In an attempt to avoid serious problems that can affect the efficiency of refueling ground-operated vehicles and aircraft during military operations, the Armed Forces of the North Atlantic Treaty Organization (NATO) are introducing the use of a unique fuel for both air and land use. The fuel that has been selected is the F-34, similar to Jet A-1, which is used in civil aviation, in order to replace diesel fuel in many applications. It has to be mentioned that tests performed with this fuel, which is kerosene type on the high frequency reciprocating rig (HFRR) have shown that such fuel is responsible for severe wear. This very high wear is related to the very low lubricity of aviation fuel. Having the idea to improve the lubricity of aviation fuel to the level of fuels used in compression ignition engines (diesel fuel), seven N,N-Bis(2-ethoxyethyl) fatty acid amides were formulated from various vegetable oils (sunflower oil, soybean oil, cottonseed oil, olive oil, tobacco seed oil, coconut oil, used frying oil), and they were evaluated as lubricity improvers of the aviation fuel. The required tribological measurements for lubricity rating were carried out by employing ISO 12156-1 test method on an HFRR instrument. The test conditions during the measurements were in the range of 55% to 58% for the relative humidity and 24 °C for the temperature. The results from the tribological measurements showed that all N,N-Bis(2-ethoxyethyl) fatty acid amides used were rated as efficient in order to provide an acceptable mean wear scar diameter (below 460 μm) at concentrations from 150 to 300 ppm. Additive concentrations below 150 ppm did not improve the lubricity at the required level. The increase of N,N-Bis(2-ethoxyethyl) fatty acid amides at concentrations over 300 ppm did not have any significant decrease in the wear scar diameter. A comparison between the N,N-Bis(2-ethoxyethyl) fatty acid amides showed that those formulated by non-polyunsaturated oils like olive oil and coconut oil seem to have better lubricity improver characteristics.

The work presented herein reports on the oxidative coupling of methane (OCM) performance of a series of Li-free and Li-doped CeO2 and CeO2 modified with Sm3+ and La3+ catalysts. The supporting materials (Ce, Sm-Ce and La-Sm-Ce metal oxides) were synthesized using the microwave assisted sol-gel method in order to achieve nanophase complex materials with increased particle surface energy and reactivity. Lithium ions were added, using the wet impregnation technique, in order to further improve the physicochemical characteristics and reinforce the activity and selectivity, in terms of C2H6 and C2H4 production. All materials were characterized using N2 adsorption-desorption, XRD, Raman spectroscopy, CO2-TPD, H2-TPR, SEM and XPS. We showed that the addition of lithium species changed the reaction pathway and drastically enhanced the production of ethylene and ethane, mainly for the promoted catalysts (Li/Sm-Ce and Li/La-Sm-Ce). In particular, the presence and the synergy between the electrophilic oxygen species (peroxide and superoxide), population of oxygen vacancy sites and the surface moderate basic sites determined the reaction pathway and the desirable product distribution.

The characteristics of the source rocks in the early to late Miocene Belait Formation of Brunei Darussalam have been evaluated through the application of Rock-Eval and biomarker analyses, as well as by organic petrographical examination. Analyses have been performed on coal, coaly shale/carbonaceous claystones and shale samples from the Formation, retrieved from outcrops across the Brunei-Muara district, and covering a wide lateral extension of the Formation. The geochemical results indicate that the coal and some carbonaceous samples (with TOC from 14.1% to 67.7%) from the Belait Formation have “good to excellent” generating potential, quantity and quality, due to their high S2 and TOC values, which are consistent with the intermediate hydrogen index (HI) values ranging from 144 to 258 mg HC/g TOC. Organic material of “fair to good” quantity, quality and hydrocarbon generating potential is recorded for the coaly shale samples in the Belait Formation. Non-coal samples generally have the lowest potential as source rocks, due to their low TOC, HI and S2 values. Within the Formation, the coal layers together with a number of coaly shale and shale layers contain type III (gas prone) and type II-III (mixed oil and gas) kerogens. This is proven by the dominance of huminite, often of fluorescent varieties, which is confirmed though maceral analysis, as well as a trend of n-alkanes skewed towards heavier compounds. Evidence of the possible generation of liquid hydrocarbon is offered by the fact that liptinite is the second most abundant maceral group in most of the samples, as well as by the perhydrous nature of part of the huminite. Furthermore, kerogen type IV (dry gas) has been identified in a majority of the coaly shale samples. Facies analysis of the Belait Formation through the use of maceral indices and biomarkers data indicates that the coals were deposited in a mangrove setting in a lower delta plain, where mainly herbaceous and arboreal plants were growing. The depositional conditions were predominantly oxic, with a possible marine influence, and hence brackish conditions. All samples are found to be thermally immature to early mature, with Tmax values ranging from 356 °C to 441 °C, huminite reflectance values of up to 0.46% and high carbon preference index (CPI) values.

It is evident that the increased focus on energy transition, will increase the demand for gas as it is the transitional fuel to the net zero CO2 emission era. The West Katakolo field is the only oil and gas discovery in Western Greece, and it is operated by Energean. The three offshore West Katakolo wells have defined both the oil and the gas zones, while onshore exploration wells have penetrated biogenic gas-saturated Plio-Pleistocene sands. This study assesses the gas generation potential of the local Plio-Pleistocene and Triassic sources using thermal maturity modelling based on the available legacy data, with limitations being addressed by running several case-scenarios. In conclusion, this study supports the generation of thermogenic and biogenic gas from the Triassic and Plio-Pleistocene sources respectively, demonstrating the importance of maturity modelling in hydrocarbon exploration, applied on the Katakolo case; a potential gas source to facilitate the energy transition in Greece.

This study examines the impact of the addition of bio-ethanol/bio-ETBE on the main volatility properties of gasoline. Although several studies have been published on the addition of ethanol or ETBE to gasoline, the simultaneous addition of these oxygenates has not been studied by taking the maximum oxygen content of 3.7% m/m into account. The EN 228:2012-A1:2017 standard specifies the requirements for marketed unleaded gasoline. This standard is able to determine, among other things, a gasoline type with a maximum oxygen content of 3.7% m/m and sets the maximum limits for ethanol content at 10% v/v and 22% v/v for ethers with a minimum five carbon atoms, such as ΕΤΒΕ. Five refinery fractions were mixed in various proportions and were used as base fuels. A total of 30 samples were prepared by blending the base fuels with bio-ethanol/bio-ETBE. In each of these base fuels, bio-ethanol was added in concentrations up to 10% v/v. Subsequently, bio-ETBE was added to each of these fuels in concentrations up to 20.8% v/v for use as a stabilizer. All of the samples were examined using the EN ISO 13016-1 and EN ISO 3405 test methods while considering the volatility requirements set by EN 228. The results showed that the addition of bio-ETBE has a beneficial effect on the volatility characteristics of the samples, as it reduces the vapor pressure of the final blend and sets all fuels in compliance with the required specification limits set by the EN 228 standard.

In April 2018, the International Maritime Organisation adopted an ambitious plan to contribute to the global efforts to reduce the Greenhouse Gas emissions, as set by the Paris Agreement, by targeting a 50% reduction in shipping’s Green House Gas emissions by 2050, benchmarked to 2008 levels. To meet these challenging goals, the maritime industry must introduce environmentally friendly fuels with negligible, or low SOX, NOX and CO2 emissions. Ammonia use in maritime applications is considered promising, due to its high energy density, low flammability, easy storage and low production cost. Moreover, ammonia can be used as fuel in a variety of propulsors such as fuel cells and can be produced from renewable sources. As a result, ammonia can be used as a versatile marine fuel, exploiting the existing infrastructure, and having zero SOX and CO2 emissions. However, there are several challenges to overcome for ammonia to become a compelling fuel towards the decarbonisation of shipping. Such factors include the selection of the appropriate ammonia-fuelled power generator, the selection of the appropriate system safety assessment tool, and mitigating measures to address the hazards of ammonia. This paper discusses the state-of-the-art of ammonia fuelled fuel cells for marine applications and presents their potential, and challenges.

For the commercial viability of a hydrogen-based transportation, hydrogen infrastructure is key. One of the major issues of hydrogen infrastructure is related to the deployment and costs of the Hydrogen Refuelling Stations (HRSs), where up to 40% of the cost is related to hydrogen compression. The introduction of Metal Hydride Hydrogen Compressors (MHHCs) in the HRSs as compression elements is a potential technology to reduce operational costs, ensure noiseless operation and increase efficiency, if renewable-based thermal energy (and/or industrial waste heat) is supplied to the system. In this work, four different two-stage MHHCs are introduced and examined in terms of compression ratio, hydrogen flow rate (compression duration), thermal energy requirements and efficiency. In addition, for comparison purposes, a three-stage MHHC is also studied. The properties of five different materials are used for the individual compression stages of the MHHCs, where all the necessary thermodynamic properties are extracted experimentally and incorporated in a commercial Multiphysics software. The unsteady heat and mass transfer equations are employed for the development of the numerical model. The hydrogenation/dehydrogenation kinetics and the temperature profile were validated against solid experimental results. In addition, to improve and accelerate the storage/release kinetics, an internal thermal management scenario has been introduced. The results show that for compression at the temperature range of 10–90 °C, the most favourable two-stage compression case (Case 3) showed a compression ratio of 11.18 ÷ 1, an isentropic efficiency of 4.54% with a thermal energy demand of 322 kJ/molH2 and a cycle time of almost 34 min.

Summary This study examines the organic matter source input, paleodepositional conditions and source rock potential of the Mid Permian Wandrawandian siltstone in the Southern Sydney Basin, Australia. The obtained data provide indications of a generally poor, gas-prone source rock potential, with TOC% values averaging close to ∼1% but generally low S2 values, barring some samples with a fair potential worth considering further investigation. The organic matter is thermally mature and having experienced high temperatures during burial.

Summary The UK offshore Forth Approaches Basin has long since been explored as a prospective petroleum system; the few exploration wells failed to point towards an economically viable asset, and hence, the basin was downgraded for further exploration. In this study, this basin is further explored, both in terms of its local hydrocarbon prospectivity and storage potential, using publicly available data. The petroleum system elements of the most prospective play (Scremerston) were assessed based on formation properties and gross depositional environment mapping, source rock maturity modelling and common risk segment mapping. Also, the basin’s carbon storage potential was assessed with respect to its capacity, reservoir and trap quality and seal integrity. Our results suggest that only deeper parts of the depocenter could have generated and stratigraphically trapped vapour hydrocarbons, yet the exact depths of this upper-limit threshold in the Carboniferous depocenter have to be delineated. On the other hand, the Upper-Carboniferous and Middle-Permian reservoir strata, hosting a low-salinity aquifer, illustrate significant storage capacity (roughly 700 Mt for the Worst-Case scenario) and sealing efficiency (through stratigraphic and residual trapping), whereas its proximity to the UK major industrial emitters adds to its applicability.

Summary This project attempts to extract information regarding the stratigraphy and source rock potential of the deeply buried deposits in the Mediterranean Ridge (South of Crete marine region). Due to the lack of deep wells in the region, the only avaliable material comes from mud volcanic (mud breccia) samples recovered from various scientific expeditions. Sedimentary cores from Gelendzhik, Moscow, Nice, Toronto and Dublin mud volcanoes were used. The actual samples of this study consists of consolidated clasts that were included in the mud breccia deposits of each core. The stratigraphic origin of the clasts were determined by studying its calcareous nannoplankton content and subsequently, rock eval pyrolysis and vitrinite reflectance measurements were performed. Combining the study’s results with seismic reflection profile images, leads to a higher-level understanding of the region’s stratigraphy and source rock distribution.