Publications

Fuel cell electric buses (FCBs) have proven to be a technically viable solution for transportation owing to various advantages such as reliability simplicity better energy efficiency and quietness of operation. However largescale adoption of FCBs is hindered by the lack of extensive and structured infrastructure and the high cost of clean hydrogen. Many studies agree that one of the significant contributors to the lack of competitiveness of green hydrogen is the cost of electricity for its production followed by transportation costs. On the one hand to reduce the investment cost of the electrolyzer high operating hours should be achieved; on the other as the number of operating hours decreases the impact of the electricity costs declines. This paper presents an innovative algorithm for a scalable hydrogen refuelling station (HRS) capable of successfully matching and identifying the most cost-efficient levelized cost of hydrogen (LCOH) produced via electrolysis and connected to the grid based on the HRS components’ cost curves and the hourly average electricity price profile. The objective is to identify the least-cost range of LCOH by considering both the electric energy and the investment costs associated with a hydrogen demand given by different FCB sizes and electrolyzer rated powers. In addition sensitivity analyses have been conducted to quantify the technology cost margins and a cost comparison between the refuelling of an FCB fleet and the recharging infrastructure required for an equivalent fleet of Battery Electric Buse (BEB) has been performed. An LCOH of around 10.5 €/kg varying from 12 €/kg (2 FCB) to 10.2 €/kg (30 FCB) has been found for the best-optimized configurations. The final major conclusion of this paper is that FCB technology is currently not economically competitive. Still a cost contraction of the electric energy price and the electrolyzer capital investment would lead to a 50% decrease in the LCOH. Furthermore increasing renewable energies into the grid may shift the electricity cost curve resulting in higher prices when the BEB recharging demand is more significant. This impact in addition to the peak power load and longer recharging times might contribute to bridging the gap with FCBs.

To achieve the shift to renewable energies efficient energy storage is of the upmost importance. Hydrogen as a chemical energy storage represents a promising technology due to its high gravimetric energy density. However the most efficient form of hydrogen storage still remains an open question. Absorption-based storage of hydrogen in metal hydrides offers high volumetric energy densities as well as safety advantages. In this work technical economic and environmental aspects of different metal hydride materials are investigated. An overview of the material properties production methods as well as possibilities for enhancement of properties are presented. Furthermore impacts on material costs abundance of raw materials and dependency on imports are discussed. Advantages and disadvantages of selected materials are derived and may serve as a decision basis for material selection based on application. Further research on enhancement of material properties as well as on the system level is required for widespread application of metal hydrides.

This paper provides an in-depth review of the current state and future potential of hydrogen fuel cell vehicles (HFCVs). The urgency for more eco-friendly and efficient alternatives to fossilfuel-powered vehicles underlines the necessity of HFCVs which utilize hydrogen gas to power an onboard electric motor producing only water vapor and heat. Despite their impressive energy efficiency ratio (EER) higher power-to-weight ratio and substantial emissions reduction potential the widespread implementation of HFCVs is presently hindered by several technical and infrastructural challenges. These include high manufacturing costs the relatively low energy density of hydrogen safety concerns fuel cell durability issues insufficient hydrogen refueling infrastructure and the complexities of hydrogen storage and transportation. Nevertheless technological advancements and potential policy interventions offer promising prospects for HFCVs suggesting they could become a vital component of sustainable transportation in the future.

In order to eliminate the local CO2 emissions from vehicles and to combat the associated climate change the classic internal combustion engine can be replaced by an electric motor. The two most advantageous variants for the necessary electrical energy storage in the vehicle are currently the purely electrochemical storage in batteries and the chemical storage in hydrogen with subsequent conversion into electrical energy by means of a fuel cell stack. The two variants can also be combined in a battery electric vehicle with a fuel cell range extender so that the vehicle can be refuelled either purely electrically or using hydrogen. The air compressor a key component of a PEM fuel cell system can be operated at different air excess and pressure ratios which influence the stack as well as the system efficiency. To asses the steady state behaviour of a PEM fuel cell range extender system a system test bench utilising a commercially available 30 kW stack (96 cells 409 cm2 cell area) was developed. The influences of the operating parameters (air excess ratio 1.3 to 1.7 stack temperature 20 °C–60 °C air compressor pressure ratio up to 1.67 load point 122 mA/cm2 to 978 mA/cm2) on the fuel cell stack voltage level (constant ambient relative humidity of 45%) and the corresponding system efficiency were measured by utilising current voltage mass flow temperature and pressure sensors. A fuel cell stack model was presented which correlates closely with the experimental data (0.861% relative error). The air supply components were modelled utilising a surface fit. Subsequently the system efficiency of the validated model was optimised by varying the air mass flow and air pressure. It is shown that higher air pressures and lower air excess ratios increase the system efficiency at high loads. The maximum achieved system efficiency is 55.21% at the lowest continuous load point and 43.74% at the highest continuous load point. Future work can utilise the test bench or the validated model for component design studies to further improve the system efficiency.

Reactor structure design plays an important role in the performance of solar-thermal methane reforming reactors. Based on a conventional preheating reactor this study proposed a cylindrical solar methane reforming reactor with multiple inlets to vary the temperature field distribution which improved the temperature of the reaction region in the reactor thereby improving the reactor performance. A multi-physical model that considers mass momentum species and energy conservation as well as thermochemical reaction kinetics of methane reforming was applied to numerically investigate the reactor performance and analyze the factors that affect performance improvement. It was found that compared with a conventional preheating reactor the proposed cylindrical reactor with inner and external inlets for gas feeding enhanced heat recovery from the exhausted gas and provided a more suitable temperature field for the reaction in the reactor. Under different operating conditions the methane conversion in the cylindrical reactor with multi-inlet increased by 9.5% to 19.1% and the hydrogen production was enhanced by 12.1% to 40.3% in comparison with the conventional design even though the total reaction catalyst volume was reduced.

Energy storage is an effective way to address the instability of renewable energy generation modes such as wind and solar which are projected to play an important role in the sustainable and low-carbon society. Economics and carbon emissions are important indicators that should be thoroughly considered for evaluating the feasibility of energy storage technologies (ESTs). In this study we study two promising routes for large-scale renewable energy storage electrochemical energy storage (EES) and hydrogen energy storage (HES) via technical analysis of the ESTs. The levelized cost of storage (LCOS) carbon emissions and uncertainty assessments for EESs and HESs over the life cycle are conducted with full consideration of the critical links for these routes. In order to reduce the evaluation error we use the Monte Carlo method to derive a large number of data for estimating the economy and carbon emission level of ESTs based on the collected data. The results show that lithium ion (Li-ion) batteries show the lowest LCOS and carbon emissions at 0.314 US$ kWh-1 and 72.76 gCO2e kWh-1 compared with other batteries for EES. Different HES routes meaning different combinations of hydrogen production delivery and refueling methods show substantial differences in economics and the lowest LCOS and carbon emissions at 0.227 US$ kWh-1 and 61.63 gCO2e kWh-1 are achieved using HES routes that involve hydrogen production by alkaline electrolyzer (AE) delivery by hydrogen pipeline and corresponding refueling. The findings of this study suggest that HES and EES have comparable levels of economics and carbon emissions that should be both considered for large-scale renewable energy storage to achieve future decarbonization goals.

This paper addresses the energy management of a standalone renewable energy system. The system is configured as a microgrid including photovoltaic generation a lead-acid battery as a short term energy storage system hydrogen production and several loads. In this microgrid an energy management strategy has been incorporated that pursues several objectives. On the one hand it aims to minimize the amount of energy cycled in the battery in order to reduce the associated losses and battery size. On the other hand it seeks to take advantage of the long-term surplus energy producing hydrogen and extracting it from the system to be used in a fuel cell hybrid electric vehicle. A crucial factor in this approach is to accommodate the energy consumption to the energy demand and to achieve this a model predictive control (MPC) scheme is proposed. In this context proper models for solar estimation hydrogen production and battery energy storage will be presented. Moreover the controller is capable of advancing or delaying the deferrable loads from its prescheduled time. As a result a stable and efficient supply with a relatively small battery is obtained. Finally the proposed control scheme has been validated on a real case scenario.

In order to effectively combat the effects of global warming all sectors must actively reduce greenhouse gas emissions in a sustainable and substantial manner. Sector coupling has emerged as a critical technology that can integrate energy systems and address the temporal imbalances created by intermittent renewable energy sources. Despite its potential current sector coupling capabilities remain underutilized and energy modeling approaches face challenges in understanding the intricacies of sector coupling and in selecting appropriate modeling tools. This paper presents a comprehensive review of sector coupling technologies and their role in the energy transition with a specific focus on the integration of electricity heat/cooling and transportation as well as the importance of hydrogen in sector coupling. Additionally we conducted an analysis of 27 sector coupling models based on renewable energy sources with the goal of aiding deciders in identifying the most appropriate model for their specific modeling needs. Finally the paper highlights the importance of sector coupling in achieving climate protection goals while emphasizing the need for technological openness and market-driven conditions to ensure economically efficient implementation.

This paper addresses the topic of the conceptual design of a regional aircraft with hybrid electric propulsion based on hydrogen fuel cells. It aims at providing an optimization-based method to design a hybrid propulsive system comprising two power sources (jet fuel and hydrogen) for the generation of the required propulsive power and at studying the impact of fuel cell technologies on the aircraft performances. Indeed by performing optimizations for two hybrid propulsive systems using either low temperature or high temperature Proton-exchange membrane fuel cells this study provides a preliminary assessment of the impact of the fuel cell operating temperature on the system design and the overall aircraft performance. First this paper gives a description of the baseline turboprop regional aircraft with a focus on its high speed and low speed flight performances which will serve as requirements for the design of the hybrid aircraft. Then the hybrid electric architecture and the sizing models of the propulsion system are presented. Finally optimizations are performed to design two parallel hybrid propulsive systems based on different fuel cells technologies and aimed at minimizing the block fuel per passenger over a mission of 200 nm. Results show how the proposed methodology and models lead to design two propulsive systems capable of reducing the fuel consumption per passenger by more than 30% compared to the baseline aircraft. The study also shows that the choice of fuel cell operating temperature has a first-order impact on the total mass of the propulsive system due to the higher cooling requirement of the low temperature fuel cells.

Self-sufficiency of buildings with carbon emission reduction can be obtained thanks to the introduction of Photovoltaics systems coupled with Hydrogen seasonal storage. To be self-sufficient over the year the electricity converted to hydrogen by electrolysis during the sunny season can be re-used with the help of fuel cells during the winter season. This article is dealing with the dimensioning methodology of a solar PV hydrogen-electrochemical system for self-sufficient buildings. We introduce the case study of the first private building in western Switzerland that will be equipped with solar hydrogen storage. Calculation results of the dimensioning of the PV system with storage will be presented. The life cycle assessment and the calculations of the environmental indicators GWP and CED will be introduced.

The natural gas (NG) reforming is currently one of the low-cost methods for hydrogen production. However the mixture of H2 and CO2 in the produced gas inevitably includes CO2 and necessitates the costly CO2 separation. In this work a novel double chemical looping involving both combustion (CLC) and sorption-enhanced reforming (SE-CLR) was proposed towards the co-production of H2 and CO (CLC-SECLRHC) in two separated streams. CLC provides reactant CO2 and energy to feed SECLRHC which generates hydrogen in a higher purity as well as the calcium cycle to generate CO in a higher purity. Techno-economic assessment of the proposed system was conducted to evaluate its efficiency and economic competitiveness. Studies revealed that the optimal molar ratios of oxygen carrier (OC)/NG and steam/NG for reforming were recommended to be 1.7 and 1.0 respectively. The heat integration within CLC and SECLRHC units can be achieved by circulating hot OCs. The desired temperatures of fuel reactor (FR) and reforming reactor (RR) should be 850 °C and 600 °C respectively. The heat coupling between CLC and SECLRHC units can be realized via a jacket-type reactor and the NG split ratio for reforming and combustion was 0.53:0.47. Under the optimal conditions the H2 purity the H2 yield and the CH4 conversion efficiency were 98.76% 2.31 mol mol-1 and 97.96% respectively. The carbon and hydrogen utilization efficiency respectively were 58.60% and 72.45% in terms of the total hydrogen in both steam and NG. The exergy efficiency of the overall process reached 70.28%. In terms of the conventional plant capacity (75×103 t y-1 ) and current raw materials price (2500 $ t-1 ) the payback period can be 6.2 years and the IRR would be 11.5 demonstrating an economically feasible and risk resistant capability.

The recent detection of natural hydrogen seeps in sedimentary basin settings has triggered significant interest in the exploration of this promising resource. If large economical resources exist and can be extracted from the sub-surface this would provide an opportunity for natural hydrogen to contribute to the non-carbon-based energy mix. The detection and exploration of hydrogen gas in the sub-surface is a significant challenge that requires costly drilling sophisticated instrumentation and reliable analytical/sampling methods. Here we propose the application of a commercial-based sensor that can be used to detect and monitor low levels of hydrogen gas emissions from geological environments. The sensitivity selectivity (K > 1000) and stability (<1 ppm/day) of the sensor was evaluated under various conditions to determine its suitability for geological field monitoring. Calibration tests showed that the hydrogen readings from the sensor were within ±20% of the expected values. We propose that chemical sensing is a simple and feasible method for understanding natural hydrogen seeps that emanate from geological systems and formations. However we recommend using this sensor as part of a complete geological survey that incorporates an understanding of the geology along with complementary techniques that provide information on the rock properties.

Today we are joined by our good friends from Enapter. The company is a leader in the clean hydrogen sector focused on AEM electrolyzer technology and innovative software solutions that make it possible to rapidly deploy and scale hydrogen production assets. For those who follow the hydrogen sector regularly it’s been hard not to hear Enapter-related news in 2021 and its impressive trajectory as they have gone public announced the plans for a brand new production facility in Germany (on which they have now begun construction) and most recently the announcement that Enapter was selected as the winner of the prestigious Earthshot prize. To do that we are absolutely delighted to have with us all the way from his home base in Thailand Thomas Chrometzka Chief Strategy Officer at Enapter and one of the people that we enjoy having on the show so much that we have brought him back again to fill us in on what he and Enapter are up to and what they have planned for the future of hydrogen.

The podcast can be found on their website

Hydrogen is regarded to be one of the most promising renewable and clean energy sources. Finding a highly efficient and cost-effective catalyst to generate hydrogen via water splitting has become a research hotspot. Two-dimensional materials with exotic structural and electronic properties have been considered as economical alternatives. In this work 2D SnSe films with high quality of crystallinity were grown on a mica substrate via molecular beam epitaxy. The electronic property of the prepared SnSe thin films can be easily and accurately tuned in situ by three orders of magnitude through the controllable compensation of Sn atoms. The prepared film normally exhibited p-type conduction due to the deficiency of Sn in the film during its growth. First-principle calculations explained that Sn vacancies can introduce additional reactive sites for the hydrogen evolution reaction (HER) and enhance the HER performance by accelerating electron migration and promoting continuous hydrogen generation which was mirrored by the reduced Gibbs free energy by a factor of 2.3 as compared with the pure SnSe film. The results pave the way for synthesized 2D SnSe thin films in the applications of hydrogen production.

The world is undergoing a substantial energy transition with an increasing share of intermittent sources of energy on the grid which is increasing the challenges to operate the power grid reliably. An option that has been receiving much focus after the COVID pandemic is the development of a hydrogen economy. Challenges for a hydrogen economy are the high investment costs involved in compression storage and long-distance transportation. This paper analyses an innovative proposal for the creation of hydrogen ocean links. It intends to fill existing gaps in the creation of a hydrogen economy with the increase in flexibility and viability for hydrogen production consumption compression storage and transportation. The main concept behind the proposals presented in this paper consists of using the fact that the pressure in the deep sea is very high which allows a thin and cheap HDPE tank to store and transport large amounts of pressurized hydrogen in the deep sea. This is performed by replacing seawater with pressurized hydrogen and maintaining the pressure in the pipes similar to the outside pressure. Hydrogen Deep Ocean Link has the potential of increasing the interconnectivity of different regional energy grids into a global sustainable interconnected energy system.

Mitigating anthropogenic climate change and achieving the Paris climate goals is one of the greatest challenges of the twenty-first century. To meet the Paris climate goals sector-specific transformation pathways need to be defined. The different transformation pathways are used to hypothetically quantify whether a defined climate target is achievable or not. For this reason a bottom-up model was developed to assess the extent of selected industrial decarbonization options compared to conventionally used technologies from an emissions perspective. Thereby the bottom-up model is used to analyze the German container and flat glass industries as an example. The results show that no transformation pathway can be compatible with the 1.5 °C based strict carbon dioxide budget target. Even the best case scenario exceeds the 1.5 °C based target by approximately +200%. The 2 °C based loose carbon dioxide budget target is only achievable via fuel switching the complete phase-out from natural gas to renewable energy carriers. Furthermore the results of hydrogen for flat glass production demonstrate that missing investments in renewable energy carriers may lead to the non-compliance with actually achievable 2 °C based carbon dioxide budget targets. In conclusion the phase-out from natural gas to renewable energies should be executed at the end of the life of any existing furnace and process emissions should be avoided in the long term to contribute to 1.5 °C based strict carbon dioxide budget target.

The ten nations of Southeast Asia collectively known as ASEAN emitted 1.65 Gtpa CO2 in 2020 and are among the most vulnerable nations to climate change which is partially caused by anthropogenic CO2 emission. This paper analyzes the history of ASEAN energy consumption and CO2 emission from both fossil and renewable energies in the last two decades. The results show that ASEAN’s renewable energies resources range from low to moderate are unevenly distributed geographically and contributed to only 20% of total primary energy consumption (TPEC) in 2015. The dominant forms of renewable energies are hydropower solar photovoltaic and bioenergy. However both hydropower and bioenergy have substantial sustainability issues. Fossil energies depend heavily on coal and oil and contribute to 80% of TPEC. More importantly renewable energies’ contribution to TPEC has been decreasing in the last two decades despite the increasing installation capacity. This suggests that the current rate of the addition of renewable energy capacity is inadequate to allow ASEAN to reach net-zero by 2050. Therefore fossil energies will continue to be an important part of ASEAN’s energy mix. More tools such as carbon capture and storage (CCS) and hydrogen will be needed for decarbonization. CCS will be needed to decarbonize ASEAN’s fossil power and industrial plants while blue hydrogen will be needed to decarbonize hard-to-decarbonize industrial plants. Based on recent research into regional CO2 source-sink mapping this paper proposes six large-scale CCS projects in four countries which can mitigate up to 300 Mtpa CO2 . Furthermore this paper identifies common pathways for ASEAN decarbonization and their policy implications.

With increasing attention to climate change the penetration level of renewable energy sources (RES) in the electricity network is increasing. Due to the intermittency of RES gas‐fired power plants could play a significant role in backing up the RES in order to maintain the supply– demand balance. As a result the interaction between gas and power networks are significantly in‐ creasing. On the other hand due to the increase in peak demand (e.g. electrification of heat) net‐ work operators are willing to execute demand response programs (DRPs) to improve congestion management and reduce costs. In this context modeling and optimal implementation of DRPs in proportion to the demand is one of the main issues for gas and power network operators. In this paper an emergency demand response program (EDRP) is implemented locally to reduce the con‐ gestion of transmission lines and gas pipelines more efficiently. Additionally the effects of optimal implementation of local emergency demand response program (LEDRP) in gas and power networks using linear and non‐linear economic models (power exponential and logarithmic) for EDRP in terms of cost and line congestion and risk of unserved demand are investigated. The most reliable demand response model is the approach that has the least difference between the estimated demand and the actual demand. Furthermore the role of the LEDRP in the case of hydrogen injection instead of natural gas in the gas infrastructure is investigated. The optimal incentives for each bus or node are determined based on the power transfer distribution factor gas transfer distribution factor available electricity or gas transmission capability and combination of unit commitment with the LEDRP in the integrated operation of these networks. According to the results implementing the LEDRP in gas and power networks reduces the total operation cost up to 11% and could facilitate hydrogen injection to the network. The proposed hybrid model is implemented on a 24‐bus IEEE electricity network and a 15‐bus gas network to quantify the role and value of different LEDRP models.

In this paper a method of efficient hydrogen production using low‐power electrolysis based on pre‐magnetic polarization was proposed in order to improve the rate of hydrogen produc‐ tion by water electrolysis with reduced energy consumption molecular polarity and stress–strain characteristics of distilled water under the condition of a pre‐magnetic field. By constructing a mi‐ crophysical model of hydrogen proton energy‐level transition and a macroscopic mathematical model corresponding to magnetization vector‐polarization hydrogen proton concentration in the pre‐magnetic field the ionic conductivity electrolyte current density interelectrode voltage and hydrogen production efficiency under a varying magnetic field were qualitatively and quantita‐ tively analyzed. In addition an adjustable pre‐magnetic polarization hydrolyzing hydrogen pro‐ duction test platform was set up to verify the effectiveness of the proposed method. The repeated test results within a magnetic field strength range of 0–10000 GS showed that the conductivity of distilled water after pre‐magnetic polarization treatment increased by 2–3 times the electrolytic current density of the PEM (Proton Exchange Membrane) increased with increasing magnetic field strength the voltage between the poles continuously decreased and the hydrogen production rate was significantly improved. When the magnetic field strength reached 10000 GS the rate of hydro‐ gen production by the electrolysis of distilled water increased by 15%–20% within a certain period of time.

Aerospace parts made of high strength steels such as landing gears and helicopter transmissions are often electroplated to satisfy various engineering specifications. However plated parts are occasionnaly rejected because of hydrogen embrittlement and the industry has few means of evaluating quantitatively the actual damage caused by hydrogen. In the present article we developed a novel method to measure the stress intensity threshold for hydrogen embrittlement (Kth) in industrial plating conditions. The method consists in plating side-grooved CT samples in industrial plating baths and measuring Kth with an incremental step loading methodology. We validated the method with a benchmark case known to produce embrittlement (omitted post-plating bake) and we used the method on a test case for which the level of embrittlement was unknown (delayed bake). For the benchmark case we measured a Kth of 49.0 MPa m0.5 for non-baked samples. This value is significantly lower than the fracture toughness of the unplated material which is 63.8 MPa m0.5 . We conclude that this novel combination of geometry and test method is efficient in quantifying hydrogen embrittlement of samples plated in industrial conditions. For the test case the Kth are respectively 57.9 MPa m0.5 and 58.8 MPa m0.5 for samples baked 100 h and 4 h after plating. We conclude that delaying the post-plating bake does not cause hydrogen embrittlement in the studied conditions. Using a finite element hydrogen diffusion analysis we argue that the side grooves on CT samples increase the sensitivity to hydrogen embrittlement in comparison to smooth samples. In smooth samples a zone of plane stress at the surface of the specimen shields hydrogen from penetrating to the center of the specimen a phenomenon which is alleviated with machining side grooves.

Hydrogen fuel cells are systems that can be successfully used to partially replace internal combustion propulsion systems. For this reason the article presents an operational analysis of energy flow along with an analysis of individual energy transmission systems. Two generations of the Toyota Mirai vehicle were used for the tests. The operational analyses were carried out on the same route (compliant with RDE test requirements) assessing the system’s operation in three driving sections (urban rural and motorway). Both generations of the drive system with fuel cells are quite different which affects the obtained individual systems operation results as well as the overall energy flow. Research was carried out on the energy flow in the fuel cells FC converter battery and electric motor using a dedicated data acquisition system. The analyses were carried out in relation to the energy of fuel cells battery energy and recovered braking energy. It was found that in the urban drive section of the second-generation system (due to its much larger mass) a slightly higher energy consumption value was obtained (by about 2%). However in the remaining phases of the test consumption was lower (the maximum difference was 18% in the rural phase). Total energy consumption in the research test was 19.64 kWh/100 km for the first-generation system compared to 18.53 kWh/100 km for the second-generation system. Taking into account the increased mass of the second-generation vehicle resulted in significantly greater benefits in the second-generation drive (up to 37% in individual drive sections and about 28% in the entire drive test).

Although recent studies have shown the possibility of running ‘standard’ spark-ignition engines with 6 pure ammonia the operating range remains limited mainly due to the unfavorable characteristics of 7 ammonia for premixed combustion and often requires the addition of a complementary fuel such as H2 8 to extend it. As the best way to add H2 is to crack ammonia directly on-board this paper focuses on 9 the impact of the upstream cracking level of ammonia on the performance and emissions of a single 10 cylinder spark ignition engine. Experiments were performed over several equivalence ratios 11 dissociation rates and load conditions. It is confirmed that only a slight rate of ammonia dissociation 12 (10%) upstream of the combustion considerably enhances the engine's operating range thanks to a 13 better combustion stability. In terms of pollutant emissions the partial dissociation of ammonia 14 especially for slightly lean mixtures induces a very clear trade-off between high NOx and high 15 unburned ammonia level for high and low ammonia dissociation rates respectively. Therefore 16 cracking NH3 does not only improve the operating range of ammonia-fueled spark ignition engines but 17 can also help to reduce NH3. However to reach the same engine output work higher ammonia fuel 18 consumption will be necessary since the global system efficiency is lower using fuel dissociation. In 19 addition the global warming effect is increased with dissociation level since a higher level of N2O is 20 generated by the hydrogen contribution.

Dedicated bioenergy combined with carbon capture and storage are important elements for the mitigation scenarios to limit the global temperature rise within 1.5 °C. Thus the productions of carbon-negative fuels and chemicals from biomass is a key for accelerating global decarbonisation. The conversion of biomass into syngas has a crucial role in the biomass-based decarbonisation routes. Syngas is an intermediate product for a variety of chemical syntheses to produce hydrogen methanol dimethyl ether jet fuels alkenes etc. The use of biomass-derived syngas has also been seen as promising for the productions of carbon negative metal products. This paper reviews several possible technologies for the production of syngas from biomass especially related to the technological options and challenges of reforming processes. The scope of the review includes partial oxidation (POX) autothermal reforming (ATR) catalytic partial oxidation (CPO) catalytic steam reforming (CSR) and membrane reforming (MR). Special attention is given to the progress of CSR for biomass-derived vapours as it has gained significant interest in recent years. Heat demand and efficiency together with properties of the reformer catalyst were reviewed more deeply in order to understand and propose solutions to the problems that arise by the reforming of biomass-derived vapours and that need to be addressed in order to implement the technology on a big scale.

On this weeks episode the team are talking all things hydrogen with Mark Neller Director at Arup. On the show we discuss the UK’s Hydrogen4Heat program where Arup has been leading the UK government’s work on the safety and practical considerations that are necessary to examine whether hydrogen could be a serious solutions for decarbonising UK residential commercial and industry heat. We also discuss the Nikola Badger the need for system wide planning when considering decarbonisation pathways for heat. All this and more on the show!

The podcast can be found on their website

This work demonstrates the need for accurate thermodynamic models to reliably quantify changes in the thermophysical properties of natural gas when blended with hydrogen. For this purpose a systematic evaluation was carried out on the predictive accuracy of three well-known models the Peng−Robinson equation of state (EoS) the multiparameter empirical GERG-2008 model and the molecular-based polar softSAFT EoS in describing the thermodynamic behavior of mixtures of hydrogen with commonly found components in natural gas. Deviations between the calculated properties and experimental data for phase equilibria critical loci second-order derivative properties and viscosities are used to determine the accuracy of the models with polar soft-SAFT performing either equally or better than the other two examined models. The evaluation for the effect of H2 content on the properties of methane simulated as natural gas at conditions for transportation reveals higher changes in blend density and speed of sound with increasing H2 content within 5% change per 5 mol % H2 added while viscosity is the least affected property changing by 0.4% for every 5 mol % H2.