Utility Consumption Research Articles

Development of a center for automated equipment processing to transform the research enterprise configuration.

The strategy of centralizing equipment sanitation and processing was developed by a top-tier public university to address the growing physical infrastructure and human resource challenges of its expanding in-vivo research enterprise. Subsequently, a center for automated equipment processing physically separate from all animal research facilities was developed and has operated consistently since 2016. The facility incorporates systems such as process automation to sanitize and sterilize equipment as efficiently as possible. Analysis of the differences between the new centralized and old distributed research enterprise configurations shows a total estimated fiscal benefit of almost US$54 m to date projected out to US$124 m through 2028. Utility consumption of operations over nine years in the new configuration was estimated to be decreased by over 125 million gallons of water, 14 million gallons of chilled water, 121 million pounds of steam, and almost 3.6 million kilowatts of electricity, with consumption savings significantly increased projected out to 2028. Additional operational and organizational benefits as well as direct research benefits were identified. The new configuration has functioned for nine years without detectable cross contamination within the research enterprise thus providing evidence that the location of equipment processing can be less of a "microbial" risk factor than previously attributed.

Turn off the faucet: Can individual meters reduce water consumption?

When consumption of water and other utilities is measured collectively for many households and the payment of such services is equally shared among members of the group, individuals may use more than what is socially optimal. In this paper, we evaluate how the installation of individual meters affects water consumption. Using administrative data from the public water utility company in Quito, Ecuador, and an event study approach, it is estimated that water consumption decreases by about 20% as a result of the introduction of individual metering. The effect is large and economically significant: in order to obtain the same effect using the price mechanism in Quito, prices would have to increase by at least 66%. Individual water metering could be a useful tool to curve down consumption in both developing and developed countries.

Comparison of energy consumption and probiotic stability with pilot scale drying processes

The production of dried probiotics offers multiple advantages including expanded storage options, ease of transportation, enhanced stability, formulation support, and incorporation into a variety of finished products. As probiotic use and application areas increase, the demand for lower production costs and increased product stability follows. The most common methods for drying include lyophilization and spray drying. Lyophilization offers high preservation of viability at the expense of production speed, while spray drying provides high throughput drying with greater loss of probiotic viability. Newer processes, such as electrostatic spray drying, have the potential to bridge the gap. The aim of this study was to evaluate the energy consumption and viability of Lacticaseibacillus rhamnosus GG (LGG) with pilot-scale conventional spray drying, electrostatic spray drying, and lyophilization. Energy consumption of the primary utilities was monitored along with LGG viability immediately and 8-12 weeks after drying. With regards to removal of water, conventional spray drying was the most energy efficient (1.2 kWh/L), followed by electrostatic spray drying (10.9 kWh/L) and lyophilization (16.9 kWh/L). When normalized against recovered viable LGG, electrostatic spray drying was the most efficient at 4.6x1010 CFU/kWh, followed by lyophilization and conventional spray drying at 1.1x1010 CFU/kWh and 4.8x107 CFU/kWh, respectively.

Current Understanding, Motivations, and Barriers Towards Implementing Sustainable Initiatives in the Hospitality Industry in the Age of Automation and Artificial Intelligence

Background:: Sustainability concerns are rapidly being acknowledged as a key concern for hospitality sectors worldwide. Sustainable initiatives immediately contribute to improved organizational performance in terms of utility consumption, waste management, and regulatory compliance, resulting in cost-effectiveness and competitive advantage through distinctiveness. Objective:: The purpose of the study is to analyze and summarize the motivations, indicators, and barriers towards applications of sustainable initiatives and modern technologies in the hospitality industry using the existing literature to develop a current understanding of the subject and know the way the current industry is thinking about it. Method:: This study is a combination of systematic and bibliometric review, where the systematic review was based on selected articles from reputed journal databases, and the bibliometric review was conducted using VOS viewer and web of science database for a period of 20 years (2002- 2022) Seven research questions were framed and answered for the systematic review. Result:: By describing the motivations, barriers, and impacts of implementing sustainability initiatives and cutting-edge technologies like AI and machine learning in the hospitality sector, the study helps practitioners and academics understand its present state for robust research. The current condition of such implantations in the hospitality sector is also discussed. Conclusion:: This study adds value by shedding light on the perspective of sustainability in the hospitality industry by considering the recommendations and practical advice for hotel management suggested in the existing literature about the application of current sustainability innovations and effective sustainability initiatives in hotel management.

Circulation of self-supplied water for significant energy recovery through heat integration

This study introduces an overhead heat-integrated distillation column (OHIDiC), a novel approach that maximizes heat recovery by multiple heat exchanges and product circulation. By utilizing the overhead vapor as a direct heat source, low-temperature feed and product water were used as cooling agents, thereby significantly reducing the condenser duty and reliance on cooling utilities. Additionally, the heated feed transfers heat to the column, leading to a substantial reduction of reboiler heat duty. Some of the heated product water is recycled back to the decanter for product cycling, while the rest is released as the final product. This circulation process ensures a continuous coolant supply, which contributes the reduction of condenser duty. Two processes were considered in this study, utilizing the water product from a non-reactive, and from a reactive separation within the system. When applied to the separation of a water-dodecanol mixture, OHIDiC reduced the condenser duty by 69.21% compared to a traditional distillation column, with a 31.46% reduction in the total utility consumption. When reactive distillation was incorporated into the OHIDiC, the higher overhead vapor temperature facilitated high heat transfer in the multiple heat exchange sections, thereby significantly reducing the total thermal load. This resulted in a reduction of up to 46.96% in total heat duty and a 36.06% decrease in CO2 emissions. These findings confirm that the OHIDiC achieves significant energy savings through the utilization of process-derived substances, with pronounced benefits when the temperature of the overhead vapor becomes higher.

Efficient multi-objective optimization and operational analysis of amine scrubbing CO2 capture process with artificial neural network

Amine scrubbing processes for post-combustion CO2 capture have been extensively studied and significantly improved via various novel designs. However, the amine scrubbers implemented nowadays were usually not optimized according to a number of different evaluation criteria. This is often due to the fact that, for high dimensional design spaces, the rigorous simulation runs needed to facilitate process optimization always calls for huge numbers of simulation software accesses and overwhelming iterative calculations. Therefore, in this study, the well-trained surrogate model was adopted to replace its rigorous counterpart for the purpose of ensuring efficient optimization runs in practical applications. In current study, two objectives, i.e., the specific equivalent work and the CO2 capture level, were both rapidly and effectively optimized in various practical scenarios with different flue gas CO2 concentrations. The corresponding operational parameters and utility consumptions were also easily obtained without additional effort. The computation results obtained so far showed that the proposed surrogate-assisted approach can be utilized to significantly reduce the computational load in practice.

Synthesis of heat-integrated water networks: Integration of heat pumps

A typical heat-integrated water network (HIWN) synthesis problem aims to minimise freshwater and utility consumption while establishing trade-offs between operating and investment costs by exploring different water and heat integration opportunities. Heat integration between hot and cold water streams is performed to save external heating and cooling utilities required to achieve the target temperatures of these streams. This paper proposes a mathematical programming approach to integrate water-to-water heat pumps into the HIWNs. A simple cascade heat pump system with isobutane as a natural working fluid enables a larger temperature lift between the heat pump source and the sink. The objective function of the proposed mixed-integer nonlinear programming (MINLP) model is to minimise the total annualised cost (TAC). The TAC includes operating costs for freshwater, heating/cooling utilities, electricity, and investment in heat exchangers and heat pumps. A sensitivity analysis is performed to evaluate the economic feasibility of the system by varying the heating/electricity cost ratio and depreciation period for the capital investment. The results show that additional utility savings can be obtained by integrating heat pumps into the HIWNs. For threshold problems, a heat pump is feasible for heating/electricity price ratios from 1.175, and heating utility is replaced by electricity for a 1:1 ratio. However, for pinched problems, the feasibility of the heat pump is shifted to lower heating/electricity price ratios, from 0.3 to 0.5, depending on the annualisation factor for the investment.

Optimizing Inventory and Pricing for Substitute Products with Soft Supply Constraints

This paper presents a profit optimization model for substitute products in a competitive, time-sensitive market with scarcity and shifting user preferences. The model maximizes profit, considering production costs and inventory maintenance. It uses a discrete choice model to represent demand, sensitivity to price, availability, and changing preferences. A two-phase PSO-type metaheuristic solution tackles the nonlinear, recursive model, efficiently managing inventories and evolving consumer preferences. The model integrates production decisions, inventories, and sales prices, considering scarcity conditions and user preferences. It uses a multinomial logit for the consumers’ demand function with soft exogenous constraints, which influence utility and change consumption preferences and choices. This research offers a tool for companies to manage stock, production, and pricing in a context where goods are substitutes, providing a new perspective on business strategy.

Techno-economic viability of bio-based methyl ethyl ketone production from sugarcane using integrated fermentative and chemo-catalytic approach: Process integration using pinch technology

Butanediols are versatile platform chemicals that can be transformed into a spectrum of valuable products. This study examines the techno-commercial feasibility of an integrated biorefinery for fermentative production of 2,3-butanediol (BDO) from sucrose of sugarcane (SC), followed by chemo-catalytic upgrading of BDO to a carbon-conservative derivative, methyl ethyl ketone (MEK), with established commercial demand. The techno-economics of three process configurations are compared for downstream MEK separation from water and co-product, isobutyraldehyde (IBA): (I) heterogeneous azeotropic distillation of MEK-water and extractive separation of (II) MEK and (III) MEK-IBA from water using p-xylene as a solvent. The thermal efficiency of these manufacturing processes is further improved using pinch technology. The implementation of pinch technology reduces 8% of BDO and 9–10% of MEK production costs. Despite these improvements, raw material and utility costs remain substantial. The capital expenditure is notably higher for MEK production from SC than BDO alone due to additional processing steps. The extraction based MEK separation is the simplest process configuration despite marginally higher capital requirements and utility consumption with slightly higher production costs than MEK-water azeotropic distillation. Economic analysis suggests that bio-based BDO is cost-competitive with its petrochemical counterpart, with a minimum gross unitary selling price of US$ 1.54, assuming a 15% internal rate of return over five-year payback periods. However, renewable MEK is approximately 16–24% costlier than the petrochemical route. Future strategies must focus on reducing feedstock costs, improving BDO fermentation efficacy, and developing a low-cost downstream separation process to make renewable MEK commercially viable.

Process intensification of tar chemical looping reforming based on ReaxFF reaction kinetics investigation

Traditional chemical processes currently produce tar as a by-product with low efficiency. This paper proposes a novel tar chemical looping reforming (t-CLR) process based on reactive force field (ReaxFF) reaction kinetics investigation to enhance its utilization efficiency. Firstly, the t-CLR process is initially established to determine the optimum operating conditions. Through ReaxFF molecular dynamics (ReaxFF-MD) simulations conducted under above conditions, the activation energies of the fuel reactor, steam reactor, and air reactor are determined to be 63.25 kJ/kmol, 107.85 kJ/kmol, and 159.53 kJ/kmol respectively. By implementing micro-dynamic parameters filling, oxygen carrier recovery, and heat integration, the optimal t-CLR process achieves a 97.60 % recovery rate of the oxygen carrier and reduces external utility consumption by 71.39 %. The comprehensive framework with macro and micro dimensions is established based on the above studies to promote the cleaner production of traditional processes. Finally, the utilization efficiency of tar is efficiently improved through t-CLR technology, which allows for an adjustable C/H ratio in syngas. The t-CLR technology can be applied to the chemical and energy industries by adding value to by-products and optimizing energy utilization. Overall, this work provides important guidance for process intensification, energy conservation, environmental protection, and waste utilization. The study further promotes the development of industrial production in a cleaner and more efficient direction.

Housing policies and energy efficiency spillovers in low and moderate income communities

Housing policies address the human dimensions of increasing urban density, but their energy and sustainability implications are hard to measure due to challenges with siloed civic data. This is especially critical when evaluating policies targeting low- and moderate-income (LMI) households. For example, a major challenge to achieving national energy efficiency goals has been participation by LMI households. Standalone energy efficiency policies, such as information-based programmes and weatherization assistance, tend to attract affluent, informed households or suffer from low participation rates. In this Article, we provide evidence that federal housing policies, specifically community development block grants, accelerate energy efficiency participation from LMI households, including renters and multifamily residents. We conduct record linkage on 5.9M observations of housing programme participation and utility consumption to quantify the hidden benefits of locally administered housing block grants in a typical entitlement community in the US Southeast. We provide long-run evidence across 16,680 properties that housing policies generate 5–11% energy savings as spillover benefits to economically burdened households not conventionally targeted for energy efficiency participation.

Process integration and systems optimization for the hydrodeoxygenation of 5-hydroxymethylfurfural to dimethylfuran

Most biomass reaction studies have focused on optimizing product yield without considering cost and emissions as key metrics; they consider pure feeds without accounting for process integration resulting from separation and recycling and often change one parameter at a time to maximize yield. Here, we propose a framework to overcome the above issues. We demonstrate it for the hydrodeoxygenation (HDO) of 5-hydroxymethylfurfural (HMF) to produce 2,5-dimethylfuran (DMF), a crucial reaction in making lignocellulosic biomass-based platform chemicals. We consider the impact of water in the feed stemming from the sugar dehydration reactor on the HDO in 2-pentanol over a Ru/C catalyst, guided by an active learning experimental design (NEXTorch toolkit), combined with Aspen Plus process flowsheet simulation, techno-economic analysis and life cycle assessment. We demonstrate that Bayesian optimization of process flowsheets significantly reduces production costs by 26% and greenhouse gas emissions by 15% after striking a balance between raw material usage, solvent loss, and utility consumption. Such reductions are strongly correlated to the product yield due to the dominant cost of the feed. Interestingly, a slight amount of water negatively impacts greenhouse gas emissions more than production costs, requiring relatively high purity in process integration.

Multi-objective optimization of heat exchanger network with disturbances based on graph theory and decoupling

Disturbance poses a significant challenge to highly coupled chemical systems. In this work, a multi-objective optimization framework is developed for reducing the impact of fluctuations on heat exchange networks (HENs) based on graph theory and decoupling. The framework bridges the gap between algebra and structure of HEN through a directed graph (Digraph) and defines the Excitation as a fluctuation impact indicator. The Non-dominated Sorting Genetic Algorithm II (NSGA-II) is improved for generating feasible solutions and global optimality, and the quasi-gradient is applied to select an equilibrium solution from the Pareto Front. Two case studies are conducted, and the equilibrium solution is selected based on quasi-gradient. For the literature case, the Excitation of the equilibrium solution and the total annual cost is reduced by 56.15% and 2.12%, respectively. For the coal-to-methanol system, the utility consumption and Excitation are 29.6% and 264.50% lower than the results of the Aspen Energy Analyzer, respectively.

Optimizing post-combustion carbon capture: A comprehensive 3E analyses of energy, exergy, and exergoeconomic aspects with solar integration

The combination of capturing CO2 from power plants and storing it has the potential to mitigate the effects of fossil fuel usage on the climate. The reduction of CO2 emissions through CCS is recognized as a viable solution, but the significant challenge lies in the need to reduce costs and energy consumption in its development. A method that can be utilized to improve the energy efficiency of capture is the implementation of exergy-based analysis, which includes both exergetic and exergoeconomic analyses. This study aims to create an exergy-based assessment of a post-combustion CO2 capture with DGA 50 wt% solvent, using ASPEN HYSYS Version 11 for a Natural Gas-fired power plant with a capture rate of 90 %. The results show that through meticulous modifications in the system's configuration, including LVC, SSF, RVC, RSR, ICA, and their combinations, the reboiler's energy consumption was significantly reduced from 11.1 GJ/Ton CO2 to 3.27 GJ/Ton CO2, and the utility consumption was reduced by approximately 6,500$/h. Additionally, we compared various configurations in terms of exergy and exergoeconomic. The plant exergy efficiency improved from 44.9 % in the standard configuration to 68.3 % for the LVC + Solar configuration. Additionally, the exergoeconomic factor improved from 3.1 % to 3.8 %.

Application of a Microeconomic Approach for Explanation of Citizen Participation in Open Government

The digital economy and the sharing economy have changed the role citizens may acquire in society. Citizens can perform at least two roles from the open government perspective: on the one hand, they can be passive users/demanders of information and, on the other hand, they can provide or produce the information in an active manner. The objective of this paper is to offer a theoretical model to explain citizens’ incentives to participate in open government projects. Which is the opportunity cost of participation for the citizen? Which are the drivers of the preferences for the social good? This model is based on the utility function and consumption theory. We complement the theoretical framework with an exploratory–descriptive analysis based on a case study’s primary data about citizen participation. In democracy projects where citizens actively collaborate and could earn monetary gains or become entrepreneurs, the opportunity cost of participation is lower than in a passive type and the amount of the social good depends on the preferences. Preferences for social goods are related to community experiences and e-government and they also affect the decision to participate. Very few studies in the field of open government have pretended to explain citizens’ participation by using microeconomic foundations.

Simulation and modification of an Ethane-Ethylene separation Unit using vapor recompression heat Pump: Energy, Exergy, and economic analyses

This paper presents a comprehensive analysis involving simulation and thermo-economic evaluation of thermal integration technology, specifically the vapor recompression method, applied to an existing ethane-ethylene distillation process. The study commences with the simulation of the current process, revealing a favorable level of accuracy as evidenced by the strong agreement between simulation outcomes and real plant data. The energy analysis highlights key parameters, with consumption rates of 0.4 kg of refrigerant per kg of vapor in the condenser and 0.743 kg of heating fluid per kg of liquid in the reboiler. Moving to the economic analysis, the total investment cost for the existing process is estimated at 16,925,333 USD. However, a noteworthy concern is the high refrigerant consumption in the condenser, leading to elevated operational costs within ethylene production facilities. Consequently, this study focuses on reducing refrigerant consumption and enhancing the thermodynamic efficiency of the ethane-ethylene distillation column. Simulation results for the proposed process demonstrate an investment cost of 968,837 USD, marking a 5.72 % reduction compared to the current process. The optimization process, driven by sensitivity analysis, determines the optimal outlet fluid pressure for the compressor, setting it at 3730 kPa. Under this optimized condition, refrigerant consumption for condensing the overhead vapors within the distillation column drops by a significant 34.29 % compared to the base case. From an energy perspective, the optimal Mechanical Vapor Recompression method leads to a substantial reduction in utility consumption, decreasing the rate for feed separation from 3.92 kg of utilities per kg of feed to 1.52 kg of utilities per kg of feed. This represents an impressive improvement in process efficiency. The exergy analysis reveals that the Joule-Thomson valve is the primary contributor to total exergy loss. Notably, the reboiler and distillation column's condenser exhibit significantly reduced exergy losses, 33.77 % and 39.05 % lower, respectively, compared to the base case. This emphasizes the positive impact of the proposed optimization on exergy efficiency.

Simulation of carbon dioxide direct air capture plant using potassium hydroxide aqueous Solution: Energy optimization and CO2 purity enhancement

While various methods of direct air capture (DAC) technology have been implemented, its widespread effectiveness hinges on achieving optimal design and process improvements, largely owing to the high energy costs involved. Literatures reports a substantial heat demand for high-temperature aqueous solutions DAC (HT DAC), ranging from 1420 to 2250 kWh per ton of CO2, accompanied by electricity consumption rates varying from 366 to 2790 kWh per ton of CO2. The present study adopts the HT DAC method with an aqueous KOH absorbent as its focus, aiming to mitigate energy consumption. Given that a substantial portion of energy consumption in comparable processes can be attributed to the calciner and slaker units, our research centers its attention on the Air Separation Unit (ASU) and the steam cycle unit, investigating their impact on the system's production capacity, the enhancement of CO2 purity, and the augmentation of equipment thermal recovery. Process optimization, results a remarkable increase in heat recovery (21.1 %) and significant reductions in utilities consumption. The outcomes indicate that this facility has the capacity to annually capture around 1.1 million tons of CO2 with a purity of 99 mol% for utilization across various industries. The process design necessitates 5.24 gigajoules (GJ) of heat and 343 kW-hours (kWh) of electricity per ton of captured CO2. Notably, in addition to fulfilling the internal electricity requirements, the facility can export 8 MWh of electricity per ton of captured CO2 to the grid.

Separation of Ternary System 1,2-Ethanediol + 1,3-Propanediol + 1,4-Butanediol by Liquid-Only Transfer Dividing Wall Column

This study focuses on separating a mixture consisting of 1,2-ethanediol (1,2-ED), 1,3-propanediol (1,3-PD), and 1,4-butanediol (1,4-BD). Vapor–liquid equilibrium (VLE) data for 1,2-ED + 1,4-BD and 1,3-PD + 1,4-BD are determined at 101.3 kPa using a modified Rose equilibrium still. The consistency of the VLE data is checked with both Redlich–Kister and Fredenslund tests. The VLE data are fitted by the Wilson, NRTL, and UNIQUAC activity coefficient models. All three models can effectively correlate the VLE data. Then, the separation of the mixture is designed with the NRTL model and its correlated binary interaction parameters. A liquid-only transfer dividing wall column (LDWC) is investigated on the basis of a direct conventional distillation sequence (DCDS). For a fair comparison, both DCDS and LDWC are optimized to minimize total annual cost using sequential iterative optimization procedures. After optimization, LDWC exhibits a 16.87% reduction in total annual cost, while cooling and heating utility consumptions are reduced by 28.40% and 19.24% compared to DCDS.

Comparison of Utilities Consumption Between Different Modalities of In-Center Haemodialysis

Comparison of Utilities Consumption Between Different Modalities of In-Center Haemodialysis

Energy, exergy, and economic analyses and optimization of a deethanizer tower of a petrochemical plant

Abstract The distillation tower’s reboiler is one of the largest energy consumers in petrochemical facilities, and reducing its energy consumption is a crucial issue. This study proposes two optimal methods, namely Direct Vapor Recompression (DVR) and External Vapor Recompression (EVR), to reduce the consumption of cold and hot utilities in a petrochemical deethanizer tower. The Pars petrochemical in Iran is taken as a case study, and the proposed methods are compared with the base case using energy, exergy, and economic approaches, simulated through Aspen HYSYS software in the steady-state design conditions. Exergy analysis reveals that the EVR and DVR methods reduce the exergy destruction of the deethanizer tower by about 70.06 % and 67.29 %, respectively, compared to the base case. Moreover, the EVR method allows for complete recycling of low-pressure vapor, reducing the total exergy destruction rate from 0.871 to 0.261 GJ/tethane. The feed separation cost for the base case, DVR, and EVR are estimated to be around 28 $/kgfeed, 21.57 $/kgfeed, and 21.14 $/kgfeed, respectively. The EVR method results in reduced utility and ethane separation cost rates from 5.153 to 3.274 $/tethane and 17.64 to 15.78 $/year. Overall, the findings suggest that both DVR and EVR methods are effective in reducing the energy consumption and costs associated with deethanizer tower operations. Moreover, real-time optimization techniques can be developed to monitor and adjust the deethanizer tower’s operating parameters, such as feed flow rate, reboiler duty, and reflux ratio.