Publications

The pathway to zero carbon emissions passing through carbon emissions reduction is mandatory in the shipping industry. Regarding the various methodologies and technologies reviewed for this purpose Life Cycle Cost Analysis (LCCA) has been used as an excellent tool to determine economic feasibility and sustainability and to present directions. However insufficient commercial applications cause a conflict of opinion on which fuel is the key to decarbonisation. Many LCCA comparison studies about eco-friendly ship propulsion claim different results. In order to overcome this and discover the key factors that affect the overall comparative analysis and results in the maritime field it is necessary to conduct the comparative analysis considering more diverse case ships case routes and various types that combine each system. This study aims to analyse which greener fuels are most economically beneficial for the shipping sector and prove the factors influencing different results in LCCA. This study was conducted on hydrogen ammonia and electric energy which are carbon-free fuels among various alternative fuels that are currently in the limelight. As the power source a PEMFC and battery were used as the main power source and a solar PV system was installed as an auxiliary power source to compare economic feasibility. Several cost data for LCCA were selected from various feasible case studies. As the difficulty caused by the storage and transportation of hydrogen and ammonia should not be underestimated in this study the LCCA considers not only the CapEx and OpEx but also fuel transport costs. As a result fuel cell propulsion systems with hydrogen as fuel proved financial effectiveness for short-distance ferries as they are more inexpensive than ammonia-fuelled PEMFCs and batteries. The fuel cost takes around half of the total life-cycle cost during the life span.

Global energy and environmental issues are becoming increasingly serious and the promotion of clean energy and green transportation has become a common goal for all countries. In the logistics industry traditional fuels such as diesel and natural gas can no longer meet the requirements of energy and climate change. Hydrogen fuel cell logistics vehicles are expected to become the mainstream vehicles for future logistics because of their “zero carbon” advantages. The GREET model is computer simulation software developed by the Argonne National Laboratory in the USA. It is extensively utilized in research pertaining to the energy and environmental impact of vehicles. This research study examines four types of logistics vehicles: hydrogen fuel cell vehicles (FCVs) electric vehicles LNG-fueled vehicles and diesel-fueled vehicles. Diesel-fueled logistics vehicles are currently the most abundant type of vehicle in the logistics sector. LNG-fueled logistics vehicles are considered as a short-term alternative to diesel logistics vehicles while electric logistics vehicles are among the most popular types of new-energy vehicles currently. We analyze and compare their well-to-wheels (WTW) energy consumption and emissions with the help of GREET software and conduct lifecycle assessments (LCAs) of the four types of vehicles to analyze their energy and environmental benefits. When comparing the energy consumption of the four vehicle types electric logistics vehicles (EVs) have the lowest energy consumption with slightly lower energy consumption than FCVs. When comparing the nine airborne pollutant emissions of the four vehicle types the emissions of the FCVs are significantly lower than those of spark-ignition internal combustion engine logistics vehicles (SI ICEVs) compression-ignition direct-injection internal combustion engine logistics vehicles (CIDI ICEVs) and EVs. This study fills a research gap regarding the energy consumption and environmental impact of logistics vehicles in China.

Hypothesis.<br/>The large-scale implementation of hydrogen economy requires immense storage spaces to facilitate the periodic storage/production cycles. Extensive modelling of hydrogen transport in porous media is required to comprehend the hydrogen-induced complexities prior to storage to avoid energy loss. Wettability of hydrogen-brine-rock systems influence flow properties (e.g. capillary pressure and relative permeability curves) and the residual saturations which are all essential for subsurface hydrogen systems.<br/>Model.<br/>This study aims to understand which parameters critically control the contact angle for hydrogen-brine-rock systems using the surface force analysis following the DLVO theory and sensitivity analysis. Furthermore the effect of roughness is studied using the Cassie-Baxter model.<br/>Findings.<br/>Our results reveal no considerable difference between H2 and other gases such as N2. Besides the inclusion of roughness highly affects the observed apparent contact angles and even lead to water-repelling features. It was observed that contact angle does not vary significantly with variations of surface charge and density at high salinity which is representative for reservoir conditions. Based on the analysis it is speculated that the influence of roughness on contact angle becomes significant at low water saturation (i.e. high capillary pressure).

Hydrogen sensors especially those operating at high temperatures are essential tools for the emerging hydrogen economy. Monitoring hydrogen under process conditions to control the reactions for detecting confined species is crucial to the safe widespread use and public acceptance of hydrogen as fuel. Hydrogen sensors must have a sensitivity ranging from traces of hydrogen (parts per million (ppm)) up to levels near the lower explosive limit (LEL = 4% H2 in the air) for safety reasons. Furthermore they need to operate in cryogenic ambient and high-temperature environments. Herein emphasis is given to hydrogen sensors based on solid oxide electrolytes (operating at high temperatures) in particular oxygen ion and proton conductors. The review is devoted to potentiometric amperometric and combined amperometric-potentiometric hydrogen sensors. Experimental results already reported in the international literature are presented and analyzed to reveal the configuration principle of operation and the applied solid electrolytes and electrodes of the high-temperature hydrogen sensors. Additionally an amperometric sensor able to detect hydrogen and steam in atmospheric air through a two-stage procedure is presented and thoroughly discussed. The discussion reveals that high-temperature hydrogen sensors face different challenges in terms of the electrodes and solid electrolytes to be used depending on the operating principle of each sensor type.

The measures needed to limit global warming pose a particular challenge to current fossil fuel exporters who must not only decarbonise their local energy systems but also compensate for the expected decline in fossil fuel revenues. One possibility is seen in the export of green hydrogen. Using Algeria as a case study this paper analyses how different levels of ambition in hydrogen exports energy efficiency and fuel switching affect the costoptimal expansion of the power sector for a given overall emissions reduction path. Despite falling costs for photovoltaics and wind turbines the results indicate that in countries with very low natural gas prices such as Algeria a fully renewable electricity system by 2050 is unlikely without appropriate policy measures. The expansion of renewable energy should therefore start early given the high annual growth rates required which will be reinforced by additional green hydrogen exports. In parallel energy efficiency is a key factor as it directly mitigates CO2 emissions from fossil fuels and reduces domestic electricity demand which could instead be used for hydrogen production. Integrating electrolysers into the power system could potentially help to reduce specific costs through load shifting. Overall it seems advisable to analyse hydrogen exports together with local decarbonisation in order to better understand their interactions and to reduce emissions as efficiently as possible. These results and the methodology could be transferred to other countries that want to become green hydrogen exporters in the future and are therefore a useful addition for researchers and policy makers.

This report analyses five case study reports in-depth across five EU countries as part of a broader analytical and critical exercise. This analytical work seeks to contribute to the development of new models for regional and local authorities aiming to boost support for Green Transition of their economies through smarter innovation policies using the smart specialisation (S3) approach. The work covered five regions from across the European Union representing a diversity of approaches to using S3 for Green Transition: the Basque Country in Spain the Centro region in Portugal the region of East and North Finland the region of Western Macedonia in Greece and the region of West Netherlands. The case studies included in this report consists of three sections on (i) Profile of the region and key development challenges; (ii) Innovation strategies and policies for green transition: incorporating societal challenges; (iii) Understanding and monitoring innovationled green transition. Drawing together the different elements presented the conclusion provides a summary overview of the case and the authors’ opinion on it.

Hydrogen addition affects the composition of exhaust gases in vehicles. However the effects of hydrogen addition to compression ignition engines in running vehicles have not been evaluated. Hydrogen‑mixed air was introduced into the air intake of a truck equipped with a direct‑ injection diesel engine and running on a chassis dynamometer to investigate the effect of hydrogen addition on fuel consumption and exhaust gas components. The reduction in diesel consumption and the increase in hydrogen energy share (HES) showed almost linear dependence where the percentage decrease in diesel consumption is approximately 0.6 × HES. The percentage reduction of CO2 showed a one‑to‑one relationship to the reduction in diesel consumption. The reduction in emissions of CO PM and hydrocarbons (except for ethylene) had one to one or a larger correlation with the reduction of diesel consumption. On the other hand it was observed that NOx emissions increased and the percentage increase of NOx was 1.5~2.0 times that of HES. The requirement for total energy supply was more when hydrogen was added than for diesel alone. In the actual running mode only 50% of the energy of added hydrogen was used to power the truck. As no adjustments were made to the engine in this experiment a possible disadvantage that could be improved by adjusting the combustion conditions.

The production storage and use of hydrogen for energy purposes will become increasingly important during the energy transition. One way to use hydrogen is to apply it to power vehicles. This green technological solution affects low-emissions transport which is beneficial and important especially in cities. The authors of this article analyzed the use of hydrogen production infrastructure for bus propulsion in the city of Katowice (Poland). The methods used in the study included a greedy algorithm and cost methods which were applied for the selection of vehicles and identification of the infrastructure for the production storage and refueling of hydrogen as well as to conduct the economic analysis during this term. The article presented the complexity of the techno-economic analysis of the infrastructure and its installation. The key element was the selection of the number of vehicles to the hydrogen production possibilities of an electrolyser and capabilities of the storage and charging infrastructure.

Norwegian offshore wind farms may be able to supply power to offshore oil and gas platforms in the near future thanks to the expeditious development of offshore wind technology. This would result in a reduction in CO2 emissions from oil and gas offshore installations which are currently powered predominantly by gas turbines. The challenge with using wind power is that offshore oil and gas installations require a fairly constant and stable source of power whereas wind power typically exhibits significant fluctuations over time. The purpose of this study is to perform a technical feasibility evaluation of using wind power to supply an offshore oil and gas installation on the basis of dynamic process simulations. Throughout the study only the topside processing system is considered since it is the most energy-intensive part of an oil and gas facility. An offshore field on the Norwegian Continental Shelf is used as a case study. The results indicate that when the processing system operates in steady-state conditions it cannot be powered solely by wind energy and another power source is required to compensate for low wind power generation intervals. An alternative would be to store wind energy during periods of high generation (e.g. by producing hydrogen or ammonia) and use it during periods of low generation. Utilizing energy storage methods wind energy can be continuously used for longer periods of time and provide a suitable constant power source for the studied case. Higher constant power can also be provided by increasing the efficiency of energy recovery and storage processes. Alternatively these two technologies may be integrated with gas turbines if the required storage cannot be provided or higher power is required. It was estimated that the integration of wind energy could result in noticeable reductions in CO2 emissions for the case study. Additionally according to the results the production storage and reuse of hydrogen and ammonia on-site may be viable options for supplying power.

Hydrogen has the physical and chemical characteristics of being flammable explosive and prone to leakage and its safety is the main issue faced by the promotion of hydrogen as an energy source. The most common scene in vehicle application is the longitudinal wind generated by driving and the original position of hydrogen concentration sensors (HCSs) did not consider the influence of longitudinal wind on the hydrogen leakage trajectory. In this paper the computational fluid dynamics (CFD) software STAR CCM 2021.1 is used to simulate the hydrogen leakage and diffusion trajectories of fuel cell vehicles (FCVs) at five different leakage locations the longitudinal wind speeds of 0 km/h 37.18 km/h and 114 km/h and it is concluded that longitudinal wind prolongs the diffusion time of hydrogen to the headspace and reduces the coverage area of hydrogen in the headspace with a decrease of 81.35%. In order to achieve a good detection effect of fuel cell vehicles within the longitudinal wind scene based on the simulated hydrogen concentration–time matrix the scene clustering method based on vector similarity evaluation was used to reduce the leakage scene set by 33%. Then the layout position of HCSs was optimized according to the proposed multi-scene full coverage response time minimization model and the response time was reduced from 5 s to 1 s.