scholarly journals Design and fabrication of multi-functional equipment to produce gaseous nitrogen/oxygen and water from ambient air

2021 ◽  
Vol 850 (1) ◽  
pp. 012006
Author(s):  
Debdutta Chatterjee ◽  
Krishnasamy Karunamurthy ◽  
Nimmagadda Sree Nigam Aditya ◽  
Deepak Dalal
Keyword(s):  
Molecular Sieves ◽  
Potable Water ◽  
Molecular Size ◽  
Ambient Air ◽  
Water Shortage ◽  
Pure Nitrogen ◽  
Industrial Sectors ◽  
The Rich ◽  
Pressure Swing ◽  
Compressor Power

Abstract Mother earth provides all the necessary resources for the existence of life. Despite the rich resources of water on our planet, majority of world’s total population experiences water shortage annually. Studies have shown that with the increase of global warming, the average humidity of ambient air is rising annually. Due to the decrease of water table on land, alternative sources of acquiring potable water can be of great utility. Out of the several methods available to tap potable water, this paper aims to achieve an alternate source of receiving fresh water directly from ambient air. This process is completely different from distillation. The ambient air also comprises a majority of Nitrogen, and this N2 is used for the purpose of creating an inert environment in packaging industries and for the purpose of extinguishing fire, a multi-functional equipment has been fabricated in order to extract water, along with pure Nitrogen gas from the residual dry air. A Pressure Swing Adsorption (PSA) system is used to separate the Nitrogen from remaining air molecules based on their relative molecular size. In the current industrial sectors, the valves required to actuate the flow of air in PSA system are controlled by PLC circuits and Cam followers. These electro-mechanical components are overpriced. In this work electronic timers are used to actuate the valve timing, which resulted in economical. The system fabricated is simple in construction and it is easy to replace the Carbon Molecular Sieves (CMS) with Zeolite Molecular Sieves in order to obtain Oxygen gas as the pure product that can be used to help Covid-19 patients using medical grade filters. The system can be scaled up with larger mass of CMS, bigger PSA towers and greater compressor power in order to increase productivity.

scholarly journals Flexible oxygen concentrators for medical applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Akhil Arora ◽  
M. M. Faruque Hasan
Keyword(s):  
Medical Condition ◽  
Oxygen Demand ◽  
Ambient Air ◽  
Pure Oxygen ◽  
Chronic Obstructive ◽  
Performance Limits ◽  
Obstructive Pulmonary Disease ◽  
5A Zeolite ◽  
Pressure Swing ◽  
Product Specifications

AbstractMedical oxygen concentrators (MOCs) are used for supplying medical grade oxygen to prevent hypoxemia-related complications related to COVID-19, chronic obstructive pulmonary disease (COPD), chronic bronchitis and pneumonia. MOCs often use a technology called pressure swing adsorption (PSA), which relies on nitrogen-selective adsorbents for producing oxygen from ambient air. MOCs are often designed for fixed product specifications, thereby limiting their use in meeting varying product specifications caused by a change in patient’s medical condition or activity. To address this limitation, we design and optimize flexible single-bed MOC systems that are capable of meeting varying product specification requirements. Specifically, we employ a simulation-based optimization framework for optimizing flexible PSA- and pressure vacuum swing adsorption (PVSA)-based MOC systems. Detailed optimization studies are performed to benchmark the performance limits of LiX, LiLSX and 5A zeolite adsorbents. The results indicate that LiLSX outperforms both LiX and 5A, and can produce 90% pure oxygen at 21.7 L/min. Moreover, the LiLSX-based flexible PVSA system can manufacture varying levels of oxygen purity and flow rate in the range 93–95.7% and 1–15 L/min, respectively. The flexible MOC technology paves way for transitioning to an envisioned cyber-physical system with real-time oxygen demand sensing and delivery for improved patient care.

scholarly journals Experimental and theoretical investigations of traditional solar still productivity in cold climatic

2021 ◽  
Vol 2119 (1) ◽  
pp. 012096
Author(s):  
Naseer T. Alwan ◽  
S E Shcheklein ◽  
O M Ali
Keyword(s):  
Experimental Data ◽  
Solar Radiation ◽  
Potable Water ◽  
Ambient Air ◽  
Solar Still ◽  
Solar Distillation ◽  
Theoretical Investigations ◽  
Weather Parameters ◽  
Theoretical Results ◽  
Acceptable Agreement

Abstract Solar distillation is an important technology to get potable water from saltwater using clean and free solar energy. In the current study, an experimental and theoretical investigation of a single-slope traditional solar still was carried out, and the freshwater productivity and thermal efficiency were evaluated for four typical days (19/06, 17/07, 22/08, and 15/09) of 2019 by implementing temperature parameters in different points of the solar still, and the weather parameters such as solar radiation, and ambient air temperature. The study showed an acceptable agreement between the experimental and theoretical results with an average of 6.6% measured deviation of the experimental data. It was noticed that the highest values of productivity were recorded on July 17, 2019.

Desiccant Degradation in Desiccant Cooling Systems: An Experimental Study

1993 ◽  
Vol 115 (4) ◽  
pp. 212-219 ◽  
Author(s):  
A. A. Pesaran
Keyword(s):  
Thermal Cycling ◽  
Silica Gel ◽  
Molecular Sieves ◽  
Cooling System ◽  
Ambient Air ◽  
Activated Alumina ◽  
Humid Air ◽  
Cooling Systems ◽  
Degradation Data ◽  
Capacity Loss

We conducted experiments to quantify the effects of thermal cycling and exposure to contamination on solid desiccant materials that may be used in desiccant cooling systems. The source of contamination was cigarette smoke, which is considered one of the worst pollutants in building cooling applications. We exposed five different solid desiccants to “ambient” and “contaminated” humid air: silica gel, activated alumina, activated carbon, molecular sieves, and lithium chloride. We obtained the moisture capacity of samples as a function of exposure time. Compared to virgin desiccant samples, the capacity loss caused by thermal cycling with humid ambient air was 10 percent to 30 percent for all desiccants. The capacity loss because of combined effect of thermal cycling with “smoke-filled” humid air was between 30 percent to 70 percent. The higher losses occurred after four months of experiment time, which is equivalent to four to eight years of field operation. Using a system model and smoke degradation data on silica gel, we predicted that, for low-temperature regeneration, the loss in performance of a ventilation-cycle desiccant cooling system would be between 10 percent to 35 percent, in about eight years, with higher value under worst conditions.

Pressure swing adsorption separation of H2S/CO2/CH4 gas mixtures with molecular sieves 4A, 5A, and 13X

2017 ◽  
Vol 53 (10) ◽  
pp. 1490-1497
Author(s):  
Howell H. Heck ◽  
Merilyn L. Hall ◽  
Rudy dos Santos ◽  
Manolis M. Tomadakis
Keyword(s):  
Molecular Sieves ◽  
Pressure Swing Adsorption ◽  
Gas Mixtures ◽  
Pressure Swing

scholarly journals Feasibility Study of Vacuum Pressure Swing Adsorption for CO2 Capture From an SMR Hydrogen Plant: Comparison Between Synthesis Gas Capture and Tail Gas Capture

2021 ◽  
Vol 3 ◽  
Author(s):  
Yan Chen ◽  
Hyungwoong Ahn
Keyword(s):  
Feasibility Study ◽  
Synthesis Gas ◽  
Pressure Swing Adsorption ◽  
Theory Model ◽  
Vacuum Pressure ◽  
Industrial Scale ◽  
Industrial Sectors ◽  
Vacuum Pressure Swing Adsorption ◽  
Pressure Swing ◽  
Hydrogen Plant

In this paper, a feasibility study was carried out to evaluate cyclic adsorption processes for capturing CO2 from either shifted synthesis gas or H2 PSA tail gas of an industrial-scale SMR-based hydrogen plant. It is expected that hydrogen is to be widely used in place of natural gas in various industrial sectors where electrification would be rather challenging. A SMR-based hydrogen plant is currently dominant in the market, as it can produce hydrogen at scale in the most economical way. Its CO2 emission must be curtailed significantly by its integration with CCUS. Two Vacuum Pressure Swing Adsorption (VPSA) systems including a rinse step were designed to capture CO2 from an industrial-scale SMR-based hydrogen plant: one for the shifted synthesis gas and the other for the H2 PSA tail gas. Given the shapes of adsorption isotherms, zeolite 13X and activated carbon were selected for tail gas and syngas capture options, respectively. A simple Equilibrium Theory model developed for the limiting case of complete regeneration was taken to analyse the VPSA systems in this feasibility study. The process performances were compared to each other with respect to product recovery, bed productivity and power consumption. It was found that CO2 could be captured more cost-effectively from the syngas than the tail gas, unless the desorption pressure was too low. The energy consumption of the VPSA was comparable to those of the conventional MDEA processes.

Dynamic column breakthrough measurements for increasing LNG production efficiency with cryogenic pressure swing adsorption

2010 ◽  
Vol 50 (2) ◽  
pp. 738
Author(s):  
Paul Hofman ◽  
Eric May ◽  
Guillaume Watson ◽  
Brendan Graham ◽  
Mark Trebble
Keyword(s):  
Natural Gas ◽  
Molecular Sieves ◽  
Production Efficiency ◽  
Primary Energy ◽  
Global Scale ◽  
Efficient Production ◽  
Kinetics Of Adsorption ◽  
Amine Solution ◽  
Adsorption Processes ◽  
Pressure Swing

The use of natural gas as a primary energy source is rapidly increasing on a global scale. To economically transport natural gas over long distances and satisfy this increase in demand, efficient production of liquefied natural gas (LNG) is required. Prior to the liquefaction of natural gas to produce LNG, it is highly desirable to remove N2 and CO2 impurities from the reservoir feed gas. Typically, CO2 is removed using a water-based amine solution. The regeneration of this amine solution is both energy intensive and costly. Furthermore, the amine solutions used are undesirable from health and environmental standpoints. Nitrogen is generally not removed prior to the liquefaction and must be separated from the end-flash vapor produced with the LNG. Conventionally this requires the construction of distillation towers operating at cryogenic conditions. In the environment of a cryogenic gas plant, adsorption-based processes for separating gases have several natural advantages over other methods. However, very little work has been done studying the efficiency of adsorption processes at the pressures and temperatures found in LNG plants. We have constructed a dynamic column breakthrough apparatus capable of measuring equilibrium adsorption and kinetics of adsorption at temperatures between 190 and 298 K and pressures to 1 MPa. This system was used to study the adsorption behaviour of N2, CO2 and CH4 on carbon molecular sieves and zeolites. This presentation will describe the measurement results and the challenges that were overcome as well as future plans to construct a larger scale apparatus.

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