Search

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.

As environmental problems become serious, many countries have been striving to change fossil-based energy to renewable and sustainable hydrogen energy. However, there are large capacity differences...

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.

In this work, a comprehensive study of CO2 methanation by coupling process simulation, economic analysis, and life cycle assessment (LCA) was conducted to find out the most practicable pathway for green methane production in terms of technical, economic, and environmental aspects. For this work, different renewable energy resources, such as hydropower, wind power, and solar power, and water electrolysis, like alkaline water electrolysis (AWE) and proton-exchange membrane water electrolysis (PWE), leading to 6 scenarios for H2 production were considered. From the economic analysis in terms of itemized cost estimation, the levelized cost of methane (LCOM) for scenarios 1 to 6 was obtained as 0.108, 0.118, 0.144, 0.121, 0.132, and 0.159 $ kWh−1, respectively. In addition, from LCA, the respective quantified environmental impacts (i.e., CO2 emission) were obtained as 0.347, 0.813, 2.33, 0.537, 0.842, and 2.52 kg CO2-eq kg H2−1 for scenarios 1 to 6, respectively. And then, the analytic hierarchy process (AHP) was carried out to decide on the most appropriate renewable energy and water electrolysis based on different criteria of renewable energy capacity with Technology readiness level (TRL) of water electrolysis, LCOM, and CO2 emission for technical, economic, and environmental criteria, respectively. From this work, H2 production from AWE with wind power (i.e., scenario 2) was selected to be the best pathway for green methane production owing to the narrow priority range of 0.130–0.191. Furthermore, scenario 5 (i.e., PWE with wind power) was determined to be the second pathway with the same reason.

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.

Integrative technoeconomic analysis (iTEA) with process simulation and economic analysis and integrative carbon footprint analysis (iCFA) of ethane steam reforming (ESR) for H2 production in a memb...

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.

H2 is regarded as an alternative to current energy carriers without CO2 emission. To supplement traditional H2 production by fossil fuels, alkaline water electrolysis (AWE) is back in the spotlight. Unfortunately, H2 production by AWE is not economically practical yet compared with current fossil fuel H2 production methods. In this context, scenario analysis was performed in this study to find a suitable and reasonable scenario in which AWE is cost-competitive in terms of the levelized cost of H2 (LCOH) on the basis of diverse economic parameters such as the unit electricity price, the learning curve, and the automation level. From scenario analysis results, it is identified that the unit electricity price is the most effective economic factor to determine the LCOH followed by the learning curve and the automation level demonstrating that the introduction of surplus electricity, inevitably generated from renewable sources, can be very crucial for H2 production from AWE to be economically viable compared with the estimated LCOH of 1.25 USD per kg H2 in 2030 targeted by the United States Department of Energy. Most importantly, it can provide technical and economic guidelines on the basis of scenario analysis results. This can be very useful for decision makers to make economic and environmental policies in Korea and will result in entering the H2 economy society in the near future.

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.

Power-to-gas (P2G) technology has gained significant attention as one of the efficient methods to utilize surplus electricity inevitably produced from renewable sources. Coupled with the Korean government's efforts to increase the portion of renewable energy, P2G technology is considered as a promising candidate to produce H2 using surplus electricity for various industrial applications. Therefore, a comprehensive techno-economic analysis of H2 production from P2G technology using a high-pressure proton exchange membrane water electrolyzer (PWE) was conducted in this study in terms of itemized cost estimation and sensitivity analysis (SA). In particular, a stochastic approach was applied to reflect economic fluctuations possibly encountered in PWE, a premature technology. Respective H2 production costs of 4.33, 3.83, and 3.67 USD kg−1 were obtained for H2 production capacities of 300, 700, and 1000 m3 h−1, which are comparable to the current H2 market price of 5–6 USD kg−1 in Korea. Electricity was the most critical economic parameter in SA. Further studies using a Monte-Carlo simulation method of stochastic uncertainty analysis for a size factor's exponent, a major cost factor at scale-up, provide stochastic guidelines for P2G technology to be competitive and prove the economically attractive option of P2G technology using a high-pressure PWE for H2 production in Korea.

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.

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.

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.

In this paper, a multi-stage catalyst-adsorbent reactor consisting of a series of catalyst and adsorbent beds is proposed for an effective tetrafluoromethane (CF4) abatement and conversion of corrosive hydrogen fluoride (HF) to CaF2, a useful chemical. Experimentally, enhanced CF4 conversions were observed in multi-stage catalyst-adsorbent reactors compared to a zero-stage reactor (catalyst bed only) confirming sorption-enhanced CF4 hydrolysis due to selective removal of HF during reaction. In addition, some useful design guidelines to select the number of stages and a proper time to replace adsorbents are presented. To develop a process simulation model to represent experimental data, Aspen HYSYS®, a commercial process simulator, was used providing a proper model to match experimental data quite reasonably. Based on experimental and simulative studies, a three- or four-stage catalyst-adsorbent reactor is recommended for CF4 abatement considering both reactor performance and capital/operating expenditures. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.

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.

This study suggests the economic potential of biochar-based biodiesel production by conducting the techno-economic analysis. The itemized cost estimation was performed by categorizing biochar production facility and biodiesel conversion plants for 30,000 ton y−1 of biodiesel production capacity. The result of sensitivity analysis shows the methanol and waste cooking oil (WCO) costs are significantly sensitive to determine a unit biodiesel production cost. When the biodiesel selling price was 1.70 $ kg−1, the discounted payback period was varied from 1.91 (not discounted) to 2.06 years (10% discounted). In addition, the break-even price of biodiesel was calculated to 1.55 $ kg−1 when the discount rate was 10%. It means that this technology is to be feasible because of commercial diesel price (0.97 to 1.88 $ kg−1). The consideration of tax exemption and subsidy for biodiesel can be good option to supply WCO based energy production.

A preliminary techno-economic analysis combining process simulation and economic analysis has been carried out to assess the feasibility of employing a new CF4 abatement and utilization process without HF effluent, where CaO was employed to convert produced HF into CaF2, a useful chemical. Moreover, the effect of employing multi-bed series reactors compared with a single-bed reactor on CaF2 production was analyzed using Aspen HYSYS® based on material and energy balances from process flow diagrams for three systems, a single-bed reactor (S-1), a two-bed series reactor (S-2), and a three-bed series reactor (S-3). From economic analysis to estimate annual operating cost savings for three systems, it was found that multi-bed series reactors (S-2 and S-3) performed better than a single-bed reactor (S-1) due to equilibrium shift by Le Chatelier's principle leading to reduced operating temperatures to produce the same amount of CaF2 as S-1. Consequently, annual cost savings of about 7 to 13% were obtained in S-2 and S-3 compared to S-1 and this can serve as a useful guideline for the efficient system design. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.

New and efficient reactor systems were proposed to treat perfluorinated compounds via catalytic decomposition. One system has a single reactor (S-1), and another has a series of reactors (S-2). Both systems are capable of producing a valuable CaF2 and eliminating toxic HF effluent and their feasibility was studied at various temperatures with a commercial process simulator, Aspen HYSYS®. They are better than the conventional system, and S-2 is better than S-1 in terms of CaF2 production, a required heat for the system, natural gas usage and CO2 emissions in a boiler, and energy consumption. Based on process simulation results, preliminary economic analysis shows that cost savings of 12.37% and 13.55% were obtained in S-2 at 589.6 and 621.4 °C compared to S-1 at 700 and 750 °C, respectively, for the same amount of CaF2 production.

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.

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.

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.