Rory F. D. Monaghan

University of Galway | NUI Galway · Department of Mechanical and Biomedical Engineering

Renewable biomass plays a crucial role in transitioning toward climate-friendly heating sources; however, not without its collateral damage in terms of the disproportionately high effects on local air quality. The associated proliferation of residential heating appliances around the world, including developed regions like Europe, where an estimated...

This paper presents the results of techno-economic modelling for hydrogen production from a photovoltaic battery electrolyser system (PBES) for injection into a natural gas transmission line. Mellitah in Libya, connected to Gela in Italy by the Greenstream subsea gas transmission line, is selected as the location for a case study. The PBES includes...

Characterisation of autoignition risk is crucial for designing and optimising low-emission combustion systems as there is an increased demand for highly reactive and novel fuel mixtures. Achieving a residence time to prevent autoignition and obtaining an adequate mixing quality is a challenging trade-off for these fuels in lean-premixed combustion...

The design and operation of premixers for gas turbines must deal with the possibility of relatively rare events causing dangerous autoignition. Rare autoignition events may occur in the presence of fluctuations of operational parameters, such as temperature and fuel composition, and must be understood and predicted. This work presents a methodology...

Quantification of aleatoric uncertainties due to the inherent variabilities in operating conditions and fuel composition is essential for designing and improving premixers in dry low-emissions (DLE) combustion systems. Advanced stochastic simulation tools require a large number of evaluations in order to perform this type of uncertainty quantificat...

This paper presents a novel method for incorporating the seasonal variations in gas demand into an assessment of the economic viability of a biomethane production and injection facility. A simulation of a gas distribution (Dx) network was built to investigate the impact of limits imposed by the gas network operator on the quantity of biomethane tha...

Biogenic renewable gas, which includes biomethane from anaerobic digestion, and biomass-derived synthetic natural gas (bioSNG), can play a role to help decarbonise future energy systems and meet renewable energy targets One way in which renewable gas can offset fossil use is by injecting it into natural gas networks. This work reviews 23 peer-revie...

The design and operation of premixers for gas turbines must deal with the possibility of relatively rare events causing dangerous autoignition. Rare autoignition events may occur in the presence of fluctuations of operational parameters, such as temperature and fuel composition, and must be understood and predicted. This work presents a methodology...

Quantification of aleatoric uncertainties due to the inherent variabilities in operating conditions and fuel composition is essential for designing and improving premixers in dry low-emissions (DLE) combustion systems. Advanced stochastic simulation tools require a large number of evaluations in order to perform this type of uncertainty quantificat...

Value Chain Assessment of Hydrothermal Conversion of Wet Residues to Energy Carriers. Future feedstock flexible carbon upgrading to bio energy dispatchable carriers (F CUBED) aims to develop an advanced process concept for the hydrothermal conversion of paper sludge, fruit and vegetables and waste olive pomace to bioenergy carriers.

This paper presents the results of techno-econo-environmental modelling of options to decarbonise fleets of four-axle trucks in the quarrying sector. The key parameter used to evaluate the performance of transitioning from diesel heavy-duty trucks (HDT) to zero- or low-emission heavy-duty trucks (ZLETs) is the total cost of carbon abatement (TCA)....

The 2018 recast European Renewable Energy Directive (RED recast) sets emissions savings criteria for renewable fuels. This paper assesses the life-cycle emissions from gasification methanation of willow to produce renewable biomethane in order to compare the heat and transport 2026 sustainability criteria in the RED recast. The criteria are more st...

Development of probabilistic modelling tools to perform Bayesian inference and uncertainty quantification (UQ) is a challenging task for practical hydrogen-enriched and low-emission combustion systems due to the need to take into account simultaneously simulated fluid dynamics and detailed combustion chemistry. A large number of evaluations is requ...

The advance in analytical methodology is critical for progress in 1) biorefinery and 2) torrefaction product commercialization. The chemical characterisation of torrefaction liquid and concentrated tar produced by Arigna Fuels’ pyrolysis plant allowed identification of polar, volatile, non-volatile compounds, species containing organically bound su...

Solid-fuel stoves are at the heart of many homes not only in developing nations, but also in developed regions where there is significant deployment of such heating appliances. They are often operated inefficiently and in association with high emission fuels like wood. This leads to disproportionate air pollution contributions. Despite the prolifer...

The main motivation of this study is to investigate detailed NOx and CO formation in high-pressure dump combustor fired with lean premixed methane-air mixture using CFD-CRN hybrid approach. Further, this study is extended to investigate the effect of H2 enrichment on emission formation in the same combustor. Three-dimensional steady RANS CFD simula...

The aim of this work is to examine the state-of-the-art turbulent flame speed (ST) correlations and optimize their adjustable parameters to best match a wide range experimental turbulent premixed combustion results. Four correlations based on previous works by Zimont, Kobayashi, Ronney and Muppala have been selected for the present study. Using a M...

The aim of this work is to examine the state-of-the-art turbulent flame speed (ST) correlations and optimize their adjustable parameters to best match a wide range experimental turbulent premixed combustion results. Four correlations based on previous works by Zimont, Kobayashi, Ronney and Muppala have been selected for the present study. Using a M...

Olive stones obtained as a by-product from olive oil extraction in combination with the favourable climate in Mediterranean countries are value-added feedstocks for the energy sector due to low moisture content (< 20 wt %), suitable calorific value (> 18.7 MJ kg⁻¹ on as received) and high bulk density (about 750 kg m⁻³). The torrefaction process at...

The results of a techno-economic model of distributed wind-hydrogen systems (WHS) located at each existing wind farm on the island of Ireland are presented in this paper. Hydrogen is produced by water electrolysis from wind energy and backed up by grid electricity, compressed before temporarily stored, then transported to the nearest injection loca...

This article assesses the impact of the energy recovery from the digestate on the economics of biomethane produced from the organic fraction of municipal solid waste. Six waste-to-energy routes are investigated and assumed to be deployed in the regional context of the Republic of Ireland. Anaerobic digestion without energy recovery, and landspreadi...

This article provides a novel designing tool that integrates life cycle and techno-economic analysis in a spatially-explicit optimisation model for the supply chain for biomass-derived synthetic natural gas production from forestry residues, identifying the configurations, including number of plants, locations, sizes, that minimise the environmenta...

Uncertainty quantification (UQ) is becoming an essential attribute for development of computational tools in gas turbine combustion systems. Prediction of emissions with a variety of gaseous fuels and uncertain conditions requires probabilistic modelling tools, especially at part load conditions. The aim of this paper is to develop a computationall...

This paper describes the development of a systematic tool chain capable of automatically extracting accurate and efficient Reduced-Order Models (ROMs)from Computational Fluid Dynamics (CFD)simulations. These ROMs can then be used to support the design and operation of Near-Zero Energy Buildings (NZEB), with a higher accuracy than traditional zonal...

Hybrid CFD- chemical reactor network (CRN) methods have been extensively used in the literature to predict emissions for combustion systems. In this approach, CFD is used to characterize a flow-field, and then detailed chemistry is modelled using a CRN to calculate emissions accurately. Although some algorithms have been developed for systematic co...

Using waste biomass materials offers the potential to reduce the greenhouse gas emissions from fossil fuels. Torrefaction is very useful for improving the fuel properties of biomass in order to better match those of coal. The aim of this work is to compare the properties of torrefied low quality biomass bri-quettes against coal equivalents. The com...

The present study aims to develop a systematic tool chain for automatically extracting accurate Reduced-Order Models (ROMs) from Computational Fluid Dynamics (CFD) simulations for use in the design and operation of near-zero energy buildings, with a higher accuracy than traditional zonal models but at a fraction of the computational cost of CFD. Th...

Green gas is a promising renewable energy carrier compatible with existing gas networks, whose environmental impact and capacity to decarbonise the energy sector is evaluated by life cycle assessment (LCA). This articles reviews 42 LCAs applied to biomethane, produced by anaerobic digestion, and bio-SNG, produced by gasification and methanation, di...

This article provides a sectorial input-output resource assessment and spatial distribution for wastes and residues that could be used as feedstock for bio-SNG production, in the case of the Republic of Ireland (ROI). European and national policies that regulate the use of agricultural and forestry residues, and tertiary waste are reviewed. Geospat...

Many sources of uncertainty exist when emissions are modeled for a gas turbine combustion system. They originate from uncertain inputs, boundary conditions, calibration, or lack of sufficient fidelity in a model. In this paper, a nonintrusive polynomial chaos expansion (NIPCE) method is coupled with a chemical reactor network (CRN) model using Pyth...

Many sources of uncertainty exist when emissions are modelled for a gas turbine combustion system. They originate from uncertain inputs, boundary conditions, calibration, or lack of sufficient fidelity in the model. In this paper, a non-intrusive polynomial chaos expansion (NIPCE) method is coupled with a chemical reactor network (CRN) model using...

This study presents a novel approach for the chemical representation of lignin for modelling the reaction kinetics of lignin in lignocellulosic biomass. This methodology relies on the definition of dimeric pseudo-components containing phenolic functionalities, i.e., p-hydroxyphenyl, guaiacyl and syringyl groups, as measured in real biomass and nati...

This study presented a techno-economic evaluation of the thermal conversion of sludge and digestate integrated with anaerobic digestion (AD) as a means of waste volume reduction, carbon emissions mitigation and energy recovery in wastewater treatment plants. The study was supported by empirical data and thermodynamic modelling of processes involved...

This study describes a lumped kinetic modelling architecture with which to simulate and predict the pyrolysis reaction kinetics of hemicellulose biopolymers. A key feature of the model is the replication of essential compositional features of biomass hemicelluloses into the chemical reaction pathways of the model. More specifically, five new model...

There is a need for fast and reliable emissions prediction tools in the design, development and performance analysis of gas turbine combustion systems to predict emissions such as NOx, CO. Hybrid emissions prediction tools are defined as modelling approaches that (1) use computational fluid dynamics (CFD) or component modelling methods to generate...

Improved process development and design of technologies such as pyrolysis and gasification of lignocellulosic biomass can be aided greatly by advanced comprehension of their chemistry and thermal reactivity. Hemicellulose and lignin have significant chemical variations within plant species and after biomass treatment, which are outside of the capab...

Ireland produces 642,000 t of separated household organic waste or “food waste” annually. In 2016, only 420,000 t of biodegradable waste was permitted to landfill following the EU Directive 1999/31/EC. Growing population and restrictive directives are making landfills unfeasible. Anaerobic digestion (AD) offers an initial waste management measure o...

Improved process development and design of technologies such as pyrolysis and gasification of lignocellulosic biomass can be aided greatly by advanced comprehension of their chemistry and thermal reactivity. Hemicellulose and lignin have significant chemical variations within plant species and after biomass treatment, which are outside of the capab...

EPA Research 216 detailing Thermodynamic Modelling of Energy Recovery Options from Digestate at Wastewater Treatment Plants Identify Pressures It is vitally important to evaluate alternative means of sludge disposal in order to avoid pollution of agricultural land. Thermal conversion technologies can address the problem of surplus sludge while als...

Seven European gas transmission system operators, including Gas Networks Ireland (GNI), have signed a joint declaration proclaiming the aim to establish a 100% CO 2-neutral gas supply by 2050. The production of bio-SNG through a nationwide gasification and methanation system can constitute the basis of renewable gas production from indigenous bioma...

Several approaches are available to model emissions of combustion systems, such as correlation-based, computational fluid dynamics (CFD) and hybrid methods. Hybrid methods are defined as modelling approaches that use CFD to generate required flow field information integrated with chemical reactor network (CRN) techniques to model finite rate chemis...

Preprint of BSA 2017 conference proceedings. This paper received a "Best Paper" award at the BSA 2017 conference organized by IBPSA Italy.

In indoor thermal environment modelling applications where dynamic local effects of fluid flows are critical, classic zonal models are not always suitable. On the other hand, CFD simulations can give accurate solutions at very high computational cost. Reduced-order models (ROMs), extracted from CFD simulations, can preserve CFD model accuracy while...

This paper presents preliminary experimental test results for a novel truck auxiliary power unit (APU) design consisting of a 1 kWe free-piston Stirling engine and 2 kWt zeolite-water adsorption chiller that is powered via waste heat from the engine's cooling jacket. A prototype system was built and tested to study the interaction dynamics between...

Ireland's 2015 Energy White Paper proposes the guidelines for a radical transformation in the energy sector in Ireland and a large reduction of CO2 emissions from 2015 to 2050. Biomass-derived synthetic natural gas (bio-SNG) via gasification and methanation (GaM) represents a potential route to decarbonise the use of natural gas. This work presents...

This paper identifies the key technical requirements for a heavy truck auxiliary power unit (APU) and explores a potential alternative technology for use in a next-generation APU which could eliminate key problems related to emissions, noise and maintenance experienced today by conventional diesel engine-vapour compression APUs. The potential perfo...

Co-firing biomass with fossil fuels is increasingly relevant to thermal power plant operators due to new, stricter sanctions relating to carbon footprints. It has been found that the use of biomass results in an altered ash composition, which leads to increased corrosion of the superheater tube walls. This paper presents results for corrosion depth...

The aim of this work is to provide insight into the state-of-the-art turbulent flame speed (ST) correlations and to determine the most appropriate correlations to use under different turbulent premixed combustion conditions. The accuracies of 16 correlations for ST are determined using a large volume of data over a range of conditions. Accuracy is...

Sustainable feedstocks such as lignocellulosic biomass and agricultural wastes can be integrated into platform chemical production systems via pyrolysis and gasification. These processes face challenges related to the use of low-quality biomass, with low energy densities and different chemical reactivities when compared to conventional fuels. Sophi...

Wastewater treatment (WWT) plants consume up to 180 MJ and produce 10-85 kg dry sludge per person every year. This will continue to increase due to more rigorous effluent quality regulations and demands. Sludge management and disposal can increase energy requirements and the carbon footprint of the plant. Anaerobic digestion (AD) offers an alternat...

Ireland’s 2015 Energy White Paper proposes the guidelines for a radical transformation in the energy sector in Ireland and a large reduction of CO2 emissions from 2015 to 2050. Biomass-derived synthetic natural gas (bio-SNG) via gasification and methanation (GaM) represents a potential route to decarbonise the use of natural gas. This work presents...

Sewage sludge is a by-product generated from municipal wastewater treatment (WWT) processes. This study examines the conversion of sludge via energy recovery from gasification/combustion for thermal treatment of dewatered sludge. The present analysis is based on a chemical equilibrium model of thermal conversion of previously-dewatered sludge with...

Wastewater treatment (WWT) plants belong to an ever-changing sector that consumes up to 180 MJ per person and produces over 27 Mt of sludge every year in Europe [1, 2]. This will continue to increase due to more rigorous demands on effluent quality and environmental regulations. Technologies for sludge treatment include thickening and dewatering, a...

Thermal conversion technologies, such as pyrolysis and gasification, are efficient processes that can integrate sustainable feedstocks such as biomass into renewable energy and platform chemical production systems, through other vectors such as bio-methane, liquid biofuels, fertilisers, and heat and power. These technologies can also use a wide ran...

Wastewater treatment (WWT) plants consume over 180 MJ per person every year. This will continue to increase due to more rigorous effluent quality regulations and demands. A WWT facility can produce between 10 and 30 dry t sewage sludge (SS) per 1000 p.e.-year. Sludge treatment and transportation to disposal sites increase WWT energy requirements by...

Co-firing biomass with traditional fuels is becoming increasingly relevant to thermal power plant operators due to increasingly stringent regulations on greenhouse gas emissions. It has been found that when biomass is co-fired an altered ash composition is formed, which leads to increased levels of corrosion of the superheater tube walls. Synthetic...

Substantial progress has been made in understanding and reducing temperature inhomogeneity in rapid compression machines (RCMs) with the help of computational modeling. To date, however, it has not been possible to investigate and map the full range of possible RCM designs, working gases, and operating conditions. In this work, we present a framewo...

Sewage sludge is a by-product generated from municipal wastewater treatment plants (WWTP). This study examines the conversion of sludge via gasification/combustion for energy recovery for thermal treatment of dewatered sludge. The present analysis is based on a chemical equilibrium model of thermal conversion of dewatered sludge with moisture conte...

This paper presents a physics-based model to describe accelerated corrosion due to alkali halide-containing deposits, which form on superheater tube walls during biomass co-firing. Increased rates of corrosion during the co-firing of peat with biomass have been identified as a limiting factor on the level of biomass which is viable to use at elevat...

Accurate modelling of the internal climate of buildings is essential if Building Energy Management Systems (BEMS) are to efficiently maintain adequate thermal comfort. Computational fluid dynamics (CFD) models are usually utilised to predict internal climate. Nevertheless CFD models, although providing the necessary level of accuracy, are highly co...

The aim of this work is to develop a Cantera-based solver to predict turbulent flame speeds (S T) in the wrinkled flamelet, corrugated flamelet and thin reaction zone regimes, in which Da> 1. The existing unstretched, freely-propagating, one-dimensional laminar flame speed solver within Cantera was modified to include (1) enhancement of property tr...

This paper describes the validation of a previously described CFD-CRN method (computational fluid dynamics–chemical reactor network) for emissions predictions for the laboratory benchmark TECFLAM S09c flame. It details CFD simulation, solution strategy, validation using, CRN generation, detailed emissions predictions and reaction pathway studies. S...

Thermal comfort is a key indicator of building performance and is proven to have a strong correlation with concentration and productivity under laboratory conditions. Typically, thermal comfort is defined using the Predicted Mean Vote (PMV) / Predicted Percentage Dissatisfied (PPD) [1]. This paper proposes a novel approach to teaching the concept o...

Rory F. D.,* ,† Rå bi Tahir,c ‡ Alberto Cuoci, § Gilles Bourque, ‡ Marc Füri, ‡ Robert L. Gordon, ‡ Tiziano Faravelli, § Alessio Frassoldati, § and Henry J. Curran

The development of accurate, flexible, and robust dynamic reduced order models (ROMs) of entrained flow gasifiers (EFGs) is an important step toward greater commercialization of that technology. Previous work by the authors described the development, validation, and sensitivity analysis of such a ROM.(1,2) This paper presents the results of dynamic...