Publications

Energy production by methanization or gasification of biomass is dependant on the chemical composition of the gas generated. The resistive sensors based on semiconductor metal oxides like the MQ series sensors are inexpensive and frequently used in gas detection. These sensors initially dedicated to detecting gas leaks in safety systems have relatively small measurement ranges (i.e. limited to concentrations below 10000 ppm). It is therefore necessary to find solutions to adapt these categories of sensors for gas measurements in the energy sector where the gas concentration is much more significant. In this article we propose a protocol using an adaptable capsule for MQ-4 and MQ-8 sensors to measure high concentrations of CH4 and H2 respectively. The technique consists of diluting the gas to be studied in a known volume of air. Three methods are proposed and compared regarding the linearity and the repeatability of the measurements. The first method was done in an airtight enclosed chamber the second method consists of directly injecting the gas on the sensor placed in an open environment and the final method was accomplished by direct injection of the gas on the sensor placed in a partially closed capsule. Comparisons show that the first technique provides the best repeatability with a maximum standard deviation of 13.88% for CH4 measurement and 5.1% for H2. However its linearity is weak (i.e. R2 ¼ 0.8637 for CH4 and R2 ¼ 0.5756 for H2). The second technique has better linearity but bad repeatability. The third technique presents the best results with R2 values of 0.9973 for the CH4 measurement and 0.9472 for H2. The use of the partially closed capsule resulted in an acceptable linear response of the sensors by up to 20% concentration of CH4 and until 13.33% concentration of H2 in the studied gas. The use of this simple and low-cost technique facilitates the characterization of combustible gases in isolated areas. It allows local operators of biomass valorization systems to control and improve their installations while avoiding the high costs of conventional measurement devices. This study hence contributes to the development of rural electrification projects in remote areas.

LaNiO3 and LaCoO3 perovskites synthesized by self-combustion were characterised and studied in the ammonia decomposition reaction for obtaining hydrogen. Both the fuel to metal nitrates molar ratio and calcination temperature were found to be crucial to synthesize perovskites by self-combustion. Moreover generating non-precursor species during synthesis and small metal size were two factors which significantly influenced catalytic activity. Hence with a citric acid to metal nitrates molar ratio equal to one a LaNiO3 perovskite was obtained with suitable physicochemical properties (specific surface area lower impurities and basicity). In addition a lower calcination temperature (650 ◦C) resulted in small and well-dispersed Ni0 crystallite size after reduction which in turn promoted the catalytic transformation of ammonia into hydrogen. For cobalt perovskites calcination temperature below 900 ◦C did not have a significant influence on the size of the metallic cobalt crystallite size. The nickel and cobalt perovskite-derived catalysts calcined at 650 ◦C and 750 ◦C respectively yielded excellent H2 production from ammonia decomposition. In particular at 450 ◦C almost 100% of the ammonia was converted over the LaNiO3 under study. Furthermore these materials displayed admirable performance and stability after one day of reaction.

For renewable hydrogen to be a significant part of the future decarbonized energy and transportation sectors a rapid and massive build-out of hydrogen production facilities will be needed. This paper describes a geospatial modeling approach to identifying the optimal locations for renewable hydrogen fuel production throughout the state of California based on least-cost generation and transport. This is accomplished by (1) estimating and projecting California renewable hydrogen demand scenarios through the year 2050 (2) identifying feedstock locations (3) excluding areas not suitable for development and (4) selecting optimal site locations using commercial geospatial modeling software. The findings indicate that there is a need for hundreds of new renewable hydrogen production facilities in the decades preceding the year 2050. In selecting sites for development feedstock availability by technology type is the driving factor."

A fuel cell vehicle has a purging system for exhausting contaminated hydrogen gas. Notwithstanding the allowable hydrogen emissions levels in the purging system are regulated by the GTR a further research on the safety requirement of emissions concentrations is therefore needed for the vehicle design into a more rational system. In the present study the effects of flow speed concentration humidity on ignition characteristics of hydrogen/air mixtures were experimentally investigated. The results demonstrate that the value of Lower Flammable Limit increased with an increase in the velocity of hydrogen/air mixtures and slightly increased with a decrease in oxygen concentration.

Delivering low-carbon heat will require the substitution of natural gas with low-carbon alternatives such as electricity and hydrogen. The objective of this paper is to develop a method to soft-link two advanced investment-optimising energy system models RTN (Resource-Technology Network) and WeSIM (Whole-electricity System Investment Model) in order to assess cost-efficient heat decarbonisation pathways for the UK while utilising the respective strengths of the two models. The linking procedure included passing on hourly electricity prices from WeSIM as input to RTN and returning capacities and locations of hydrogen generation and shares of electricity and hydrogen in heat supply from RTN to WeSIM. The outputs demonstrate that soft-linking can improve the quality of the solution while providing useful insights into the cost-efficient pathways for zero-carbon heating. Quantitative results point to the cost-effectiveness of using a mix of electricity and hydrogen technologies for delivering zero-carbon heat also demonstrating a high level of interaction between electricity and hydrogen infrastructure in a zero-carbon system. Hydrogen from gas reforming with carbon capture and storage can play a significant role in the medium term while remaining a cost-efficient option for supplying peak heat demand in the longer term with the bulk of heat demand being supplied by electric heat pumps.

A 10-minute tour of hydrogen industry technology and terminology for those who are new to the sector or who would simply like a quick review of the basics behind this burgeoning energy source.

Podcast can be found on their website

This paper reviews the background to New Energy Vehicles (NEV) policies in China and the key scientific and market challenges that need to be addressed to accelerate fuel cells (FCs) in the rapidly developing NEV market. The global significance of the Chinese market key players core FC technologies and future research priorities are discussed.

Hydrogen energy one of the energy sources of the future represents a substantial issue which affects the industries and national technologies that will develop in the future. In order to utilize hydrogen energy a hydrogen supply chain is required so that hydrogen can be processed and transported to vehicles. It is helpful for technology and policy development to analyze technologies necessary to charge the hydrogen energy generated into vehicles through the supply chain to discover technologies with high potential for future development. The purpose of this paper is to identify promising technologies required in storing transporting and charging vehicles generated by the hydrogen fuel supply chain. Afterward the promising technologies identified are expected to help researchers set a direction in researching technologies and developing related policies. Therefore we provide technology information that can be used promisingly in the future so that researchers in the related field can utilize it effectively. In this paper data analysis is performed using related patents and research papers for technical analysis. Promising technologies that will be the core of the hydrogen fuel supply chain in the future were identified using the published patents and research paper database (DB) in Korea the United States Europe China and Japan. A text mining technique was applied to preprocess data and then a generic topographic map (GTM) analysis discovered promising technologies. Then a technology roadmap was identified by analyzing the promising technology derived from patents and research papers in parallel. In this study through the analysis of patents and research papers related to the hydrogen supply chain the development status of hydrogen storage/transport/charging technology was analyzed and promising technologies with high potential for future development were found. The technology roadmap derived from the analysis can help researchers in the field of hydrogen research establish policies and research technologies.

This paper discusses the techno-economic assessment of hydrogen production from biogas with conventional systems. The work is part of the European project BIONICO whose purpose is to develop and test a membrane reactor (MR) for hydrogen production from biogas. Within the BIONICO project steam reforming (SR) and autothermal reforming (ATR) have been identified as well-known technologies for hydrogen production from biogas. Two biogases were examined: one produced by landfill and the other one by anaerobic digester. The purification unit required in the conventional plants has been studied and modeled in detail using Aspen Adsorption. A pressure swing adsorption system (PSA) with two and four beds and a vacuum PSA (VPSA) made of four beds are compared. VPSA operates at sub-atmospheric pressure thus increasing the recovery: results of the simulations show that the performances strongly depend on the design choices and on the gas feeding the purification unit. The best purity and recovery values were obtained with the VPSA system which achieves a recovery between 50% and 60% at a vacuum pressure of 0.1 bar and a hydrogen purity of 99.999%. The SR and ATR plants were designed in Aspen Plus integrating the studied VPSA model and analyzing the behavior of the systems at the variation of the pressure and the type of input biogas. The SR system achieves a maximum efficiency calculated on the LHV of 52% at 12 bar while the ATR of 28% at 18 bar. The economic analysis determined a hydrogen production cost of around 5 €/kg of hydrogen for the SR case.

Fire spread between vehicles provides a potential risk in parking areas with many vehicles. Several reported very large fires caused the loss of a great number of vehicles. These fires seem to be in contradiction to the European design rules for car parks assuming only a very limited number of vehicles may be on fire at the same time. The fire spread in a car park environment is dependent on many factors of both the vehicles and the structure e.g. the latter has an impact on the rate of fire spread due to reradiation of the vehicles heat release. Therefore a CFD model is established to develop a tool to assess vehicles and better understand fire scenarios in different structures. Further the model enables testing of building design to prevent and mitigate such fires scenarios involving hydrogen vehicles. In this study a real layout of a car park is modelled to investigate the effects of hydrogen emergency releases that have used different TPRD diameters. The results provide insight into the behaviour of hydrogen cars and the release pattern of the TPRD's as well as the temperature development of the concrete ceiling and concrete beams above the cars. It shows that the TPRD diameter has a little effect on the TPRD activation time of the no.1 vehicle when the amount of H2 in the tank is the same. For the surface temperature of the ceiling and beam the peak temperature for a 1mm diameter TPRD release is found highest.