Life cycle cost analysis to examine the economical feasibility of hydrogen as an alternative fuel

This study uses a life cycle costing (LCC) methodology to identify when hydrogen can become economically feasible compared to the conventional fuels and which energy policy is the most effective at fostering the penetration of hydrogen in the competitive fuel market. The target hydrogen pathways in this study are H₂ via natural gas steam reforming (NG SR), H₂ via naphtha steam reforming (Naphtha SR), H₂ via liquefied petroleum gas steam reforming (LPG SR), and H₂ via water electrolysis (WE). In addition, the conventional fuels (gasoline, diesel) are also included for the comparison with the H₂ pathways.     

A study on the environmental aspects of hydrogen pathways in Korea

In this study, the environmental aspects of H₂ pathways are analyzed according to plausible H₂ production methods, production capacity, and distribution options in Korea, using life cycle assessment (LCA) methodology. The target H₂ pathways analyzed are H₂ via naphtha steam reforming (Naphtha SR), H₂ via natural gas steam reforming (NG SR), H₂ via liquefied petroleum gas steam reforming (LPG SR), H₂ via water electrolysis with wind power (WE[Wind]), and H₂ via water electrolysis with Korea electricity mix (WE[KEM]). The results are then compared with those of conventional fuels (gasoline, diesel, and LPG) to identify which H₂ pathway has less environmental impact than the conventional fuels.     

Life cycle environmental and economic analyses of a hydrogen station with wind energy

This study aimed to identify the environmental and economic aspects of the wind-hydrogen system using life cycle assessment (LCA) and life cycle costing (LCC) methodologies. The target H₂ pathways are the H₂ pathway of water electrolysis (WE) with wind power (WE[Wind]) and the H₂ pathway of WE by Korean electricity mix (WE[KEM]). Conventional fuels (gasoline and diesel) are also included as target fuel pathways to identify the fuel pathways with economic and environmental advantages over conventional fuels. The key environmental issues in the transportation sector are analyzed in terms of fossil fuel consumption (FFC), regulated air pollutants (RAPs), abiotic resource depletion (ARD), and global warming (GW). The life cycle costs of the target fuel pathways consist of the well-to-tank (WTT) costs and the tank-to-wheel (TTW) costs. Moreover, two scenarios are analyzed to predict potential economic and environmental improvements offered by wind energy-powered hydrogen stations.     

Life cycle evaluation of hydrogen and other potential fuels for aircrafts

In the present study, hydrogen and some other alternative fuels (such as ammonia, methanol, ethanol, liquefied natural gas) are considered for aviation applications under a comprehensive life cycle assessment study and are evaluated comparatively with the conventional kerosene based jet fuel for various impact categories. Therefore, this study is performed with a well-to-wake approach to evaluate the overall life cycle of an aircraft running on these conventional and alternative fuels. Both conventional and renewable fuel routes are considered for the production of ammonia and hydrogen fuels. Although there are modifications required to fulfill the aviation fuel specifications for such alternative fuels, the long term viability and environmental sustainability make them attractive solutions for the future of aviation industry. This study uses a life cycle assessment of an average aircraft utilizing various alternative aviation fuels to determine the relative environmental impact of each life cycle phase. The life cycle phases included in the analyses are as follows: (i) production, operation and maintenance of the aircraft, (ii) construction, maintenance and disposal of the airport, (iii) production, transportation and utilization of the aviation fuel in the aircraft. The results show that hydrogen and liquefied natural gas represent more environmentally benign alternatives although fuel costs are higher compared to ammonia, jet fuel and methanol. The total GHG emissions from hydropower based ammonia and hydrogen are calculated to be about 0.24 kg CO₂ eq. per traveled tonne-km and 0.03 kg CO₂ eq. per traveled tonne-km, respectively. Renewable based ammonia and hydrogen fueled aircrafts can further decrease the overall environmental impact in many categories allowing a brighter future for aviation industry.     

Alternative fuel buses currently in use in China: Life-cycle fossil energy use,GHG emissions and policy recommendations

The Chinese government has enacted policies to promote alternative vehicle fuels (AVFs) and alternative fuel vehicles (AFVs), including city bus fleets. The life cycle (LC), energy savings (ES) and GHG reduction (GR) profiles of AVFs/AFVs are critical to those policy decisions. The well-to-wheels module of the Tsinghua-CA3EM model is employed to investigate actual performance data. Compared with conventional buses, AFVs offer differences in performance in terms of both ES and GR. Only half of the AFVs analyzed demonstrate dual benefits. However, all non-oil/gas pathways can substitute oil/gas with coal. Current policies seek to promote technology improvements and market creation initiatives within the guiding framework of national-level diversification and district-level uniformity. Combined with their actual LC behavior and in keeping with near- and long-term strategies, integrated policies should seek to (1) apply hybrid electric technology to diesel buses; (2) encourage NG/LPG buses in gas-abundant cities; (3) promote commercialize electric buses or plug-in capable vehicles through battery technology innovation; (4) support fuel cell buses and hydrogen technology R&D for future potential applications; and (5) conduct further research on boosting vehicle fuel efficiency, applying low-carbon transportation technologies, and addressing all resultant implications of coal-based transportation solutions to human health and natural resources.     

A life cycle impact analysis of various hydrogen production methods for public transportation sector

Reducing greenhouse gas emissions is an important task to reduce the adverse effects of climate change. A large portion of greenhouse gas emissions apparently originates from the transportation sector. Therefore, adopting cleaner technologies with lower emission footprints has become vital. For this reason, in this study, a life cycle impact analysis of hydrogen production technologies as an alternative to fossil fuels and the utilization of hydrogen in fuel cell electric buses is carried out. According to the results of this study, the operational contributions of internal combustion engines have a significant impact on life cycle impact analysis indicators. The global warming potentials of clean hydrogen production technologies result in much lower results compared to conventional hydrogen production technologies. Also, almost all indicators for biohydrogen production technologiess yield lower results because of the wastewater removal. The global warming potential results of hydrogen production methods are found to be 6.8, 1.9, 2.1, 0.5, 0.2, and 7.9 kg CO₂ eq./kg H₂ for PV electrolysis, wind electrolysis, high temperature electrolysis, dark fermentation, photo fermentation and conventional hydrogen production, respectively. However, the chemicals used in PV and wind turbine production increased the ecotoxicological indicators. On the other hand, hydrogen utilization in buses is a better option environmentally. The global warming potentials for PV electrolysis, wind electrolysis, high temperature electrolysis, dark fermentation, photo fermentation, conventional hydrogen, compressed natural gas bus, and diesel bus are found to be 0.060, 0.016, 0.018, 0.007, 0.006, 0.053, 0.082, and 0.125 kg CO₂ eq./p.km, respectively. The results are especially important in terms of reducing the effects at the source and optimizing the systems.     

Blending blue hydrogen with natural gas for direct consumption: Examining the effect of hydrogen concentration on transportation and well-to-combustion greenhouse gas emissions

Jurisdictions are looking into mixing hydrogen into the natural gas (NG) system to reduce greenhouse gas (GHG) emissions. Earlier studies have focused on well-to-wheel analysis of H₂ fuel cell vehicles, using high-level estimates for transportation-based emissions. There is limited research on transportation emissions of hythane, a blend of H₂ and NG used for combustion. An in-depth analysis of the pipeline transportation system was performed for hythane and includes sensitivity and uncertainty analyses. When hythane with 15% H₂ is used, transportation GHG emissions (gCO2eq/GJ) increase by 8%, combustion GHG emissions (gCO2eq/GJ) decrease by 5%, and pipeline energy capacity (GJ/hr) decreases by 11% for 50–100 million m³/d pipelines. Well-to-combustion (WTC) emissions increase by 2.0% without CCS, stay the same with a 41% CCS rate, decrease by 2.8% for the 100% CCS scenario, and decrease by 3.6% in the optimal CO₂-free scenario. While hythane contains 15% H₂ by volume only 5% of the gas’ energy comes from H₂, limiting its GHG benefit.     

Life cycle cost analysis: A case study of hydrogen energy application on the Orkney Islands

Hydrogen can compensate for the intermittent nature of some renewable energy sources and encompass the options of supplying renewables to offset the use of fossil fuels. The integrating of hydrogen application into the energy system will change the current energy market. Therefore, this paper deploys the life cycle cost analysis of hydrogen production by polymer electrolyte membrane (PEM) electrolysis and applications for electricity and mobility purposes. The hydrogen production process includes electricity generated from wind turbines, PEM electrolyser, hydrogen compression, storage, and distribution by H₂ truck and tube trailer. The hydrogen application process includes PEM fuel cell stacks generating electricity, a H₂ refuelling station supplying hydrogen, and range extender fuel cell electric vehicles (RE-FCEVs). The cost analysis is conducted from a demonstration project of green hydrogen on a remote archipelago. The methodology of life cycle cost is employed to conduct the cost of hydrogen production and application. Five scenarios are developed to compare the cost of hydrogen applications with the conventional energy sources considering CO₂ emission cost. The comparisons show the cost of using hydrogen for energy purposes is still higher than the cost of using fossil fuels. The largest contributor of the cost is the electricity consumption. In the sensitivity analysis, policy supports such as feed-in tariff (FITs) could bring completive of hydrogen with fossil fuels in current energy market.     

From hydrocarbon to hydrogen–carbon to hydrogen economy

In the near- to medium-term future, hydrogen production will continue to rely on fossil fuels, and will, therefore, remain a potential source of significant CO₂ emissions into the atmosphere. Conventional CO₂ sequestration strategies offer rather expensive and ecologically uncertain solutions. The objective of this paper is to explore novel approaches to solving energy and environmental problems associated with the production of hydrogen from fossil fuels. The paper discusses the technological, environmental and economical aspects of large-scale production of hydrogen and carbon by the catalytic dissociation of natural gas (NG). The authors propose a scenario of fossil-based “hydrogen–carbon” infrastructure, where the hydrogen component of NG is used as a clean energy carrier (e.g., in transportation) and the carbon component is used in several application areas: structural materials, power generation, soil amendment and environmental remediation. This scenario will allow a smooth transition from the current hydrocarbon-based economy to a hydrogen–carbon economy as a half-way point to the ultimate hydrogen-from-renewables economy of the future.     

Development of Oshawa hydrogen hub in Canada: A case study

Consumption of fossil fuels, which makes an immense contribution to greenhouse gas emissions, must be reduced. Hydrogen emerges as a unique solution to serve as fuel, energy carrier and feedstock because it is a clean, abundant, environmentally friendly and energy intensive gas. This study aims to investigate the development of a potential hydrogen hub located in Oshawa, Canada, which is aimed to provide a hydrogen infrastructure for future hydrogen economy. Numerous life cycle assessment and cost assessment studies are conducted to investigate what benefits such a hydrogen will bring to the city. The results show that fuel cell electric buses emit 89% fewer pollutants. Also, 60% of overall CO₂ reduction is possible with a gradual transition to fuel cell technology within 20 years. However, in order for hydrogen infrastructure and costs to compete with fossil fuels, high-scale projects need to be developed with governmental incentives.     

Experimental investigation on NG dual fuel engine improvement by hydrogen enrichment

The crude oil graduate depletion, as well as aspects related to environmental pollution and global warming instigated many researches concerning alternative fuels. Natural gas (NG) is one of the most attractive available fuels. A promising technique for its use in internal combustion engines is the dual fuel concept. One of the main problems with this technique is that, at low loads, the engine efficiency decreases compared to conventional diesel. The unburned hydrocarbons and carbon monoxide emissions are also higher in dual fuel mode. An effective method to compensate the demerits of limited lean-burn ability and slow burning velocity of NG is to mix it with a fuel that possesses wide flammability limit and fast burning velocity. Hydrogen (H₂) is thought to be the best gaseous candidate for natural gas.In the present work, NG enrichment with various H₂ blends is investigated as a technique for improving dual fuel mode, especially at low loads. Impact on engine performance and emissions is experimentally examined. Total BSFC is considerably reduced. An important benefit in terms of BTE, reaching to increase a 12% with the 10%H₂ blend compared to the pure NG case, is also achieved. THC and CO emissions are in general reduced as a result of the improvement of gaseous fuel utilization. CO₂ emissions are also in general reduced. Even though a slight increase is in overall observed for NO_x emissions, it's almost insignificant.     

An experimental investigation of incomplete combustion of gaseous fuels of a heavy-duty diesel engine supplemented with hydrogen and natural gas

This paper investigates the emissions of the unburned gaseous fuels of a heavy-duty diesel engine converted to operate under natural gas (NG)-diesel and hydrogen (H₂)-diesel dual fuel combustion mode. The detailed effects of the addition of H₂, NG, engine load, and engine speed on the exhaust emissions of the unburned H₂, methane (CH₄), and carbon monoxide (CO) were experimentally investigated. The combustion efficiencies of CH₄ and H₂ supplemented were also examined and compared.     

Environmental life cycle assessment of alternative fuels for city buses: A case study in Oujda city,Morocco

The road transport sector, particularly public transport, generates significant greenhouse gas emissions due to the excessive use of petroleum-based fuels. The use of alternative fuels with lower environmental impacts is therefore a major challenge to move towards a more sustainable public transport sector. In this context, the current study presents an environmental life cycle assessment of alternative buses, including hybrid (diesel-electricity), electric, and fuel cell buses at a city level in Oujda, Morocco. This study is perfromed according to three main outputs: total energy use by fuel type, GHG emissions, and criteria air pollutants. It is concluded that electric and fuel cell buses represent efficient and sustainable alternatives to public transport during the operational phase and their deployment in Oujda city can potentially offer significant environmental savings in terms of GHG emissions and air pollutants during both the WTT and TTW phases.     

Hydrogen supplemented natural gas effect on a DI diesel engine operating under dual fuel mode with a biodiesel pilot fuel

In order to slow down the continuing environmental deterioration, regulations for pollutant emissions limitations are increasingly rigorous. The development of new alternative fuels for internal combustion engines is a very interesting solution not only to overcome the pollution problem but also because of the petroleum shortage. In this context, the present work investigates the improvement of a DI diesel engine operating at constant speed (1500 rpm) and under dual fuel mode with eucalyptus biodiesel and natural gas (NG) enriched by various H₂ quantities (15, 25 and 30 by v%). The eucalyptus biodiesel quantity injected into the engine cylinder is kept constant, to supply around 10% of the engine nominal power, for all examined engine loads. The engine load is further increased using only the gaseous fuel (NG+H₂), which is introduced with the intake air. The effect of H₂/NG blending ratio on the combustion parameters, performance and pollutant emissions of the engine is investigated and compared with those of pure NG case. An important benefit in terms of brake specific fuel consumption, reaching a decrease of 4–10% with the 25% H₂ blend compared to the pure NG case, is achieved. Concerning the pollutant emissions, NG enrichment with H₂ is an efficient solution to enhance the combustion process and hence reduce carbon monoxide, unburned hydrocarbon and soot emissions at high loads where they are important for pure NG. However for the nitrogen oxide emissions, NG blending with H₂ is attractive only at low and medium loads where their levels are lower than pure NG.     

Impact of energy supply infrastructure in life cycle analysis of hydrogen and electric systems applied to the Portuguese transportation sector

Hydrogen and electric vehicle technologies are being considered as possible solutions to mitigate environmental burdens and fossil fuel dependency. Life cycle analysis (LCA) of energy use and emissions has been used with alternative vehicle technologies to assess the Well-to-Wheel (WTW) fuel cycle or the Cradle-to-Grave (CTG) cycle of a vehicle's materials. Fuel infrastructures, however, have thus far been neglected. This study presents an approach to evaluate energy use and CO₂ emissions associated with the construction, maintenance and decommissioning of energy supply infrastructures using the Portuguese transportation system as a case study. Five light-duty vehicle technologies are considered: conventional gasoline and diesel (ICE), pure electric (EV), fuel cell hybrid (FCHEV) and fuel cell plug-in hybrid (FC-PHEV). With regard to hydrogen supply, two pathways are analysed: centralised steam methane reforming (SMR) and on-site electrolysis conversion. Fast, normal and home options are considered for electric chargers. We conclude that energy supply infrastructures for FC vehicles are the most intensive with 0.03–0.53 MJ_eq/MJ emitting 0.7–27.3 g CO_2eq/MJ of final fuel. While fossil fuel infrastructures may be considered negligible (presenting values below 2.5%), alternative technologies are not negligible when their overall LCA contribution is considered. EV and FCHEV using electrolysis report the highest infrastructure impact from emissions with approximately 8.4% and 8.3%, respectively. Overall contributions including uncertainty do not go beyond 12%.     

Conversion of fossil and biomass fuels to electric power and transportation fuels by high efficiency integrated plasma fuel cell (IPFC) energy cycle

The IPFC is a high efficiency energy cycle, which converts fossil and biomass fuel to electricity and co-product hydrogen and liquid transportation fuels (gasoline and diesel). The cycle consists of two basic units, a hydrogen plasma black reactor (HPBR) which converts the carbonaceous fuel feedstock to elemental carbon and hydrogen and CO gas. The carbon is used as fuel in a direct carbon fuel cell (DCFC), which generates electricity, a small part of which is used to power the plasma reactor. The gases are cleaned and water gas shifted for either hydrogen or syngas formation. The hydrogen is separated for production or the syngas is catalytically converted in a Fischer–Tropsch (F–T) reactor to gasoline and/or diesel fuel. Based on the demonstrated efficiencies of each of the component reactors, the overall IPFC thermal efficiency for electricity and hydrogen or transportation fuel is estimated to vary from 70 to 90% depending on the feedstock and the co-product gas or liquid fuel produced. The CO₂ emissions are proportionately reduced and are in concentrated streams directly ready for sequestration. Preliminary cost estimates indicate that IPFC is highly competitive with respect to conventional integrated combined cycle plants (NGCC and IGCC) for production of electricity and hydrogen and transportation fuels.     

Analysis of the cost of hydrogen infrastructure for buses in London

The use of hydrogen (H₂) as transport fuel is often said to suffer from the ‘chicken and egg’ problem: vehicles that depend on H₂ cannot go on the roads due to the lack of an adequate infrastructure, and the almost non-existent fleet of H₂ vehicles on the roads makes it economically unsound to build a H₂ infrastructure.Although both hydrogen vehicles (fuel cell and internal combustion engine) and the related infrastructure have been (and are being) developed and some are commercially available, cost is seen as a major barrier. With today's technologies, H₂ only becomes competitive with petrol and diesel when produced at large quantities, suitable for supplying e.g. thousands of H₂ buses. The question is, how might this point be reached, and are there least cost infrastructural pathways to reach it. This paper tries to address the latter question, using the early development of a H₂ infrastructure for buses in London as a case study.The paper presents some of the analyses and results from a Ph.D. project (in progress) being undertaken at Imperial College London, funded by EPSRC (Grant GR/R50790/01). The results presented here illustrate that cost of hydrogen production and delivery vary mainly with levels of hydrogen demand and delivery distances, as well as other logistic criteria; least cost production–delivery pathways have been identified for various hydrogen demand scenarios and refuelling station set-ups. Another important conclusion is that the pattern of converting a group of refuelling stations to hydrogen (e.g. a group of refuelling stations for buses in London) has a significant effect on the unit cost of hydrogen.     

Towards the Hydrogen Economy in Paraguay: Green hydrogen production potential and end-uses

This study was conducted to estimate the potential for green H₂ in Paraguay. A total production potential of 22.5 × 10⁶ tons/year was obtained with a main contribution (93.34%) from solar photovoltaic. The greatest potential for producing H₂ from solar and wind resources is in the Western region, and from hydro resources is in the Eastern region of the country. Two end-uses of green H₂ were assessed: (1) automotive transportation, replacing gasoline and diesel; and (2) residential energy, replacing firewood and LPG for cooking in households across the country. In 16 of the 17 departments, green H₂ is able to replace the overall consumption of gasoline and diesel, as well as firewood and LPG. Finally, energy service cost (mobility), environmental aspects and CO₂ emissions were considered for three urban mobility technologies for the Metropolitan Area of Asunción. Results show that the mobility cost of fuel cell hybrid electric buses is still very high in comparison to diesel buses and battery electric buses. However, when a longer driving range is required, fuel cell hybrid electric buses could become a viable alternative in the long term. From an environmental point of view, green H₂ used in fuel cell hybrid electric buses has the potential to save about 96% of CO₂ emissions in comparison to diesel buses. It is concluded that the estimated green H₂ production potential favors the incorporation of the Hydrogen Economy in Paraguay.     

Environmental impact categories of hydrogen and ammonia driven transoceanic maritime vehicles: A comparative evaluation

In this study, carbon-free fuels -ammonia and hydrogen-are proposed to replace heavy fuel oils in the engines of maritime transportation vehicles. Also, it is proposed to use hydrogen and ammonia as dual fuels to quantify the reduction potential of greenhouse gas emissions. An environmental impact assessment of transoceanic tanker and transoceanic freight ship is implemented to explore the impacts of fuel substituting on the environment. In the life cycle analyses, the complete transport life cycle is taken into account from manufacture of transoceanic freight ship and tanker to production, transportation and utilization of hydrogen and ammonia in the maritime vehicles. Several hydrogen and ammonia production routes ranging from municipal waste to geothermal options are considered to comparatively evaluate environmentally benign methods. Besides global warming potential, environmental impact categories of marine sediment ecotoxicity and marine aquatic ecotoxicity are also selected in order to examine the diverse effects on marine environment. Being carbon-neutral fuels, ammonia and hydrogen, yield significantly minor global warming impacts during operation. The ecotoxicity impacts on maritime environment vary based on the production route of hydrogen and ammonia. The results imply that even hydrogen and ammonia are utilized as dual fuels in the engines, the global warming potential is quite lower in comparison with heavy fuel oil driven transoceanic tankers. Geothermal energy sourced hydrogen and ammonia fuelled transoceanic tankers release about 0.98 g and 1.65 g CO₂ eq. per tonne-kilometer, respectively whereas current conventional heavy fuel oil tanker releases about 5.33 g/tonne-kilometer CO₂ eq. greenhouse gas emissions.     

Clean fuel options with hydrogen for sea transportation: A life cycle approach

In this study, two potential fuels, namely hydrogen and ammonia, are alternatively proposed to replace heavy fuel oils in the engines of sea transportation vehicles. A comparative life cycle assessments of different types of sea transportation vehicles are performed to investigate the impacts of fuel switching on the environment. The entire transport life cycle is considered in the life cycle analyses consisting of production of freight ship and tanker; operation of freight ship and tanker; construction and land use of port; operation, maintenance and disposal of port; production and transportation of these clean fuels. Various environmental impact categories, such as global warming, marine sediment ecotoxicity, marine aquatic ecotoxicity, acidification and ozone layer depletion are selected in order to examine the diverse effects of switching to clean fuels in maritime transportation. As a carbon-free fuel for marine vehicle engines, ammonia and hydrogen, yield considerably lower global warming impact during the operation. Furthermore, numerous production methods of alternative fuels are evaluated to comparatively show environmentally benign options. The results of this study demonstrate that if ammonia is even partially utilized in the engines of ocean tankers as dual fuel (with heavy fuel oils), overall life cycle greenhouse gas emissions per tonne-kilometer can be decreased about 27% whereas it can be decreased by about 40% when hydrogen is used as dual fuel.