44 research outputs found
CO2 capture and storage from power plant flue gas using gas hydrate-based technologies
The climate system is changing globally, and there is substantial evidence that subsea
permafrost and gas hydrate reservoirs are melting in high-latitude regions of the Earth,
resulting in large volumes of CO2 (from organic carbon deposits) and CH4 (from gas
hydrate reserves) venting into the atmosphere. As one of the main contributors to global
climate change, power plants produce a substantial proportion of global anthropogenic
CO2 emissions. Here, we developed techniques to capture and storage CO2 (CCS) present
in power plant flue gases based on gas hydrate technologies. First, we experimentally
measured the thermodynamic properties of different flue gases, followed by modelling
and tuning the equations of states. Second, we proposed injection of flue gas into methane
gas hydrate reservoirs as an option for economically sustainable production of natural gas
as well as CCS. The optimum injection conditions were found and reaction kinetics was
investigated in realistic conditions and well characterised systems. Third, kinetics of flue
gas hydrate formation for both the geological storage of CO2 and the secondary sealing
of CH4/CO2 release in one simple process was investigated, followed be thoroughly
investigation of hydrate formation kinetics using a highly accurate in house developed
device. Finally, effect of the proposed methods on permeability and mechanical strength
of the geological formations was investigated
Hydrogen energy futures – foraging or farming?
Exploration for commercially viable natural hydrogen accumulations within the Earth's crust, here compared to ‘foraging’ for wild food, holds promise. However, a potentially more effective strategy lies in the in situ artificial generation of hydrogen in natural underground reservoirs, akin to ‘farming’. Both biotic and abiotic processes can be employed, converting introduced or indigenous components, gases, and nutrients into hydrogen. Through studying natural hydrogen-generating reactions, we can discern pathways for optimized engineering. Some reactions may be inherently slow, allowing for a ‘seed and leave’ methodology, where sites are infused with gases, nutrients, and specific bacterial strains, then left to gradually produce hydrogen. However, other reactions could offer quicker outcomes to harvest hydrogen. A crucial element of this strategy is our innovative concept of ‘X’ components—ranging from trace minerals to bioengineered microbes. These designed components enhance biotic and/or abiotic reactions and prove vital in accelerating hydrogen production. Drawing parallels with our ancestors' transition from hunter-gathering to agriculture, we propose a similar paradigm shift in the pursuit of hydrogen energy. As we transition towards a hydrogen-centric energy landscape, the amalgamation of geochemistry, advanced biology, and engineering emerges as a beacon, signalling a pathway towards a sustainable and transformative energy future
Surface Chemistry Can Unlock Drivers of Surface Stability of SARS-CoV-2 in Variety of Environmental Conditions
The surface stability and resulting transmission of the SARS-CoV-2, specifically in indoor environments, have been identified as a potential pandemic challenge requiring investigation. This novel virus can be found on various surfaces in contaminated sites such as clinical places, however, the behaviour and molecular interactions of the virus with respect to the surfaces are poorly understood. Regarding this, the virus adsorption onto solid surfaces can play a critical role in transmission and survival in various environments. In this article, firstly an overview of existing knowledge concerning viral spread, molecular structure of SARS-CoV-2, and the virus surface stability is presented. Then, we highlight potential drivers of the SARS-CoV-2 surface adsorption and stability in various environmental conditions. This theoretical analysis shows that different surface and environmental conditions including temperature, humidity, and pH are crucial considerations in building fundamental understanding of the virus transmission and thereby improving safety practices
Understanding Hysteresis and Gas Trapping in Dissociating Hydrate-Bearing Sediments Using Pore Network Modeling and Three-Dimensional Imaging
Development of a coupled geophysical–geothermal scheme for quantification of hydrates in gas hydrate-bearing permafrost sediments
Geochemical interactions in geological hydrogen Storage: The role of sandstone clay content
Hydrogen holds promise as a clean energy alternative, crucial for achieving global decarbonization goals and net-zero carbon emissions. Its low volumetric energy density necessitates underground storage in sandstone formations to maintain year-round supply. The efficacy of such storage hinges on the geochemical interplay between hydrogen and the host sandstone. Despite the slow reaction rates in sandstone, the influence of its clay composition on hydrogen interaction remains underexplored. In this study, we specifically investigate the geochemical interactions of hydrogen with clay-bearing sandstone formations under controlled conditions, simulating storage scenarios. This study evaluates the impact of clay on hydrogen-sandstone geochemistry after 75 days of injection at 1500 psi and 75 °C into Berea and Bandera gray sandstone cores, utilizing microcomputed tomography to assess changes in pore structure. Our results reveal that, even in sandstones with high clay content, there is negligible alteration in porosity and mineral content, as well as minimal clay and quartz dissolution or expansion over storage time, indicating stability in these formations. These findings provide crucial insights for selecting suitable geological formations for hydrogen storage, supporting the global shift towards sustainable energy systems Our study contributes to the global efforts in decarbonization by providing essential guidance on the feasibility of using clay-bearing sandstone formations for efficient and sustainable hydrogen storage
Insights into the climate-driven evolution of gas hydrate-bearing permafrost sediments: implications for prediction of environmental impacts and security of energy in cold regions
The present study investigates the evolution of gas hydrate-bearing permafrost sediments against the environmental temperature change. The elastic wave velocities and effective thermal conductivity (ETC) of simulated gas hydrate-bearing sediment samples were measured at a typical range of temperature in permafrost and wide range of hydrate saturation. The experimental results reveal the influence of several complex and interdependent pore-scale factors on the elastic wave velocities and ETC. It was observed that the geophysical and geothermal properties of the system are essentially governed by the thermal state, saturation and more significantly, pore-scale distribution of the co-existing phases. In particular, unfrozen water content substantially controls the heat transfer at sub-zero temperatures close to the freezing point. A conceptual pore-scale model was also proposed to describe the pore-scale distribution of each phase in a typical gas hydrate-bearing permafrost sediment. This study underpins necessity of distinguishing ice from gas hydrates in frozen sediments, and its outcome is essential to be considered not only for development of large-scale permafrost monitoring systems, bus also accurate quantification of natural gas hydrate as a potential sustainable energy resource in cold regions
Lined rock caverns:A hydrogen storage solution
The inherent intermittency of renewable energy sources frequently leads to variable power outputs, challenging the reliability of our power supply. An evolving approach to mitigate these inconsistencies is the conversion of excess energy into hydrogen. Yet, the pursuit of safe and efficient hydrogen storage methods endures. In this perspective paper, we conduct a comprehensive evaluation of the potential of lined rock caverns (LRCs) for hydrogen storage. We provide a detailed exploration of all system components and their associated challenges. While LRCs have demonstrated effectiveness in storing various materials, their suitability for hydrogen storage remains a largely uncharted territory. Drawing from empirical data and practical applications, we delineate the unique challenges entailed in employing LRCs for hydrogen storage. Additionally, we identify promising avenues for advancement and underscore crucial research directions to unlock the full potential of LRCs in hydrogen storage applications. The foundational infrastructure and associated risks of large-scale hydrogen storage within LRCs necessitate thorough examination. This work not only highlights challenges but also prospects, with the aim of accelerating the realization of this innovative storage technology on a practical, field-scale level.</p