4.6 Article

Greenhouse Gas (CHF3) Separation by Gas Hydrate Formation

Journal

ACS SUSTAINABLE CHEMISTRY & ENGINEERING
Volume 5, Issue 6, Pages 5485-5492

Publisher

AMER CHEMICAL SOC
DOI: 10.1021/acssuschemeng.7b00821

Keywords

F-gas separation; Gas hydrate; CHF3; Greenhouse gas

Funding

  1. Midcareer Research Program through the National Research Foundation of Korea (NRF) by the Ministry of Science, ICT & Future Planning [NRF-2014R1A2A1A11049950]
  2. Korea Institute of Energy Technology Evaluation and Planning (KETEP) through Human Resources Program in Energy Technology - Ministry of Trade, Industry and Energy, Republic of Korea [20164030201010]

Ask authors/readers for more resources

In this study, the feasibility of gas hydrate-based greenhouse gas (CHF3) separation was investigated with a primary focus on thermodynamic, structural, and cage-filling characteristics of CHF3 + N-2 hydrates. The three-phase (hydrate (H)-liquid water (L-w)-vapor (V)) equilibria of CHF3 (10%, 20%, 40%, 60%, and 80%) + N-2 + water systems provided the thermodynamic stability conditions of CHF3 + N-2 hydrates. Powder X-ray diffraction revealed that the structure of the CHF3 + N-2 hydrates was identified as sI (Pm3n) for all the CHF3 concentration ranges considered in this study. A pressure composition diagram obtained at two different temperature conditions (279.15 and 283.15 K) demonstrated that 40% CHF3 could be enriched to 88% CHF3 by only one step of hydrate formation and that separation efficiency was higher at the lower temperature. Furthermore, Raman spectroscopy revealed that CHF3 molecules preferentially occupy large (5(12)6(2)) cages of the structure I (sI) hydrate during CHF3 + N-2 hydrate formation. The overall experimental results clearly demonstrated that the hydrate-based separation process can offer highly concentrated CHF3 and would be more effective for recovering CHF3 from exhaust gas when it constitutes a hybrid system with existing separation methods.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

Article Engineering, Environmental

Mechanism and kinetics of guest exchange in sII hydrate - Flue gas replacement as revealed by experimental and computational approaches for hydrocarbon recovery and CO2 sequestration

Wonjung Choi, Woojin Go, Yohan Lee, Junghoon Mok, Yongwon Seo

Summary: This study investigated the kinetics of guest exchange in sII hydrate - flue gas replacement and elucidated the replacement mechanism and guest exchange characteristics. The results showed that at higher pressure during replacement, increased CO2 inclusion led to higher production of CH4 and C3H8 and a lower N-2/CO2 ratio in the hydrate phase. Additionally, molecular dynamics simulations demonstrated that the expansion or shrinkage of hydrate cages caused by guest exchange had a significant impact on the lattice parameter of the replaced hydrates.

CHEMICAL ENGINEERING JOURNAL (2021)

Article Thermodynamics

Experimental investigation of the exact role of large-molecule guest substances (LMGSs) in determining phase equilibria and structures of natural gas hydrates

Joonseop Lee, Dongyoung Lee, Yongwon Seo

Summary: This study investigated the complex phase behavior and structures of natural gas hydrates containing large molecule guest substances (LMGSs). Methylcyclopentane (MCP) and 2,2-dimethylbutane (neohexane, NH) were chosen as LMGSs for CH4 (90%) + C3H8 (10%) hydrates. The presence of LMGSs did not affect the equilibrium curves of the CH4 + C3H8 hydrates, with CH4 and LMGSs primarily in sH and CH4 and C3H8 encapsulated in sII. The experimental results provide insights into the role of LMGSs in natural gas hydrates.

ENERGY (2021)

Article Multidisciplinary Sciences

Connectivity-informed drainage network generation using deep convolution generative adversarial networks

Sung Eun Kim, Yongwon Seo, Junshik Hwang, Hongkyu Yoon, Jonghyun Lee

Summary: Stochastic network modeling is often limited by high computational costs, but this study shows that DCGANs can effectively reproduce drainage networks using a novel connectivity-informed method. By converting drainage network images to directional information and training the network with different samples, DCGANs outperformed traditional methods in generating accurate drainage networks. This highlights the potential of DCGANs in high contrast images common in earth and material sciences.

SCIENTIFIC REPORTS (2021)

Article Engineering, Environmental

Separation efficiency and equilibrium recovery ratio of SF6 in hydrate-based greenhouse gas separation

Gyeol Ko, Joonseop Lee, Yongwon Seo

Summary: The feasibility of hydrate-based sulfur hexafluoride (SF6) separation was examined by measuring the three-phase equilibria of SF6 + N-2 hydrates, constructing a pressure-composition diagram, identifying the hydrate type using powder X-ray diffraction, and measuring the dissociation enthalpy with a high-pressure micro-differential scanning calorimeter. Experimental results demonstrated the selective capture of SF6 in the hydrate phase, with the hydrate-based method requiring lower initial concentration and pressure compared to the liquefaction method.

CHEMICAL ENGINEERING JOURNAL (2021)

Article Energy & Fuels

Complex Phase Behaviors and Structural Coexistence of Natural Gas Hydrates Containing Large-Molecule Guest Substances

Joonseop Lee, Gyeol Ko, Junghoon Mok, Yongwon Seo

Summary: The study investigated the complex phase behaviors and structural coexistence of NGHs containing LMGSs, revealing the coexistence of sII and sH hydrates in CH4 + C2H6 + LMGS + water mixtures through NMR and PXRD analysis. The findings provide insights into the formation and dissociation processes of these hydrates, with sII being the final structure at equilibrium dissociation points.

ENERGY & FUELS (2021)

Article Thermodynamics

Optimal driving force for the dissociation of CH4 hydrates in hydrate-bearing sediments using depressurization

Wonjung Choi, Junghoon Mok, Yohan Lee, Jaehyoung Lee, Yongwon Seo

Summary: The study experimentally investigated three driving forces for the dissociation of CH4 hydrates and found that a constant modified chemical potential-based driving force (Δμ) can consistently control the depressurization process, demonstrating remarkable consistency across a wide temperature range.

ENERGY (2021)

Article Engineering, Environmental

Evaluation of kinetic salt-en ric hment behavior and separation performance of HFC-152a hydrate-based desalination using an experimental measurement and a thermodynamic correlation

Junghoon Mok, Wonjung Choi, Yongwon Seo

Summary: This study investigated the thermodynamic stability and kinetic growth behavior of HFC-152a hydrate, finding that HFC-152a hydrate has a higher hydration capacity in the presence of NaCl. The results suggest that HFC-152a may be a superior candidate for the HBD process.

WATER RESEARCH (2021)

Article Thermodynamics

Effects of pressure and temperature conditions on thermodynamic and kinetic guest exchange behaviors of CH4 - CO2 + N2 replacement for energy recovery and greenhouse gas storage

Junghoon Mok, Wonjung Choi, Jonghyuk Lee, Yongwon Seo

Summary: The guest swapping process of CH4 - CO2 + N-2 replacement in NGH reservoirs can be influenced by pressure and temperature conditions, leading to accelerated CO2 and enhanced N-2 inclusion during the replacement process. This study provides valuable insights into the replacement mechanism occurring in NGH reservoirs with different conditions.

ENERGY (2022)

Article Engineering, Environmental

Synergistic inhibition effects of hydrophilic monomeric substances on CH4 hydrate as revealed by experimental and computational approaches

Woojin Go, Dongyoung Lee, Yongwon Seo

Summary: The study suggests that glycine is the best kinetic hydrate inhibitor among urea, acetamide, and glycine, while combinations of urea and acetamide, urea and glycine, and acetamide and glycine, show synergistic inhibition effects on CH4 hydrate. Among these combinations, urea and acetamide exhibit the best synergism. The findings also highlight the potential of hydrophilic monomeric substances as effective KHIs and propose a new method to understand the mechanism of hydrate inhibition through experimental and computational analyses.

CHEMICAL ENGINEERING JOURNAL (2021)

Article Engineering, Chemical

Theoretically achievable efficiency of hydrate-based desalination and its significance for evaluating kinetic desalination performance of gaseous hydrate formers

Junghoon Mok, Wonjung Choi, Yongwon Seo

Summary: This study examined the thermodynamic and kinetic features of different gas hydrate formers to determine the energy-efficient gaseous hydrate former for hydrate-based desalination (HBD). The results showed that the efficiency of HBD was affected by factors such as initial salinity, operating pressure, and initial subcooling temperature. The study also found that the thermodynamic stability and intrinsic formation kinetics of gas hydrates significantly impacted HBD efficiency.

DESALINATION (2022)

Article Green & Sustainable Science & Technology

Optimal absorbents of CO2 hydrate formation and energy consumption analysis for district cooling application under low pressure conditions

Jungjoon Park, Joon Ho Park, Dongyoung Lee, Yongwon Seo, Yong Tae Kang

Summary: Hydrate-based CO2 capture technology has vast potential and cost effectiveness. However, the direct capture and utilization of hydrate slurries are challenging. Thermodynamic promoters have been introduced to alleviate the formation conditions. By evaluating key parameters, optimal conditions for hydrate slurry-based cold thermal transportation are determined. It is proposed to replace conventional systems with a CO2 hydrate slurry cooling system, demonstrating a significant reduction in energy consumption.

JOURNAL OF CLEANER PRODUCTION (2022)

Article Engineering, Environmental

Efficient dual-function inhibitors for prevention of gas hydrate formation and CO2/H2S corrosion inside oil and gas pipelines

Abdolreza Farhadian, Woojin Go, Soyeong Yun, Alireza Rahimi, Mohammad Reza Nabid, Danial Iravani, Yongwon Seo

Summary: In this study, the performance of newly synthesized waterborne polyurethanes (WPUs) as dual-function gas hydrate and corrosion inhibitors was evaluated through experimental and computational approaches. The results showed that WPUs effectively inhibited hydrate formation and protected against corrosive gases.

CHEMICAL ENGINEERING JOURNAL (2022)

Article Engineering, Environmental

Fused aromatic networks as a new class of gas hydrate inhibitors

Hyuk-Jun Noh, Dongyoung Lee, Woojin Go, Gyucheol Choi, Yoon-Kwang Im, Javeed Mahmood, Yongwon Seo, Jong-Beom Baek

Summary: Fused aromatic networks (FANs) have attracted attention due to their electronic properties and stability. 3D organic networks and 2D layered structures were found to be effective gas hydrate inhibitors with outstanding stability under high-pressure/low-temperature conditions.

CHEMICAL ENGINEERING JOURNAL (2022)

Article Thermodynamics

Experimental and computational investigation of hydrophilic monomeric substances as novel CO2 hydrate inhibitors and potential synergists

Woojin Go, Soyeong Yun, Dongyoung Lee, Yongwon Seo

Summary: This study evaluated easily decomposable monomeric substances as kinetic hydrate inhibitors for CO2 hydrate. Experimental and computational results showed that glycine exhibited the best inhibition effect among single inhibitors, and combinations of urea with acetamide and acetamide with glycine had synergistic inhibition effects on CO2 hydrate. Molecular dynamics simulations provided insights into the nucleation and formation behaviors of CO2 hydrate in the presence of inhibitors. The findings contribute to the development of new biodegradable CO2 hydrate inhibitors and enhance the safety of CO2 transportation and storage.

ENERGY (2022)

Article Chemistry, Physical

Thermodynamic and structural features of chlorodifluoromethane (a sI-sII dual hydrate former) plus external guest (N2 or CH4) hydrates and their significance for greenhouse gas separation

Junghoon Mok, Junkyu Lim, Wonjung Choi, Soyeong Yun, Joonseop Lee, Gyeol Ko, Yongwon Seo

Summary: A new sI-sII dual hydrate former was investigated for its potential significance in gas separation, showing that external guests like CH4 and N-2 can promote the formation of sII hydrates with CHClF2. The study revealed the thermodynamic and structural features of CHClF2 hydrates, providing insights for understanding and designing the hydrate-based CHClF2 separation process.

PHYSICAL CHEMISTRY CHEMICAL PHYSICS (2021)

No Data Available