Antarctic krill (Euphausua superba) need to undergo freeze-drying to facilitate lipid extraction, but freeze-drying is time-consuming and energy-intensive, resulting in high processing costs. Microwave heating technology can reduce freeze-drying time and lower energy consumption costs. The objective of this study was to establish a drying kinetic model to help the microwave freeze-drying process by predicting krill drying time and evaluating the impact of the drying process on krill quality. The results showed that changing the microwave power did not alter the total energy requirement to complete drying when the sample weight was fixed. The total energy requirement for microwave drying increases with the sample weight. Comparing the three methods of freeze-drying (FD), microwave freeze-drying (MWFD), and hot-air drying at 55 °C (HAD) showed that they took 18, 0.67, and 16 h, respectively, to reach the drying endpoint for krill. Overall, HAD resulted in browning, shrinkage, and quality... [more]

Carbon dioxide geological storage is one of the key measures to control and alleviate atmospheric carbon dioxide content. To better grasp the developmental dynamic and trend of carbon dioxide geological storage research over the world, promoting the research of CO2 storage theory and technology, 5052 related studies published in the past 22 years were collected from the Web Of Science database. The annual published articles on carbon dioxide geological storage research, partnerships, research hotspots, and frontiers were analyzed by using the knowledge map method of article analysis. The results show that the articles on the carbon dioxide geological storage are increasing yearly. The United States, China, and the United Kingdom are the most active countries; meanwhile, Tianfu Xu and Xiaochun Li from China are experts with the most achievements in the field of carbon dioxide geological storage. Although the theoretical and research frameworks for geological storage of CO2 are abundant,... [more]

Examining boiler failure causes is crucial for thermal power plant safety and profitability. However, traditional approaches are complex and expensive, lacking precise operational insights. Although data-driven approaches hold substantial potential in addressing these challenges, there is a gap in systematic approaches for investigating failure root causes with unlabeled data. Therefore, we proffered a novel framework rooted in data mining methodologies to probe the accountable operational variables for boiler failures. The primary objective was to furnish precise guidance for future operations to proactively prevent similar failures. The framework was centered on two data mining approaches, Principal Component Analysis (PCA) + K-means and Deep Embedded Clustering (DEC), with PCA + K-means serving as the baseline against which the performance of DEC was evaluated. To demonstrate the framework’s specifics, a case study was performed using datasets obtained from a waste-to-energy plant i... [more]

Overlapping uranium and coal resources are widely distributed in the basins of China. The current uranium−coal coordinated mining model, mining interaction, and multi-phase and multi-field coupling mechanisms remain unclear, thereby substantially restricting the mining of overlapping uranium and coal resources. This article reviews the overlapping uranium−coal mining technology and conditions, summarizes the main problems faced by the coordinated mining of coexisting uranium−coal resources, proposes a dynamic coordinated mining technology system for the entire life cycle of coexisting uranium−coal resources, and describes the multiphase and multifield coordinated mining of co-associated uranium−coal resources. The multifield coupling mechanism clarifies the solid−liquid−gas three-phase spatiotemporal coupling effects of the stress, fracture, seepage, geochemical, pressure, and microbial fields, and explains the safe and efficient mining technology of uranium and coal resources, and the... [more]

Catalytic studies hydrogen production via steam reforming of ethanol (SRE) are essential for process optimization. Likewise, selecting the ideal support for the active phase can be critical to achieve high conversion rates during the catalytic steam reforming process. In this work, copper-based catalysts were synthesized using two different supports, NaY zeolite and Nb2O5/Al2O3 mixed oxides. The materials were prepared using wet impregnation and characterized for their physicochemical properties using different analytical techniques. Differences in the catalyst morphologies were readily attributed to the characteristics of the support. The Cu/NaY catalyst exhibited a higher specific surface area (210.40 m2 g−1) compared to the Cu/Nb2O5/Al2O3 catalyst (26.00 m2 g−1), resulting in a homogeneous metal dispersion over the support surface. The obtained results showed that, at 300 °C, both the Cu/Nb2O5/Al2O3 and Cu/NaY catalysts produced approximately 50% hydrogen and 40% acetaldehyde, but w... [more]

Flow meters are extensively utilized in fields such as chemical engineering, petroleum, and aerospace, and are an indispensable component of modern industry. This paper examines the metrological properties of a dual-rotor turbine flow meter within its measurable flow range through experimental approaches and investigates the cavitation flow dynamics within the flow meter using numerical methods. First, the flow characteristics curve of the dual-rotor turbine flow meter was established experimentally, and the accuracy of numerical simulation results was validated. Secondly, the transient characteristics of the cavitation cavity were revealed using the Z-G-B cavitation model and dynamic mesh technology. Finally, entropy production theory was applied to investigate the energy losses caused by cavitation, analyzing the contributions of different types of energy losses during the cavitation process. Flow calibration experiments and numerical simulations reveal an increase in the meter coeff... [more]

For the safe and efficient utilization of hydrogen-enriched natural gas combustion in industrial gas-fired boilers, the present study adopted a combination of numerical simulation and field tests to investigate its adaptability. Firstly, the combustion characteristics of hydrogen-enriched natural gas with different hydrogen blending ratios and equivalence ratios were evaluated by using the Chemkin Pro platform. Secondly, a field experimental study was carried out based on the WNS2-1.25-Q gas-fired boiler to investigate the boiler’s thermal efficiency, heat loss, and pollutant emissions after hydrogen addition. The results show that at the same equivalence ratio, with the hydrogen blending ratio increasing from 0% to 25%, the laminar flame propagation speed of the fuel increases, the extinction strain rate rises, and the combustion limit expands. The laminar flame propagation speed of premixed methane/air gas reaches the maximum value when the equivalence ratio is 1.0, and the combustio... [more]

This study conducted in situ combustion oxidation experiments on crude oil from Block D within the Liaohe Oilfield, utilizing a kettle furnace low-pressure oxidation reaction method at various temperatures. The molecular composition of oxidation products was analyzed using gas chromatography−mass spectrometry (GC−MS) and high-resolution mass spectrometry. The results reveal that the molecular composition of the products remains relatively stable up to 300 °C, exhibiting a slight increase in C13-C30 alkanes. The ratio of the peak area for C21 to bisnorhopane is 0.082. From 300 °C to 450 °C, compounds with long alkyl chains gradually undergo thermal cracking, resulting in a significant increase in the production of alkanes within the C10−C30 range. The concentration of saturated hydrocarbons produced through thermal cracking reaches its maximum at a temperature of 400 °C. The most abundant peak of n-alkane is observed at C21, with a quantified ratio of peak area for C21 to bisnorhopane a... [more]

Diversion is a crucial technique for effectively improving shale reservoir production by creating more complex fracture networks. Evaluating diversion effectiveness is necessary to optimize the parameters in hydraulic fracturing. Water hammer diagnostics, an emerging fracturing diagnosis technique, evaluate diversion effectiveness by analyzing water hammer signals. The water hammer attenuation, as indicated by the oscillation time, correlates with the complexity of fracture networks. However, it remains unclear whether the oscillation time is associated with diversion effectiveness. This paper elucidates the relationship between the water hammer oscillation time and diversion effectiveness by taking the probability of diversion and the treating pressure response as the evaluation criteria. Initially, a high-frequency pressure sensor was installed at the wellhead to sample the water hammer signals. Next, the oscillation times were determined using the feature extraction method. Simultan... [more]

The algal limestone reservoir has extremely low permeability, developed dissolution pores and weak structural planes, and has heterogeneity. There is a problem of significant differences in single-well production after fracturing in oilfield sites. It is crucial to clarify the matching relationship between hydraulic fracture parameters and production. This article establishes a triple medium seepage mathematical model of “fracture—dissolution pore—matrix pore” considering the lithological characteristics of algal limestone, which is used to predict the cumulative production of horizontal wells after fracturing, and its reliability is verified through example well production data. The influence of fracture parameters on the production of horizontal wells was revealed through numerical simulation, filling the gap in the study of parameters for the stimulation of algal limestone reservoirs. The results indicate that the proposed triple medium model can accurately characterize the characte... [more]

This paper presents the energy, exergy, and economic analysis of a new cogeneration cycle for the simultaneous production of power and cooling operating with an ammonia−water mixture. The proposed system consists of an absorption cooling system integrating a reheater, a separation tank, a compressor, a turbine, and an expansion valve. In addition, internal rectification is applied, improving the system’s performance. Mass, energy, and exergy balances were applied to each system’s component to evaluate its performance. Additionally, the costs of each component were determined based on economic equations, which take into account mass, heat flows, and temperature differences. A parametric analysis found that the system reached an energy utilization factor of 0.58 and an exergy efficiency of 0.26 using internal rectification at TG = 120 °C, TA = 30 °C, and TE = 10 °C. The power produced by the turbine was 26.28 kW, and the cooling load was 366.8 kW. The output costs were estimated at 0.071... [more]

There is a need to drastically reduce greenhouse gas emissions. While significant progress has been made in electrifying transport, heavy duty transportation and aviation are not likely to be capable of electrification in the near term, spurring significant research into biofuels. When coupled with carbon capture and storage, biofuels can achieve net-negative greenhouse gas emissions via many different conversion technologies such as fermentation, pyrolysis, or gasification to produce ethanol, gasoline, diesel, or jet fuel. However, each pathway has a different efficiency, capital and operating costs, and potential for carbon capture, making the optimal pathway dependent on policy and spatial factors. We use the Integrated Markal-EFOM System model applied to the USA, adding a rich suite of biofuel and carbon capture technologies, region-specific CO2 transportation and injection costs, and government incentives from the Inflation Reduction Act. We find that under current government ince... [more]

Aiming to mitigate the environmental impact derived from fossil fuels, we propose an integrated carbon capture-biomass gasification process is proposed to produce low-carbon hydrogen as an alternative energy carrier. The process begins with the pre-treatment of empty fruit bunches (EFB), involving grinding, drying, torrefaction, and pelletization. The resulting EFB pellet is then fed into a dual gasifier, followed by a catalytic cracking of tar and water gas shift reaction to produce syngas, aiming to increase its H2 to CO ratio. Subsequently, we explore two alternatives (DEPG and MEA) for syngas upgrading by removing CO2. Finally, a PSA system is modeled to obtain H2 at 99.9% purity. The pre-treatment stage densifies the biomass from an initial composition (%C 46.47, %H 6.22, %O 42.25) to (%C 54.10, %H 6.09, %O 28.67). The dual gasifier operates at 800°C, using steam as a gasifying agent. The resulting syngas has a volume concentration (%CO 20.0, %CO2 28.2, %H2 42.2, %CH4 5.9). Next s... [more]

This study delves into the development and examination of various mathematical models for conventional steam-methane reforming (SMR) reactors, establishing a foundational basis for an electrified SMR reactor design. Distinct mathematical models with different scales and dimensions are derived. A basic 1D-fluid, 0D-catalyst (1D-0D) pseudo-homogeneous model is validated with plant data, and progressively advanced to a 2D-0D model considering radial transfer, then further extended to a rigorous 2D-1D model considering transfer phenomena between catalyst particle and fluid. Simulation cases are conducted under uniform design parameters, heat source and operation conditions. Comparative analyses focus on several key performance aspects, including temperature, reaction rate distribution, and outlet characteristics such as temperature, pressure, flow rate, composition and CH4 conversion. The models effectively describe the industrial SMR reactor behavior. Influences of scale and dimension of... [more]

The placement of wind turbines is a crucial design element in wind farms, given the energy losses resulting from the wake effect. Despite numerous studies addressing the Wind Farm Layout Optimization (WFLO) problem, considering multiple directions to determine wind turbine spacing and layout remains limited. However, relying solely on one predominant direction may lead to overestimating energy production, and loss of energy generation. This work introduces a novel mathematical programming optimization framework to solve the WFLO problem, emphasizing the wind energy's nonlinear characteristics and wake effect losses. Comparisons with traditional layout approaches demonstrate the importance of optimizing wind farm layouts during the design phase. By providing valuable insights into the renewable energy sector, this research aims to guide future wind farm projects towards layouts that balance economic considerations with maximizing energy production.

As a promising electricity storage system, Liquid Air Energy Storage (LAES) has the main advantage of being geographically unconstrained. LAES has a considerable potential in energy efficiency improvement by utilizing compression heat and integrating with other systems. In this work, the Stirling Engine (SE) is introduced to improve the energy efficiency of the LAES system. Three LAES-SE systems are modelled in Aspen HYSYS and optimized by the Particle Swarm Optimization (PSO) algorithm. The studied systems include (i) the LAES system with 3 compressors and 3 expanders (3C+3E) using an SE to recover the compression heat, (ii) the 3C+3E LAES system with LNG regasification and SE, and (iii) the 3C+3E LAES system with solar energy and SE. The optimization results show that the Round-Trip Efficiencies (RTEs) of the LAES-SE system and the LNG-LAES-SE systems are 68.2% and 73.7%, which are 3.2% and 8.7% points higher than the basic 3C+3E LAES-ORC system with an RTE of 65.0%. For the Solar-LA... [more]

A novel process system which integrates an isopropanol-based chemical heat pump with a post-combustion carbon capture unit was proposed, designed, and analyzed. The system uses low-quality waste heat (~80°C) produced through the CO2 adsorption step of a carbon capture process and upgrades that heat to a higher temperature (~150°C) using the chemical heat pump. The chemical heat pump is powered mostly by the waste heat and requires only a small amount of electricity. The higher temperature heat produced can be used in the desorption stage of the CO2 capture process, displacing a portion of the existing fossil energy required. The energy and exergy performance characteristics of the chemical heat pump were computed using the results of a steady state simulation in a systems analysis. Using exergy cost correlations, the profitability of the chemical heat pump concept was estimated. It was found that for this particular configuration, the fossil energy load of desorption could be reduced b... [more]

The decarbonization of the society has a very high effect on the power grids as especially the energy generation will be almost completely shifted to CO2-neutral sources such as wind and solar. This implies significant design changes to the power grids and power systems, which lie between the electricity producers and consumers. In this paper, we discuss both the generation and consumer side, including the grid changes and required data exchange to support the transition.

This study focuses on optimizing solid oxide electrolysis cell (SOEC) systems for efficient and durable long-term hydrogen (H2) production. While the elevated operating temperatures of SOECs offer advantages in terms of efficiency, they also lead to chemical degradation, which shortens cell lifespan. To address this challenge, dynamic degradation models are coupled with a steady-state, two-dimensional, non-isothermal SOEC model and steady-state auxiliary balance of plant equipment models, within the IDAES modeling and optimization framework. A quasi-steady state approach is presented to reduce model size and computational complexity. Long-term dynamic simulations at constant H2 production rate illustrate the thermal effects of chemical degradation. Dynamic optimization is used to minimize the lifetime cost of H2 production, accounting for SOEC replacement, operating, and energy expenses. Several optimized operating profiles are compared by calculating the Levelized Cost of Hydrogen (LC... [more]

Most integrated energy system (IES) optimization frameworks employ the price-taker approximation, which ignores important interactions with the market and can result in overestimated economic values. In this work, we propose a machine learning surrogate-assisted optimization framework to quantify IES/market interactions and thus go beyond price-taker. We use time series clustering to generate representative IES operation profiles for the optimization problem and use machine learning surrogate models to predict the IES/market interaction. We quantify the accuracy of the time series clustering and surrogate models in a case study to optimally retrofit a nuclear power plant with a polymer electrolyte membrane electrolyzer to co-produce electricity and hydrogen.

Sustainability encompasses many wicked problems involving complex interdependencies across social, natural, and engineered systems. We argue holistic multiscale modeling and decision-support frameworks are needed to address multifaceted interdisciplinary aspects of these wicked problems. This review highlights three emerging research areas for artificial intelligence (AI) and machine learning (ML) in molecular-to-systems engineering for sustainability: (1) molecular discovery and materials design, (2) automation and self-driving laboratories, (3) process and systems-of-systems optimization. Recent advances in AI and ML are highlighted in four contemporary application areas in chemical engineering design: (1) equitable energy systems, (2) decarbonizing the power sector, (3) circular economies for critical materials, and (4) next-generation heating and cooling. These examples illustrate how AI and ML enable more sophisticated interdisciplinary multiscale models, faster optimization algor... [more]

In this work, we consider the thermo-mechanical exergy of a substance for cold applications, even as it approaches absolute zero. This is relevant for cold-service applications such as refrigeration, liquefied natural gas, air separation, and liquid hydrogen. We demonstrate how the optimization formulation for the determination of exergy is the most suitable way for process systems engineers to think about exergy. We provide an illustrative example by computing thermo-mechanical exergy of neon approaching absolute zero. We also discuss how this result relates with the Third Law of Thermodynamics, both how it is used to compute thermo-mechanical exergy, but also what it implies about the validity of the results and the equations used to compute them.

Improving the emergency response effectiveness of coal mines in response to water hazard accidents not only plays a vital part in minimizing the resultant losses, but also functions as an important index for evaluating the emergency response capability of coal mines. Therefore, it is of great necessity to test the emergency response capability of coal mines. In this study, an effectiveness measurement index system for the emergency response system that comprises two primary indexes (i.e., response capability and service capability) and six secondary indexes (i.e., accident information transmission, emergency command and control, emergency rescue and mitigation, emergency management, personnel team, and prevention and preparation) was constructed. Additionally, a technique for order preference by similarity to ideal solution (TOPSIS) model for evaluating the effectiveness of the integral emergency response system for coal mine water hazard accidents, based on combination weighting, was... [more]

In the past decade, significant advances in reservoir stimulation and enhanced oil recovery technologies have resulted in rapid production growth in unconventional reservoirs [...]

The noteworthy stability of Dion−Jacobson (DJ) phase two-dimensional perovskites marks them as potential contenders for use in optoelectronic applications. Nonetheless, their proliferation is considerably stymied by the constrained charge transport properties inherent to them. This bottleneck is adeptly navigated by deploying 2D-DJ perovskite top layers, seamlessly integrated on 3D perovskite films. We unveil a novel organic cation salt, 4-(Aminomethyl)piperidine (4AMP), as a potent facilitator for treating perovskite photovoltaic films. By employing the annealing technique, we facilitated the in situ creation of a hybrid 2D/3D architecture. Contrasted with conventional 3D architectures, the delineated perovskite heterojunctions with a 2D/3D structure exhibit superior enhanced charge separation, and mitigate photovoltaic losses by proficiently passivating intrinsic defects. The size-graded perovskite 2D/3D structure engineered herein significantly elevates the charge transfer performan... [more]