Utility Consumption Research Articles

Techno-economic analysis of heating techniques for transportation of heavy crude oils by land pipeline

Three approaches (heat exchangers with steam, heat exchangers with thermal oil, and direct fired heaters) were analyzed for heating pipeline to transport a heavy crude oil (viscosity of 62,745 cSt a 15.6 °C, and 11.78° API gravity). The selected pipeline has a length of 62.7 km and transports 33.12 m3/h (5000 BPD) of heavy crude oil. With the calculated temperature drop (4.39 °C/km) and pressure drop (0.25 kg/cm2/km), five heating and pumping points each 12.53 km were determined to maintain the required temperature and pressure for the transportation of heavy crude oil. For each heating system, mass and energy balance was done to calculate the size of equipment and utilities consumption. Capital expenditures (CAPEX) and operational expenditures (OPEX) were obtained to identify which heating system exhibits the lowest operating costs. The results indicate that the best heating system is with direct fired heaters from both technical and economic points of view (lower number of equipment, easy and flexible operation, commercial experience, and lower consumption of utilities). OPEX and CAPEX for heating system is with direct fired heaters were 0.32 USD/bbl and 0.78 USD/bbl, respectively. This indicates that the price of heavy crude oil should be 1.1 USD/bbl higher than that at the production point. By means of a sensitivity analysis, it was demonstrated that temperature drop is the determining variable that affects the number of heating points. Increasing temperature from 4.39 to 7 °C/km increased the number of heating point from 5 to 8. A 50% increase of OPEX (utilities) resulted the total costs to be 35% higher with respect to the base case for the evaluated heating systems.

Heat exchanger network optimisation considering different shell-side flow arrangements

Heat exchanger network synthesis (HENS) is an effective tool for heat recovery in chemical and petrochemical industries. This study aims to show a method for HENS with the consideration of different shell-side flow arrangements in shell-and-tube heat exchangers. The proposed MINLP model is modified from the stage-wise superstructure model, incorporating newly developed correlations for shell-side pressure drop calculation for the helical baffle. The objective is to minimise the total annual cost (TAC) with a trade-off between the cost of different shell-side heat exchangers, utility cost, and pumping cost. The selection of baffle design is decided by the saved pumping cost and the increased area cost. The proposed model is tested from different points of view: with/without utility constraints and different statuses of the streams. Three case studies are presented and compared with the results from the literature. The proposed method with different shell-side baffles can reduce the heat transfer area and pressure drop. For fixed utility consumptions, the TAC in a case study is decreased by 8.9% with mixed baffle types. Although the unit per area cost of the helical baffle is higher than the segmental baffle, the increased investment cost could be compensated by the reduced operation cost, especially for plants with high viscosity streams and long-term cost-saving.

Simulation studies of the existing cogeneration system and alternative conceptions to improve the energy efficiency for an ethylene petrochemical plant

Energy efficiency is relevant for the competitiveness and growth of global industries. In this way, simulation studies aiming to increase energy efficiency can be useful for both retrofitting and greenfield projects. Few ethylene process licensors hold the technologies; however, they present different proposals for projects with varying energy efficiency and integration degrees. In the present work, simulation studies of the cogeneration system of a petrochemical plant located in Brazil were performed in order to identify alternative configurations to increase the electricity production without affecting the heat supply to meet the process thermal demand. The cogeneration system of the analyzed plant includes an electric energy conversion system composed of turbo-generators, back-pressure and extraction/condensing steam turbines driving electricity generators, compressors and pumps, and heat exchangers. The simulation studies were performed using the HYSYS software to simulate design conditions and validate the model with the actual plant's experimental measurements. New cogeneration configurations were proposed in subsequent simulations, aiming at increasing electricity generation. In addition, exergetic efficiency and environmental analysis of the simulated configurations and an economic estimate for the most efficient proposal were performed. The results showed that the best alternative improved the electricity generation, increased the energy utilization factor by up to 16.2%, reduced greenhouse gas emissions by 22.8%, increased global exergetic efficiency by 28.9% and decreased the steam production and cold utility consumption of the cogeneration system compared to the design conditions.

Integrated Process for Producing Glycolic Acid from Carbon Dioxide Capture Coupling Green Hydrogen

A novel process path is proposed to produce glycolic acid (GA) from CO2 as the feedstock, including CO2 capture, power-to-hydrogen, CO2 hydrogenation to methanol, methanol oxidation to formaldehyde, and formaldehyde carbonylation units. The bottlenecks are discussed from the perspectives of carbon utilization, CO2 emissions, total site energy integration, and techno-economic analysis. The carbon utilization ratio of the process is 82.5%, and the CO2 capture unit has the largest percentage of discharge in carbon utilization. Among the indirect emissions of each unit, the CO2 hydrogenation to methanol has the largest proportion of indirect carbon emissions, followed by the formaldehyde carbonylation to glycolic acid and the CO2 capture. After total site energy integration, the utility consumption is 1102.89 MW for cold utility, 409.67 MW for heat utility, and 45.98 MW for power. The CO2 hydrogenation to methanol makes the largest contribution to utility consumption due to the multi-stage compression of raw hydrogen and the distillation of crude methanol. The unit production cost is 834.75 $/t-GA; CO2 hydrogenation to methanol accounts for the largest proportion, at 70.8% of the total production cost. The total production cost of the unit depends on the price of hydrogen due to the currently high renewable energy cost. This study focuses on the capture and conversion of CO2 emitted from coal-fired power plants, which provides a path to a feasible low-carbon and clean use of CO2 resources.

Synthesis of multiperiod heat exchanger networks: Minimum utility consumption in each period

Heat exchanger networks in real industrial processes often have to be designed for varying parameters of the process streams that renders multiperiod heat exchanger network synthesis essential in industrial realization. However, three standing issues must be considered in the synthesis procedure. (1) The generated network should be efficient in all periods, preferably consuming minimum utility. (2) This network should also be structurally as simple as possible for minimizing the investment cost and making the process controllable. Furthermore, (3) all or the n-best networks that fulfilled the first two principles must be considered for the selection of the most preferred industrial realization. The method proposed in the current work satisfies all three requirements simultaneously; it has been the only known method with these properties. The method primarily relies on the formerly developed P-graph-based heat exchanger network synthesis procedure. Three case studies demonstrate the application of the proposed method.

A voice controlled smart home automation system using artificial intelligent and internet of things

The objective of this work is to take a step further in this direction by incorporating voice control and artificial intelligence (AI) into internet of things (IoT)-based smart home systems to create more efficient automated smart home systems. Accordingly, a home automation system proposal is presented, in which the related functions can be controlled by voice commands using an android or web application via a chat form. The user issues a voice command, which is deciphered by natural language processing (NLP). To accommodate the user’s request, the NLP classifies it into operation commands. Arduino and Raspberry Pi are used to translate the commands extracted from NLP into reality. Based on this, home applications can be controlled. Also, the utilities consumption could be calculated, saved, and paid on time. This is in addition to the introduction of a machine learning (ML)-based recommendation system for automated home appliance control. In this approach, the mobile or web application is considered as the central controller, deciding the appropriate actions to fulfill the user’s desires. The presented work has been put into practice and tested. It proved to be applicable, as well as having the potential for making home life more comfortable, economic, and safe.

Design and Operation of Multipurpose Production Facilities Using Solar Energy Sources for Heat Integration Sustainable Strategies

Industrial production facilities have been facing the requirement to optimise resource efficiency, while considering sustainable goals. This paper addresses the introduction of renewable energies in production by exploring the combined design and scheduling of a multipurpose batch facility, with innovative consideration of direct/indirect heat integration using a solar energy source for thermal energy storage. A mixed-integer linear programming model is formulated to support decisions on scheduling and design selection of storage and processing units, heat exchange components, collector systems, and energy storage units. The results show the minimisation of utilities consumption, with an increase in the operational profit using combined heat integration strategies for the production schedule. A set of illustrative case-study examples highlight the advantages of the solar-based heat storage integration, assessing optimal decision support in the strategic and operational management of these facilities.

The effect of subjective well‐being on consumption behavior

AbstractThe article studies the causal effect of subjective well‐being on the consumption behavior of individuals aged 50 and above using data from the English Longitudinal Study of Aging (ELSA). To establish a causal link between subjective well‐being and six distinct types of consumption (food consumed at home, food consumed outside of home, spending on clothing, leisure consumption, monthly rent, and utility consumption), it exploits the longitudinal dimension of the dataset and instruments for subjective well‐being. The analysis reveals that subjective well‐being positively affects spending on food outside of home and leisure activities, while having no significant effect on the consumption of food consumed at home, clothing, monthly rent, and utilities. These results imply that people with higher levels of subjective well‐being are more engaged in social and leisure activities, such as going out for dinner, which offers important implications for both long‐term, as well as habitual buying behavior.

Integration of an Absorption Chiller to a Process Applying the Pinch Analysis Approach

In addition to the consumption of hot utilities, there is also a significant cost associated with the consumption of cold utilities when there is a high demand for cooling. A promising solution for cooling is an absorption chiller (AC), which uses heat instead of electricity for cooling. A thermodynamic approach for evaluating AC integrated with a process is presented in this work. A model for assessing the properties and duties of an AC cycle was developed. The integration of a combined process-AC system was evaluated using the Grand Composite Curve. Three different options of integration were analyzed: (i) above the Pinch, (ii) below the Pinch, and (iii) across the Pinch. AC represents the combined effect of a heat engine and a heat pump, as the generator together with the absorber and condenser has the function of a heat engine, while the evaporator combined with the absorber and condenser mimics the function of a heat pump. The comparison between the non-integrated and integrated process-AC systems has revealed that the proper placement of AC is across or below the Pinch and the improper is above the Pinch. If AC was entirely integrated below the Pinch, the integration would result in a complete (100%) reduction in the consumption of hot utility for the operation of AC. The most suitable placement of AC with double reduction of hot utility consumption and complete reduction of both hot and cold utility to operate AC is across the Pinch due to the pumping of heat through AC from below to above the Pinch.

Toward Economical and Sustainable Production of Renewable Plastic: Integrative System-Level Analyses.

2,5-Furandicarboxylic acid (FDCA) is one of the promising renewable plastic monomers enabling to address several environmental issues, instead of petroleum-based terephthalic acid (TPA). In this study, an integrative process for the co-production of FDCA and furfural as well as activated carbon was developed, and the economic feasibility and environmental sustainability for the proposed process were evaluated. In the proposed process, there were major four catalytic conversion reactions: (1) hydrolysis of biomass to its derivatives (cellulose, hemicellulose, and lignin), (2) dehydration of hemicellulose to furfural, (3) dehydration of cellulose to 5-hydroxymethylfurfural (HMF), and (4) successive oxidation of HMF to FDCA. Particularly, a heat exchanger network coupled with a heat pump was established to minimize the utility consumption, thereby reducing 72 % of the heating requirement. Techno-economic analysis revealed that the minimum selling price of FDCA was $1380 ton-1 , which is comparable to that of petroleum-based TPA ($1445 ton-1 ). Uncertainty analysis using the Monte Carlo simulation method was employed to quantify the risk associated with the unforeseen market condition. From the life-cycle assessment, we observed that the proposed process is more environmentally sustainable than conventional TPA production in terms of climate change and fossil depletion metrics.

Optimal operation of heat exchanger networks through energy flow redistribution

AbstractThis article presents a novel energy flow redistribution methodology to achieve optimal operation of heat exchanger networks. The proposed method aims to manipulate the propagation path of a disturbance through the network to reduce its impact on utility consumption. Specifically, an optimization problem is formulated to generate new duty targets for heat exchangers of the network when a disturbance is encountered. Subsequently, a feedback control system is designed to track these targets by manipulating bypasses around the process heat exchangers. The effectiveness of the proposed framework is illustrated with the help of three benchmark examples. The proposed approach can handle disturbances in inlet as well as target temperature, inlet flow and heat transfer coefficient of individual heat exchangers.

Optimal integration of organic Rankine cycles into process heat exchanger networks: A simultaneous approach

Organic Rankine cycles can produce power from various low-to-medium temperature heat sources efficiently, and may be integrated into industrial processes to recover low-grade waste heat for improved energy efficiency. This paper presents a mathematical programming model for the synthesis of organic Rankine cycle-integrated heat exchanger networks. The model is based on an organic Rankine cycle representation of four alternative configurations and a modified stage-wise superstructure, where heat exchange between process streams and organic Rankine cycle streams can take place in all the stages. In addition, the flowrate and operating temperatures of the working fluid are treated as variables, and its thermodynamic properties (e.g. enthalpies and pump/turbine outlet temperatures) are correlated as functions of the temperatures. This allows the organic Rankine cycle and the heat exchanger network to be optimised simultaneously, with the objective of maximising the net power output or minimising the overall energy cost. Two literature examples are used to illustrate the proposed approach. The results show that apart from producing power, the organic Rankine cycle can reduce the cold utility consumption by up to 26% when integrated with a process. Furthermore, the overall energy cost can be minimised by increasing the net power output optimally (by 54.6%), despite increased hot (+38.9%) and cold utility requirements (+19.5%). The proposed approach is thus useful in assessing the benefits from process integration of organic Rankine cycles.

The Effect of COVID-19 on Household Utilities Consumption

The Effect of COVID-19 on Household Utilities Consumption

The Effect of COVID-19 on Household Utilities Consumption

The Effect of COVID-19 on Household Utilities Consumption

Comparative Study between Slasher or Sheet Denim and Rope Denim

Denim is one of the most important RMG products made from the colored warp and white weft. The warp is colored before sizing in the preparatory processes. There are mainly two important routes of preparatory processes for producing the weaver’s beam e.g. (i) slasher or sheet denim and (ii) Rope denim. After the production of the weaver’s beam, the weaving is the same as usual. It is widely believed that the two routes of making the weavers beam attributes many differences in the ultimate fabric. The work reported in the paper is an analytical comparison between the impact of the two routes on weaving and fabric characteristics. The study was conducted in a reputed denim manufacturing industry located in Dhaka Bangladesh having both slasher and rope denim facilities. It was revealed that in the case of rope the elongation or stretching of warp yarn is more in rope dyeing than that occurs in a slasher. Regarding the method of spinning, it was observed that the elongation of the ring-spun yarns was more than that of open-end spun yarns. It was also observed that the higher the set length the higher was elongation or stretching of the warp yarns. The single warp yarn tension recorded on the loom was found to vary too much for the slasher beam than that obtained from the rope beam. The warp breakage in the loom is more in the slasher beam than that in the rope beam. Due to more breakage in the loom, the fabric quality of slasher beams is slightly inferior to that of rope. The production capacity of rope is almost double or more than that of slashers. The dyeing and washing characteristics of rope denim fabrics are better than that of slasher, which was due to the greater capacity of the dye boxes and dyeing in rope form. In the cases of all other fabric characteristics too, the rope denim is somewhat better than slasher denim. The consumption of water and utilities (steam supply, air compressor, etc.) are much higher for rope arrangement than the sheet. It seems that the differences are not much significant except dyeing characteristics.

Conceptual design and techno-economic analysis of a coproduction system for ethylene glycol and LNG from steel mill off-gases

Coke oven gas and Linz Donawitz gas are pollutive off-gases of steel mill plants. Their potential chemical value can be used to produce high value-added chemicals and fuels by means of coproduction. Thus, a novel coproduction system for ethylene glycol and liquid natural gas from steel mill off-gases (CG-ELNG) is proposed and optimized through a rigorous process modeling and simulation. The thermodynamic and technoeconomic performance of the proposed process are analyzed and compared with the conventional standalone ethylene glycol and liquid natural gas production processes. Results show that the optimal feed ratio of coke oven gas and Linz Donawitz gas is 2.42 to have the most suitable hydrogen to carbon ratio and the highest resource utilization efficiency of the proposed processes. The exergy efficiency of the process is high to 60.45%, which is 10.05% higher than that of the standalone off-gases based ethylene glycol production process. The total production cost is reduced by 17.46%, and internal rate of return is improved by 7.47% in comparison with the standalone processes. In addition, the sensitivity analysis results reveal that the fluctuations of raw material, utilities consumption, and production capacity have much lower impact on the proposed process than the standalone processes. Therefore, the findings of this study provide a newly promising direction for highly efficiently utilization of steel off-gases.

Energy efficient design through structural variations of complex heat-integrated azeotropic distillation of acetone-chloroform-water system

This study presents enhanced energy savings through structural variations of a heat-integrated distillation column for the separation of ternary azeotropic mixture. The conventional sequence has a decanter followed by pressure-swing distillation (PSD) columns for separating acetone-chloroform-water azeotropic mixture. Based on a significant temperature gradient of the PSD, a double annular column was proposed in order that the heat from hot fluid to cold fluid passed through the shared column wall. The heat transferred to the stages near the reboiler could replace the use of external utility, thereby reducing the total energy consumption of the process. For accurate calculations of heat transfer rate, the trays with the double annular structure were simulated by computational fluid dynamics. However, the energy saving was not effective since the structure could not afford to utilize all the heat transferred and additional energy was required to recover. The newly proposed (partial double annular) structure transferred heat from a high-pressure column to two low-pressure columns. It demonstrated 7,807.78 kW of the theoretical energy saving which was almost double of the heat transfer amount. Consequently, the total utility consumption and total annual cost was reduced by 21.79% and 11.32%, respectively, compared to the conventional sequence.

COVID-19 Lockdown and the Impact on Mobility, Air Quality, and Utility Consumption: A Case Study from Sharjah, United Arab Emirates

This study presents an analysis of the impact of COVID-19 lockdown on people’s mobility trends, air quality, and utility consumption in Sharjah, United Arab Emirates (UAE). Records of lockdown and subsequent easing measures, infection and vaccination rates, community mobility reports, remotely sensed and ground-based air quality data, and utility (electricity, water, and gas) consumption data were collected and analyzed in the study. The mobility trends reflected the stringency of the lockdown measures, increasing in the residential sector but decreasing in all other sectors. The data showed significant improvement in air quality corresponding to the lockdown measures in 2020 followed by gradual deterioration as the lockdown measures were eased. Electricity and water consumption increased in the residential sector during the lockdown; however, overall utility consumption did not show significant changes. The changes in mobility were correlated with the relevant air quality parameters, such as NO2, which in turn was highly correlated to O3. The study provides data and analysis to support future planning and response efforts in Sharjah. Furthermore, the methodology used in the study can be applied to assess the impacts of COVID-19 or similar events on people’s mobility, air quality and utility consumption at other geographical locations.

Techno-Economic Analysis for the Production of 2,3-Butanediol from Brewers’ Spent Grain Using Pinch Technology

2,3-Butanediol (BDO) is a versatile platform chemical with great potential as the precursor for various value-added derivatives across different industrial sectors. This work thus presents a techno-economic feasibility study for microbial BDO production from C5 and C6 sugars derived from brewers’ spent grain (BSG). Water-soluble carbohydrates obtained from pretreatment were further utilized for the biogas generation. Besides, the solid residue generated after fermentation and biogas were used to generate high-pressure steam and electricity. The process integration was carried out using pinch technology for various BDO titers and plant capacities. The pinch analysis helped in the reduction of hot and cold utility consumption by about 34 and 18%, respectively. The minimum hot and cold utility consumption was 4.59 and 10.97 MW for 100 MT BSG per day with 100 g/L BDO titer, respectively. The cooling water consumption was decreased, and electricity generation was increased with the increase in BDO titer, while the BDO production cost reduced marginally. For 100 MT BSG per day, the BDO production cost was US$1.84, US$1.76, and US$1.74/kg for BDO titers of 80, 100, and 120 g/L, respectively. However, the unitary BDO production cost was only US$1.07 for 2000 MT BSG per day. For 100 g/L BDO titer, the minimum BDO selling price was US$3.63 and US$2.00/kg for 100 and 2000 MT BSG per day, respectively, with 8.5% return on investment and 5 years as the payback period.

Integrative technical, economic, and environmental sustainability analysis for the development process of biomass-derived 2,5-furandicarboxylic acid

The utilization of biomass, a bountiful and renewable natural resource, has become increasingly important with respect to climate change and environmental regulation. The conversion of lignocellulosic biomass to 2,5-furandicarboxylic acid (FDCA) is a particularly promising technology that is essential for polyethylene furanoate production, which can replace existing petroleum-derived terephthalic acid. This study presents a new process design for economic FDCA production from lignocellulosic biomass. The economics of the process are maximized by introducing an effective biomass fractionation method based on catalytic conversion and separation subsystems. Pinch analysis coupled with a heat pump was performed to minimize the utility consumption in the process, thereby reducing the heating requirement by 66.3%. Furthermore, the integrative economic feasibility and environmental sustainability of the process were systematically assessed via techno-economic analysis (TEA) and life-cycle assessment (LCA). The TEA determined a minimum FDCA selling price of $1,520/ton that can increase to $5,203/ton given cost growth and performance at the pioneer plant. Moreover, sensitivity analysis identified the principal cost drivers of the process. LCA showed the environmental impact of each subsystem of the process and revealed that exchanging fossil-based electricity sources for renewable sources and technology can lead to a more environmentally friendly process. Integrative process design can provide comprehensive perspectives for decision-makers.