photocatalytic activity was prominent compared with the common TiO2-based photocatalyst, with the rate constants 5 and 3.1 times higher under visible light and xenon lamp, respectively. When we applied it in the photocatalytic degradation of tetracycline hydrochloride (TCH, such as 10 ppm) under the visible light without adding any oxidants, the total removal efficiency was as high as 94% after 40 min. The mechanism of this good photocatalytic efficiency was illustrated by the scavenger trapping tests, which showed that this unique structure of TiO2-rGO composite induced by the Pickering emulsion can significantly enhance the light absorption ability, accelerate the separation rate of electron-hole pairs, increase the adsorption capacity of organic pollutants, and hence improve the photocatalytic efficiency.