Basic Engineering Design for Natural Gas Processing Projects

Shirazian

2018

J. Phys. Chem. C

The high reactivity of lithium with gas molecules under ambient conditions plays a key role, negative or positive, depending on the purpose, in its wide applications. However, the underlying mechanism is still unclear. A facilitated dissociation of water in the presence of lithium (Li) under ambient conditions is revealed using molecular simulations. The subsequent reactions with other gases are investigated to elucidate the role of water in enabling lithium–gas reactions. The in-depth understanding of controlled lithium reactively opens up a new avenue of designing highly selective gas separation processes. A controlled exclusive reaction of lithium with nitrogen in the nitrogen/methane mixture would provide infinite selectivity of nitrogen over methane, revolutionizing the natural gas purification industry.

Section: Introductionmentioning

confidence: 99%

Facilitated Dissociation of Water in the Presence of Lithium Metal at Ambient Temperature as a Requisite for Lithium–Gas Reactions

Shirazian

2018

J. Phys. Chem. C

“…There are some experimental research studies on the density of the H 2 –CO 2 and H 2 –CO 2 –CH 4 mixtures and the H 2 –CO 2 –CH 4 –CO–H 2 O system in the supercritical region of water. , There are also some numerical research studies on the density, − specific heat, thermal conductivity, and viscosity of the hydrogen mixtures at high temperatures and high pressures. The Reynolds number and the flow regime of the working fluid, which is important in the design of the pumps and tubes, are closely related to the viscosity of the working fluid. − The viscosity data of the working fluid are also needed for the estimation of the temperature field inside the flow system . Therefore, the viscosity of the hydrogen mixtures is important for the design and optimization of the gasification system.…”

Section: Introductionmentioning

confidence: 99%

Viscosity Measurements of the H₂–CO₂, H₂–CO₂–CH₄, and H₂–H₂O Mixtures and the H₂–CO₂–CH₄–CO–H₂O System at 280–924 K and 0.7–33.1 MPa with a Capillary Apparatus

Cheng

et al. 2020

J. Chem. Eng. Data

The viscosity of hydrogen mixtures in the supercritical region of water is significant for the optimization of the gasification process of organic substances in supercritical water. In this work, a capillary apparatus was developed for measuring the viscosity of fluids and their mixtures at 279−980 K and up to 34 MPa. The viscosities of pure water, nitrogen, and hydrogen at 279−980 K and 0.5−31.0 MPa were measured, and the results were compared with the reference equations. Then, the viscosities of the H 2 − CO 2 and H 2 −CO 2 −CH 4 mixtures at 280−677 K and 0.7−33.1 MPa and of the H 2 −H 2 O mixtures and the H 2 −CO 2 −CH 4 −CO−H 2 O system at 720−924 K and 19.9−31.1 MPa were measured. The expanded relative uncertainty (k = 2) for the dynamic viscosity was estimated as 0.05. The viscosity data of the hydrogen mixtures were compared with those predicted using the equation of Wilke considering the nonideal gas effect. The absolute relative deviations between the calculated and experimental dynamic viscosities are less than 4.87%.

“…from different sources, such as raw or pretreated natural gas, postcombustion flue gas, biogas, etc. , Among various practices, N 2 removal from pretreated natural gas streams, which mainly contains N 2 and CH 4 , is of great interest to achieve a high-purity CH 4 stream as methane is regarded as a source of clean energy that generates much lower emissions than coal . Such a practice is one of the most challenging gas separation applications − because of the similar physical chemistry properties between these two molecules. In addition, industrial applications require separation techniques to be cost-effective and highly efficient .…”

Section: Introductionmentioning

confidence: 99%

Theoretical Study of Moisture-Pretreated Lithium as Potential Material for Natural Gas Upgrading

Hanif

et al. 2018

Ind. Eng. Chem. Res.

For efficient natural gas upgrading at near ambient temperatures, moisture-pretreated lithium is proposed as a reactive adsorbent, and its separation performance was examined for selected gas mixtures (involving combination of CH 4 , CO 2 , O 2 , N 2 , and/or H 2 ) by theoretical studies. For evaluating the proposed adsorbent, we used density functional theory calculations as well as temperature-programmed kinetic Monte Carlo calculations. Contributions of different mechanisms for the gas capture were examined, including diffusion, adsorption, and reaction. Among these mechanisms, reaction was found to be the dominant factor during the gas-capture process. In contrast to the conventional reactive adsorbents where gases directly react with adsorbents and thus are captured, the gas-capture mechanism herein follows the reaction between gases and species generated upon pre-exposure of lithium to moisture. The proposed separation process is thermodynamically favorable and would progress spontaneously. It is shown that for several gas mixtures containing methane, a perfect selectivity can be achieved in which a high-purity methane gas stream is the final gas product while the other gaseous components are transformed to corresponding solid products.