Well-to-wheel analysis of hydrogen fuel-cell electric vehicle in Korea

This study provides methodologies, data collection and results of well-to-wheel greenhouse gas analysis of various H₂ production pathways for fuel-cell electric vehicle (FCEV) in Korea; naphtha cracking, steam methane reforming, electrolysis and coke oven gas purification. The well-to-wheel (WTW) greenhouse gas emissions of FCEV are calculated as 32,571 to 249,332 g-CO₂ eq./GJ or 50.7 to 388.0 g-CO₂ eq./km depending on the H₂ production pathway. The landfill gas (on-site) pathway has the lowest GHG emissions because the carbon credit owing to use landfill gas. The electrolysis with Korean grid mix (on-site) pathway has the highest GHG emissions due to its high emission factor of the power generation process. Furthermore, the results are compared with other powertrain vehicles in Korea such as internal combustion engine vehicle (ICEV), hybrid electric vehicle (HEV) and electric vehicle (EV). The averaged WTW result of FCEV is 35% of ICEV, is 47% of HEV, and is 63% of EV.     

Large-scale long-distance land-based hydrogen transportation systems: A comparative techno-economic and greenhouse gas emission assessment

Interest in hydrogen as an energy carrier is growing as countries look to reduce greenhouse gas (GHG) emissions in hard-to-abate sectors. Previous works have focused on hydrogen production, well-to-wheel analysis of fuel cell vehicles, and vehicle refuelling costs and emissions. These studies use high-level estimates for the hydrogen transportation systems that lack sufficient granularity for techno-economic and GHG emissions analysis. In this work, we assess and compare the unit costs and emission footprints (direct and indirect) of 32 systems for hydrogen transportation. Process-based models were used to examine the transportation of pure hydrogen (hydrogen pipeline and truck transport of gaseous and liquified hydrogen), hydrogen-natural gas blends (pipeline), ammonia (pipeline), and liquid organic hydrogen carriers (pipeline and rail). We used sensitivity and uncertainty analyses to determine the parameters impacting the cost and emission estimates. At 1000 km, the pure hydrogen pipelines have a levelized cost of $0.66/kg H₂ and a GHG footprint of 595 gCO₂eq/kg H₂. At 1000 km, ammonia, liquid organic hydrogen carrier, and truck transport scenarios are more than twice as expensive as pure hydrogen pipeline and hythane, and more than 1.5 times as expensive at 3000 km. The GHG emission footprints of pure hydrogen pipeline transport and ammonia transport are comparable, whereas all other transport systems are more than twice as high. These results may be informative for government agencies developing policies around clean hydrogen internationally.     

Well-to-wheels analysis of hydrogen based fuel-cell vehicle pathways in Shanghai

Due to high energy efficiency and zero emissions, some believe fuel cell vehicles (FCVs) could revolutionize the automobile industry by replacing internal combustion engine technology, and first boom in China. However, hydrogen infrastructure is one of the major barriers. Because different H₂ pathways have very different energy and emissions effects, the well-to-wheels (WTW) analyses are necessary for adequately evaluating fuel/vehicle systems. The pathways used to supply H₂ for FCVs must be carefully examined by their WTW energy use, greenhouse gases (GHGs) emissions, total criteria pollutions emissions, and urban criteria pollutions emissions.     

Low-carbon hydrogen production via electron beam plasma methane pyrolysis: Techno-economic analysis and carbon footprint assessment

Electron beam plasma methane pyrolysis is a hydrogen production pathway from natural gas without direct CO₂ emissions. In this work, two concepts for a technical implementation of the electron beam plasma pyrolysis in a large-scale hydrogen production plant are presented and evaluated in regards of efficiency, economics and carbon footprint. The potential of this technology is identified by an assessment of the results with the benchmark technologies steam methane reforming, steam methane reforming with carbon capture and storage as well as water electrolysis. The techno-economic analysis shows levelized costs of hydrogen for the plasma pyrolysis between 2.55 €/kg H₂ and 5.00 €/kg H₂ under the current economic framework. Projections for future price developments reveal a significant reduction potential for the hydrogen production costs, which support the profitability of plasma pyrolysis under certain scenarios. In particular, water electrolysis as direct competitor with renewable electricity as energy supply shows a considerably higher specific energy consumption leading to economic advantages of plasma pyrolysis for cost-intensive energy sources and a high degree of utilization. Finally, the carbon footprint assessment indicates the high potential for a reduction of life cycle emissions by electron beam plasma methane pyrolysis (1.9 kg CO₂ eq./kg H₂ – 6.4 kg CO₂ eq./kg H₂, depending on the electricity source) compared to state-of-the-art hydrogen production technology (10.8 kg CO₂ eq./kg H₂).     

Hydrogen production from wind energy in Western Canada for upgrading bitumen from oil sands

Hydrogen is produced via steam methane reforming (SMR) for bitumen upgrading which results in significant greenhouse gas (GHG) emissions. Wind energy based hydrogen can reduce the GHG footprint of the bitumen upgrading industry. This paper is aimed at developing a detailed data-intensive techno-economic model for assessment of hydrogen production from wind energy via the electrolysis of water. The proposed wind/hydrogen plant is based on an expansion of an existing wind farm with unit wind turbine size of 1.8 MW and with a dual functionality of hydrogen production and electricity generation. An electrolyser size of 240 kW (50 Nm³ H₂/h) and 360 kW (90 Nm³ H₂/h) proved to be the optimal sizes for constant and variable flow rate electrolysers, respectively. The electrolyser sizes aforementioned yielded a minimum hydrogen production price at base case conditions of $10.15/kg H₂ and $7.55/kg H₂. The inclusion of a Feed-in-Tariff (FIT) of $0.13/kWh renders the production price of hydrogen equal to SMR i.e. $0.96/kg H_2, with an internal rate of return (IRR) of 24%. The minimum hydrogen delivery cost was $4.96/kg H₂ at base case conditions. The life cycle CO₂ emissions is 6.35 kg CO₂/kg H₂ including hydrogen delivery to the upgrader via compressed gas trucks.     

Cost assessment and evaluation of various hydrogen delivery scenarios

In this paper, performance and cost assessment studies, including the stages of hydrogen storage, transmission and distribution of three different hydrogen delivery pathways are undertaken comparatively. The produced hydrogen is stored under different temperatures and pressures and then transported to the nearby cities for distribution. In addition, three different methods for the transportation of the produced hydrogen to the distribution centers are studied, which are as transportation for hydrogen by the pressurized tanks, cryogenic liquid hydrogen tanker and the gas pipelines. Moreover, the transmission options from the distribution center to the target consumer are also examined for three different conditions. As a result, the hydrogen production capacity, the levelized cost of energy distribution (in $/kg), the infrastructure costs (truck, tanker number, gas line costs, etc.) for the selected transmission scenario are calculated. Furthermore, the environmental impact (greenhouse gas (GHG) emissions) and some application parameters of the proposed system (e.g., number of hydrogen fuel stations and the distance between the stations, length of the distribution lines, etc.) are also determined. The highest levelized cost of delivery is obtained as 8.02 $/kg H₂ for the first scenario whereas the lowest cost is obtained as 2.73 $/kg H₂ for the third scenario.     

World energy analysis: H2 now or later?

This is a study of world energy resource sustainability within the context of resource peak production dates, advanced energy use technologies in the transportation and electricity generation energy use sectors, and alternative fuel production including hydrogen. The finding causing the most concern is the projection of a peak in global conventional oil production between now and 2023. In addition, the findings indicate that the peak production date for natural gas, coal, and uranium could occur by 2050. The central question is whether oil production from non-conventional oil resources can be increased at a fast enough rate to offset declines in conventional oil production. The development of non-conventional oil production raises concerns about increased energy use, greenhouse gas emissions, and water issues. Due to the emerging fossil fuel resource constraints in coming decades, this study concludes that it is prudent to begin the development of hydrogen production and distribution systems in the near-term. The hydrogen gas is to be initially used by fuel cell vehicles, which will eliminate tailpipe greenhouse gas emissions. With a lowering of H₂ production costs through the amortization of system components, H₂ can be an economic fuel source for electricity generation post-2040.     

Decarbonization synergies from joint planning of electricity and hydrogen production: A Texas case study

Hydrogen (H₂) shows promise as an energy carrier in contributing to emissions reductions from sectors which have been difficult to decarbonize, like industry and transportation. At the same time, flexible H₂ production via electrolysis can also support cost-effective integration of high shares of variable renewable energy (VRE) in the power system. In this work, we develop a least-cost investment planning model to co-optimize investments in electricity and H₂ infrastructure to serve electricity and H₂ demands under various low-carbon scenarios. Applying the model to a case study of Texas in 2050, we find that H₂ is produced in approximately equal amounts from electricity and natural gas under the least-cost expansion plan with a CO₂ price of $30–60/tonne. An increasing CO₂ price favors electrolysis, while increasing H₂ demand favors H₂ production from Steam Methane Reforming (SMR) of natural gas. H₂ production is found to be a cost effective solution to reduce emissions in the electric power system as it provides flexibility otherwise provided by natural gas power plants and enables high shares of VRE with less battery storage. Additionally, the availability of flexible electricity demand via electrolysis makes carbon capture and storage (CCS) deployment for SMR cost-effective at lower CO₂ prices ($90/tonne CO₂) than for power generation ($180/tonne CO₂). The total emissions attributable to H₂ production is found to be dependent on the H₂ demand. The marginal emissions from H₂ production increase with the H₂ demand for CO₂ prices less than $90/tonne CO₂, due to shift in supply from electrolysis to SMR. For a CO₂ price of $60/tonne we estimate the production weighted-average H₂ price to be between $1.30–1.66/kg across three H₂ demand scenarios. These findings indicate the importance of joint planning of electricity and H₂ infrastructure for cost-effective energy system decarbonization.     

Technoeconomic analysis for hydrogen and carbon Co-Production via catalytic pyrolysis of methane

Catalytic Methane Pyrolysis (CMP) is an innovative method to convert gaseous methane into valuable H₂ and carbon products. The catalytic approach to methane pyrolysis has the potential to decrease the required operating temperature for methane decomposition from >1000 °C to under 700 °C. In this work, a novel inexpensive catalyst is discussed that displays low operating temperatures, while still maintaining high reactivity and long proven lifetimes. The kinetics associated with the catalyst's performance are modeled and a correlation was developed for use with practical simulation tools. A techno-economic assessment was conducted applying experimentally determined kinetics for the CMP reaction with the specific catalyst. Two process concepts that utilize CMP using the novel catalyst are presented in this work. Optimizations were considered in these processes and the CO₂ emissions and cost of hydrogen production of the two optimized cases, CMP with H₂ combustion (CMP-H₂) and CMP with CH₄ Combustion (CMP-CH₄), are compared to that of the current industrial standard for hydrogen production, Steam Methane Reforming with carbon capture and sequestration (SMR-CCS). Both of the proposed concepts convert methane into gaseous hydrogen and valuable carbon products, graphitic carbon to carbon Nano fibers. The carbon price was treated as a variable to determine the sensitivity of hydrogen production cost to the carbon price. The analysis indicates that cost of hydrogen production is highly dependent on the recovery and sale of carbon byproducts. Based on Aspen modeling of these two concepts for large scale hydrogen production (216 tons/day), the cost of hydrogen production, without considering carbon sales, was estimated to be $<3.25/kg, assuming a natural gas price of $7/MMBTU and conservative catalyst cost of $8/kg. Assuming 100% recovery of carbon, the price can be reduced to $0/kg by selling the carbon at <$1/kg. A market assessment suggests that values of graphitic carbon and carbon fibers range from ~$10/kg and ~$25–113/kg, respectively. The cost of H₂ production via conventional SMR is ~$2.2/kg when accounting for the cost of CO₂ sequestration. The proposed processes produce a maximum of 0–2 kg CO₂/kg H₂ in contrast to the 10 kg CO₂/kg H₂ produced via conventional SMR-CCS. The process displays an enormous potential for competitive economics accompanied by reduced greenhouse gas emissions.     

Challenges for renewable hydrogen production from biomass

The increasing demand for H₂ for heavy oil upgrading, desulfurization and upgrading of conventional petroleum, and for production of ammonium, in addition to the projected demand for H₂ as a transportation fuel and portable power, will require H₂ production on a massive scale. Increased production of H₂ by current technologies will consume greater amounts of conventional hydrocarbons (primarily natural gas), which in turn will generate greater greenhouse gas emissions. Production of H₂ from renewable sources derived from agricultural or other waste streams offers the possibility to contribute to the production capacity with lower or no net greenhouse gas emissions (without carbon sequestration technologies), increasing the flexibility and improving the economics of distributed and semi-centralized reforming. Electrolysis, thermocatalytic, and biological production can be easily adapted to on-site decentralized production of H₂, circumventing the need to establish a large and costly distribution infrastructure. Each of these H₂ production technologies, however, faces technical challenges, including conversion efficiencies, feedstock type, and the need to safely integrate H₂ production systems with H₂ purification and storage technologies.     

Options for net zero emissions hydrogen from Victorian lignite. Part 1: Gaseous and liquefied hydrogen

This two-part paper investigates the feasibility of producing export quantities (770 t/d) of blue hydrogen meeting international standards, by gasification of Victorian lignite plus carbon capture and storage (CCS). The study involves a detailed Aspen Plus simulation analysis of the entire production process, taking into account fugitive methane emissions during lignite mining. Part 1 focusses on the resources, energy requirements and greenhouse gas emissions associated with production of gaseous and liquefied hydrogen, while Part 2 focusses on production of ammonia as a hydrogen carrier.In this study, the proposed process comprises lignite mining, lignite drying and milling, air separation unit (ASU), dry-feed entrained flow gasification, gas cooling and cleaning, sour water-gas shift reaction, acid gas removal, pressure swing adsorption (PSA) for hydrogen purification, elemental sulphur recovery, CO₂ compression for transport and injection, hydrogen liquefaction, steam and gas turbines to generate all process power, plus an optional post-combustion CO₂ capture step. High grade waste heat is utilised for process heat and power generation. Three alternative process scenarios are investigated as options to reduce resource utilisation and greenhouse gas emissions: replacing the gas turbine with renewable energy from off-site wind turbines, and co-gasification of lignite with either biomass or biochar. In each case, the specific net greenhouse gas intensity is estimated and compared to the EU Taxonomy specification for sustainable hydrogen.This is the first time that a coal-to-hydrogen study has quantified the greenhouse gas emissions across the entire production chain, including upstream fugitive methane emissions. It is found that both gaseous and liquefied hydrogen can be produced from Victorian lignite, along with all necessary electricity, with specific emissions intensity (SEI) of 2.70 kg CO₂-e/kg H₂ and 2.73 kg CO₂-e/kg H₂, respectively. These values conform to the EU Taxonomy limit of 3.0 kg CO₂-e/kg H₂. This result is achieved using a Selexol™ plant for CO₂ capture, operating at 89.5%–91.7% overall capture efficiency. Importantly, the very low fugitive methane emissions associated with Victorian lignite mining is crucial to the low SEI of the process, making this is a critical advantage over the alternative natural gas or black coal processes.This study shows that there are technical options available to further reduce the SEI to meet tightening emissions targets. An additional post-combustion MDEA CO₂ capture unit can be added to increase the capture efficiency to 99.0%–99.2% and reduce the SEI to 0.3 kg CO₂-e/kg H₂. Emissions intensity can be further reduced by utilising renewable energy rather than co-production of electricity on site. Net zero emissions can then be achieved by co-gasification with ≤1.4 dry wt.% biomass, while a higher proportion of biomass would achieve net-negative emissions. Thus, options exist for production of blue hydrogen from Victorian lignite consistent with a ‘net zero by 2050’ target.     

Towards net-zero compatible hydrogen from steam reformation – Techno-economic analysis of process design options

Increased consumption of low-carbon hydrogen is prominent in the decarbonisation strategies of many jurisdictions. Yet prior studies assessing the current most prevalent production method, steam reformation of natural gas (SRNG), have not sufficiently evaluated how process design decisions affect life cycle greenhouse gas (GHG) emissions. This techno-economic case study assesses cradle-to-gate emissions of hydrogen produced from SRNG with CO₂ capture and storage (CCS) in British Columbia, Canada. Four process configurations with amine-based CCS using existing technology and novel process designs are evaluated. We find that cradle-to-gate GHG emission intensity ranges from 0.7 to 2.7 kgCO₂e/kgH₂ – significantly lower than previous studies of SRNG with CCS and similar to the range of published estimates for hydrogen produced from renewable-powered electrolysis. The levelized cost of hydrogen (LCOH) in this study (US$1.1–1.3/kgH₂) is significantly lower than published estimates for renewable-powered electrolysis.     

Techno-economic analysis and life cycle assessment of hydrogen production from different biomass gasification processes

The paper presents techno-economic analyses and life cycle assessments (LCA) of the two major gasification processes for producing hydrogen from biomass: fluidized bed (FB) gasification, and entrained flow (EF) gasification. Results indicate that the thermal efficiency of the EF-based option (56%, LHV) is 11% higher than that of the FB-based option (45%), and the minimum hydrogen selling price of the FB-based option is $0.3 per kg H₂ lower than that of the EF-based option. When a carbon capture and liquefaction system is incorporated, the efficiencies of the EF- and FB-based processes decrease to 50% and 41%, respectively. The techno-economic analysis shows that at a biomass price of $100 per tonne, either a minimum price of $115/tonne CO_2e or a minimum natural gas price of $5/GJ is required to make the minimum hydrogen selling price of biomass-based plants equivalent to that of commercial natural gas-based steam methane reforming plants. Furthermore, the LCA shows that, biomass as a carbon-neutral feedstock, negative life cycle GHG emissions are achievable in all biomass-based options.     

Potential of green ammonia production in India

The threat of climate change is forcing the world to decarbonize all economic sectors. Ammonia primarily used for fertilizer production and a potential, ‘hydrogen carrier’ currently accounts for ~27% of global hydrogen consumption and ~1% of global greenhouse gas emissions. In this analysis, we assess the techno-economic potential of ammonia production using onshore wind, open-field photovoltaic and batteries for both domestic usage and export scenarios in India, which is currently one of the world's largest producer and importer of ammonia. Our results reveal that India's potential can comfortably satisfy global ammonia demand with lowest ammonia costs of 723 EUR/t_NH3 and 765 EUR/t_NH3 for the domestic and export scenario, respectively. To compete with conventional ammonia production a carbon tax of 224–335 €/t_CO2 would be required. Finally, costs of shipping liquid hydrogen and the ‘hydrogen carrier’ ammonia are similar here giving other economic, environmental and safety factors higher relevance.     

Life-cycle analysis of energy use and greenhouse gas emissions of gas-to-liquid fuel pathway from steel mill off-gas in China by the LanzaTech process

The LanzaTech process can convert carbon monoxide-containing gases produced by industries, such as steel manufacturing, into valuable fuel products. The life-cycle analysis (LCA) of energy use and greenhouse gas emissions from the LanzaTech process has been developed for a Chinese setting using the original Tsinghua China Automotive LCA model along with a customized module developed principally for the process. The LCA results demonstrate that LanzaTech gas-to-liquid (GTL) processing in China’s steel manufacturing is favorable in terms of life-cycle fossil energy and can reduce greenhouse gas emissions by approximately 50% compared with the conventional petroleum gasoline. The LanzaTech process, therefore, shows advantages in both energy-savings and a reduction in greenhouse gas emissions when compared with most bio-ethanol production pathways in China.     

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.     

Consequential environmental system analysis of expected offshore wind electricity production in Germany

Taking advantage of offshore wind power appears to be of special significance for the climate protection plans announced by the German Federal Government. For this reason, a comprehensive system analysis of the possible CO₂ reduction including the consideration of all relevant processes has to be performed. This goal can be achieved by linking a life-cycle assessment model of offshore wind utilisation with a stochastic model of the German electricity market. Such an extended life-cycle assessment shows that the CO₂ emissions from the construction and operation of wind farms are low compared with the substitution effects of fossil fuels. Additionally, in the German electricity system, offshore wind energy is the main substitute for medium-load power plants. CO₂ emissions from the modified operation and the expansion of conventional power plants reduce the CO₂ savings, but the substitution effect outweighs these emissions by one order of magnitude. The assumptions of the model, shown here to be above all CO₂ certificate prices, have a considerable influence on the figures shown due to a significant effect on the future energy mix.     

Utilizing hydrogen energy to reduce greenhouse gas emissions in Canada's residential sector

An analysis of the potential to reduce greenhouse gas emissions in the residential sector by using hydrogen energy is reported. The residential sectors in provinces across Canada are considered. Greenhouse gas emissions are determined from the consumption of fossil fuels associated with the energy requirements in the residential sector. The use of hydrogen technologies in the residential sector is compared to conventional systems. The results are determined to vary by province, with the greatest attainable annual reductions in greenhouse gas emissions observed for heating to be in Alberta (7.2 t CO₂) and for power generation to be in Saskatchewan (7.2 t CO₂). The results suggest that hydrogen technologies for heating and power generation are promising options for reducing greenhouse gas emissions in Canada and its provinces.     

Comprehensive evaluation of effects of straw-based electricity generation: A Chinese case

Greater use of renewable energy is being aggressively promoted to combat climate change by the Chinese government and by other governments. Agricultural straw is the kind of renewable energy source that would become a pollution source if it is not well utilized. We select the Shiliquan straw-based electricity generation project in Shandong Province, China as a case and assess environmental externalities of straw utilization in power plants by using life-cycle analysis. Results show that straw-based electricity generation has far fewer greenhouse gas (GHG) emissions than that of coal-based electricity generation. Improvement in the energy efficiency of equipment used for straw’s pretreatment would lead to a decrease of GHG emissions and energy consumption in the life-cycle of straw-based electricity generation. In case 400 million tonnes of wasted straw in China could be used as a substitute for 200 million tonnes of coal, annually the straw 291 Terrawatt hours (TWh) of electricity could be generated, resulting in an annual total CO₂ emissions savings of 193 million tonnes. Straw-based electricity generation could be a high-potential alternative for electricity generation as well as an incentive for utilizing wheat straw instead of burning it in the field.     

Recent advances in membrane technologies for hydrogen purification

Planet Earth is facing accelerated global warming due to greenhouse gas emissions from human activities. The United Nations agreement at the Paris Climate Conference in 2015 highlighted the importance of reducing CO₂ emissions from fossil fuel combustion. Hydrogen is a clean and efficient energy carrier and a hydrogen-based economy is now widely regarded as a potential solution for the future of energy security and sustainability. Although hydrogen can be produced from water electrolysis, economic reasons dictate that most of the H₂ produced worldwide, currently comes from the steam reforming of natural gas and this situation is set to continue in the foreseeable future. This production process delivers a H₂-rich mixture of gases from which H₂ needs to be purified up to the ultra-high purity levels required by fuel cells (99.97%). This driving force pushes for the development of newer H₂ purification technologies that can be highly selective and more energy efficient than the traditional energy intensive processes of pressure swing adsorption and cryogenic distillation. Membrane technology appears as an obvious energy efficient alternative for producing the ultra-pure H₂ required for fuel cells. However, membrane technology for H₂ purification has still not reached the maturity level required for its ubiquitous industrial application. This review article covers the major aspects of the current research in membrane separation technology for H₂ purification, focusing on four major types of emerging membrane technologies (carbon molecular sieve membranes; ionic-liquid based membranes; palladium-based membranes and electrochemical hydrogen pumping membranes) and establishes a comparison between them in terms of advantages and limitations.