Increasing Energy Costs Research Articles

Forward Osmosis for Metal Processing Effluents under Similar Osmotic Pressure Gradients.

Water recovery from aqueous effluents in the mining and metals processing industry poses a unique challenge due to the high concentration of dissolved salts typically requiring energy intensive methods of treatment. Forward osmosis (FO) is a lower energy technology which employs a draw solution to osmotically extract water through a semi-permeable membrane further concentrating any feed. Successful FO operation relies on using a draw solution of higher osmotic pressure than the feed to extract water while minimizing concentration polarization to maximize the water flux. Previous studies employing FO on industrial feed samples commonly used concentration instead of osmotic pressures for feed and draw characterization; this led to misleading conclusions on the impact of design variables on water flux performance. By employing a factorial design of experiments methodology, this study examined the independent and interactive effects on water flux by: osmotic pressure gradient, crossflow velocity, draw salt type, and membrane orientation. With a commercial FO membrane, this work tested a solvent extraction raffinate and a mine water effluent sample to demonstrate application significance. By optimizing with osmotic gradient independent variables, water flux can be improved by over 30% without increasing energy costs or compromising the 95-99% salt rejection of the membrane.

Optimal design of pressure swing adsorption units for hydrogen recovery under uncertainty

Abstract The paper proposes an approach to the optimal design of pressure swing adsorption (PSA) units for hydrogen recovery under uncertainty, which provides a reasonable margin of the potential resource of the PSA hydrogen unit and compensates for the negative impact of a random change in uncertain parameters within specified limits. A heuristic iterative algorithm is proposed to solve the design problem with a profit criterion, which is guaranteed to provide the technological requirements for the PSA unit, regardless of the values that take uncertain parameters from the specified intervals of their possible change. An experimental verification of the approach with the root-mean-square error of 19.43 % has been carried out. Optimization problems of searching for a combination of mode and design parameters under uncertainty for a range of 4-bed 4-step VPSA units with a capacity of 100–2000 L/min STP have been solved taking into account the requirements for hydrogen purity of 99.99+ %, gas inlet velocity of 0.2 m/s, and bed pressure drop (no more than 1 atm). It has been established that taking into account uncertainties leads to an increase in energy costs by 8–10 %, a decrease in profit by 10–15 %, and a decrease in hydrogen recovery by 4–5 %, which is a payment for the uninterrupted operation of the PSA unit. The effect of uncertain parameters (percentage composition of the gas mixture; gas temperature; the diameter of adsorbent particles) on the key indicators of the PSA process (recovery, profit, hydrogen purity, unit capacity) has been established and trends in adsorption duration, adsorption and desorption pressure, P/F ratio, valve capacity, bed length, adsorber diameter for design of hydrogen PSA unit, which are necessary for subsequent design and scaling of units.

Co-optimization of configuration and operation for distributed multi-energy system considering different optimization objectives and operation strategies

This study constructs a distributed multi-energy system (DMES) more suitable for development in the cities, which introduces renewable energy and energy storage technologies. Moreover, a novel multi-objective co-optimization framework for configuration and operation is proposed to address the design complexities of DMES. In the modeling process, the output and efficiency of the equipment vary with the load rate considered. In the solution process, the Pareto solution with three objectives (exergy, environment and economy) is obtained by an improved non-dominated sorting genetic algorithm-II (NSGA-II) using the maximum rectangular method, and then the trade-off solution is recognized by the entropy weight method. Finally, the impact of different objectives, operation strategies and system components on the system design is further explored. A hotel in Xi’an is selected as an illustrative example. The results prove that the improved NSGA-II can obtain a more uniform Pareto frontier. Furthermore, the capacity of renewable energy devices is identical for diverse operation strategies or optimization objectives. Compared to the two-objective optimization, the three-objective optimization reduces emissions by 28.86% but reduces energy efficiency by 1.51% and increases costs by 5.92%. Compared to the following thermal load strategy, the following electric load strategy reduces emissions by 27.96%, while increases energy efficiency and costs by 0.84% and 6.2%. Additionally, renewable energy sources and energy storage technologies, especially wind turbines, have a significant impact on the energy supply system of sustainable urban development.

Switch-Off Policies in Job Shop Controlled by Workload Control Concept

The reduction in emissions and the increase in energy costs push companies to identify solutions to reduce energy consumption in production systems. One of the approaches proposed in the literature is the shutdown of machines to reduce energy consumption in the idle state. This solution does not affect production processes and can be applied in various manufacturing fields. This paper proposes switch-off policies in manufacturing systems under a workload control system. The shutdown policies developed consider the number of items in the queue and the calculation derived from the workload control mechanism. Simulation models have been developed to test the proposed policies using the case always on as a benchmark, considering different levels of absorbed power in the inactivity and warm-up states and different warm-up times. The results highlight how the switch policies that include the workload evaluation drastically reduce the number of on/off activities, assuring lower energy consumption.

Chemical composition, particle size, and molecular weight distributions of chemically degraded guar gum solutions

AbstractChemical degradation of guar gum solutions via the addition of a strong oxidant is a common process step in hydraulic fracturing. Unfortunately, this degradation step leads to the formation of an insoluble precipitate which clogs the porous rock formation, reducing efficiency, reducing oil recovery potential, and increasing energy costs. The chemical composition, particle size, and molecular weight distributions of the oxidatively degraded guar (“broken guar”) are largely unknown, making it difficult to develop mitigation strategies. In this work, broken guar gum solutions are systematically analyzed to understand the origin of the observed residue. Our results indicate that cellulose fibers and proteins, rather than galactomannan oligomers, are the two major components (>50%) of the solid residue (the water‐insoluble fraction of broken guar). This finding suggests that removal of the cellulose fiber and proteins from the guar source material may be a potential residue mitigation strategy. Separately, we provide evidence for a potential second mitigation strategy employing chemical additives to reduce aggregation of the insoluble species, effectively reducing their potential to cause formation damage.

Understanding the effect of metamictization on the efficiency of zircon milling

Six commercially available zircon sands were characterised by XRD, SEM, BET and helium pycnometry to determine their degree of metamictization. These sands were categorized into pairs denoted as high, medium or low levels of metamictization. The six samples were subsequently dry milled under identical conditions and their milling behaviour was tracked by measuring the particle size distribution at regular intervals. Samples with low levels of metamictization were found to achieve a marginally smaller particle size than samples with high levels of metamictization after prolonged milling. This was attributed to two potential mechanisms during breakdown – brittle fracture in the former due to retained hardness, in comparison to a more ductile resistance to fracture in the latter due to reduced hardness. However, no clear trend between specific metamictization characteristics and milling behaviour was found. The results reveal a poorer overall milling efficiency for high metamict samples, which has implications such as increased energy costs, poor quality product and a need for further processing of samples exhibiting high levels of metamictization. This study creates a novel link between the milling behaviour of zircon and its level of metamictization. The knowledge gained holds strong importance for industrial entities wishing to carry out and maintain an efficient milling process, with feed material quality likely to become more variable in future years.

TOO HOT FOR SUSTAINABLE DEVELOPMENT: CLIMATE CHANGE AND ENERGY EFFICIENCY

Previous studies have focused on the benefits of adaptation in mitigating the negative effect of climate change on economic production, neglecting that adaptive energy input cannot be directly translated into output, which may be a barrier to sustainable development. Based on panel data from 280 cities in China from 2003 to 2016, we first calculate the energy efficiency as a proxy for sustainable development by using the nonradial directional distance function (NDDF) method. Second, we estimate energy efficiency as a function of temperature shocks, and we use these estimates to predict future potential impacts from climate change. We find three primary results: First, higher temperatures substantially reduce energy efficiency. Second, the heat effect on energy efficiency is homogenous across regions with different climates, suggesting that while adaptations in hot regions can mitigate the harmful effects of heat on output, this mitigation is completely offset by the concomitant increase in energy costs. Third, the energy efficiency would decrease by 2.82% in the medium term (2041–2060) and by 12.02% in the long term (2061–2080), under the assumption that carbon dioxide emissions continue to increase throughout the 21st century. These findings suggest that moderate adaptations to climate change are crucial for sustainable development.

Bölgesel Isıtma Sisteminde Kullanılabilecek Jeotermal Kaynakların Türkiye Ekonomisine Katkısı ve Karbon Salınımı Açısından Analizinin Yapılması

Energy, which has an important position both in the world and in Türkiye, is essential for many primary areas, such as heating-cooling and production. After the industrial revolution, replacing simple machines with steam engines started the adventure of energy dependence and gave strategic energy importance. This situation has played a critical role in reshaping human history. In addition, due to the limited fossil energy resources and the continuous increase in energy costs, countries have started to develop new energy policies for their interests. Thus, scientists have accelerated their work in the field of energy efficiency. District heating systems, one of the best examples of renewable energy use, are the main subject of this study. District heating can be defined as the heating of a building, neighborhood, or city with power plants installed in one or more centers. This study aims to calculate the financial benefit of the district heating systems to be created with the use of geothermal resources in Türkiye to the Türkiye economy and its contribution to the goals of carbon neutrality. As a result of the use of a geothermal-sourced district heating system, a 1.58% reduction will be achieved in Türkiye's annual greenhouse gas emissions. With current investment amounts, the amortization period of 1,000,000 residential equivalent geothermal sourced district heating system implementation is approximately 13 years. Numerical methods were used in this study.

Personalized displacement ventilation as an energy-efficient solution for airborne disease transmission control in offices

There is evidence to suggest that airborne droplets play an important role in the transmission of respiratory diseases. The highest risk of exposure to these pathogens is in indoor environments, where airflow control has been recognized as one of the most effective engineering means to combat its spread. However, this can contribute to a significant increase in energy costs, as conventional ventilation is often not designed to remove contaminants efficiently. In this study, Computational Fluid Dynamics simulations were used to analyze how a novel ventilation approach, called Personalized Displacement Ventilation (PerDiVent), can simultaneously reduce both pathogenic airborne transmission and reduce energy costs in an open office. In addition, thermal comfort and noise were investigated to assess the practicality of the concept. PerDiVent was found to reduce the risk of cross infection by a factor of 1.08–2.0 compared to mixing ventilation in the worst and best case scenarios analyzed, and lead to savings in mechanical power of at least 30%. Furthermore, there is great potential to further improve the system and to increase the stated numbers substantially with relatively simple alterations to the design. Tools that can be used to great advantage for such optimization are also proposed in this work. These include a simple integral model and analytical metrics to estimate the reduction in cross-infection risk and energy savings as a function of PerDiVent’s effectiveness in removing contaminants. Finally, the system has a modular and highly flexible arrangement, which makes it suitable for retrofitting purposes in various indoor environments and integration with current ventilation systems. The concept shows great promise for the future, where ventilation is required to create healthier and more sustainable environments.

Designing a Policy-Making Model for Biomass Energy Development Training in the Agricultural Supply Chain Sector

This basic-applied and hybrid survey aimed to design and validate a policy-making model for biomass energy development training in the agricultural supply chain sector. Creating a supply chain for basic agricultural products by including a wide range of agricultural subsectors from the supply of required production inputs to the final consumer’s access to the goods will lead to an increase in the productivity of the agricultural sector as well as the upstream and downstream industries related to it. Therefore, considering the importance of creating an optimal supply chain for various agricultural products, in this study, the situation of the supply chain of agricultural products in the country has been examined. Considering that the lack of appropriate policies regarding the management of the supply chain of agricultural products can lead to the inefficiency of the supply chain of agricultural products in various stages including supply of inputs, production and distribution, and marketing of products, it is suggested that planning and related policies should be implemented in order to improve the infrastructure that leads to increasing the efficiency of some logistics subsystems such as transportation, warehousing, communication, and information systems. Purposive sampling was used in the qualitative part, and stratified random sampling was utilized in the quantitative part. The data were collected by reviewing resources and interviewing ten experts, who were mainly policy-making managers of biomass energy development training and academic researchers. The interviews continued until reaching theoretical saturation, and the samples of the quantitative part included 384 members of the environmental and agricultural Jihad employees, who were selected based on Cochran’s formula. The effective components of the education policy of biomass energy development and their factors were identified by the exploratory method and evaluated through descriptive-survey research. The validity and reliability of the components were examined, and Cronbach’s alpha of all components was higher than 0.7. The essential components of the effective factors were measured in the education policy of biomass energy development in the agricultural sector. The model validity was verified through the structural equation method, and the selection of concepts, dimensions, and indicators was highly accurate and could provide a suitable framework for developing a policy perspective document for biomass energy education. According to the coding results, the development and acceptance of biomass energy systems by the Ministry of Agriculture Jihad and Environment in the country is unsuitable and sustainable, considering the passage of more than a decade of designing and implementing plans. According to experts, some farmers implement this method in their fields for one or two years and return to traditional methods after accepting this technology. The main achievements are as a core category or phenomenon conditions to casual conditions path with coefficient 0.916 is significant. Strategies to the core category or phenomenon conditions’ path with a coefficient of 0.051 are significant. Strategies to contextual conditions’ path with coefficients 1.231 are significant. Strategies for intervening condition path with coefficients 2.235 are significant. Consequences to strategies’ path with coefficients 0.807 are significant. Therefore, the development of biomass energy is an inevitable necessity, considering the erosion and reduction of soil organic matter, increasing energy costs, and other factors.

Investigating the effects of natural gas, nuclear energy, and democracy on environmental footprint and energy risk in France: Does financial inclusion matter?

To alleviate their energy poverty, most European nations, including France, import the bulk of their oil, natural gas, and coal needs, damaging the environment. The government has expanded its nuclear energy industry to lessen its reliance on imported fossil fuels and for energy security. The current investigation analysis the influence of natural gas, nuclear energy, democracy, and financial inclusion on carbon footprint and energy security from 2000Q1 to 2018Q4. The results of the Bounds test demonstrate that there are long-term interactions between the variables studied. Based on the estimates of the Auto Regressive Distributed Lag (ARDL) model results, nuclear energy, natural gas, and financial inclusion contribute to environmental degradation by increasing the carbon footprint. However, democracy has a role in mitigating long and short-term emissions. Nuclear energy and democracy, on the other hand, help to reduce energy risks while increasing energy costs. The outcomes of the Competition Competence Reports (CCR) test show that all findings are robust and consistent. Moreover, the study results confirmed the existence of the U-shaped EKC hypothesis. The study provides significant policy suggestions that improve energy security and enhance environmental quality. The study suggests that policymakers should exploit the productive capabilities of nuclear energy so that it can achieve energy security. Moreover, it does not have to be at the expense of the quality of its environment. The policy maker should use natural gas as a bridge that accelerates the energy transition since natural gas is the least emitting fossil energy. Likewise, within the framework of democracy, associations and political parties must be encouraged to consider environmental sustainability in their political programs.

Optimization of Microgrid Energy Cost with Electrical Vehicles and Demand Response

Challenges with current power systems include increasing energy costs and Greenhouse gasses. Participation in distributed generators (DGs) and demand response (DR) strategies inside the distribution network may solve these issues. This paper's primary objective is to suggest an energy management system (EMS) strategy for campus microgrid reduce all the issues mentioned above. To practice this strategy a microgrid is considered. Conventionally the microgrid uses a utility grid to fulfill load demands. But in the proposed model the integration of a micro turbine, photovoltaic (PV) system, battery energy storage system (BESS), and Electric vehicles is proposed. Mix integer linear programming MILP technique is used in MATLAB to solve the non-linear optimization problem. The energy management system EMS and demand response policies are used to optimally schedule the available resources and reduce energy costs. The integration of EVs is also observed as source and load. The simulation results are discussed and different case studies are analyzed. Simulation results show that 46% cost saving is observed while using EVs in the system as source. The real-time energy interruption problem is also observed in this paper.

Definition of agronomic circular economy metrics and use for assessment for a nanofertilizer case study

Circular economy has become global priority, and fertigation make large contribution. Modern circular methodologies base their definitions, besides on waste minimisation and recovery, on the product usage U and lifetime L. We have modified a commonly used equation for the mass circularity indicator (MCI) to permit MCI determination for agricultural cultivation. We defined U as intensity for diverse investigated parameters of plant growth and L as the bioavailability period. In this way, we compute circularity metrics for the plantgrowth performance when exposed to three nanofertilizers and one biostimulant, as compared to no-use of micronutrients (control 1), and micronutrients supplied via conventional fertilizers (control 2). We determined an MCI of 0.839 for best nanofertilizer performance (1.000 denotes full circularity), while the MCI of conventional fertilizer was 0.364. Normalised to control 1, U was determined as 1.196, 1.121 and 1.149 for manganese, copper and iron-based nanofertilizers, respectively, while U was 1.709, 1.432, 1.424 and 1.259 for manganese, copper, iron nanofertilizers and gold biostimulant when normalised to control 2, respectively. Based on the learning of the plant growth experiments, a tailored process design is proposed for the use of nanoparticles with pre-conditioning, post-processing and recycling steps. A life cycle assessment shows that the additional use of pumps for this process design does not increase energy costs, while preserving environmental advantages related to the lower water usage of the nanofertilizers. Moreover, the impact of the losses of conventional fertilisers by missing absorption of plant roots, which is presumed to be lower for the nanofertilizers.

Burden of the global energy price crisis on households

The Russia–Ukraine conflict has triggered an energy crisis that directly affected household energy costs for heating, cooling and mobility and indirectly pushed up the costs of other goods and services throughout global supply chains. Here we bridge a global multi-regional input–output database with detailed household-expenditure data to model the direct and indirect impacts of increased energy prices on 201 expenditure groups in 116 countries. On the basis of a set of energy price scenarios, we show that total energy costs of households would increase by 62.6–112.9%, contributing to a 2.7–4.8% increase in household expenditures. The energy cost burdens across household groups vary due to differences in supply chain structure, consumption patterns and energy needs. Under the cost-of-living pressures, an additional 78 million–141 million people will potentially be pushed into extreme poverty. Targeted energy assistance can help vulnerable households during this crisis. We emphasize support for increased costs of necessities, especially for food. The Russia–Ukraine war triggered an energy crisis that affected the cost of many goods and services. Guan et al. model the direct and indirect impacts of increased energy prices across expenditure groups and countries, finding temporary increases in total household energy costs of 63–113% under different scenarios.

Increasing Energy Efficiency Based on the Kaizen Approach

The energy crisis, an increasing concern of the industrial sector, is characterized by increased energy costs and low energy availability. As part of an effort to increase energy efficiency, the present study assessed the impact of applying lean tools on the energy consumption of a manufacturing organization. Using the Kaizen approach, the organization’s processes were analyzed to identify the main vulnerabilities and make the required changes to increase consumption performance. Several technical improvements were performed to reach increased energy efficiency. Results showed an energy efficiency increase; consumption was reduced by up to 7.5% in the production line, 3.5% in the extruder stage, and up to 20% for the injection stage of the manufacturing process. The results suggest that the organization’s energy reduction targets have been achieved. Standardization of procedures was useful in the development of Kaizen projects which could be applied with certain limitations. The implications of these results for understanding energy consumption reduction are discussed.

Energy Efficiency Analysis of Pumping Systems Impacted by the Golden Mussel: A Case Study in the Brazilian Amazon

Pumping systems, especially those used in the water supply sector and in industrial and hydroelectric facilities, are commonly infested by the golden mussel. This causes an increase in maintenance operations (e.g., system shutdowns for cleaning) that can generate an increased energy cost. The geographical expansion of the golden mussel in Latin America presents an economic risk, not only to the ecosystem in general, but also to the energy sector. The imminence of its spread in the Amazon region, one of the main river basins in South America, is cause for concern with regard to the problems that bioinvasion of this species can cause. Given the absence of studies on the loss of energy efficiency in pumping systems impacted by the golden mussel, this study proposes a methodology to estimate the increase in energy consumption and costs of pumping under such bioinfestation. For the standardization of the methodology and development of mathematical calculations (both novel and improved equations), data from the literature (the growth of the golden mussel as a function of infestation time) and an analysis of the dimensions (length and height) of a sample of mussels available in the laboratory were considered. These data were used to calculate the roughness generated by the mussel infestation in the pumping suction and discharger pipe, which was necessary to determine the loss of energy efficiency (load loss, power consumption, and cost of pumping) resulting from the increase in energy consumption for pumping. This methodology was applied to a pumping station representative of the Brazilian Amazon as a case study. The results show an average increase in economic indicators (consumption and cost of pumping) after the system undergoes bioinfestation. This total increase corresponded to 19% and 44% in the first and second years, respectively, achieving a stabilization of the increase in the cost of pumping at 46%, in the 30 months of operation. Our results demonstrate the pioneering nature of the proposal, since these are the first quantitative data on the energy efficiency of pumping systems associated with bioinfestation by the golden mussel. These results can also be used to estimate the increase in costs caused by golden mussel bioinfestation in the raw water pumping systems of other facilities.

The relation of energy cost of walking with gait deviation, asymmetry, and lower limb muscle co-activation in children with cerebral palsy: a retrospective cross-sectional study

BackgroundCompared to typically developing children, children with cerebral palsy (CP) have increased energy expenditure during walking, limiting activity and participation. Insight into whether the also deviating and more asymmetric gait with increased muscle co-activation contributes to this increased energy expenditure is important for clinical decision making. The aim of this study was to investigate the relation between energy cost of walking with gait deviation, asymmetry, and muscle co-activation in children with CP.MethodsForty ambulant children with CP, with Gross Motor Function Classification System (GMFCS) level I (N = 35) and II (N = 5), aged between 5-17y, were tested at one or two occasions with 24 weeks in between, resulting in 71 observations. Gross energy cost (J/kg/m) was measured during a 5-min walk test at self-selected speed. From a 3-dimensional gait analyses, kinematic variables and electromyography were extracted to calculate the gait deviation index (GDI) and co-activation index. The relation between energy cost and GDI, GDI asymmetry, and co-activation index of the lower limb muscles was evaluated through mixed model analyses. Height was included to control for growth-related variation.ResultsGait deviation and height combined explained about 40% of the variance in gross energy cost. No significant contribution was found for gait asymmetry or co-activation index.ConclusionsThis cross-sectional study indicates that increased gait deviation contributes to increased energy cost of walking in children with GMFCS level I and II.

Energy Efficiency Issues in Buildings: Analysis of World Practice

At present, the volume of world energy consumption is continuously and rapidly increasing, which is a consequence of the industrialization process, population growth, increase in energy costs for the extraction of natural resources, etc. Therefore, the importance of solving the problem of energy efficiency is of paramount importance for modern civilization. In this work, there is an analysis of international experience of energy efficient construction. The main directions of energy-efficient development are highlighted. It’s shown that the classical method of heat loss calculations wrongly takes into account the wind effect. The more correct one is required. At the same time, it is worth applying linguistic variables and fuzzy logic, which adequately describe states that are described by verbal statements, and not by numerical values. In conclusion, the most emerging tasks for our Republic are selected: optimal placement of the building on the general plan of the city, incl. maintaining the distance between buildings under the construction and urban-planning regulations; proper heat insulation of the building envelope by the orientation of facades and depending on the climatic parameters of the outside air; air-tightening of building avoiding in- and exfiltration; maximum possible automation of engineering systems up to integration from smart house to smart city level; modernization and optimization of the operation of engineering systems; maximum use of renewable and secondary (such as exhaust air) energy sources; rejection of the classical calculation method of heat loss estimation, which takes into account the effect of wind speed, and to develop a new methodology.

Macroeconomic and Uncertainty Shocks’ Effects on Energy Prices: A Comprehensive Literature Review

GDP, monetary variables, corruption, and uncertainty are crucial to energy policy decisions in today’s interrelated world. The global energy crisis, aggravated by rising energy prices, has sparked a thorough analysis of its causes. We demonstrate the significance of categorizing research by influence channels while focusing on their implications for energy policy decisions. We investigate the growing number of studies that use GDP, inflation, central banks’ characteristics, corruption, and uncertainty as critical factors in determining energy policies. Energy prices fluctuate because energy policies shift the supply–demand equilibrium. We categorise the effects and show that GDP, economic policy uncertainty, and, most notably, specific economic conditions and extreme events play a significant role in determining energy prices. We observed that energy consumption, GDP growth, and energy prices have a bidirectional, causal relationship. Still, the literature has not established which causative direction is the most significant. Taxes, interest rates, and corruption also significantly determine energy prices, although the origins of corruption have not been adequately examined. Lastly, uncertainty generally increases energy costs, but this relationship requires additional research in terms of the features of countries, conditions, and, most importantly, the theoretical backgrounds used.

Continuous hydrate-based CO2 separation from H2 + CO2 gas mixture using cyclopentane as co-guest

CO2 separation from H2 + CO2 gas mixture is a necessary technology for a stable supply of blue hydrogen. Among CO2 separation technology, hydrate-based CO2 separation is an environmentally and economically superior technology. Cyclopentane (CP) was selected as guest compound to enable hydrate-based CO2 separation under thermodynamic conditions closer to normal pressure and temperature. Hydrate-based continuous CO2 separation experiments are conducted in the H2 + CO2 + CP + H2O system at 284 K. The results of these experiments showed that mole fraction of H2 in the gas phase reached 0.9 at the steady state in the H2 + CO2 + CP + H2O system after the CO2 was extracted via hydrate formation. At the same time, more H2 was incorporated into the mixed hydrate during this process as the concentration of H2 in the gas phase increases post hydrate formation. Therefore, it was demonstrated that hydrate-based CO2 separation was successful in H2 + CO2 + CP + H2O system at 284 K but there is also increase of energy costs caused by H2 loss. The PXRD results identified H2 + CO2 + CP hydrate as structure II hydrate. Although H2 + CO2 + Tetrahydropyran (THP) hydrate also forms structure II hydrate, more H2 is encapsulated in the H2 + CO2 + CP mixed hydrate than in the H2 + CO2 + THP mixed hydrate. This difference may be caused by the difference in the lattice constants of CP and THP hydrates, which arises from the difference in molecular size of CP and THP, from the differences between the large guest–host interactions, and from differences arising from hydrogen bonding of THP with the host water framework which can decrease the H2 holding capacity. In this study, it was revealed that the molecular diameter of the guest molecules need also to be considered in addition to the phase equilibrium conditions of the hydrates when selecting guest compound of hydrates.