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Microalgae have the potential to utilize the nutrients in livestock urine and manure (LUM) for the production of useful biomass, which can be used as a source of bioindustry. This study aims to evaluate the economic benefits of LUM feedstock that have not been clearly discussed before. Two types of photobioreactors were designed with a capacity of 200 m3 d-1. Using the experimental data, the economic feasibility of the suggested processes was evaluated via techno-economic analysis. Itemized cost estimation indicated that the submerged membrane photobioreactor has a lower unit production cost (5.4 $ to 5.1 $ kg−1) than the conventional photobioreactor system (14.6 $ to 13.8 $ kg−1). In addition, LUM-based growth is another good option for reducing the unit production cost of biomass. The revenues from lowering the cost of LUM treatment significantly contribute to enhancing the economic profitability, where the break-even prices were 1.18 $ m−3 (photobioreactor) and 0.98 $ m−3 (submerged membrane photobioreactor). Finally, this study provides several emerging suggestions to reduce microalgal biomass production costs.

Environmental issue such as global warming caused serious natural disasters such as flood and drought due to CO2 emission. Global countries cooperate to address the global warming represented by Paris Agreement, which encouraged actions to restrict CO2 emission and global average temperature increase. H2 has been received more attention than before due to its eco-friendly property. Fuel cell and fuel cell electric vehicle (FCEV) are the widely used H2 application in terms of energy and transportation sector. However, most of the researches were carried out related to H2 supply chain. In hence, in this study, economic analysis considering total cost of ownership (TCO) of FCEV was conducted and correlation between TCO and market share of FCEV was figured out by drawing a regression curve. Finally, an optimization model was developed to obtain the optimal H2 fueling station arrangement model in case of 2022, 2030, and 2040 depending on learning rate (8, 13, and 18%). The $ 46,444.2 of TCO was computed considering three years of ownership length. In addition, 4.3, 31.7, and 94.0% of maker share in 2040 were reached in case of 8, 13, and 18% of learning rate, respectively. Finally, it was unveiled that H2 fueling station is preferred to construct equally in nation and the construction region will be shifted to a higher population density region as time passed.

Hydrogen (H2) is currently receiving significant attention as a sustainable energy carrier. Steam methane reforming (SMR) accounts for approximately 50% of H2 production methods worldwide. However, SMR is concern because of the prodigious carbon dioxide (CO2) emissions that have resulted in a global climate emergency. CO2 emissions remain, although some efforts have been made in a membrane reactor (MR) coupled with membranes to improve the H2 yield. A sorption-enhanced membrane reactor (SEMR) has been proposed as a next-generation process for simultaneous H2 production and CO2 capture. In this study, the thermodynamic and economic evaluation of SEMR were implemented using a process simulation, an itemized cost estimation, a sensitivity analysis (SA), and an uncertainty analysis (UA). The thermodynamic analysis results revealed that unit H2 production costs of 4.53, 1.98, and 3.04 $ kgH2−1 were obtained at 773 K for a conventional packed-bed reactor (PBR), a MR, and a SEMR, respectively. The SA results identified PSA as the most critical economic parameter for a unit H2 production cost for a PBR, whereas natural gas is determined to be the most influential parameter for a MR and a SEMR. The UA results from a Monte-Carlo simulation provided a broad range of unit H2 production costs, with 4.26–5.44 $ kgH2−1 for a PBR, 1.61–2.94 $ kgH2−1 for a MR, and 2.83–4.19 $ kgH2−1 for an SEMR. This indicates that using a SEMR for next-generation H2 production and CO2 capture is beneficial.

A techno-economic analysis (TEA) was conducted to evaluate the economic profitability and feasibility for a H2 energy storage system using an alkaline and a polymer electrolyte membrane water electrolysis for 1 MW water electrolysis operation. Many economic analysis methods such as itemized cost estimation, profitability analysis using a cumulative cash flow diagram, and uncertainty analysis employing a Monte-Carlo simulation method were utilized to perform a TEA. In particular, a renewable energy certificate (REC) was considered as an additional benefit of a renewable energy use. From itemized cost estimation, respective levelized costs of H2 of 7.21 and 9.19 $ kgH2−1 were obtained for both H2 energy storage systems in an alkaline and a polymer electrolyte membrane water electrolysis by considering current economy situation and therefore it is still difficult to be cost-competitive compared to a commercial H2 production cost. From profitability and uncertainty analysis results, an appropriate REC weight was confirmed in terms of discounted profitability criteria like a discounted payback period, a net present value, a present value ratio, and a discounted cash flow rate of return. In addition, a REC weight was affected on a net present value compared to a REC trading cost fluctuation.

According to global trend of transition to a hydrogen society, needs for alternative hydrogen (H2) production methods have been on the rise. Among them, methanol steam reforming (MSR) in a membrane reactor (MR) has received a great attention due to its improved H2 yield and compact design. In this study, 3 types of economic analysis – itemized cost estimation, sensitivity analysis, and uncertainty analysis – and integrative carbon footprint analysis (iCFA) were carried out to investigate economic and environmental feasibility. Unit H2 production costs of MSR in a packed-bed reactor (PBR) and an MR for various H2 production capacities of 30, 100, 300, and 700 m3 h−1 and CO2 emission rates for both a PBR and an MR in H2 production capacity of 30 m3 h−1 were estimated. Through itemized cost estimation, unit H2 production costs of a PBR and an MR were obtained and scenario analysis was carried out to find a minimum H2 production cost. Sensitivity analysis was employed to identify key economic factors. In addition, comprehensive uncertainty analysis reflecting unpredictable fluctuation of key economic factors of reactant, labor, and natural gas obtained from sensitivity analysis was also performed for a PBR and an MR by varying them both simultaneously and individually. Through iCFA, lowered CO2 emission rates were obtained showing environmental benefit of MSR in an MR.

Economic uncertainty analysis of employing a membrane reactor (MR) equipped with H2O separation membranes for a synthetic natural gas (SNG) production as simultaneous power-to-gas and CO2 utilization technologies was carried out. Based on previously reported reaction kinetics, process simulation models were created for a conventional packed-bed reactor (PBR) and an MR. Deterministic economic analysis showed the unit SNG production cost of 1.67 $ kgSNG−1 in an MR compared to 1.82 $ kgSNG−1 in a PBR for a SNG production capacity of 1000 kg d−1, showing about 8% cost reductions in the MR. From sensitivity analysis, raw material and labor were identified as the key economic factors to affect a unit SNG production cost for all cases studied. Stochastic economic analysis using a Monte-Carlo simulation method provided better insights for economic-uncertainty associated with premature technology like a SNG production in an MR using H2O separation membranes by presenting a wide range of SNG production costs and their probability.

As an appropriate hydrogen supply system for high temperature polymer electrolyte membrane fuel cells, steam reforming of methanol (SRM) is proposed because reformate gas including low quality H2 with some impurities can be directly used as the fuel. In this study, we compare two SRM systems with and without the use of tail gas from pressure swing adsorption and comprehensive economic analysis is performed for the SRM process with the use of tail gas to estimate a unit H2 production cost (CUHP) based on historical data of natural gas and the CO2 allowance prices for Korea, Europe, Western Climate Initiative (WCI), and Regional Greenhouse Gas Initiative (RGGI). From deterministic economic analysis with a H2 production capacity of 700 m3 h−1, the CUHP values are 6.88 $ kgH2−1 for Korea, 6.84 $ kgH2−1 for Europe, 6.50 $ kgH2−1 for WCI, and 6.54 $ kgH2−1 for RGGI, respectively. Furthermore, additional two scenarios, pessimistic and optimistic ones (Scenario 1 and 2, respectively), are investigated to evaluate the current level of CUHP values for H2 production capacities from 30 to 700 m3 h−1. With a Monte-Carlo simulation method, stochastic economic analysis is carried out to predict the ranges of potential CUHP values for each region. The CUHP values for WCI and RGGI show the narrow distributions meaning lower change of CUHP; however, a wide range of distribution for Korea and Europe suggest that there is considerably higher variation, demonstrating the necessity of stochastic uncertainty analysis when assessing the economic feasibility.

In this paper, we report an integrated techno-economic analysis of glycerol steam reforming (GSR) targeting distributed H2 refueling stations for a H2 production capacity of 700 m3 h−1. A process simulation based on mass and energy balances was performed to identify the product yield at effect of temperature and water/glycerol ratio. The results show that temperature of 900 K and a water/glycerol ratio of 9 are optimal to techno-economically operate a GSR process. An economic analysis using itemized cost estimation, sensitivity analysis (SA), and profitability analysis (PA) was carried out to investigate the economic feasibility of GSR for distributed H2 refueling stations. The unit H2 production cost was 4.46 $ kgH2−1 at the optimum conditions identified in the process simulation, and the most influential economic key factor was the reactant from the SA. Meaningful economic indicators such as net present value, discounted payback period, present value ratio, and rate of return on investment were obtained from the PA through a discounted cash flow diagram. Moreover, a cumulative probability analysis based on an uncertainty analysis using a Monte-Carlo simulation method was applied to unit H2 production cost and B/C ratio calculations to quantify the risk of a proposed GSR process as premature technology providing crucial guidelines to decision-makers.

Computational fluid dynamics (CFD) studies have been carried out for CO2 reforming of methane in both a packed-bed reactor (PBR) and a membrane reactor (MR) with a heating tube as a heat source at the center of a reactor. The effect of a reactor geometry on the temperature and H2 and CH4 concentration profiles within a PBR and a MR have been investigated numerically by changing the distance of membranes from the center of a heating tube (Dcenter = radial distance between the center of the reactor and the center of the membrane) for a given heating tube temperature. The distances of the center of the membranes in a MR from the reactor center were 0.028 m, 0.03 m, 0.033 m, 0.035 m, 0.038 m, 0.04 m, 0.042 m, 0.044 m and 0.045 m. With the help of COMSOL Multiphysics® modeling software, it was possible to visualize temperature and concentration profiles both axially and radially. Interestingly, it was found that H2 enhancement is proportional to both Dcenter and the magnitude of the H2 flux. Further studies for the effect of a heating tube radius proposed an optimum radius for a maximum H2 yield enhancement in a MR. Consequently, it turned out that CFD studies can be used as a critical guideline for an efficient reactor design focusing on a reactor geometry in a MR for given conditions.

Process simulation and design as well as economic analysis were carried out to evaluate technical and economic feasibility of steam reforming of methanol in a membrane reactor (MR) for ultra-pure H2 production. Using a commercial process simulator, Aspen HYSYS®, comparative studies were conducted to investigate the effect of operating conditions including the H2 permeance (1 × 10−5 - 6 × 10−5 mol m−2 s−1 Pa−1), a H2O sweep gas flow rate (1–20 kmol h−1), and a reaction temperature (448–493 K) in a conventional packed-bed reactor (PBR) and the MR using a previously reported reaction kinetics. Improved performances such as methanol conversions and H2 yields were observed in the MR compared to the PBR and several design guidelines for the MR were obtained to develop H2 separation membranes with optimal H2 permeance and to select a suitable H2O sweep gas flow rate. In addition, economic analysis based on itemized cost estimations was conducted for a small-sized H2 fueling station by calculating a unit H2 production cost for both the PBR and the MR reflecting a current economic status in Korea. As a result, a cost saving of about 23% was obtained in the MR (7.24 $ kgH2−1) compared to the PBR (9.37 $ kgH2−1) confirming the benefit of employing the MR for ultra-pure H2 production.

In this study, a techno-economic analysis for the bridging technology of hybrid methanol production based on tri-reforming of methane integrated with water electrolysis is performed. Focusing on the technical and economic parameters of three representative types of water electrolyzer (alkaline, proton exchange membrane, and solid oxide electrolysis), the process flow diagram for the targeted process is built and key economic parameters are confirmed. Based on the results of the simulation model and values of economic entries, itemized cost estimation reflecting the current status of water electrolyzers is conducted to evaluate the methanol production costs. Furthermore, the future production costs of methanol are estimated according to the projected values of system efficiencies, the lifetimes, and the future investment costs of three different water electrolyzer types. The results of methanol production costs in the present and the future are compared with the market prices of methanol in three different regions (U.S., Europe, and China) to verify the economic viability of the process. Considering the reported annual working hours of electrolyzers and the predicted decline of electricity prices generated from renewable energy sources such as photovoltaics and on-shore wind energy, operating hours of the plant and electricity prices for water electrolysis to be economically competitive are varied for more practical prediction for methanol production costs. In conclusion, the profitable operating conditions of the process to achieve a 20% margin in the regions in the present and the future are suggested concerning plant working hours and the levelized cost of electricity for each water electrolysis system.

The well-established Haber-Bosch (HB) process (industrial ammonia production) is a significant contributor to the world’s carbon emissions as it is a major consumer of natural gas as well as being energy-intensive in general. This work addresses the challenge of decarbonizing the HB process in a novel way as it, for the first time, presents a conceptual process integration with a supercritical CO2 Allam power cycle, therefore transforming gaseous CO2 emissions into a valuable side product in a form of liquid CO2. Detailed process design and flowsheet simulation using Aspen Plus ® was used as a basis for scale-up and techno-economic assessment of two cases (electrical grid dependent and independent). The results indicated that using this process design NH3 production reaches profitability at scales larger than 2 ton h−1 to 5.4 ton h−1 and at current global NH3 prices, the cost of manufacturing decrease, due to scale-up stabilizes at ∼ 30 ton h−1. Finally, this novel process integration achieves a significant reduction in gaseous CO2 emissions (compared to conventional HB process) of 68 % to 96 %, which indicates great potential for economically feasible green NH3.

In this paper, we report economic feasibility studies focusing on profitability analysis of high pressure polymer electrolyte membrane (PEM) water electrolysis for distributed H2 refueling stations in Korea. From capital and operating costs, a unit H2 production cost of 6.24 $ kgH2−1 was obtained for a H2 capacity of 700 m3 h−1, which is equivalent to handling about 300 fuel cell electric vehicles. Based on cost estimations, profitability analysis using cash flow diagrams was performed to assess the economic feasibility of high pressure PEM water electrolysis and various key economic indicators like net present value (NPV), discounted payback period (DPBP), and present value ratio were obtained for both different discount rates and capacity factors. In conclusion, employment of high pressure PEM water electrolysis was found to be economically profitable showing reasonably high NPVs (16–52 MM$) and short DPBPs (4–7 years).

With the increased production of shale gas through a new drilling technology of hydraulic fracturing, much attention has been directed to various utilization methods for ethane accounting for about 7% of shale gas. As an efficient utilization method for ethane, ethane steam reforming in a membrane reactor is proposed in this paper to provide improved reactant conversions and product yields thus leading to a reduced operating temperature. To assess techno-economic feasibility of ethane steam reforming in a membrane reactor, parametric studies focusing on a H2 selectivity and economic analysis predicting profitability from cash flow diagrams based on a purified hydrogen in Korea were performed simultaneously providing very useful design and economic guidelines to implement a membrane reactor for ethane steam reforming.

With the aim of producing hydrogen at low cost and with a high conversion efficiency, steam methane reforming (SMR) was carried out under moderate operating conditions in a Pd-based composite membrane reactor packed with a commercial Ru/Al2O3 catalyst. A Pd-based composite membrane with a thickness of 4–5 μm was prepared on a tubular stainless steel support (diameter of 12.7 mm, length of 450 mm) using electroless plating (ELP). The Pd-based composite membrane had a hydrogen permeance of 2.4 × 10−3 mol m−1 s−1 Pa−0.5 and an H2/N2 selectivity of 618 at a temperature of 823 K and a pressure difference of 10.1 kPa. The SMR test was conducted at 823 K with a steam-to-carbon ratio of 3.0 and gas hourly space velocity of 1000 h−1; increasing the pressure difference resulted in enhanced methane conversion, which reached 82% at a pressure difference of 912 kPa. To propose a guideline for membrane design, a process simulation was conducted for conversion enhancement as a function of pressure difference using Aspen HYSYS®. A stability test for SMR was conducted for ∼120 h; the methane conversion, hydrogen production rate, and gas composition were monitored. During the SMR test, the carbon monoxide concentration in the total reformed stream was

Spent coffee waste (SCW) is extremely attractive to be exploited and utilized as a material source for energy generation and chemical production. This study concerned bio-oil production via non-catalytic and catalytic fast pyrolysis using SCW in a bubbling fluidized-bed reactor (BFR). In particular, a comparative analysis of the quality of the bio-oil produced was conducted for non-catalytic (using silica sand as the bed material) and catalytic (using dolomite, HZSM-5, hematite, and magnetite as the catalyst) fast pyrolysis. Scale-up modeling confirmed using the experimental data was performed at a feed rate of 100 kg h−1 (1,000-fold capacity), which showed different orders in the quality of energy (hematite > magnetite > dolomite > HZSM-5 > silica, in order of energy from highest to lowest) owing to the realistic integration of the BFR with other components in plants, such as the combustor, compressor, and separator. Further, techno-economic analysis of scale-up system revealed that the unit production costs of bio-oil were 0.0151, 0.0034, 0.0143, 0.0095, and 0.0102 $ MJ−1 for silica, dolomite, HZSM-5, hematite, and magnetite, respectively (dolomite > hematite > magnetite > HZSM-5 > silica, in order of unit cost from lowest to highest). Among them, dolomite and hematite showed competitive unit production costs compared to the price of conventional crude oil (0.0098 $ MJ−1). The importance of coupling laboratory-scale experimental results with scale-up modeling and economic analysis has thus been demonstrated for practical feasibility studies of the SCW pyrolysis for bio-oil production.

This study comprehensively investigates hydrogen production from green ammonia reforming, including synthesis of catalysts, reactor development, process integration, and techno-economic analysis. In-house developed Ru/La–Al2O3 pellet catalyst having perovskite structure showed high catalytic activity of 2827 h−1 at 450 °C and stability over 6700 h at 550 °C, exceeding the performance of the majority of powder catalysts reported in the literature. A scalable 12-faceted reactor adopting the as-produced catalyst was designed to enhance heat transfer, producing over 66 L min−1 of hydrogen with state-of-the-art ammonia reforming efficiency of 83.6 %. Near-zero CO2 emission of hydrogen extraction from green ammonia was demonstrated by-product gas recirculation as a combustion heat source. A techno-economic assessment was conducted for system scales from 10 kW to 10 MW, demonstrating the effect of reduced minimum hydrogen selling prices from 7.03 USD kg−1 at small modular scales to 3.98 USD kg−1 at larger industrial scales. Sensitivity analyses indicate that hydrogen selling prices may reduce even further (up to 50 %). The suggested hydrogen production route from green NH3 demonstrates superior CO2 reduction ranging from 78 % to 95 % in kg CO2 (kg H2)−1 compared to biomass gasification and steam methane reforming. These findings can be used as a basis for following economic and policy studies to further validate the effectiveness of the suggested system and process for H2 production from NH3.

Alkaline water electrolysis has been in the spotlight for green H2 production using electricity generated from renewable energy because of its high technology readiness level and low investment. However, commercialization of alkaline water electrolysis is challenging because of the low current density. Therefore, a techno-economic and environmental assessment was conducted for green H2 production by alkaline water electrolysis with experimental data from the advanced alkaline water electrolysis system of the Korea Institute of Energy Research (KIER) to identify the potential of this technology. Based on techno-economic analysis results, the stack cost and unit electricity price must be below 0.035 $ kWh−1 and 406 $ kW−1, respectively, to make this technology cost-competitive compared to the conventional H2 production method (

The steel sector is one of the most carbon-intensive industries, and the sustainable strategies to reduce CO2 emission on integrated mill plants are discussed continuously. By renewable H2 utilization on blast furnace (BF), it is expected to achieve both sustainable operation and CO2 emission reduction. We evaluate the application of the solid oxide electrolysis cell (SOEC) process as a source of H2 for use as an alternative to CO as the reductant in a BF. We mathematically formulated a BF model and developed an integrated BF-SOEC process. We performed techno-economic analysis to suggest the maximum H2 injection for the technical aspect, and demonstrated the process’ economic viability, considering the learning-by-doing effects on the price of the SOEC system. We also estimated the net reduction of global warming potentials and carbon intensity. Our findings showed that the coke replacement ratio ranged from 0.255 ∼ 0.334 k g C o k e ∙ k g H 2 - 1 depending on injection conditions and that 25 k g H 2 ∙ t H M - 1 was an acceptable maximum injection rate within the stable range of BF operating indexes. We calculated H2 production cost to be US$ 8.84 ∼ 8.88 k g H 2 - 1 in the present, but it is expected to be decreased to US$ 1.41 ∼ 4.04 k g H 2 - 1 by 2050. Economic parity with the existing BF process will be reached between the years 2036 and 2045, depending on the maturity of the SOEC process. Injection of 25 k g H 2 ∙ t H M - 1 can reduce CO2 emission by 0.26 ∼ 0.32 t C O 2 - e q . ∙ t H M - 1 We expect that this sustainable strategy to reduce CO2 emission from integrated mill plants will widen applications of H2 utilization in BFs if the economic efficiency of SOEC systems can be increased.

For utilization of valuable raw material of landfill gas (LFG), CH4 and CO2 which are the major chemical constituents in LFG can be reacted to produce H2 by so-called catalytic dry reforming of CH4 (CDR). In this study, the impact of applying a membrane reactor (MR) for CDR is investigated in terms of energy, economic, and environmental aspects (3E). Due to the intrinsic limitation of an MR being able to operate at lower temperature than the temperature of a conventional chemical reactor (packed-bed reactor, PBR), two different process configurations are invented for an MR and a PBR separately using a commercial process simulator. Based on different process configurations, comparative techno-economic analysis is conducted for an MR and a PBR at the same temperature as well as different temperature. It is identified that energy efficiency and productivity of the process are related to the operating temperature which directly affects variation of CH4 and CO2 conversion. However, it turns out that operating at higher temperature is not always better than lower temperature due to the additional CO2 emissions and fuel costs. Especially, it is revealed that an MR will overcome its low operating temperature and accomplishes economic viability compared to a PBR by developing its durability and permeability.

In this paper, we report techno-economic analysis for CO2 reforming of a medium-grade landfill gas in a membrane reactor (MR) for a H2 production capacity of 7 m3 h−1 in Korea. Parametric studies for the effect of key operating conditions like a H2 permeance, a H2O sweep gas flow rate, and temperature on the performance in a conventional packed-bed reactor (PBR) and a MR were conducted using Aspen HYSYS®, a commercial process simulator. Based on process simulation studies, economic analysis was carried out to find a unit H2 production cost for both a PBR and a MR. Respective unit H2 production costs of 9.72 and 6.46 $ kgH2−1 were obtained for a PBR and a MR showing about 34% reduction in the MR. Sensitivity analysis was employed to identify key economic factors to determine a unit H2 production cost with labor the most influential factor for both reactors. Probability analysis (PA) was performed with influential factors based on a Monte-Carlo simulation method as uncertainty analysis and a cumulative probability (CP) curve was created for a PBR and a MR under various discount rates from 2 to 10% and key factor ranges from ±10 to ±40%. PA using stochastic approach provided a wide range of a unit H2 production cost coupled with its probability and a critical CP value at which the effect of key factor range on a unit H2 production cost was reversed.

Synthetic natural gas (SNG) production from captured CO2 and H2 produced by water electrolysis using renewable energy is of increasing interest for low-carbon fuel production, CO2 utilization technology, and unstable renewable energy storage. In this study, the effect of voltage degradation in a water electrolyzer, a core technology for SNG production, on the unit production cost of SNG production and CO2 emissions, with different water electrolysis types such as alkaline electrolysis (AEL), proton exchange membrane electrolysis (PEMEL), and solid oxide electrolysis (SOEL), was identified through techno-economic and environmental assessment. In particular, the energy efficiency, unit production cost of SNG, and CO2 emissions were identified based on the change in the power consumption caused by voltage degradation. Moderate voltage loss results in a decrease in energy efficiency from 53.8% to 48.8% in AEL, 55.3% to 47.0% in PEMEL, and 76.3% to 51.2% in SOEL. Moreover, respective SNG unit production costs of 140.3–170.2 USD MWh−1, 157.5–203.1 USD MWh−1, and 153.1–353.5 USD MWh−1 for AEL, PEMEL, and SOEL, respectively, were obtained, showing an increase in SNG production cost due to the voltage degradation. Furthermore, total CO2 emissions for the SNG production process were investigated considering voltage degradation as well as electricity generation sources.

Economic analysis with uncertainty analysis based on a Monte-Carlo simulation method was performed for hydrogen production from high pressure PEM water electrolysis targeting a hydrogen production capacity of 30 Nm 3 h −1 in Korea. With key economic parameters obtained from sensitivity analysis (SA), a cumulative probability curve was constructed for a unit H 2 production cost fully reflecting unpredictable price fluctuations in H 2 production equipment, construction, electricity, and labor from ±10% to ±50%. In addition, economic analysis for a net present value (NPV) with uncertainty analysis for revenue (REV), fixed capital investment (FCI), and cost of manufacturing (COM) provided cumulative probability curves with different discount rates and more reliable NPVs (-$ 69,000 ∼$1,308,000) for high pressure PEM water electrolysis under development in Korea. This economic analysis based on uncertainty can serve as important economic indicators suitable for premature technology like high pressure PEM water electrolysis currently being in progress in Korea.

Economic evaluation for water electrolysis compared to steam methane reforming has been carried out in terms of unit hydrogen production cost analysis, sensitivity analysis, and profitability analysis to assess current status of water electrolysis in Korea. For a hydrogen production capacity of 30 Nm3 h−1, the unit hydrogen production cost was 17.99, 16.54, and 20.18 $ kg H2−1 for alkaline water electrolysis (AWE), PEM water electrolysis (PWE), and steam methane reforming (SMR), respectively with 11.24, 10.66, and 11.80 for 100 Nm3 h−1 and 8.12, 7.72, and 7.59 $ kg H2−1 for 300 Nm3 h−1. With sensitivity analysis (SA), the most influential factors on the unit hydrogen production cost depending on the hydrogen production capacity were determined. Lastly, profitability analysis (PA) presented a discounted payback period (DPBP), net present value (NPV), and present value ratio (PVR) for a different discount rate ranging from 2 to 14% and it was found that a discounted cash flow rate of return (DCFROR) was 14.01% from a cash flow diagram obtained for a hydrogen production capacity of 30 Nm3 h−1.

In this study, various economic analysis methods, such as cost estimation considering experience rate, scenario analysis, and uncertainty analysis employing Monte-Carlo simulation method, were conducted for green NH3 production using modified Haber-Bosch process to select the appropriate water electrolysis (WE) type among alkaline WE(AWE), polymer electrolyte membrane WE (PWE), and solid oxide electrolysis cell (SOEC) and then evaluate the economic feasibility compared to conventional NH3 production. With the highest learning rate for each WE type and the lowest unit electricity price in 2045, the respective levelized costs of NH3 (LCOA) are 174.0, 283.1, and 327.3 $ ton−1 for AWE, PWE, and SOEC, respectively in the order of LCOEs from lowest to highest. Conversely, the LCOAs are 868.7, 999.9, and 709.6 $ ton−1 for AWE, PWE, and SOEC, respectively, when considering the highest learning rate and the highest unit electricity price of 0.06 $ kWh−1, owing to the lower energy consumption of SOEC compared to other WE technologies. Therefore, we confirm the considerable potential of SOEC for the production of green NH3 by the modified Haber-Bosch process.

In conventional biomass-to-biofuel production processes, cellulose and hemicellulose are converted only to biofuels. However, to improve the economics of the process, it is desirable that some fractions of biomass be produced as fuels and other fractions as chemicals. This coproduction of fuels and chemicals also enables a flexible response to the market conditions of bioproducts, rather than producing only biofuels or biochemicals. Moreover, the use of all fractions, not only cellulose and hemicellulose but also lignin, improves the economics of the process. We propose a biorefinery strategy for the coproduction of liquid hydrocarbon fuels and chemicals from lignocellulosic biomass. In this study, all three primary components of biomass were converted into high-value products that can be commercialized: (1) cellulose, which is converted into butene oligomers (BO) for transportation fuels, (2) hemicellulose, which is converted into 1,5-pentanediol (1,5-PDO) that can be used as polyester and polyurethane components, and (3) lignin, which is converted into carbon products, such as carbon fibers or battery anodes. By maximizing the biomass utilization up to 47.8% from biomass to valuable products, the economic viability of the proposed process can be increased. Technoeconomic analysis shows that the minimum selling price of BO is $4.21 per gallon of gasoline equivalent in the integrated strategy, indicating that it is a promising alternative to current biofuel production approaches.

Numerical modeling studies have been performed for a methane dry reforming using a shell and tube type packed-bed reactor and a membrane reactor both with a heating tube as heat source in the center of a reactor. Mathematical models for a reformer bed, a heating tube, and an insulating jacket coupled with reaction kinetics were proposed to investigate axial and radial temperature and concentration profiles within both reactors with a reformer temperature of 923 K and heating tube temperatures from 1023 to 1223 K. 3-D visualizations of temperature, CH4 conversion, CH4 concentration, and H2 concentration profiles were possible by COMSOL Multiphysics modeling software and significant variations within both reactors were observed providing a critical guideline for an efficient reactor design. Further studies for the effect of hydrogen mass flux on a hydrogen yield enhancement revealed that a threshold hydrogen mass flux in a membrane reactor to outperform a packed-bed reactor exists with a trend of a lower threshold hydrogen mass flux for a higher heating tube temperature.

With the growing concern about environmental issues including high CO2 emission, which is the main contributor to global warming resulting in climate change, CO2 utilization technologies have received much attention. Among diverse technologies, renewable methanol synthesis using H2 generated from the water electrolysis and the CO2 captured from various industrial processes as well as the atmosphere has received significant attention. In this context, the technical and economic feasibility analysis of renewable methanol synthesis was conducted in this study. Using a commercial process simulation program, Aspen HYSYS®, parametric studies were conducted to investigate the effects of diverse operating parameters, such as the reaction pressure, temperature, and H2/CO2 ratio, on the technical performance of this process. Under the optimum conditions of 100 bar and 493 K derived from thermodynamic studies, an economic analysis was performed to estimate the unit methanol production costs at different methanol production capacities using itemized cost estimation, sensitivity analysis, and predictive cost analysis. Predictive cost analysis was conducted to determine how the unit methanol production cost could be rendered reasonable compared to the existing one, which indicated that decreasing the renewable H2 production cost as well as increasing in the CO2 tax credit for a methanol production capacity of 100 ton per day would make the renewable methanol synthesis an economically feasible process.

An environmental issue such as global warming causing series of disasters has been considered as a serious matter, which asks global cooperation, leading the Paris Agreement. As a result, considerable attention has been paid to H2 due to utilization and storage of renewable electricity expected to increase as time passes. A polymer membrane electrolyte (PEM) water electrolysis using renewable electricity generating from bioenergy, geothermal, onshore wind, etc., has been introduced to store electricity in form of H2. For preparing successful H2 society, an economic analysis was conducted considering PEM water electrolyzer cell replacement and renewable electricity resources to figure out economic feasibility. In this study, profitability analysis by drawing discounted cash flow diagram and uncertainty analysis using Monte-Carlo simulation based on itemized cost estimation result were carried out. The results presented that replacement preferred to occur at 2.20 V of max voltage of the PEM water electrolysis cell if electricity price is low and degradation rate is high. Furthermore, H2 selling price has been more influential factor to a net present value (NPV) than renewable electricity price and hydro and onshore wind energies are regarded as promising renewable electricity resources to achieve goal of H2 production cost. Moreover, CO2 footprint analysis was conducted to provide guidelines on the replacement of PEM water electrolysis in terms of environmental aspect.

The ultimate goal of this work is technical and economic feasibility analysis of a methane dry reforming (MDR) using a coke oven gas (COG) for a H2 production capability of 700 m3 h−1 because this technology is the promising alternative approach to H2 production as well as CO2 utilization. From process simulation works, process flow diagram is created for MDR using COG and validated by performance results from the previously reported literature. With a process flow diagram to be confirmed via model validation, the best reaction temperature of 1073 K is observed in terms of methane conversion. Based on process simulation results, economic analysis is performed. Furthermore, case studies focusing on an operating expense are conducted to consider various aspects of a CO2 price and confirm the effect of CO2 price on unit H2 production cost. Respective H2 production costs of 3.27, 2.71, and 2.38 $ kgH2−1 for a case 1 (reference), a case 2 (case 1 ​+ ​CO2 absorption), and a case 3 (case 2 ​+ ​CO2 from a blast furnace) are obtained. In addition, uncertainty analysis is performed to suggest the possible H2 production cost range for each case by considering the uncertainty of CO2 price fluctuation. Consequently, it is expected that a MDR using a COG is feasible for a H2 production as well as CO2 utilization technology compared to the current by-product H2 cost if carbon cap-and-trade system is activated.

Following the adoption of the Paris Agreement, H2 has come to be considered a promising alternative energy carrier owing to its eco-friendly characteristics. However, H2 is mostly obtained via carbon-based production methods, which account for approximately 96% of the global H2 yield and emit CO2 as a by-product. A membrane reactor (MR) was introduced to produce H2 more efficiently via a positive chemical equilibrium shift, according to Le Chatelier’s principle. CaO was employed as a CO2 adsorbent in an MR to form a sorption-enhanced membrane reactor (SEMR), in which the additional CO2 removal enhanced the equilibrium shift. Additionally, the direction of sweep gas through the membrane with respect to that of the reactants, i.e., co-current or counter-current flow, was found to affect the performance of the reactors. In this study, numerical simulations based on chemical reaction kinetics were carried out to investigate the effects of the employment of H2 separation membrane and/or CO2 adsorbent as well as those of co-current and counter-current flows. Based on the numerical simulation results, H2 yield rates of 0.00143, 0.00145, 0.00127, 0.00121, and 0.00852 mol s−1 were achieved using the SEMR with counter-current flow, SEMR with co-current flow, MR with counter-current flow, MR with co-current flow, and a packed-bed reactor, respectively. This showed that an SEMR can be used to not only enhance H2 production but also achieve this in an environment-friendly manner.

Summary For a sustainable hydrogen economy, large-scale transportation and storage of hydrogen becomes increasingly important. Typically, hydrogen is compressed or liquified, but both processes are energy intensive. Liquid organic hydrogen carriers (LOHCs) present a potential solution for mitigating these challenges while making use of the existing fossil fuel transportation infrastructure. Here, we present a process intensification strategy for improved LOHC dehydrogenation and an example of clean power generation using solid oxide fuel cells. Four LOHC candidates—ammonia, biphenyl-diphenylmethane eutectic mixture, N-phenylcarbazole, and N-ethylcarbazole—have been compared as stand-alone and integrated systems using comprehensive process simulation. “Temperature cascade” dehydrogenation was shown to increase the energy generated per unit mass (kWh/kg LOHC) by 1.3–2 times in an integrated system compared to stand-alone LOHC systems, thus providing a possibility for a positive impact on a LOHC-based hydrogen supply chain.

The simplified direct-transesterification (DT) process was compared to the conventional biodiesel production process based on a reported previous experimental work with economic standpoint. Based on the process flow diagram, capital and operating costs were itemized properly and then unit biodiesel production cost was calculated. The results show the biodiesel production costs were 18.2 $ kg−1 (conventional process) and 12.5 $ kg−1 (DT process), respectively. Sensitivity analysis shows the source of biomass and chemical consumption are the major factors to determine total biodiesel production cost. The affecting factors were a solvent recycling, yield of biodiesel, and plant capacity and these values were varied to evaluate the variation of unit biodiesel production cost. As a result, the maximized biodiesel production cost went down to 3.5 $ kg−1, which is cost-competitive with other reported values of production cost.

In this paper, techno-economic feasibility assessment on ammonia decomposition as a CO x -free H 2 production method for a small-scale on-site H 2 refueling station with a capacity of 30 m 3 h −1 in Korea was conducted to evaluate the feasibility of the proposed process in terms of technical and economic aspects. A robust process simulation model validated by experimental data from a laboratory-scale reactor was developed. Based on the process simulation model, economic feasibility studies were performed in terms of itemized cost estimation, profitability analysis, and sensitivity analysis. The itemized cost estimations showed a reduced unit H 2 production cost of 6.27 $ kgH 2 −1 for 30 m 3 h −1 compared to 9.97 $ kgH 2 −1 for 0.9 m 3 h −1 (laboratory). The unit H 2 selling price considering both production and dispensing was 9.06 $ kgH 2 −1 , comparable to the current equivalent gasoline cost of 10.65 $ kgH 2 −1 . Different depreciation methods produced slight differences in the net present value, discounted payback period, and present value ratio. For a new depreciation method, the net present value was $318,666, the discounted payback period was 2.24 years, and the present value ratio was 3.35, which confirmed the economic feasibility of this technology. Sensitivity analysis showed that the most important economic factor for the unit H 2 production cost was the raw material (ammonia); in addition, the H 2 selling price considerably affected the net present value, which critically influenced the profitability of the proposed project.

Power-to-gas (P2G) has been proposed as an innovative energy storage system for a long period of time to manage unbalanced electricity generated from renewable energy. Here we report economic feasibility studies and uncertainty analysis of P2G technology for synthetic natural gas (SNG) production in Korea. Economic analysis in terms of itemized cost estimation was carried out based on capital cost and operating cost, and then a unit SNG production cost of 0.094 USD kWh−1 was obtained for a SNG production capacity of 700 m3 h−1, which is still higher than a conventional natural gas price in Korea (0.038˜0.069 $ kWh−1). With a Monte-Carlo simulation method, uncertainty analysis was performed to predict the possible changes in a unit SNG production cost and a net present value due to fluctuating the renewable H2 cost (1.84˜2.76 USD kgH2−1), CO2 capture cost (48˜111 USD tonCO2−1), and CO2 tax credit (16˜24 USD tonCO2−1) as a tool of quantifying risks associated with a premature P2G technology. The analysis confirmed the economical infeasibility of P2G technology in Korea requiring significant advancement in P2G technology and stability in CO2 tax credit and also suggesting a future drive for the detailed analysis of environmental impacts considering the life cycle of produced SNG.