Total Annual Cost Research Articles

Optimization of the process for separating ethylene glycol and 1,2-butanediol using reactive distillation-assisted separation based on a parallel stochastic algorithm framework

The process of separating ethylene glycol and 1,2-butanediol with reactive distillation is intricate, with many variables involved, leading to a time-consuming and inefficient optimization process. To expedite the optimization process, this study proposes a new parallel stochastic algorithm framework. This research shows that the framework is 36.8 times faster than the serial framework. The reactive distillation-assisted separation process of ethylene glycol and 1,2-butanediol is optimized using the parallel stochastic algorithm framework. The optimization process duration is 810 min. Based on the optimal design, the process is further intensified by incorporating the dividing wall column and intermediate reboiler. Compared to the base process, the intensified process exhibited reductions of 8.89 %, 10.18 %, and 9.83 % in total capital cost, total operating cost, and total annual cost, respectively.

Prescribing patterns and medications costs in patients on maintenance hemodialysis and peritoneal dialysis.

Polypharmacy is a significant clinical issue for patients on dialysis but has been incompletely studied. We investigated the prevalence and costs of polypharmacy in a population-based cohort of participants treated with hemodialysis (HD) or peritoneal dialysis (PD). We studied adults aged≥20 years in Alberta, Canada receiving maintenance HD or PD as of March 31, 2019. We characterized participants as users of 0-29 drug categories of interest and those aged≥65 as users/non-users of potentially inappropriate medications (PIM). We calculated the number of drug categories, daily pill burden, total annual cost, and annual cost per participant, and compared this to an age- and sex-matched cohort from the general Alberta population. Among 2248 participants (mean age 63 years; 39% female) on HD (n=1781) or PD (n=467), the median number of prescribed drug categories was 6 [interquartile range (IQR) 4, 8]; median daily pill burden was 8.0 (IQR 4.6, 12.6) pills/day, with 5% prescribed≥21.7 pills/day, and 16.5% prescribed≥15 pills/day. Twelve % were prescribed at least one drug that is contraindicated in kidney failure. The median annual per participant cost was ${\$}$3,831, totaling approximately ${\$}$11.6 million annually for all participants. When restricting to the 1063 participants aged≥65, the median number of PIM categories was 2 (IQR 1, 2), with a median PIM pill burden of 1.2 pills/day (IQR 0.5, 2.4). Compared to PD participants, HD participants had similar daily pill burden, higher use of PIM, and higher annual per participant cost. Pill burden and associated costs for participants on dialysis were more than 3-fold and 10-fold higher, respectively, compared to the matched participants from the general population. Participants on dialysis have markedly higher use of prescription medications and associated costs than the general population. Effective methods to de-prescribe in the dialysis population are needed.

Optimal design of a combined Power-Heating-Oxygen system for plateau hotel buildings

The Qinghai–Tibet Plateau of China is a region of low atmospheric pressure and oxygen deficiency, with a high heating demand in the winter; therefore, plateau hotel buildings have a demand for comprehensive power-heating-oxygen loads. Solar energy resources are particularly abundant in plateau areas, where a combined multi-energy system based on solar energy can be designed to meet the demand of plateau hotel buildings for multiple loads. However, currently, there is a relative lack of methods for the optimal design and performance evaluation of combined power-heating-oxygen (CPHO) systems. Thus, this study proposes a CPHO system model for plateau hotels, and provides two operation strategies, i.e., power priority and oxygen priority. Taking the minimum total annual cost of the combined system as the optimization objective, an optimized CPHO system model for plateau hotels has been proposed, followed by a case study of a hotel in Qilian County, Qinghai Province. Results showed that: 1) Compared with the conventional combined power-heating (CCPH) system, the CPHO system saw reductions of 0.8% and 1.3% in its total annual cost under the operation strategies of power priority and oxygen priority, respectively. 2) The energy self-consumption (SC) rates of the CCPH system and CPHO system under the operation strategies of power priority and oxygen priority were 84.8%, 64.2%, and 89.8%, respectively; with power self-sufficiency (PSS) rates of 8.3%, 49.9%, and 29.5%, and oxygen self-sufficiency (OSS) rates of 0.0%, 3.2%, and 4.7%, respectively. 3) The total annual cost of the CPHO system was affected slightly by the cost of photovoltaics (PVs) and energy storage devices, and significantly by the price of oxygen. When the price of oxygen was 8 yuan per normal cubic meter(Nm3) or above, the CPHO system was economically efficient under the operation strategy of oxygen priority. When the price of oxygen was 10yuan/Nm3 or above, the system was economically efficient under both operation strategies.

Synthesis of heat-integrated water networks considering detailed heat exchanger design

This paper introduces a mathematical programming approach for synthesising heat-integrated water networks (HIWNs) with a detailed heat exchanger design. A common assumption of constant heat capacities of water streams is relaxed. The specific heat capacity of water is now considered as a nonlinear function of temperature to avoid errors in calculating energy balances. In addition, most previous works have assumed constant individual heat transfer coefficients for water streams and utilities when estimating heat transfer areas. This assumption can lead to significant over- or under-estimation of heat transfer areas. In this research, individual and overall heat transfer coefficients for heat exchangers are calculated based on the detailed design of plate heat exchangers for heat recovery. 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 and utilities, pumping costs for overcoming pressure drops in heat exchangers, and investment costs for heat exchangers. Three examples are solved in this work to verify the proposed model.

Power system investment optimization to identify carbon neutrality scenarios for Italy

In 2021 the European Commission has proposed the Fit-for-55 policy package, requiring European countries to reduce their CO2 emissions by 55% with respect to 1990 by the year 2030, a first step to achieve carbon neutrality by 2050. Energy system modeling can be a valuable tool for national policymakers to choose the most appropriate technologies to achieve these goals efficiently. This article presents a model of the Italian power system realized employing the open energy modeling framework, Oemof. A linear programming optimization is implemented to evaluate how to minimize system costs at decreasing CO2 emissions in 2030. The developed tool is applied to evaluate different research questions: (i) pathway towards full decarbonization and power self-sufficiency of the electricity sector in Italy, (ii) relevance of flexibility assets in power grids: li-ion batteries, hydrogen storage and transmission lines reinforcement. A 55% CO2 emissions reduction for the actual Italian power sector can be achieved through an increase of 30% of the total annual system cost. Achieving complete decarbonization and self-sufficiency increases significatively annual expenditures. However, cost mitigation is plausible through the integration of sector coupling methodologies or the adoption of a broader spectrum of technological solutions. Flexibility measures appear instrumental for decarbonization, particularly transmission lines, demanding a substantial expansion beyond the stated plans for 2030. This infrastructure is crucial in Italy to facilitate the transfer of renewable electricity generated in the Southern regions to the Northern areas, where a large portion of the electricity demand is located.

P-725 Automated follicular tracking with three-dimensional ultrasound and SonoAVC saves costs: debunking myths

Abstract Study question What is the incremental cost per patient and the budgetary impact of the SonoAVCTMfollicle technique compared to two-dimensional ultrasound in a private assisted reproduction center? Summary answer Our results support the implementation of follicular tracking with 3D ultrasound and SonoAVCTM from an economic point of view. What is known already Advantages of follicular tracking with 3D US and SonoAVC include increased precision and reproducibility, increased patient comfort, decreased ultrasonographer’s time and improved workflow. The main benefit of SonoAVC is that it allows quick measurements of follicular volume, which has been shown to be more precise than 2D diameters for estimation of follicular size. Until now, it has been assumed that 3D ultrasound represents an increase in costs, this being the main justification of professionals who refuse to implement it. Study design, size, duration Cost study and economic analysis. The costs associated with the adoption of the SonoAVC™follicle software and the 2D ultrasound were estimated as well as the cost of medical dedication time. Since the cost of the equipment represents an initial investment, we proceeded to annualize it. For the economic analysis we calculated a) cost for each patient included in the study and b) total annual cost for a private center to incorporate the SonoAVC™follicle program. Participants/materials, setting, methods Population: patients treated in our center in 2019 (N = 295). Budget impact analysis was performed from the perspective of a private assisted reproduction center with a 5-year time horizon. The analysis was adapted to three scenarios according to the size of the center: a private center with: a) 600 cycles/year including IVF/ICSI and oocyte donation b) 300 cycles/year and c) 100 cycles/year. Main results and the role of chance Equivalent annual cost of the ultrasound device and transvaginal probe after annualization was 3985.93 € for 2D and 4572.10 € for 3D. The corresponding cost per patient/cycle was 13,51€ for 2D and 15,50 € 3D. Medical dedication time cost was 5,6 € for 2D follicular monitoring and 3,3 € for 3D follicular monitoring. Total cost per patient/cycle for follicular monitoring, including hardware and medical dedication was 69,5€ for 2D and 48,5€ for 3D ultrasound. For the budget impact analysis, three different sizes of centers were considered: 600, 300 and 100 cycles/year. In all of them there was a saving with 3D ultrasound of 2101 €, 6303 € and 12606 € respectively. The net budgetary impact over 5 years, i.e., the difference between the current scenario (2D ultrasound) and the new scenario (3D ultrasound with SonoAVC™follicle) for a center with approximately 300 cycles/year, would be 31.515€. Therefore, the implementation of the new technique with SonoAVC™follicle would save costs. Limitations, reasons for caution In centers 600 cycles/year an extra ultrasound device may be included in the analysis. Wider implications of the findings Follicular monitoring with 3D ultrasound is cheaper than 2D ultrasound even in small centers and this saving is greater the larger the center is. Therefore, our results demonstrate that cost savings are another added advantage of follicular monitoring with 3D ultrasound and sonoAVC. Trial registration number not applicable

Comparison and optimization of CO2 purification units for CCS applications

Several promising CO2 capture technologies, like oxy-combustion, adsorption and membranes, feature a purity of the captured CO2 stream which is insufficient for the storage site or the transport system. In these cases, a CO2 Purification Unit (CPU) is required to lower the concentrations of O2, N2 and Ar at the limits allowed by the storage site/transport system. In this work, the available CO2 Purification processes have been reviewed and the six main schemes have been simulated in Aspen Plus and optimized. Their performance have been ranked based on six selected key performance indicators: total annual cost, Specific cost per ton of captured CO2, specific energy consumption, recovery, purity, and O2 concentration in the purified CO2. The techno-economic optimization is repeated for different carbon tax values and for three different feed streams compositions. The results of the optimization show that flash-based CPUs cannot meet the requirements for CO2 storage due to a high concentration of O2 (>1000 ppm) but they feature a low specific cost (5.8–25.9 €/tonCO2 depending on the feedgas and plant size), low specific energy consumption (124.9–436.1 kJ/tonCO2) and acceptable recovery (94.60–99.46 %). The distillation-based CPU can meet the requirements for CO2 storage, but these CPUs have the highest cost (52–112 % higher than flash-based CPU) and the lowest recovery. The optimal CPUs are the ones which combine both distillation column and flash separation. These CPUs meet the oxygen requirements for CO2 storage (<10 ppm) while providing the highest purity (99.997–99.999 %), high recovery (90.61–99.32 %) at a limited cost (6.1–36.0 euro/tonCO2).

Epidemiology, Treatment Patterns, and Cost Analysis of Immune Thrombocytopenia in Spain between 2014 and 2020: A Population-based Study.

Background Immune thrombocytopenia (ITP) is characterised by low platelet counts and often leads to bleeding, fatigue, and reduced health-related quality of life. Methods This observational, retrospective, population-based study using BIG-PAC® database included Spanish paediatric and adult patients with primary ITP diagnosed in primary care and hospitals between 2014 and 2020 (median follow-up: 4 years). Epidemiology, baseline/clinical characteristics, treatment trends, healthcare resources and costs were analysed. Results The BIG-PAC® database contains records of 1,818,588 patients; 170 adults and 27 children with ITP were included in our analysis. ITP prevalence and annual incidence per 100,000 were estimated in 10.8 (2.8 in chronic ITP [cITP] patients) and 1.5 (0.3 in cITP patients), respectively. Epistaxis was the most common bleeding event, followed by genitourinary and gastrointestinal bleeding; >50%/> 75% of ITP/cITP patients reported fatigue. Chronic patients had lower platelet counts at baseline and required more transfusions. Corticosteroids, immunosuppressants, and thrombopoietin receptor agonists were the most used agents in first-, second- and third-line treatment, respectively. Thirty-five patients, all of them in chronic phase, underwent splenectomy. Patients had on average 13.9, 6.6, and 1.2 visits/year to primary care, haematology/internal medicine, and emergency departments, respectively. More than one-fourth of adult patients took on average 16.3 days of sick leave annually. Mean annual total health care costs were €10,741 (ITP patients) and €19,809 (cITP patients). Conclusion This is the first study to provide an overall perspective on the situation of the Spanish ITP population in terms of epidemiology, treatment trends, health care resources and costs, highlighting unmet patient needs, and direct and indirect costs/resource use between 2014 and 2020.

Registry cost description of carpal tunnel release in Finland in 2011–2015

ObjectivesIn this study, we evaluated the amount of public funds spent on the operative treatment of carpal tunnel syndrome (CTS) in Finland in 2011–2015.DesignA registry-based cost burden study.SettingThe data were...

Process comparison and performance evaluation of different entrainers for pressure swing extractive distillation refining gasoline additives based on multi-objective optimization and process intensification

As a new gasoline additive, methyl tertiary amyl ether (TAME) can improve the antiknock performance and quality of gasoline. This study uses an energy-saving process for separating TAME/methanol (MeOH)/H2O by pressure-swing extractive distillation with different entrainers based on multi-objective optimization and 4E analysis. The 1entrainers are screened by the difference in relative volatility of components under different entrainer conditions, and the electrostatic potential of the molecular surface of the system and entrainers are analyzed. Multi-objective optimization of the pressure swing extractive distillation process with 5 different entrainers is carried out based on the generation non-dominated sorting genetic algorithm (NSGA-Ⅱ) optimization scheme, and the Pareto frontier is optimized by the minimum distance method. The results indicate that the extraction schemes of 1,3-propanediol (PDO) and dimethyl sulfoxide (DMSO) have excellent economic and environmental benefits through comprehensive analysis. As an effective means of process intensification, the application of heat pump technology can further reduce process costs and environmental pollution. The coefficient of heating performance (COP) is used to find the most suitable pairing route for heat pump-assisted processes, achieving the goal of reducing gas emissions and energy use. Then, different processes are evaluated in terms of economy, energy consumption, environment, and exergy loss. The results show that the process intensification scheme based on heat pump technology can effectively improve the economic and environmental benefits of the process, reducing the annual total cost (TAC) and gas emissions by 9.19% and 23.55%, respectively. This study provides the selection and reference for azeotrope separation of TAME and recycling of wastewater.

Healthcare costs related to respiratory syncytial virus in paediatric intensive care units in the Netherlands: a nationwide prospective observational study (the BRICK study)

The implementation of the approved respiratory syncytial virus (RSV) preventive interventions in immunisation programmes is advancing rapidly. Insight into healthcare costs of RSV-related paediatric intensive care unit (PICU) admissions is lacking, but of great importance to evaluate the impact of implementation. Therefore, this study aimed to determine the total annual RSV-related paediatric intensive care healthcare costs in the Netherlands. A nationwide prospective, observational, multicenter study was performed from September 2021 until June 2023. The total annual RSV-related healthcare costs on PICUs in the Netherlands were calculated using RSV-related costs (subgroup I) and consequential costs (subgroup II and III). Subgroup I comprised all PICU admitted infants ≤12 months of age with laboratory-confirmed RSV infection. Subgroup II and III consisted of postponed elective PICU admissions and refused acute PICU admissions due to RSV-related lack of PICU capacity. A total of 424 infants with RSV-related PICU admission were included. Median age at PICU admission was 46 days (IQR 25-89). The median length of PICU admission was 5 days (IQR 3-8). The total RSV-related PICU costs are € 3,826,386 in 2021-2022, and € 3,183,888 in 2022-2023. Potential costs averted by RSV preventive interventions is € 1.9 to € 2.6 million depending on season, and the duration of protection. RSV-related PICU admissions cost €3.1 to €3.8 million in the Netherlands during one season. The introduction of new RSV preventive interventions into the Dutch immunisation programme will generate significant cost-savings on PICUs and decreases the admission burden of PICUs. None.

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.

An alternative to methanol recovery from ternary mixture: Replacing extractive with reactive distillation for maximizing economical potential and resource recovery

This paper investigates the recovery of methanol from the propylene oxide (PO)/methanol/water mixture using reactive distillation (RD). The mixture presents a challenge due to the azeotrope formation between PO and methanol. To overcome this challenge, three RD scenarios, designated as Case 1, Case 2, and Case 3, are proposed. The primary principle underlying these cases is leveraging a reaction between PO and water, resulting in the production of propylene glycol (PG). This reaction consumes PO and thus eliminates the PO-methanol azeotrope, and reduces reboiler duty via the release of reaction heat. Case 1 utilizes one reactive distillation column (RDC) and one conventional distillation column (CDC) to recover methanol while reducing a quarter of the water content via the PO-water reaction. High purity methanol is obtained in the RDC distillate, while high purity PG is collected at the bottom of the CDC. Likewise, Case 2 follows the same approach as Case 1, with an additional PO stream to halve the water content. On the other hand, Case 3 employs a single RDC with a greater additional PO stream to react with all water content in the mixture, yielding high purity methanol at the distillate and PG at the bottom. These cases are simulated using Aspen Plus software, and their designs are optimized to minimize the total annual cost (TAC). The results are compared to a base case, represented by the side-stream extractive distillation (SSED) method. Cases 1, 2, and 3 demonstrate TAC reductions of 7.8 %, 27.7 %, and 60 %, respectively, compared to the base case. Additionally, the PG produced by the PO-water reaction presents opportunities for generating extra profit of 6.356 × 107 $ a−1, 7.248 × 107 $ a−1, and 8.98 × 107 $ a−1 in Cases 1, 2, and 3, respectively. Given the financial benefits observed in each case, these configurations may serve as attractive alternative methods for methanol recovery from the PO/methanol/water mixture.

A penalty-free hybrid algorithm framework based on feasible stream matching principle for large-scale heat exchanger networks synthesis

In this work, a penalty-free hybrid stochastic-deterministic algorithm framework is proposed for large-scale heat exchanger networks (HENs) synthesis (HENS), formulated as a computationally-hard mixed-integer nonlinear programming (MINLP) problem. In the outer level, an improved genetic algorithm (GA) is developed to optimize process stream matches represented by integer variables whose values are generated by a unique heat exchanger vector. Unlike previous researches, the improved GA does not rely on any penalty terms, because we propose a feasible stream matching principle to exclude all infeasible process stream matches and only feasible matches are considered in optimization process. In the inner level, a reduced-size MINLP model is solved using deterministic methods to minimize total annualized costs (TACs), which are then used to evaluate the fitness of candidate HENs. Through this way, the proposed framework combines deterministic and stochastic methods to enhance optimization efficiency and global search capability. Illustrative tests on six benchmark cases demonstrate that the framework can efficiently achieve lower-cost solutions compared to deterministic, stochastic, or hybrid methods. The results show a decrease in TAC for all six cases and a reduction in solution time ranging from 11.1% to 97.2%. Importantly, the proposed framework can be extended to solve MINLP problems in other process networks.

A fix and optimize method based approximate dynamic programming approach for the strategic fleet sizing and delivery planning problem

AbstractLogistics related costs constitute a major part in total cost of a product in general. Considering a company that delivers goods to its customers using its owned fleet, fleet ownership and operational costs together with the inventory costs compose the total logistics costs. In this study, we suggest an approximate Dynamic Programming algorithm, with a look ahead strategy, that uses the fix and optimize method as the imbedded heuristic for solving integrated fleet composition and replenishment planning problem. The total annual distribution cost factors considered in the problem are vehicle ownership costs, approximate routing costs, and inventory related costs. In this problem, we aim to minimize the total logistic cost by optimizing the fleet composition, replenishment patterns, and customers assigned to each vehicle in the fleet. We produced a set of reasonably large instances randomly and showed the efficacy of the suggested solution method.

Impact of temporal resolution on the design and reliability of residential energy systems

Future energy systems incorporating high shares of intermittent renewable energy sources are often designed using optimization-based, bottom-up energy system models. However, such models are generally limited to single years and hourly resolutions. This study quantifies the precision loss between hourly and sub-hourly-resolved data for the design and operation of a self-sufficient residential multi-energy system with respect to total costs, system design, and reliability using both averaging and sampling data methods. In this case study, the total annual cost is underestimated by 1.7% with the average hourly data relative to the fully-resolved minute resolution data, mainly due to the sizing of the photovoltaic inverter and battery. This is a result of the sub-hourly peaks in the supply and demand data that are evened out, significantly impacting the sub-electrical system. The results show up to 89 kWh of the annual lost load of the total electrical and thermal load, and a penalty cost of up to €894 (+24%) based on the value of the lost load. Another method, which employs regular sampling of the original time series, shows unpredictable behavior with respect to the tendency of either over- or underestimating system costs and components’ capacities depending on the selected samples. Both the sampling and averaging methods highlight that while hourly resolution may suffice for total system cost approximations, it falls short of sizing dynamically-operated components and meeting stringent reliability requirements. Future research may aim to enhance the temporal resolution of global intermittent renewable energy sources and reduce the computational expenses associated with minute-level resolutions.

Multi-Objective Optimization of an Energy Community Powered by a Distributed Polygeneration System

This paper presents a multi-objective optimization model for the integration of polygeneration systems into energy communities (ECs), by analyzing a case study. The concept of ECs is increasingly seen as beneficial for reducing global energy consumption and greenhouse gas emissions. Polygeneration systems have the potential to play a crucial role in this context, since they are known for producing multiple energy services from a single energy resource, besides the possibility of being fed also by renewable energy sources. However, optimizing the configuration and operation of these systems within ECs presents complex challenges due to the variety of technologies involved, their interactions, and the dynamic behavior of buildings. Therefore, the aim of this work is developing a mathematical model using a mixed integer linear programming (MILP) algorithm to optimally design and operate polygeneration systems integrated into ECs. The model is applied to a case study of an EC comprising nine buildings in a small city in the northeast of Italy. The work rests on the single- and multi-objective optimization of the polygeneration systems taking into account the sharing of electricity among the buildings (both self-produced and/or the purchased from the grid), as well as the sharing of heating and cooling between the buildings through a district heating and cooling network (DHCN). The main results from the EC case study show the possibility of reducing the total annual CO2 emissions by around 24.3% (about 1.72 kt CO2/year) while increasing the total annual costs by 1.9% (about 0.09 M€/year) or reducing the total annual costs by 31.9% (about 1.47 M€/year) while increasing the total annual CO2 emissions by 2.2% (about 0.16 kt CO2/year). The work developed within this research can be adapted to different case studies, such as in the residential–commercial buildings and industrial sectors. Therefore, the model resulting from this work constitutes an effective tool to optimally design and operate polygeneration systems integrated into ECs.

Reactive distillation configuration for the production of ethyl acrylate

Esters of acrylic acid have many industrial applications, but existing industrial processes are not economical. Ethyl acrylate, a precursor to polymers and other chemicals is one of them. The existing method of production of ethyl acrylate by esterification of acrylic acid with ethanol using a homogeneous catalyst and reactor-distillation combination has limitation in terms of product purity, corrosion and existence of possible side reactions. The present work proposes a novel reactive distillation (RD) column configuration for ethyl acrylate production, with 99.99 % acrylic acid conversion and 99.99 % ethyl acrylate purity with no effluent stream. The proposed configuration is analyzed using Aspen Plus steady-state simulation software. Sequential iterative sensitivity analysis is performed to obtain all structural and operating parameters leading to a minimum Total Annual Cost (TAC). The result shows that, there is 10.8 % improvement in the purity of aqueous stream using RD configuration compared to existing method and the overall TAC of the process at desired conditions is 87.77 × 103 $/year.

Novel side-reactor dividing wall column and reactive distillation process for enhanced electronic-grade propylene glycol monomethyl ether acetate production

The semiconductor industry is experiencing rapid growth and has become one of the largest sectors in the world. Propylene glycol monomethyl ether acetate (PGMEA) is prized for its exceptional properties and its ability to meet the stringent requirements as a solvent for electronic processing. This work aims to enhance the production of electronic-grade PGMEA through a practical and advanced intensified configuration. First, the kinetic reactor for propylene glycol monomethyl ether (PGME) synthesis has been modeled and pinpointed optimal operating conditions through sensitivity analysis. Subsequently, several process alternatives incorporating intensified techniques, such as the dividing wall column (DWC), pressure swing distillation (PSD), reactive DWC (RDWC), and side-reactor DWC (SR-DWC), have been investigated. These processes have been systematically designed and optimized through a sequential design procedure. Response surface methodology, a practical optimization method, has been employed to optimize the complex column's structure with the help of Aspen Plus and Minitab. Energy requirements and costs of all process alternatives were evaluated for a fair comparison. The SR-DWC-RD process has emerged as the most promising option, as it can save up to 11.5 % in energy requirements and 19.9 % in total annual costs. This practical design, complete with detailed optimal design parameters, presents significant opportunities for improving industrial PGMEA production.

Cost Analysis of Oral Phenazopyridine vs Intravesical Lidocaine for Preprocedural Analgesia for Intradetrusor OnabotulinumtoxinA Injections.

Office administration of intradetrusor onabotulinumtoxinA is commonly used to treat overactive bladder. For preprocedure analgesia, either 50 mL 2% intravesical lidocaine instillation for 20 to 30 minutes or 200 mg oral phenazopyridine can be used. Phenazopyridine is associated with shorter appointment times and is noninferior to lidocaine for pain control in this setting. We performed a cost analysis of phenazopyridine vs lidocaine for analgesia before office intradetrusor onabotulinumtoxinA injection for the treatment of idiopathic overactive bladder. A health care sector-perspective cost analysis was performed. The following assumptions were made: (1) similar efficacy of each medication in providing adequate analgesia, (2) similar physician ease of performing the procedure with either analgesic, and (3) similar patient satisfaction with either analgesic. Average cost of medications, adverse reactions, nursing tasks, and office visit time were found in publicly available data. Sensitivity analyses were performed using TreeAge Pro 2021, R1 software. Phenazopyridine is less costly compared to lidocaine per visit for office intradetrusor onabotulinumtoxinA injection ($827 vs $925). A difference of $98 per procedure provides a total annual cost savings of over $24 million if all procedures are performed with phenazopyridine instead of lidocaine. Sensitivity analysis showed that phenazopyridine remained less costly under most circumstances, and threshold analysis provided exact circumstances under which phenazopyridine is no longer cost saving. Phenazopyridine provides cost savings compared to lidocaine for analgesia before office intradetrusor onabotulinumtoxinA injection for the treatment of idiopathic overactive bladder. If adopted by providers nationwide, phenazopyridine may reduce health care spending and minimize office visit time while maintaining patient pain control and satisfaction.