Exergoeconomic Analysis in a Cement Production Plant

2020 ◽  
Author(s):  
J. Fajardo ◽  
A. Mendoza ◽  
D. Barreto ◽  
H. Valle
Keyword(s):  
Rotary Kiln ◽  
Relative Difference ◽  
Accurate Information ◽  
Production Plant ◽  
Production Plan ◽  
Exergy Destruction ◽  
Cement Production ◽  
Total Cost ◽  
Significant Difference ◽  
Exergoeconomic Analysis

Abstract A dry-type Cement Production Plan of 151 Tons per hour was taken as a case of study to implement an exergoeconomic analysis. In this paper, the exergy destruction and the investment costs of the system’s units were calculated to obtain accurate information about the performance of the process, from the exergoeconomic factor and the relative difference cost. Conventional exergoeconomic analysis showed that the total cost of exergy destruction is 4206537 USD/h. The Calciner and the Rotary Kiln cause 62% of the total cost of the exergy destruction. The lowest values of the exergoeconomic factor were calculated for Calciner (0.01%), Clinker Cooler (0.01%), Rotary Kiln (0.02%), and Raw Mill (0.04%). The significant difference in relative cost was calculated for Calciner (42%) and Rotary Kiln (54.21%). The above implies that this equipment should be considered for an investment that allows the decrease of the exergy destruction cost and the increase of the exergetic efficiency.

Conventional and Advanced Exergoeconomic Analysis in a Nitric Acid Production Plant

2019 ◽  
Author(s):  
J. Fajardo ◽  
A. Buelvas ◽  
H. Valle
Keyword(s):  
Nitric Acid ◽  
Acid Production ◽  
Catalytic Converter ◽  
Thermodynamic Efficiency ◽  
Production Plant ◽  
Exergy Destruction ◽  
Total Cost ◽  
Total Investment ◽  
Advanced Analysis ◽  
Exergoeconomic Analysis

Abstract An advanced exergoeconomic analysis (AEA) allows determining the part of Exergy Destruction and total investment costs that can be avoided. The results of the advanced analysis show the economic costs to be reduced and improvements that can be achieved for the system in terms of the overall efficiency. A Nitric Acid Production Plant of 350 tons/day was taken as case of study to implement a conventional and advanced exergoeconomic analysis. In this work, the investment costs and exergy destruction of the components of the system were divided into 2 groups such as endogenous/exogenous and avoidable/unavoidable parts to obtain accurate information about the performance of the plant. Conventional exergoeconomic analysis showed that 58.5% of the total cost of the exergy destruction is caused by the catalytic converter with a cost rate of 687.84 $/h. The highest values of the exergoeconomic factor were for Tail Gas Desuperheater (99.01%), Condenser (96.35%) and Tail Gas Heater (87%). The costs of the production process can be improved by reducing the total investment of these three components. The lowest value of exergoeconomic factor was calculated for the Catalytic Converter (15.25%) which implies that thermodynamic efficiency of this equipment must be enhanced. Based on AEA results, most exergy destruction of the Catalytic Converter is avoidable and exogenous. The destruction cost of the avoidable exergy for this component was 54.4 $ / h, which means that more than 50% of the total cost of the exergy destruction of the Catalytic Converter can be minimized to improve the performance of other equipment of the plant. Most exergy destruction costs for Tail Gas Heater, Absorption Tower and Air Heater, are unavoidable and endogenous and they cannot be reduced by improving the performance of these equipments. In addition, the cost of the exergy destruction of the Tail Gas Desuperheater is largely unavoidable (66.9 $ / h). In particular, 85%, 88% and 83% of the investment cost of the Tail Gas Desuperheater, the Absorption Tower and the Catalytic Converter, respectively, are exogenous; that is, it is only affected by the structure of the plant and the operation of the other components, but not by its internal thermodynamic inefficiencies.

Exergoeconomic Analysis in a Cement Production Plant

2021 ◽  
Author(s):  
Juan Fajardo ◽  
Deibys Barreto ◽  
Andrea Mendoza ◽  
Harold Valle
Keyword(s):  
Production Plant ◽  
Cement Production ◽  
Exergoeconomic Analysis

scholarly journals Revealing Changes in the Stem Form and Volume Allocation in Diverse Boreal Forests Using Two-Date Terrestrial Laser Scanning

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 835
Author(s):  
Ville Luoma ◽  
Tuomas Yrttimaa ◽  
Ville Kankare ◽  
Ninni Saarinen ◽  
Jiri Pyörälä ◽  
...  
Keyword(s):  
Tree Growth ◽  
Point Cloud ◽  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Point Clouds ◽  
Stem Volume ◽  
Accurate Information ◽  
Stem Form ◽  
Monitoring Period ◽  
Significant Difference

Tree growth is a multidimensional process that is affected by several factors. There is a continuous demand for improved information on tree growth and the ecological traits controlling it. This study aims at providing new approaches to improve ecological understanding of tree growth by the means of terrestrial laser scanning (TLS). Changes in tree stem form and stem volume allocation were investigated during a five-year monitoring period. In total, a selection of attributes from 736 trees from 37 sample plots representing different forest structures were extracted from taper curves derived from two-date TLS point clouds. The results of this study showed the capability of point cloud-based methods in detecting changes in the stem form and volume allocation. In addition, the results showed a significant difference between different forest structures in how relative stem volume and logwood volume increased during the monitoring period. Along with contributing to providing more accurate information for monitoring purposes in general, the findings of this study showed the ability and many possibilities of point cloud-based method to characterize changes in living organisms in particular, which further promote the feasibility of using point clouds as an observation method also in ecological studies.

scholarly journals Conventional and Advanced Exergoeconomic Analysis of a Compound Ejector-Heat Pump for Simultaneous Cooling and Heating

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3511
Author(s):  
Ali Khalid Shaker Al-Sayyab ◽  
Joaquín Navarro-Esbrí ◽  
Victor Manuel Soto-Francés ◽  
Adrián Mota-Babiloni
Keyword(s):  
Heat Pump ◽  
Exergy Analysis ◽  
Waste Heat ◽  
District Heating ◽  
Cost Comparison ◽  
Exergy Destruction ◽  
Pump System ◽  
Heat Pump System ◽  
Destruction Rate ◽  
Exergoeconomic Analysis

This work focused on a compound PV/T waste heat driven ejector-heat pump system for simultaneous data centre cooling and waste heat recovery for district heating. The system uses PV/T waste heat as the generator’s heat source, acting with the vapour generated in an evaporative condenser as the ejector drive force. Conventional and advanced exergy and advanced exergoeconomic analyses are used to determine the cause and avoidable degree of the components’ exergy destruction rate and cost rates. Regarding the conventional exergy analysis for the whole system, the compressor represents the largest exergy destruction source of 26%. On the other hand, the generator shows the lowest sources (2%). The advanced exergy analysis indicates that 59.4% of the whole system thermodynamical inefficiencies can be avoided by further design optimisation. The compressor has the highest contribution to the destruction in the avoidable exergy destruction rate (21%), followed by the ejector (18%) and condenser (8%). Moreover, the advanced exergoeconomic results prove that 51% of the system costs are unavoidable. In system components cost comparison, the highest cost comes from the condenser, 30%. In the same context, the ejector has the lowest exergoeconomic factor, and it should be getting more attention to reduce the irreversibility by design improving. On the contrary, the evaporator has the highest exergoeconomic factor (94%).

Comparison of stapler and handsewn anastomosis techniques in creating an ileal conduit following radical cystectomy

2021 ◽  
pp. 1
Keyword(s):  
Postoperative Complications ◽  
Ileal Conduit ◽  
Perioperative Complications ◽  
Movement Time ◽  
Oral Intake ◽  
Total Cost ◽  
Handsewn Anastomosis ◽  
Significant Difference ◽  
The Mean ◽  
Mean Time

Background and objective: Ileal conduit for urinary diversion can be completed using either end-to-end handsewn or stapled anastomosis. This study aimed to compare stepled and handsewn anastomosis methods in terms of complications, hospitalization and cost. Materials and methods: Forty-three patients were included in the hand-sewn and 44 patients in the stapler group. After creating an ileal conduit, continuity of the loop was achieved either with handsewn or stapler method. Patients' demographic data, time to onset of bowel movement, time to transit to oral intake, time to removal of the drain, perioperative and postoperative complications, mortality and total costs were retrospectively recorded and compared between the two groups. Results: There was no statistically significant difference between the groups in terms of the mean to the onset of bowel movements (p = 0.51) and the mean time to transit to oral intake (p = 0.23). The mean time to removal of the drain was significantly lower in the stapler group (p = 0.023). Perioperative complications were seen in eight patients in the handsewn group, while none of the patients in the stapler group developed perioperative complication (p = 0.003). Postoperative complications were similar between both groups (p = 0.75). The duration of hospitalization was statistically significantly lower in the stapler group (p = 0.004) and the mean total cost was statistically significantly more advantageous (p < 0.001). Conclusion: No significant difference was found between stapler and handsewn anastomosis techniques in terms of postoperative complications. On the other hand, hospitalization and total cost were in favour of stapler technique, showing that this technique can be used safely.

scholarly journals Costing out Educational Needs for Khyber Pakhtunkhwa

2019 ◽  
Vol IV (II) ◽  
pp. 34-42
Author(s):  
Noor Jehan ◽  
Muhammad Idris
Keyword(s):  
Rural Students ◽  
Total Cost ◽  
Khyber Pakhtunkhwa ◽  
Pocket Money ◽  
Significant Difference ◽  
Urban Student ◽  
Education Needs ◽  
Successful School ◽  
Grade One ◽  
The Cost

This study was undertaken for costing out education needs for Khyber Pakhtunkhwa based on location, gender, district and grade. The sample consisted of 778 schools, including 364 females and 414 males. The study used descriptive statistics for analysis. It was found that rural students get slightly less pocket money than urban students. The cost of average monthly stationery, uniform cost, teacher cost and total cost for urban student was higher than for rural students. District Haripur was found to be the most successful school district. It was further found that better results need good financing. The study also confirmed that the girl student cost is less than a boy student. It was also concluded that the pocket money on average increases with grade. There was no significant difference of stationery cost across grades while grade one and grade four students’ cost on uniform was slightly higher than other grades.

A rolling horizon approach for production planning and condition-based maintenance under uncertain demand

2019 ◽  
Vol 233 (6) ◽  
pp. 1014-1028
Author(s):  
Lin Wang ◽  
Zhiqiang Lu ◽  
Yifei Ren
Keyword(s):  
Service Level ◽  
Condition Based Maintenance ◽  
Uncertain Demand ◽  
Programming Approach ◽  
Production Plan ◽  
Rolling Horizon ◽  
Decision Point ◽  
Total Cost ◽  
New Information ◽  
Maintenance Plan

In reality, the forecast of uncertainties often becomes more accurate with the approaching of the forecasted period. This article proposes a rolling horizon approach to dynamically determine the production plan and the maintenance plan for a degradation system under uncertain environment. In each rolling horizon, demand forecasts are updated with new information from customers, and the degradation level of system is confirmed by inspection. By taking advantage of the updated uncertainties, at each decision point, the maintenance plan is determined by an advance-postpone balancing approach and the production plan is optimized by a heuristic algorithm in a two-stage stochastic model. Numerical results validate that the rolling horizon approach has great superiority over traditional stochastic programming approach in terms of real total cost and service level.

scholarly journals Complications Associated with Triple Arthrodesis Versus Non-Fusion Flatfoot Reconstruction: A Matched Cohort Study

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0039
Author(s):  
William V. Probasco ◽  
Benjamin E. Stein ◽  
Cyrus Fassihi ◽  
Lea McDaniel
Keyword(s):  
Postoperative Complication ◽  
Multivariate Regression ◽  
Financial Burden ◽  
Cost Of Care ◽  
Wound Complications ◽  
Complication Rates ◽  
Triple Arthrodesis ◽  
Total Cost ◽  
Significant Difference ◽  
Reconstruction Group

Category: Hindfoot; Midfoot/Forefoot; Other Introduction/Purpose: Pes planovalgus is a very common deformity of the foot, often resulting from adult acquired flatfoot disorder (AAFD). This deformity in its early stages is treated conservatively with non-operatively modalities such as bracing, however in its later stages often requires surgical correction of the deformity in order to improve the pain and function of the extremity. Two commonly performed procedures in the correction of this type of deformity are a triple arthrodesis or joint sparing flatfoot reconstruction. The objective of this study was to identify whether differences existed in the financial burden or complication rates of non-fusion flatfoot reconstruction versus triple arthrodesis. Methods: The PearlDiver Database was queried from 2006-2013 to identify all Medicare patients who were admitted for a triple arthrodesis or non-fusion flatfoot reconstruction. 2308 patients were identified in each cohort and statistically matched in a 1:1 manner to control for influence of demographics and/or comorbidities. Postoperative complication rates (within 30 days) were evaluated and broken down into major (PE/DVT, MI, CVA, sepsis, mortality, nerve injury) and minor (UTI, PNA, hardware failure, transfusion, wound complications) categories. Additionally, total cost of care including cost of readmissions, and readmission within 30 days were evaluated. Results: No significant differences were noted in the postoperative complication rates between the two procedures within the first 30 days post-operatively in the initial univariate regression. There was a significant difference in the rate of 30 day readmission with 2.3% of triple arthrodeses being readmitted vs. 1.08% in the non-fusion joint reconstruction group (p=.002). Adjusted multivariate regression yielded similar results, with no significant differences in postoperative complication rates. The difference in readmission rate remained significant in the multivariate regression (OR 2.13, 95% CI 1.33-3.51, p=.002). Significant differences were also noted for mean total cost of care, with a higher mean total cost identified for the fusion group (x=7,868.0) compared to the reconstruction group (x=4,064.49, p<.001, Adjusted 𝛽𝛽 3,836.71, 95% CI 3,525.23 to 4,148.19, p<.001). Conclusion: This study compared triple arthrodesis versus joint-sparing flatfoot reconstruction. Within this study group there was no difference in complications between the two procedures. There was a significantly higher incidence of 30-day readmission in the triple arthrodesis group by about 2-fold. When comparing the total cost of care, there was a significantly higher cost associated with the triple arthrodesis, which cost on average about $3800 more than joint sparing flatfoot reconstruction. While revealing with regard to the aforementioned variables within the first 30 days post-operatively, further research needs to be conducted on the long term outcomes of these procedures. [Table: see text][Table: see text][Table: see text]

scholarly journals Performance Evaluation of an Ironmaking System with Environmental Costs

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Huimin Liu ◽  
Qiqiang Li
Keyword(s):  
Formation Process ◽  
Carbon Dioxide Emissions ◽  
Environmental Costs ◽  
Analysis Method ◽  
Analysis Model ◽  
Total Cost ◽  
Iron Smelting ◽  
System Product ◽  
Environmental Emissions ◽  
Exergoeconomic Analysis

This paper proposes an exergoeconomic analysis method that considers environmental costs to make up for the lack of description of environmental costs in the traditional matrix model exergoeconomic analysis method. This method tracks the formation process of the product cost through life cycle and makes a useful exploration for revealing the true cost of the system product. According to actual needs, the principles for the construction of environmental emissions of products are proposed, and a detailed exergoeconomic analysis model is established by taking the iron smelting system as an example. Through calculation and analysis, the formation process and change rule of unit exergoeconomic cost of products in the system are revealed. Especially, considering the exergoeconomic cost of carbon emissions, the results show that the three most influential substances are sinter, coke, and pellets. When carbon dioxide emissions are considered, the total cost will increase by 165.3 CNY/t iron, and unit exergoeconomic cost gradually increases with the progress of the production process.

scholarly journals Conventional and Advanced Exergy and Exergoeconomic Analysis of a Spray Drying System: A Case Study of an Instant Coffee Factory in Ecuador

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5622
Author(s):  
Diana L. Tinoco-Caicedo ◽  
Alexis Lozano-Medina ◽  
Ana M. Blanco-Marigorta
Keyword(s):  
Spray Drying ◽  
Industrial Scale ◽  
Spray Dryer ◽  
Exergy Destruction ◽  
Steam Generation ◽  
Instant Coffee ◽  
Cost Rate ◽  
Drying System ◽  
Drying Section ◽  
Exergoeconomic Analysis

Instant coffee is produced worldwide by spray drying coffee extract on an industrial scale. This production process is energy intensive, 70% of the operational costs are due to energy requirements. This study aims to identify the potential for energy and cost improvements by performing a conventional and advanced exergy and exergoeconomic analysis to an industrial-scale spray drying process for the production of instant coffee, using actual operational data. The study analyzed the steam generation unit, the air and coffee extract preheater, the drying section, and the final post treatment process. The performance parameters such as exergetic efficiency, exergoeconomic factor, and avoidable investment cost rate for each individual component were determined. The overall energy and exergy efficiencies of the spray drying system are 67.6% and 30.6%, respectively. The highest rate of exergy destruction is located in the boiler, which amounts to 543 kW. However, the advanced exergoeconomic analysis shows that the highest exergy destruction cost rates are located in the spray dryer and the air heat exchanger (106.9 $/h and 60.5 $/h, respectively), of which 47.7% and 3.8%, respectively, are avoidable. Accordingly, any process improvement should focus on the exergoeconomic optimization of the spray dryer.

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