Underground hydrogen storage: A comprehensive review

Increased emissions of greenhouse gasses into the atmosphere has adversely been contributing to global warming as a result of burning fossil fuels. Therefore, the energy sectors have been looking into renewable sources such as wind, solar, and hydro energy to make electricity. However, the strongly fluctuating nature of electricity from such energy sources requires a bulk energy storage system to store the excess energy as a buffer and to fulfill the demand constantly. Underground storage is a proven way to store a huge amount of energy (electricity) after converting it into hydrogen as it has higher energy content per unit mass than other gases such as methane and natural gas. This paper reviews the technical aspects and feasibility of the underground storage of hydrogen into depleted hydrocarbon reservoirs, aquifers, and manmade underground cavity (caverns). Mechanisms of underground hydrogen storage (UHS) followed by numerous phenomena such as hydrodynamics, geochemical, physiochemical, bio-chemical, or microbial reactions have been deliberated. Modeling studies have also been incorporated in the literature to assess the feasibility of the process that are also reviewed in this paper. Worldwide ongoing lab study, field study together with potential storage sites have been reported as well. Technical challenges along with proper remedial techniques and economic viability have been briefly discussed. Finally, this paper delivers some feasible strategies for the underground hydrogen storage process, which would be helpful for future research and development of UHS.     

Investigation Into the Effects of the Patch-Type FSS Superstrate on the High-Gain Cavity Resonance Antenna Design

Results of modeling, design, simulation and fabrication are presented for a high-gain cavity resonance antenna (CRA), employing highly-reflective patch-type superstrates. In order to determine the resonant conditions, the antenna is first analyzed using the transverse equivalent network (TEN) model, as well as the well known simple ray-tracing method. Prior to that, a highly-reflective patch-type frequency selective surface (FSS) is designed in order to be employed as the superstrate layer of the CRA. Next, a 2.5-D full-wave analysis software package, based on the method of moments (ANSOFT Designer v4.0), is utilized to analyze the antenna structure. Using this full-wave analyzer, the input impedance properties of an actual antenna are investigated as well. Then, a 3-D full-wave analyzer, based on the finite element method (ANSOFT HFSS), is used to extract the directivity and radiation patterns of the CRA, taking into account the finiteness of the substrate, superstrate and ground plane. Some previously unaddressed issues, such as the effects of the FSS superstrate on the input impedance characteristics of the probe-fed microstrip patch antenna, acting as the excitation source of the CRA are also studied. The effects of the highly-reflective FSS superstrate size on the CRA directivity, and explicitly its aperture efficiency, are investigated as well. A comparative study is also performed between CRAs with patch-type FSS and high permittivity dielectric superstrates. Measurement results are provided to support the modelings and simulations.      

A novel group decision model based on mean–variance–skewness concepts and interval-valued fuzzy sets for a selection problem of the sustainable warehouse location under uncertainty

Recently, sustainable warehouse location has been regarded as one of the most critical and significant decision problems for long-term planning in the supply chain. This strategic decision can be effected by different quantitative and qualitative evaluation criteria via three dimensions of the sustainability. Main theme of the paper is to select the most optimal location decision from a number of potential sustainable warehouse candidates. For this purpose, this paper presents a novel multi-criteria decision-making model by a group of supply chain experts or decision makers with interval-valued fuzzy setting and asymmetric uncertainty information. Concepts of mean, variance and skewness are introduced into the proposed group decision model, and their mathematical relations are defined based on a fuzzy possibilistic statistical approach. Then, new relations in this model are presented for obtaining ideal solutions under uncertainty with two high and low values of the possibilistic mean and possibilistic standard deviation, along with the possibilistic cube root of skewness. In addition, novel separation measures and new fuzzy ranking index of hybridized relative closeness coefficients are presented to provide final preference order of warehouse location candidates under uncertain conditions. Finally, a sustainable warehouse location selection problem in a pharmaceutical company is presented and solved by the proposed group decision model to demonstrate its applicability and suitability.

     

Inactivation of cytochrome P450s 2B1, 2B4, 2B6, and 2B11 by arylalkynes

The time-dependent loss of the 7-ethoxy-4-trifluoromethylcoumarin (EFC) O-deethylase activity of rat P450 2B1, rabbit P450 2B4, or dog P450 2B11 by 1-ethynylnaphthalene (1EN), 2-ethynylnaphthalene (2EN), 2-(1-propynyl)naphthalene (2PN), 1-ethynylanthracene (1EA), 2-ethynylanthracene, 2-ethynylphenanthrene, 3-ethynylphenanthrene, 9-ethynylphenanthrene (9EPh), 9-(1-propynyl)phenanthrene (9PPh), 4-ethynylpyrene (4EP), and 4-(1-propynyl)biphenyl (4PbP) was investigated. The rate constants for inactivation by the arylalkynes in descending order of effectiveness for the top five compounds were 9EPh>9PPh>1EN, 2EN, 2PN for 2B1, 9EPh>2EN>4EP>1EN, 1EA for 2B4, and 9EPh>1EA>4EP, 9PPh>2EN for 2B11. The size and the shape of the aromatic ring system and the placement of the alkyne functional group were important for inactivation. The most effective inactivator with all the isozymes was 9EPh. This compound also inactivated the EFC activity in microsomes from human lymphoblastoid cells expressing human P450 2B6. The specificity of 9EPh for the inhibition or inactivation of different P450 activities in microsomes from rats treated with various inducing agents was determined by measuring lidocaine, testosterone, p-nitrophenol, or erythromycin metabolism. The greatest effect was observed with the 2B-specific products from lidocaine and testosterone, whereas no effect was seen with p-nitrophenol or erythromycin. When the covalent binding of [3H]2EN to microsomal protein was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography, a radiolabeled protein band that corresponds to 2B1 was observed in the lanes containing microsomes from rats treated with phenobarbital and, to a lesser extent, pyridine and isosafrole after incubation with NADPH. When these microsomes were incubated with [3H]9EPh or [3H]1EP, two NADPH-dependent bands were radiolabeled. One corresponded to 2B1/2 and the other to a protein of approximately 59 kDa, which was observed in the lanes from phenobarbital-treated male and female rats and pyridine-treated male rats. No radiolabeled bands were observed with [3H,14C]4PbP with any of the microsomes.     

A stabilized foam formulation using FTP-SDS surfactants for wettability alteration and flow diversion in carbonate fractured oil reservoirs

Foam injection contributes to improved oil recovery through flow diversion, reduction of interfacial tension (IFT), and wettability alteration of the rock while its stability is an issue. In this article, nitrogen-foam was optimally formulated using fluorocarbon tubiguard protect (FTP) surfactant stabilized with sodium dodecyl sulfate (SDS) co-surfactant that was later experimentally considered for oil recovery in a fractured carbonate rock taken from an oil field in the Middle East. The results showed that the 5:1 volume ratio of fluorocarbon surfactant and SDS (FS51) generates a stable foaming agent with ability of changing the wettability of the carbonate rock surfaces to an intermediate gas-wet state. A series of core-flood experiments at HPHT conditions were also carried out and designed to properly represent matrix-fracture media using both a horizontally and vertically oriented setup. The oil saturated cores were flooded with nitrogen gas first followed by foam injection. It was concluded that foam can divert the gas to flow from fractures to the matrix blocks and result in a significant oil recovery. The contact angle tests that performed after core-flood experiments revealed the wettability changes of fracture surfaces from an oil-wet to a gas-wet state. This allows gas to be imbibed into the matrix blocks by capillary force and results in enhancement of ultimate oil recovery. This study revealed that trapped oil in matrixes blocks that had not been drained during the gas injection process could be produced by designing a stable foam that sustainably diverts injected fluid from fractures to matrix zone.