Hervé Jeanmart

Catholic University of Louvain | UCLouvain · Institute of Mechanics, Materials and Civil Engineering (IMMC)

In pursuit of reducing greenhouse gas emissions, the European Union plans to annually import ten million tonnes of renewable hydrogen. While the economic viability of hydrogen importation is established, environmental assessments are limited to comparisons and lack an evaluation of absolute sustainability. Therefore, we conducted a multi-objective...

The transition from fossil fuels to clean energy sources requires the supply of gaseous fuels from renewable origin for a number of applications. Such applications include in particular high-temperature heat for industries, and Combined Heat and Power (CHP) for flexible, decentralized power production. Gasification of lignocellulosic biomass is a g...

As our society grows more interconnected through digital and physical platforms, the number of ways to carry out work-related tasks has increased quickly. Work may no longer be linked to a physical space. Many consider the productive environment created by the COVID-19 lockdowns as clear evidence that hybrid work may be successful, hence advancing...

Traditionally, small to medium size (less than 10 MW), cogeneration based on biomass traditionally involves a downdraft gasifier coupled with an internal combustion engine [1]. One of the main difficulties in these power and heat units involving a gasifier and an internal combustion engine is the added cost and complexity of the syngas conditioning...

Thermochemical gasification of biomass produces a syngas that suffers two main drawbacks: a low energy density, measured by its Lower Heating Value (LHV) and the residual tar content. In this paper, steam injection and air enrichment are studied as ways to tackle both challenges. We have conducted experiments on wood chips gasification in a pilot-s...

Energy crops on marginal lands are seen as an interesting option to increase biomass contribution to the primary energy mix. However, in the literature there is currently a lack of integrated assessments of margin land availability, energy crop production potential and supply chain optimisation. Assessing the potential and the cost of these resourc...

Accurate temperature measurements in reactive combustion systems are crucial for kinetic and heat transfer studies. Intrusive temperature measurement methods, such as thermocouples, are still widely used in experimental combustion research applications. Thin wire customized type B thermocouples, (Pt Rh6%-Pt Rh30%), coated with BeO (Beryllium oxide)...

Experimental results of the impact of steam injection in a two-stage downdraft gasifier, and its impact on syngas composition, LHV and tar content

The complexity of bottom-up energy system models has progressively grown to enhance the representativeness of the system under analysis. Among them, whole-energy system models aim at representing the energy resources, conversion technologies, and energy demands of regions (i.e., a country) in its entirety. Despite this effort leading to an increase...

Biomass is a key renewable resource for energy transition and climate change mitigation. It can be used for either energy purposes (production of heat, electricity, and fuel) or non-energy demand (e.g., chemicals). This raises the question of the optimal use of biomass in energy systems. In the literature, this optimal use is often determined for o...

Ongoing work presented at the "Journées d’Etudes" of the Belgian Section: Combustion Institute held at Ghent University (March, 2022)

This paper introduces the design of a biomass gasification reactor with specific constraints for its manufacturing and operation in the West African conditions. The foreseen applications are the valorisation into heat and electricity of agricultural biomass residues. Rice husk is chosen as the reference fuel for the design. Local manufacturing is a...

Wind and solar energies present a time and space disparity that generally leads to a mismatch between the demand and the supply. To harvest their maximum potentials, one of the main challenges is the storage and transport of these energies. This challenge can be tackled by electrofuels, such as hydrogen, methane, and methanol. They offer three main...

There is currently no consensus regarding whether or not renewable energies are capable of supplying all of our energy needs in the near future. To shed new light on this controversy, this paper develops a methodology articulating a macroeconomic model with two sectors (energy and non-energy) and an energy model that is able to calculate the maximu...

Access to abundant and affordable primary energy resources has been recognised as an essential factor for the prosperity of human societies. To measure their quality, understood as the ease with which the energy system can extract and transform them into a form useful to society, the concept of energy return on investment (EROI) is widely used. Yet...

Air quality is a growing concern worldwide because of its impacts on both the environment and the human health. The road transport sector is a major contributor to this poor air quality. To reduce the emission of particulate matter, all diesel passenger cars were equipped with diesel particulate filters since the EURO5b emission standard. Unfortuna...

Coke oven gas (COG) is a valuable by-product of coke-making process, due to its high H2 content and calorific value. The potential exploitation of COG as an energy carrier requires a proper characterization of its kinetic behavior. Moreover, the residual presence of aromatic compounds in COG can potentially affect both its combustion efficiency and...

Increasing the biodiesel content of diesel fuels is encouraged because of its reduced carbon footprint. Pure rapeseed methyl ester (RME)and used cooking oil methyl ester (UCOME) are characterised by well-to-tank greenhouse gas (GHG) reductions of 54% and 88% compared to pure B0 petrodiesel, respectively. Captive fleets such as public transport buse...

The interest in ammonia as a high-density hydrogen carrier for long-term electricity storage is growing. A clean and efficient Combined Heat and Power (CHP) system is envisioned for power production from stored ammonia, to which Homogeneous-Charge Compression-Ignition (HCCI) engines are promising. Although recent preliminary studies showed a high e...

The necessity of neutralizing the increase of the temperature of the atmosphere by the reduction of greenhouse gas emissions, in particular carbon dioxide (CO2), as well as replacing fossil fuels, leads to a necessary energy transition that is already happening. This energy transition requires the deployment of renewable energies that will replace...

Different scenarios at different scales must be studied to help define long term policies to decarbonate our societies. In this work, we analyse the Belgian energy system in 2035 for different carbon emission targets, and accounting for electricity, heat, and mobility. To achieve this objective, we applied the EnergyScope Typical Days open source m...

The amount of energy striking the earth’s surface in one hour is higher than global annual societies energy use, yet the fraction of incoming solar radiation that can be harvested is significantly constrained. A global grid-cell methodology was adopted to assess the available global solar energy potential taking into account four constraints: land-...

Internal combustion engines have been improved for many decades. Yet, complex phenomena are now resorted to, for which any optimum might be unstable: noise, low-temperature heat release timing, stratification, pollutant sweet spots, and so on. In order to make reliable statements on an improvement, one must specify the uncertainty related to it. St...

The transition towards more sustainable, fossil-free energy systems is interlinked with a high penetration of stochastic renewables, such as wind and solar. Integrating these new energy resources and technologies will lead to profound structural changes in energy systems, such as an increasing need for storage and a radical electrification of the h...

The transition towards more sustainable, fossil-free energy systems is interlinked with a high penetration of stochastic renewables, such as wind and solar. In this context, energy storage technologies of different kinds-namely electrical, thermal and chemical-are commonly expected to play a major role; however, this role is seldom quantified using...

The transition to renewable energies means a shift from centralised applications burning high energy density fuels, to decentralised applications powered by intermittent sources (wind and solar radiation). The fraction of the available renewable energy that can sustainably be harvested is greatly constrained by physical, technical and geographical...

This document summarizes the discussions held during a workshop on the energy transition, organized by several Belgian academic and industrial experts. All the questions raised above are addressed in a general way, trying to express and justify the different points of view, starting from works published in the literature.

The document summarizes the discussions held during a workshop on the energy transition, organized by several Belgian academic and industrial experts. All the questions raised above are addressed in a general way, trying to express and justify the different points of view, starting from works published in the literature.

In most Rapid Compression Machine (RCM) operations, it is sought to have a homogeneous temperature field inside the core region of the reaction chamber so that the adiabatic core assumption may be appropriately applied. Pistons with crevice on their side have shown to be effective in producing a uniform temperature field at the end of the compressi...

Ce numéro spécial de Regards économiques croise les regards d’ingénieurs et d’économistes pour étudier les possibles impacts de la transition énergétique sur la croissance économique. Cette transition peut être définie comme la transformation des modes actuels de production et de consommation de l'énergie. L’angle d’analyse ne concerne pas un pays...

Ce numéro spécial de Regards économiques croise les regards d’ingénieurs et d’économistes pour étudier les possibles impacts de la transition énergétique sur la croissance économique. Cette transition peut être définie comme la transformation des modes actuels de production et de consommation de l'énergie. L’angle d’analyse ne concerne pas un pays...

For long-term storage, part of the excess renewable energy can be stored into various fuels, among which ammonia and hydrogen show a high potential. To improve the power-to-fuel-to-power overall efficiency and reduce NOx emissions, the intrinsic properties of Low Temperature Combustion (LTC) engines could be used to convert these carbon-free fuels...

The world has experienced several energy transitions. During the end of the XIX century, coal became the first energy resource before biomass. After WWII, the thermodynamic quality of hydrocarbons made them the first primary energy resource. Finally, today due to global warming threats, humanity starts a decarbonising energy transition from fossil...

To face climate changes and energy dependency, governments encourage their industries and communities to increase the share of renewable energy (RE). However, the RE production is mostly inflexible. The risk of unmatching electricity market grows. Tools such as power plant flexibility, import/export, demand side management, storage and RE curtailme...

The use of creviced pistons in Rapid Compression Machines (RCMs) has proven to be very efficient in making the temperature homogeneous inside the reaction chamber but has the disadvantage of inducing an unintended mass transfer from the reaction chamber to the crevice, especially during the preliminary heat release of two-stage ignition processes....

In the frame of power-to-fuels, the present study focuses on the use of the simple storage fuels that are hydrogen, ammonia, methane and methanol for power and heat production with Homogeneous-Charge Compression-Ignition (HCCI) engines. Therefore, a HCCI 0-Dimensional model able to predict auto-ignition timings was used to determine if a single eng...

Three flat flames of ethyl valerate (C7H14O2) at different equivalence ratios, 0.81, 0.95 and 1.31 have been stabilized at 55 mbar and analyzed using gas chromatography. Based on the experimental results, a detailed kinetic model of ethyl valerate combustion, containing 211 species and 1368 reactions, has been elaborated. The model predictions agre...

Looking ahead to 2050 many countries intend to utilise wind as a prominent energy source. Predicting a realistic maximum yield of onshore and offshore wind will play a key role in establishing what technology mix can be achieved, specifying investment needs and designing policy. Historically, studies of wind resources have however differed in their...

Ammonia and hydrogen can be produced from water, air and excess renewable electricity (Power-to-fuel) and are therefore a promising alternative in the transition from fossil fuel energy to cleaner energy sources. An Homogeneous-Charge Compression-Ignition (HCCI) engine is therefore being studied to use both fuels under a variable blending ratio for...

In combined heat and power plants operated with biomass syngas, the removal of condensible tars is a necessary but expensive step (up to one third of the installation and maintenance costs). This step is required because the syngas has to be cooled down to avoid knocking in the spark ignition engines traditionally used in such plants. To remove the...

In the recent years, a growing interest for opportunity solid fuels, such as short-rotation energy crops and agro biomass, is observed. The combustion (or gasification) of these fuels often leads to operational issues due to the presence of liquid matter, including agglomeration or slag formation in reactors. The characterization of these fuels con...

The filtration of condensable tars is a necessary step before biomass syngas can be used in spark ignition engines. In small scale gasifiers, this step represents one third of the investment cost and create several issues of maintenance. Since tar related problems occur primarily due to tar condensation, an alternative system is being developed whe...

Power generation from biomass gasification through the use of spark ignition engines requires the cooling of the biomass syngas to avoid knock. This cooling leads to the condensation of tar impurities, which foul and clog up critical process components leading to significant maintenance issues and costs. Conventionally, tar related problems are add...

In Rapid Compression Machines (RCM), several phenomena can induce inhomogeneities inside the reaction chamber. The benefits of using a creviced piston have been largely demonstrated through good agreement with the widely used adiabatic core assumption. Still, temperature inhomogeneities due to wall heat transfer cannot be avoided. These induce spat...

La transition écologique et sociale peut se penser à partir du haut : guidée par l'Etat, par le recours à des réglementations juridiques et à des incitants économiques, et par l'outil de la planification pour passer à une société bas carbone. Elle peut aussi se réfléchir comme résultant d'initiatives locales dans les domaines de l'alimentation, de...

The transition towards 100% renewable electricity production already raises several challenges at only 20-30% of renewable share. To match energy production and consumption, there will be a need for massive daily and seasonal electricity storage, in particular for fluctuating sources such as wind and solar. Power-to-fuel is one of the energy storag...

Solid biomass ash related issues and adequate fuel characterization, especially for fuels with similar thermochemical properties, are still major challenges in combustion. As a consequence, the fuel switching and the valorization of unconventional available fuels are hazardous. An integrated strategy to characterize biomass fuels for ash related is...

Since a few years, energy utilities are facing business model disruptions: grid parity of renewable technologies, stable or decreasing demand - especially in the EU -, acceleration of digital innovations within the smart-home market, uncertain policy directives and influential customers' opinions. If, in the past, the lack of entrepreneurial cultur...

Fouling of heat exchangers in biomass combustion plants is an operational problem that can lead to a severe decrease of boilers efficiency and availability. To counteract deposition, additives are used to bind the vaporized alkali in high melting temperature structures, such as solid phosphates or aluminum-silicates. Fouling during the combustion o...

According to the European Biomass Association, bioenergy represents about 60% of the EU's total consumption of renewables. The EERA Bioenergy, section of the European Energy Research Alliance, indicates that agricultural residues and non-food crops should be used at farm- and village-scales, while low quality biomass and waste could be used for med...

Oral presentation at the JDE 2016, hosted at the UCL.

Propanal (C2H5CHO) is a crucial intermediate oxygenated species in hydrocarbons and oxygenated fuels combustion, thus motivating a better understanding of its kinetics. In this study, two premixed at flames of propanal/hydrogen/oxygen/argon, a stoichiometric and a rich, are stabilized at low pressure (27 mbar) on a burner. Species mole fraction pro...

Fouling from the processing of residual biomass fuels in combustion applications is a major concern. This paper discusses the fouling behaviour of sunflower hulls with a high phosphorus (P) content by means of a broad fuel characterisation strategy including advanced predictive indices, the fuel selective leaching, multiple deposition tests in a Dr...

The addition of acetone to stoichiometric and rich hydrogen/oxygen/argon flames has been investigated by measuring the intermediate species concentrations. Two premixed acetone/hydrogen/oxygen/argon flames were stabilized at low pressure (27 mbar) on a Spalding-Botha type burner at two equivalence ratios, ϕ = 1.1 and 1.72. Identification and monito...

Book of abstracts from the 4th KIC InnoEnergy Scientists Conference, Berlin (20-22 Oct. 2015).

Gasification proposes to convert a large variety of biomass, including wastes, into a convenient fuel in the form of syngas. Syngas usually presents a lower heating value (LHV) below 6MJ/Nm3. This LHV is due to the high nitrogen content of syngas (45-50%) as air is usually used as the gasifying agent in small-scale applications. It is low in compar...

In the recent years, a growing interest for low-quality and economically less expensive biomass fuels is observed, in both small-scale and large-scale combustion plants. The combustion of these fuels often portends technical issues, which include agglomeration of inorganic particles in fluidized beds and slag formation in combustors. In this work,...