Natural Gas Internal Combustion Engine Research Articles

Comparative analysis of different heat transfer models, energy and exergy analysis for hydrogen-enriched internal combustion engine under different operation conditions

The implementation of hydrogen as a fuel in internal combustion engines is widely considered a favorable optimal due to its zero-carbon emissions and high energy content. Heat transfer from engine cylinder walls has a major role on engine combustion, performance and emission characteristics. In this study, heat transfer analysis conducted by different heat transfer models and identify the best model to analyse the energy and exergy analysis of hydrogen enriched internal combustion engine. A series of experiments were conducted on a compressed natural gas internal combustion engine across varying hydrogen fractions, EGR ratios, engine speeds and load conditions to capture in-cylinder pressure data and heat transfer rate. The authors compared six distinct models for heat transfer based on absolute percentage errors of maximum pressure and indicated mean effective pressure. These models systematically incorporated into a quasi-dimensional combustion model (QDCM) on MATLAB for hydrogen-compressed natural gas engine, accounting for diverse operating conditions. Convective heat transfer models, including Woschni, Nusselt, Hohenberg, Han, Eichelberg, and Assanis correlations were employed. Comparative analyses were undertaken to identify the most precise correlation for predicting engine in-cylinder pressure and heat transfer rates with experimental results across a broad spectrum of operational conditions. The Woschni model, as presented, is most suitable for the QDCM of the hydrogen-compressed natural gas fuel blend. This suitability is indicated by the close alignment of Taylor length and turbulent intensity coefficients to 1, as well as the minimal absolute percentage error observed for indicated mean effective pressure. It is also observed that heat transfer rate is increased by increasing the engine load 25 %, 50 %, 75 % and 100 % as 49.57 J/deg, 129.26 J/deg, 245.35 J/deg and 250.62 J/deg respectively and heat transfer rate is decreased by increasing the speed of engine 1100 rpm, 1200 rpm, 1500 rpm and 1700 rpm as 137.34 J/deg, 134.21 J/deg, 95.33 J/deg and 48.57 J/deg respectively. The energy and exergy analyses revealed that elevating the engine load corresponds to a reduction in exergy destruction. Brake energy increased 15 % by increasing the load conditions from 25 % to 100 % and decreased 7 % by increasing the speed from 1100 rpm to 1700 rpm. Another significant finding from this study is that the values of both energy and exergy efficiencies were 38.42 % and 40.12 % respectively obtained by thermodynamic analyses.

Commercial Fleet Vehicle Additions and Replacements and the Potential Market Penetration for Electric Vehicles

Commercial fleets can play a major role in the rapid evolution of plugin hybrid electric vehicles (PHEV) and battery electric vehicles (BEV) market penetration. Using survey data in this analysis we identify groups of commercial fleets based on the attributes of the next vehicle planned to be added to a fleet and the propensity of replacing a current vehicle with an electric vehicle. We first develop principal components representing dimensions of the desired vehicle characteristics (price, efficiency, size and fuel type, timing of vehicle procurement, replacement of current vehicle or addition to the fleet, and intended purchase of new, used, or leased). Using 8 principal components capturing approximately 91.55% of the variance in the variables listed above and hierarchical clustering we derive six distinct market segments. One segment contains 43.5% of the total responses preferring a PHEV to replace a current vehicle in the fleet, it is a segment that is composed of 100% PHEV preferring respondents and almost all of them expect to purchase a small vehicle and 92% will do that within 5 years. The average price they expect to pay is approximately $27,000 and the expected efficiency to be about 55 miles per gallon equivalent (MPGe). Another segment contains 91.0% BEV preferring respondents who are only 11.6% of the sample. This segment also prefers small vehicles to replace vehicles in their fleet, possibly leasing and expecting to pay approximately $46,800 with an efficiency of about 100 MPGe. The other four segments are dominated by gasoline, diesel, and natural gas internal combustion engine vehicles.

Effects of low-grade gas composition on the energy/exergy performance of a polygeneration system (CH 2 HP) based on biomass gasification and ICE

Bio-hydrogen from sustainable biomass (i.e. agro-industrial residues) gasification can play a relevant role in the hydrogen economy, providing constant hydrogen from renewable sources. Nowadays, most hydrogen production systems integrate one or more water-gas shift (WGS) units to maximize the hydrogen yield that, however, needs additional syngas treatments, investment and operational costs. Besides, different electricity inputs are needed along the process to power the compression of raw syngas, shifted syngas, and pure hydrogen to the desired pressure. This common process integration with WGS generates a kind of off-gas from the hydrogen separation unit whose composition may or may not be suitable for power production, depending on the operating conditions of the gasification unit. In this regard, this work proposes a different approach in which no WGS reactors are involved and the off-gas is used to generate heat and power to provide the energy input needed by the system. In particular, the authors tested the bio-syngas and the corresponding off-gas in a 4-cylinders, spark ignition natural gas internal combustion engine operated in cogeneration mode with the aim to analyse the effect of removing the hydrogen from the original bio-syngas on mechanical/electric and thermal power, on fuel efficiency and CO2 specific emission.

Energy and economic analysis feasibility of CO2capture on a natural gas internal combustion engine

AbstractCO2capture by amine scrubbing is a widely developed technology in its most advanced stage of evolution. However, it has never been used to capture CO2from mobile sources. The present study performs an energy and economic analysis of an amine scrubbing CO2capture storage (CCS) system, which takes for the amine regeneration process the waste heat from the exhaust gases of a turbocharged natural gas internal combustion engine (mobile source). The selected engine for the study is an M936G, widely used in freight and passenger transport. A primary and a tertiary amine were chosen for the simulations. In order to reduce volume and increase autonomy, captured CO2is stored as a liquid, therefore, a specific installation is planned. The system is hybridised with an organic rankine cycle (ORC) to reduce the energy penalty on the CCS system. Results show that a CCS system operating with Monoethanolamine (MEA) at 30 wt% achieved a maximum CO2capture rate of 66%, with a penalty over the power engine of only 10%. On the other hand, the economic analysis showed that the CCS system with MEA and without ORC is 31.8% cheaper than a hydrogen fuel cells bus and 26% cheaper than a battery‐electric bus. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.

A Review of the Effect of Compressed Natural Gas (CNG) on Combustion and Emission Performance of Internal Combustion Engines

In order to reduce the environmental pollution caused by conventional internal combustion engines, the application of natural gas in internal combustion engines and the combustion and emission performance of natural gas internal combustion engines have been widely studied by scholars. Because the physical and chemical properties of natural gas are different from those of conventional gasoline or diesel, the operating performance of natural gas internal combustion engines in practical applications is also different from that of conventional internal combustion engines. This paper presents the physicochemical properties of compressed natural gas, the two combustion modes (premixed combustion and non-homogeneous diffusion combustion) in internal combustion engines and the effect of compressed natural gas on the performance of internal combustion engines. Compared with gasoline engines, natural gas internal combustion engines have relatively lower power and higher effective power loss; lower effective fuel consumption rate in terms of economy; and lower CO and NOx emissions than gasoline engines in terms of emissions.

Effects of Dilution and Flammability Changes on Mixture Reactivity in a Natural Gas Internal Combustion Engine

ABSTRACT Changes in the flammability characteristics of a combusting mixture and its ‘dilution’ levels – characterized, respectively, by the mixture’s equivalence ratio and residual gas fraction – can have significant impacts on the nature of combustion in internal combustion engines. These combustion changes can manifest as variations in combustion phasing and repeatability, and affect engine efficiency, emissions, and performance. The current work uses experimental, high-speed, in-cylinder CO2 concentration data from a single-cylinder, natural gas-fueled engine to track compositional variations in the combusting mixture; and then uses a chemical kinetics solver to isolate the effects of flammability and dilution changes on the mixture’s ‘reactivity,’ which is characterized by its laminar flame speed (LFS) and ignition delay (ID). It is found that LFS changes are driven strongly by the trapped equivalence ratio, while ID changes are driven primarily by dilution and pressure changes. Additionally, the effects of LFS changes on the overall combustion phasing are found to be more pronounced than those from ID changes, as the former influences both the combustion initiation and propagation processes.

Heavy Duty Natural Gas Single Cylinder Research Engine Installation, Commissioning, and Baseline Testing

Natural Gas (NG) Internal Combustion Engines (ICE) are a promising alternative to diesel engines for on-road heavy-duty applications to reduce greenhouse gas and harmful pollutant emissions. NG engines have not been widely adopted due to the lower thermal efficiency compared with diesel engine counterparts. To develop the base knowledge required to reach the desired efficiency, a Single Cylinder Engine (SCE) is the most effective platform to acquire reliable and repeatable data. A SCE test cell was developed using a Cummins 15-liter six-cylinder heavy-duty engine block modified to fire one cylinder (2.5-liter displacement). A Woodward Large Engine Control Module (LECM) is integrated to permit implementation of real-time advanced combustion control. Intake and exhaust characteristics, fuel composition, and exhaust gas recirculated substitution rate (EGR) are fully adjustable. A high-speed data acquisition system acquires in-cylinder, intake, and exhaust pressure for combustion analysis. The baseline testing shows reliable and consistent results for engine thermal efficiency, indicated mean effective pressure (IMEP), and coefficient of variance of the IMEP over a wide range of operating conditions while achieving effective control of all engine control and operation variables. This test cell will be used to conduct a research program to develop new and innovative control algorithms and CFD optimized combustion chamber designs, allowing ultra-high efficiency and low emissions for NG ICE heavy-duty on-road applications.

Comparative Analysis of Intelligence Optimization Algorithms in the Thermo-Economic Performance of an Energy Recovery System Based on Organic Rankine Cycle

Abstract This paper compares the performance of a group of intelligent algorithms such as the genetic algorithm (GA), particle swarm optimization (PSO), and repulsive particle swarm optimization (RPSO) based on the optimization of thermo-economic indicators such as the payback period (PBP), the levelized energy cost (LEC), the specific investment cost (SIC), and also in the optimization of the thermodynamic process (net power output) of an energy recovery system in a 2 MW natural gas internal combustion engine based on an organic Rankine cycle. Four parameters were considered to analyze and compare the performance of these algorithms: integral of squared error (ISE), integral of absolute error (IAE), integral of time-weighted absolute error (ITAE), and the integral of time-weighted squared error (ITSE). Analyses of variances (ANOVA) were proposed for each of the parameters studied. The PSO and RPSO algorithms presented the best performance in terms of the mean and the standard deviation of the ISE, IAE, ITAE, and ITSE parameters. Significant differences were not found between the three algorithms in terms of the parameters considered. However, significant differences did exist when comparing groups (pairs) of algorithms considering a significance level of 5%. The ANOVA analysis showed that ITAE was the most affected parameter by population size, while the IAE and ITSE parameters were the less affected. In the optimization, the PSO algorithm obtained the best performance in terms of convergence with values of 0.1110 USD/kWh (LCOE), 4.6971 years (PBP), 1114 USD/kWh (SIC), and 173.64 kW (Wnet). PSO-based algorithms obtained better performance in computational terms compared with the genetic algorithms.

Regenerative Organic Rankine Cycle as Bottoming Cycle of an Industrial Gas Engine: Traditional and Advanced Exergetic Analysis

This investigation shows a traditional and advanced exergetic assessment of a waste heat recovery system based on recuperative ORC (organic Rankine cycle) as bottoming cycle of a 2 MW natural gas internal combustion engine. The advanced exergetic evaluation divides the study into two groups, the avoidable and unavoidable group and the endogenous and exogenous group. The first group provides information on the efficiency improvement potential of the components, and the second group determines the interaction between the components. A sensitivity analysis was achieved to assess the effect of condensing temperature, evaporator pinch, and pressure ratio with net power, thermal efficiencies, and exergetic efficiency for pentane, hexane, and octane as organic working fluids, where pentane obtained better energy and exergetic results. Furthermore, an advanced exergetic analysis showed that the components that had possibilities of improvement were the evaporator (19.14 kW) and the turbine (8.35 kW). Therefore, through the application of advanced exergetic analysis, strategies and opportunities for growth in the thermodynamic performance of the system can be identified through the avoidable percentage of destruction of exergy in components.

Model calibration and exergoeconomic optimization with NSGA-II applied to a residential cogeneration

New construction buildings should consider high efficiency energy systems according to European Directives. An optimized micro-cogeneration system is an effective solution to improve the energy efficiency of the residential sector. For this reason, this work presents a novel method to model and optimize a micro-cogeneration based on a natural gas internal combustion engine. The facility, which is located in an experimental plant, provides the equivalent domestic hot water and heating demand of three single-family dwellings. The main aim of this work is to optimize the cost and exergy efficiency of the facility. First, the micro-cogeneration is modeled in TRNSYS. Then, Morris sensitivity analysis is used to detect the model variables for a posterior calibration with experimental data. The employed calibration method is a multi-objective optimization of the error functions between simulated and measured data with the NSGA-II algorithm. After the calibration, optimization with NSGA-II is applied again to the control variables of the model to minimize the cost and to improve the exergy efficiency. The optimized performance produces a daily cost reduction of 24.5%, an exergy efficiency improvement of 21% and a gas consumption decrease of 15%. We also demonstrate the importance of addressing the facility inertia in the models to obtain accurate simulation outputs. The novelty of this work is to present a methodology to optimize the exergoeconomic performance of micro-cogeneration systems by model calibration and optimization using multi-objective optimization with genetic algorithms.

Exergy, Economic, and Life-Cycle Assessment of ORC System for Waste Heat Recovery in a Natural Gas Internal Combustion Engine

In this article, an organic Rankine cycle (ORC) was integrated into a 2-MW natural gas engine to evaluate the possibility of generating electricity by recovering the engine’s exhaust heat. The operational and design variables with the greatest influence on the energy, economic, and environmental performance of the system were analyzed. Likewise, the components with greater exergy destruction were identified through the variety of different operating parameters. From the parametric results, it was found that the evaporation pressure has the greatest influence on the destruction of exergy. The highest fraction of exergy was obtained for the Shell and tube heat exchanger (ITC1) with 38% of the total exergy destruction of the system. It was also determined that the high value of the heat transfer area increases its acquisition costs and the levelized cost of energy (LCOE) of the thermal system. Therefore, these systems must have a turbine technology with an efficiency not exceeding 90% because, from this value, the LCOE of the system surpasses the LCOE of a gas turbine. Lastly, a life cycle analysis (LCA) was developed on the system operating under the selected organic working fluids. It was found that the component with the greatest environmental impact was the turbine, which reached a maximum value of 3013.65 Pts when the material was aluminum. Acetone was used as the organic working fluid.

Micro-multigeneration prospects for residential applications in Italy

The development of multigeneration systems is evolving in different directions. One of the main directions is the extended application of the technologies at smaller sizes. Micro-multigeneration solutions aim at becoming competitive at the size of the residential users. The cost of the technologies, in particular the cost of the cogenerator, is a major limitation to the diffusion of micro-multigeneration, especially in countries (e.g., Italy) where residential customers have a limited usage of electricity to supply their facilities. This paper discusses the prospects for the application of micro-multigeneration in Italy. The modelling and analysis of a residential micro-multigeneration system are developed from the energy efficiency and economic assessment viewpoints. The analysis is carried out on a typical system composed of a natural gas internal combustion engine, a small-scale photovoltaic plant, a backup boiler, thermal energy storage and electrical energy storage. A specific analysis tool has been implemented to address the operational planning of this system during a time period of one year. The whole model has been constructed from real data of thermal and electrical demand in a housing complex in Italy. The annual running cost and the primary energy savings occurring to serve the multi-energy demand have been considered in the operational assessment. From an economical viewpoint, the model considers the price of natural gas related to the cogeneration system, the electricity prices and all the tax breaks allowed in Italy. In this way, different scenarios have been constructed and assessed. The results indicate the impact of providing incentives on the purchase cost of the technologies, leading to increase the diffusion of micro-multigeneration solutions for the residential sector in the next years.

Small scale bio-LNG plant: Comparison of different biogas upgrading techniques

In this paper, a comparison of two different small bio-LNG plants for upgrading and liquefaction have been conducted. In the first configuration liquefaction of the biomethane occurred after the upgrading with conventional processes; in the second configuration, cryogenic upgrading occurred within the liquefaction process, removing CO2 in solid state. For both the two configurations, a two-pressure levels Joule-Brayton reverse cycle, with nitrogen as working fluid, has been considered as refrigeration cycle. The two systems have been simulated and optimized in ASPEN HYSYS, determining the values of the various working parameters which minimized the energy specific consumption.Results showed that a bio-LNG plant with cryogenic upgrading did not require any pre-treatment of raw biogas and reached a very promising energy consumption: 0.61 kWh/Stm3 of raw biogas processed, equivalent to 1.45 kWh/kg of bio-LNG produced. Bio-LNG plants with standard upgrading techniques required between 0.57 and 0.72 kWh/Stm3 without considering additions for heating and raw biogas pre-treatment.A sensitivity analysis concerning CH4 content in bio-LNG and intercooling temperature has been accomplished for bio-LNG plants with cryogenic upgrading, proving their impact in specific energy consumption.A standalone bio-LNG plant cryogenic upgrading, with a natural gas internal combustion engine for energy supply, has been studied and briefly discussed. Some solutions for waste heat utilization have been proposed (digesters warming, energy recovery).

Some energetic and ecological aspects of different city bus drive systems

This paper presents the analysis and comparison of energy and environmental properties of various city bus systems: diesel and compressed natural gas internal combustion engines, trolleybus, and battery electric bus. It is based on experimental research on fuel and energy consumption of city buses with aforementioned propulsion systems carried out under similar driving conditions – on the same city bus lines in Belgrade and Novi Sad, and on evaluation of energy efficiency and CO2 emission of real electricity production in Serbia. In this way, “tank-to-wheel” and “well-to-wheel” energy consumption and CO2 emissions of considered bus driving systems have been evaluated and compared. The results show all complexity of the matter since benefits of application of different systems largely depends on bus exploitation conditions and even more of the conditions of electric energy production. The compressed natural gas internal combustion engine compared to the Diesel engine provides obviously benefit in harmful gas emissions. However, CO2 emissions are on a similar level, while energy efficiency is even less. Electric propulsion systems provide undoubtedly benefit in energy consumption, harmful gases and CO2 emissions if tank-to-wheel conditions are considered, but well-to-wheel characteristics strongly depend on the condition of electric energy production.

Dynamic analysis of the dual-loop Organic Rankine Cycle for waste heat recovery of a natural gas engine

Natural gas internal combustion engines for electric generating are important primary movers in distributed energy systems. However, more than half of the energy is wasted by exhaust, jacket water and so on. Therefore, it is very meaningful to recover the waste heat, especially the exhaust heat. The DORC (Double loop ORC) is regarded as a suitable way to recover exhaust heat and it can produce electric required by users all the year around. As the waste heat recovery system of the engine, it often works under different working conditions owing to the varying energy demand of users. However, there is few study on the part-load performance of the DORC under different working conditions. Consequently, the dynamic math model of the DORC for waste heat recovery of a natural gas engine with 1000kW rated power is established by Simulink in this work. With the PID control of the system, the static performance and dynamic behavior of the DORC under five typical engine working conditions are simulated and analyzed. Besides, the effects of the mass flow rate of the HT (high temperature) cooling water which is the connection between the two loops on the DORC performance are researched as well. The results illustrate that the DORC can improve the efficiency of the combined system quite well from 100% to 60% engine working condition, showing good working condition adaptability. Besides, enlarging the mass flow rate of the HT cooling water can enhance the output power of the DORC system, but not very obviously.

Analysis of the economic feasibility and reduction of a building’s energy consumption and emissions when integrating hybrid solar thermal/PV/micro-CHP systems

The aim of this paper is to assess the performance of several designs of hybrid systems composed of solar thermal collectors, photovoltaic panels and natural gas internal combustion engines. The software TRNSYS 17 has been used to perform all the calculations and data processing, as well as an optimisation of the tank volumes through an add-in coupled with the GENOPT® software. The study is carried out by analysing the behaviour of the designed systems and the conventional case in five different locations of Spain with diverse climatic characteristics, evaluating the same building in all cases. Regulators, manufacturers and energy service engineers are the most interested in these results.Two major contributions in this paper are the calculations of primary energy consumption and emissions and the inclusion of a Life Cycle Cost analysis. A table which shows the order of preference regarding those criteria for each considered case study is also included. This was fulfilled in the interest of comparing between the different configurations and climatic zones so as to obtain conclusions on each of them. The study also illustrates a sensibility analysis regarding energy prices. Finally, the exhaustive literature review, the novel electricity consumption profile of the building and the illustration of the influence of the cogeneration engine working hours are also valuable outputs of this paper, developed in order to address the knowledge gap and the ongoing challenges in the field of distributed generation.

Optimization Design of Capacity and Operation Strategy for Building Level Distributed Energy System

Combined cooling, heating, and power (CCHP) system is an effective solution to implement energy-step-utilization, and achieve energy conservation and emissions reduction. In this paper, the energy requirements are obtained by energy consumption simulation on a building and are classified to several subcategories by energy grade of exergy. The CCHP systems include natural gas internal combustion engine, heat recovery system, gas boiler, absorption chiller, and heat exchangers. The economic efficiency, energy efficiency, and environmental benefits are taken in account to establish a multi-objective evaluation methodology. According the energy balance principle, an integrated optimization model of CCHP system is established by the means of non-liner programming (NLP). The optimization model will automatic match the energy demands’ grade and the result will show the capacity of all the equipment and the operation strategy in the whole year. The computational results also prove the integrated optimization method is valid.

Total cost of ownership, social lifecycle cost and energy consumption of various automotive technologies in Italy

This paper estimates the total cost of ownership, social lifecycle cost and energy consumption of 66 cars with different fuel/powertrains available in Italy in 2013. The aim is to provide the various private and public decision makers with information that could allow them to better understand the current market penetration of the various automotive technologies and to predict the future one. It is found that the car operated by conventional fuels (gasoline, diesel) is currently the least expensive as far as the total costs of ownership are concerned. The bi-fuel liquefied petroleum gas (LPG) and the bi-fuel compressed natural gas (CNG) internal combustion engine vehicles are in the same price range. Both the battery electric vehicles (BEVs) and, especially, the hybrid ICEVs are more expensive. On the contrary, the social lifecycle costs of the BEVs are the lowest, thanks not only to their zero air pollutants' emissions in the use phase but also to their reduced noise emissions. The amount of the social costs relative to the total cost of ownership, estimated using recent European parameters, represents at the most 6% of the total cost. Consequently, even if the external costs were internalized, the alternative fuel vehicles would not become convenient for the final consumer from a monetary point of view. Considering the energy consumption, with the 2011 Italian energy production mix, the BEVs and the diesel hybrid are the most energy efficient cars. Focusing on 7 specific models, and simulating realistic scenarios, it is found that the relative ranking of the BEVs in terms of total costs improves moderately when the traveled distance increases, subsidies are introduced and battery price drops. However, the BEVs become convenient only when the annual distance traveled is at least 20,000 km, a value much higher than the current Italian average and posing serious issues in terms of vehicles' range. Only a joint reduction of the battery price to €240/kWh from initial estimated cost of €412/kWh and the introduction of a subsidy would make the BEVs competitive with the current average Italian annual distance traveled.

A TOPSIS method to evaluate the technologies

Purpose – This paper aims to evaluate nine types of electrical energy generation options with regard to seven criteria. The analytic hierarchy process (AHP) was used to perform the evaluation. The TOPSIS method was used to evaluate the best generation technology. Design/methodology/approach – The options that were evaluated are the hydrogen combustion turbine, the hydrogen internal combustion engine, the hydrogen fuelled phosphoric acid fuel cell, the hydrogen fuelled solid oxide fuel cell, the natural gas fuelled phosphoric acid fuel cell, the natural gas fuelled solid oxide fuel cell, the natural gas turbine, the natural gas combined cycle and the natural gas internal combustion engine. The criteria used for the evaluation are CO2 emissions, NOX emissions, efficiency, capital cost, operation and maintenance costs, service life and produced electricity cost. Findings – The results drawn from the analysis in technology wise are as follows: natural gas fuelled solid oxide fuel cells>natural gas combined cycle>natural gas fuelled phosphoric acid fuel cells>natural gas internal combustion engine>hydrogen fuelled solid oxide fuel cells>hydrogen internal combustion engines>hydrogen combustion turbines>hydrogen fuelled phosphoric acid fuel cells> and natural gas turbine. It shows that the natural gas fuelled solid oxide fuel cells are the best technology available among all the available technology considering the seven criteria such as service life, electricity cost, O&M costs, capital cost, NOX emissions, CO2 emissions and efficiency of the plant. Research limitations/implications – The most dominant electricity generation technology proved to be the natural gas fuelled solid oxide fuel cells which ranked in the first place among nine alternatives. The research is helpful to evaluate the different alternatives. Practical implications – The research is helpful to evaluate the different alternatives and can be extended in all the spares of technologies. Originality/value – The research was the original one. Nine energy generation options were evaluated with regard to seven criteria. The energy generation options were the hydrogen combustion turbine, the hydrogen internal combustion engine, the hydrogen fuelled phosphoric acid fuel cell, the hydrogen fuelled solid oxide fuel cell, the natural gas fuelled phosphoric acid fuel cell, the natural gas fuelled solid oxide fuel cell, the natural gas turbine, the natural gas combined cycle and the natural gas internal combustion engine. The criteria used for the evaluation were efficiency, CO2 emissions, NOX emissions, capital cost, O&M costs, electricity cost and service life.

Multi-criteria evaluation of hydrogen and natural gas fuelled power plant technologies

This paper evaluates nine types of electrical energy generation options with regard to seven criteria. The options use natural gas or hydrogen as a fuel. The Analytic Hierarchy Process was used to perform the evaluation, which allows decision-making when single or multiple criteria are considered. The options that were evaluated are the hydrogen combustion turbine, the hydrogen internal combustion engine, the hydrogen fuelled phosphoric acid fuel cell, the hydrogen fuelled solid oxide fuel cell, the natural gas fuelled phosphoric acid fuel cell, the natural gas fuelled solid oxide fuel cell, the natural gas turbine, the natural gas combined cycle and the natural gas internal combustion engine. The criteria used for the evaluation are CO 2 emissions, NO X emissions, efficiency, capital cost, operation and maintenance costs, service life and produced electricity cost. A total of 19 scenarios were studied. In 15 of these scenarios, the hydrogen turbine ranked first and proved to be the most preferred electricity production technology. However since the hydrogen combustion turbine is still under research, the most preferred power generation technology which is available nowadays proved to be the natural gas combined cycle which ranked first in five scenarios and second in eight. The last in ranking electricity production technology proved to be the natural gas fuelled phosphoric acid fuel cell, which ranked in the last position in 13 scenarios.