Effect of Adsorption Duration and Purge Flowrate on Pressure Swing Adsorption Performance

Research on Oil and Gas Adsorption Optimization Based on CFD Modeling and Process Simulation

In the process of oil extraction and refining, some of the liquid light hydrocarbon components will inevitably evaporate into the atmosphere, causing serious air pollution and safety hazards. This paper is focused on oil and gas adsorption systems to comprehensively optimize key parameters by combining computational fluid dynamics (CFD) modeling with process simulation, enabling the efficient treatment of hazardous materials. First, a CFD model of the hydrocarbon adsorption process is established to the porous media model by a user-defined function (UDF). Subsequently, the mass transfer process of oil and gas in porous media is successfully simulated to obtain the gas distribution in an industrial fixed bed adsorption tower. The adsorption tank is intensified, and the gas distribution in the tank is improved by optimizing the height-to-diameter ratio of the equipment and the design of the intake distributor. Third, the cyclic two-tank adsorption model of the pressure swing adsorption (PSA) process is established for key parameters optimization. Finally, the operating parameters and conditions of the PSA process are suspected by considering five factors affecting the adsorption efficiency: adsorption time, adsorption pressure, adsorption temperature, feed flow rate, and purge ratio of the washing step.

Continuous multi-column sorption-enhanced dimethyl ether synthesis (SEDMES): Dynamic operation

In this work the continuous production of dimethyl ether (DME) by sorption-enhanced DME synthesis (SEDMES) technology has been demonstrated for the first time with a multi-column test-rig. A continuous single-pass carbon yield up to 95%, higher than ever reported before, has been achieved. The multi-column experiments have also shown that SEDMES can be operated at lower temperatures (220°C) than previously reported. This allows a higher temperature rise, making higher conversions possible while allowing even larger reactor tube diameters. Whereas the anticipated multi-tubular reactor concept is complex and costly, larger reactors could facilitate the economic valorisation. The SEDMES reactor model cannot only describe the transient behaviour of the process during the cyclic steady-state well, but also the dynamic approach towards the cyclic steady-state is adequately captured. Capturing the dynamic operation is of large interest with respect to process flexibility, especially for Power-to-X systems.

Rational Design of Carbon-Based Porous Aerogels with Nitrogen Defects and Dedicated Interfacial Structures toward Highly Efficient CO2 Greenhouse Gas Capture and Separation

CO₂ capture from flowing flue gases through adsorption technology is essential to reduce the emission of CO₂ to the atmosphere. The rational design of highly efficient carbon-based absorbents with interfacial structures containing interconnected porous structures and abundant adsorption sites might be one of the promising strategies. Here, we report the synthesis of nitrogen-doped carbon aerogels (NCAs) via prepolymerized phenol-melamine-formaldehyde organic aerogels (PMF) by controlling the addition amount of ZnCl₂ and the precursor M/P ratio. It has been revealed that NCAs with a higher specific surface area and interconnected porous structures contain a large amount of pyridinic nitrogen and pyrrolic nitrogen. These would act as the intrinsic adsorption sites for highly effective CO₂ capture and further improve the CO₂/N₂ separation efficiencies. Among the prepared samples, NCA-1-2 with a high micropore surface area and high nitrogen content exhibits a high CO₂ adsorption capacity (4.30 mmol g^-1 at 0 °C and 1 bar) and CO₂/N₂ selectivity (36.5 at 25 °C, IAST). Under typical flue gas conditions (25 °C and 1.01 bar), equilibrium gas adsorption analysis and dynamic breakthrough measurement associated with a high adsorption capacity of 2.65 mmol g^-1 at 25 °C and 1.01 bar and 0.81 mmol g^-1 at 25 °C and 0.15 bar. This rationally designed N-doped carbon aerogel with specific interfacial structures and high CO₂ adsorption capacity, high selectivity, and adsorption performance remained pretty stable after multiple uses.

Optimization and Recovery of a Pressure Swing Adsorption Process for the Purification and Production of Bioethanol

Today, there are new technologies to produce bioethanol: one of them is the Pressure Swing Adsorption (PSA) process. This process has displaced other separation technologies due to the use of natural adsorbents and its methodology to obtain high purities with a lower energy cost. The aim of this work focuses on the optimization of the PSA process (experimental case) to obtain a higher recovery and production of bioethanol using lower energy consumption. The results are favorable since the energy cost is reduced to a range of 60% and 62%, obtaining purities above 99% wt of ethanol and recovery between 75% and 77.41%. The bioethanol produced and purified in the different scenarios meets international standards to be used as a fuel or oxygenating additive.