Effect of Operating Decisions on the Design and Energy Consumption of Inverted Batch Distillation Column

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
Aboubaker Z Masoud ◽  
Iqbal M Mujtaba
Keyword(s):  
Energy Consumption ◽  
Energy Cost ◽  
Cooling Water ◽  
Problem Formulation ◽  
Capital Cost ◽  
Design Stage ◽  
Market Demand ◽  
Batch Distillation ◽  
Operating Decisions ◽  
Utility Cost

In this paper, the effect of operating decisions on the design and energy consumption for inverted batch distillation is considered. In distillation, utility cost is a function of column vapour load (V). We present a different type (as compared to what is available in the existing literature) of optimisation problem formulation and show that for a fixed market demand scenario minimisation of V for a given N will not only minimise the utility cost (cooling water + energy cost) and the capital cost but will also maximise the profitability of the operation. Also, with several examples of binary separation, it is shown that the decision of operating policy (such as constant reboil ratio, time dependent reboil ratio, etc.) at the design stage can have a significant impact on the capital and utility cost and overall profitability. This will in turn have significant effect on global warming as savings in utility cost reflects savings in energy cost. For difficult separations, which are capital and energy intensive, 40% savings in capital cost, 60% savings in utility and 70% improvement in profitability are possible if operating decisions are taken at the design stage.

scholarly journals Heat Exchanger Network Retrofit of an Oleochemical Plant through a Cost and Energy Efficiency Approach

2021 ◽  
Vol 5 (2) ◽  
pp. 17
Author(s):  
Valli Trisha ◽  
Kai Seng Koh ◽  
Lik Yin Ng ◽  
Vui Soon Chok
Keyword(s):  
Energy Consumption ◽  
Heat Exchanger ◽  
Cost Effective ◽  
Capital Cost ◽  
Global Market ◽  
Annual Saving ◽  
Heat Exchanger Network ◽  
First Case ◽  
Payback Time ◽  
Better Than

Limited research of heat integration has been conducted in the oleochemical field. This paper attempts to evaluate the performance of an existing heat exchanger network (HEN) of an oleochemical plant at 600 tonnes per day (TPD) in Malaysia, in which the emphases are placed on the annual saving and reduction in energy consumption. Using commercial HEN numerical software, ASPEN Energy Analyzer v10.0, it was found that the performance of the current HEN in place is excellent, saving over 80% in annual costs and reducing energy consumption by 1,882,711 gigajoule per year (GJ/year). Further analysis of the performance of the HEN was performed to identify the potential optimisation of untapped heating/cooling process streams. Two cases, which are the most cost-effective and energy efficient, were proposed with positive results. However, the second case performed better than the first case, at a lower payback time (0.83 year) and higher annual savings (0.20 million USD/year) with the addition of one heat exchanger at a capital cost of USD 134,620. The first case had a higher payback time (4.64 years), a lower annual saving (0.05 million USD/year) and three additional heaters at a capital cost of USD 193,480. This research has provided a new insight into the oleochemical industry in which retrofitting the HEN can further reduce energy consumption, which in return will reduce the overall production cost of oleochemical commodities. This is particularly crucial in making the product more competitive in its pricing in the global market.

scholarly journals Review on Urban Heat Island in China: Methods, Its Impact on Buildings Energy Demand and Mitigation Strategies

2021 ◽  
Vol 13 (2) ◽  
pp. 762
Author(s):  
Liu Tian ◽  
Yongcai Li ◽  
Jun Lu ◽  
Jue Wang
Keyword(s):  
Energy Consumption ◽  
Urban Heat Island ◽  
Building Energy ◽  
Design Stage ◽  
Heat Island ◽  
Building Energy Consumption ◽  
Rapid Urbanization ◽  
Substantial Impact ◽  
Urban Heat ◽  
The Impact

High population density, dense high-rise buildings, and impervious pavements increase the vulnerability of cities, which aggravate the urban climate environment characterized by the urban heat island (UHI) effect. Cities in China provide unique information on the UHI phenomenon because they have experienced rapid urbanization and dramatic economic development, which have had a great influence on the climate in recent decades. This paper provides a review of recent research on the methods and impacts of UHI on building energy consumption, and the practical techniques that can be used to mitigate the adverse effects of UHI in China. The impact of UHI on building energy consumption depends largely on the local microclimate, the urban area features where the building is located, and the type and characteristics of the building. In the urban areas dominated by air conditioning, UHI could result in an approximately 10–16% increase in cooling energy consumption. Besides, the potential negative effects of UHI can be prevented from China in many ways, such as urban greening, cool material, water bodies, urban ventilation, etc. These strategies could have a substantial impact on the overall urban thermal environment if they can be used in the project design stage of urban planning and implemented on a large scale. Therefore, this study is useful to deepen the understanding of the physical mechanisms of UHI and provide practical approaches to fight the UHI for the urban planners, public health officials, and city decision-makers in China.

Study on the impacts of peaking factors on a water distribution system in Germany

2010 ◽  
Vol 10 (2) ◽  
pp. 165-172 ◽  
Author(s):  
K. Diao ◽  
M. Barjenbruch ◽  
U. Bracklow
Keyword(s):  
Energy Consumption ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Design Stage ◽  
Water Age ◽  
Specific System ◽  
Average Water

This paper aims to explore the impacts of peaking factors on a water distribution system designed for a small city in Germany through model-based analysis. As a case study, the water distribution network was modelled by EPANET and then two specific studies were carried out. The first study tested corresponding system-wide influences on water age and energy consumption if the peaking factors used at design stage are inconsistent with ones in real situation. The second study inspected the possible relationship between the choice of peaking factors and budgets by comparing several different pipe configurations of the distribution system, obtained according to variety of peaking factors. Given the analysis results, the first study reveals that average water age will increase if peaking factors estimated at design stage are larger than real values in that specific system, and vice versa. In contrast, energy consumption will increase if peaking factors defined for system design are smaller than ones in real case, and vice versa. According to the second study, it might be possible to amplify peaking factors for design dramatically by a slight increase in the investment on this system. However, further study on budget estimation with more factors and detailed information considered should be carried out.

A Novel Hybrid Method Based on Three-Stage Extraction and DEA-CCR Models for Selecting the Optimal Conditions for Citronella Oil Extraction

2021 ◽  
Author(s):  
Thaithat Sudsuansee ◽  
Narong Wichapa ◽  
Amin Lawong ◽  
Nuanchai Khotsaeng
Keyword(s):  
Energy Consumption ◽  
Flow Rate ◽  
Energy Cost ◽  
Oil Extraction ◽  
Steam Flow ◽  
Oil Yield ◽  
Steam Flow Rate ◽  
Citronella Oil ◽  
Extraction Model ◽  
Ccr Model

In citronella oil extraction process by steam distillation, inefficient use of steam is the main cause of excessive energy consumption that affects energy cost and oil yield. This research is aimed to reduce the energy cost and increase the oil yield by studying the steam used in the process. The proposed method is the three-stage extraction model combined with the Data Envelopment Analysis developed by Charnes, Cooper and Rhodes (DEA-CCR model). Although the three-stage extraction model has been widely used, there is no research integrate this model with DEA-CCR model. It is well known that DEA-CCR model is an effective tool to evaluate efficiency of decision making units/alternatives. The advantages of this research were presented as the calculation of the optimum distillation conditions, including the steam flow rate and the distillation time, were achieved as discussed in this article. The study was comprised of 3 parts. Firstly, the three-stage extraction model for citronella oil was formulated. Secondly, the results of the proposed model were calculated under different conditions, classified by steam flow rates from 5,000 to 60,000 cm3/min for the distillation period of 15–180 min. Finally, the DEA-CCR model was utilized to evaluate and rank alternatives. The results expressed that the best condition for producing citronella oil was at the steam flow rate of 40,000 cm3/min and the distillation time of 60 min. The optimal energy cost and percentage of oil yield were equal to 0.440 kWh/mL and 0.7%, respectively. When comparing to the experimental results, the percentage error of optimal energy cost and oil yield were slightly different, with a value of 0.98% and 0.85%, respectively. Moreover, the energy consumption was also reduced by 34.6% compared to the traditional operating conditions.

Energy Consumption Analysis of Level Circulating Cooling System in Sanhejian Deep Coal Mine

2011 ◽  
Vol 396-398 ◽  
pp. 516-519
Author(s):  
Yi Zhang ◽  
Dong Ming Guo ◽  
Li Meng
Keyword(s):  
Energy Consumption ◽  
Coal Mine ◽  
Cooling System ◽  
Cooling Water ◽  
Deep Mining ◽  
Heat Damage ◽  
Deep Coal Mine ◽  
Energy Consumption Analysis ◽  
Process System ◽  
Technical Issues

With the deep mining in coal mine, heat damage is one of the technical issues need to be solved. HEMS cooling system in Sanhejian Coal Mine is a process system for high-temperature heat damage controlling in deep coal mine, in which cool energy extracted to reduce work face’s ambient temperature to achieve heat damage controlling. Part of the cool energy is from the level circulating of cooling water in -700 level main raodway, the other is from the mine water. We analyze the energy consumption of every subsystem during operation of the HEMS system, which could provide a theoretical basis and technical guidance on more efficiently running of cooling system deep in the future.

Energy Consumption in Leisure Centres – A Comparative Study

1997 ◽  
Vol 8 (3) ◽  
pp. 207-225
Author(s):  
A.J. Griffiths ◽  
P.J. Bowen ◽  
B.J. Brinkworth ◽  
I.R. Morgan ◽  
A Howarth
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Comparative Study ◽  
Energy Cost ◽  
Good Practice ◽  
The Other ◽  
Occupancy Rate ◽  
The Government ◽  
The Uk ◽  
High Band

The Sports and Recreation sector within the UK uses the equivalent of 3 millions tonnes of coal per year to supply the activities demanded by an ever increasing sports conscience society. The government has attempted to stimulate energy efficiency in this sector through the use of good practice guides and case studies. A comparative study was undertaken to analyse the performance of two leisure complexes in the Seven Valley degree day region. One site had double the occupancy rate of the other. It was found that the energy consumption per user was approximately 10 kWh for both sites. However the energy cost per user showed a large difference: for Site A this index was 31p/user compared to 15p/user at Site B. The primary causes of this difference are attributed to variation in energy mix between the two sites, as well as a difference in the price paid for primary fuel. Indices based on floor area of the facilities exhibit similar trends, and furthermore show that both sites were in the high band of energy consumption. This indicated that both sites had the potential to make significant energy-related savings, and a further breakdown of electrical, natural gas and water consumption per site is used to identify these potential savings in a rapidly expanding sector.

scholarly journals Hybrid-Model-Based Deep Reinforcement Learning for Heating, Ventilation, and Air-Conditioning Control

2021 ◽  
Vol 8 ◽  
Author(s):  
Huan Zhao ◽  
Junhua Zhao ◽  
Ting Shu ◽  
Zibin Pan
Keyword(s):  
Reinforcement Learning ◽  
Energy Consumption ◽  
Hybrid Model ◽  
Learning Process ◽  
Energy Cost ◽  
Air Conditioning ◽  
Electricity Price ◽  
Learning Efficiency ◽  
Model Based ◽  
Model Free

Buildings account for a large proportion of the total energy consumption in many countries and almost half of the energy consumption is caused by the Heating, Ventilation, and air-conditioning (HVAC) systems. The model predictive control of HVAC is a complex task due to the dynamic property of the system and environment, such as temperature and electricity price. Deep reinforcement learning (DRL) is a model-free method that utilizes the “trial and error” mechanism to learn the optimal policy. However, the learning efficiency and learning cost are the main obstacles of the DRL method to practice. To overcome this problem, the hybrid-model-based DRL method is proposed for the HVAC control problem. Firstly, a specific MDPs is defined by considering the energy cost, temperature violation, and action violation. Then the hybrid-model-based DRL method is proposed, which utilizes both the knowledge-driven model and the data-driven model during the whole learning process. Finally, the protection mechanism and adjusting reward methods are used to further reduce the learning cost. The proposed method is tested in a simulation environment using the Australian Energy Market Operator (AEMO) electricity price data and New South Wales temperature data. Simulation results show that 1) the DRL method can reduce the energy cost while maintaining the temperature satisfactory compared to the short term MPC method; 2) the proposed method improves the learning efficiency and reduces the learning cost during the learning process compared to the model-free method.

scholarly journals Multi-Objective Optimization of Home Appliances and Electric Vehicle Considering Customer’s Benefits and Offsite Shared Photovoltaic Curtailment

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2852
Author(s):  
Yeongenn Kwon ◽  
Taeyoung Kim ◽  
Keon Baek ◽  
Jinho Kim
Keyword(s):  
Energy Consumption ◽  
Energy Cost ◽  
Consumption Pattern ◽  
Consumption Data ◽  
Battery Capacity ◽  
Home Energy Management ◽  
Residential Demand ◽  
Home Energy Management System ◽  
Demand Patterns ◽  
Ev Charging

A Time-of-Use (TOU)-tariff scheme, helps residential customers to adjust their energy consumption voluntarily and reduce energy cost. The TOU tariff provides flexibility in demand, alleviate volatility caused by an increase in renewable energy in the power system. However, the uncertainty in the customer’s behavior, causes difficulty in predicting changes in residential demand patterns through the TOU tariff. In this study, the dissatisfaction model for each time slot is set as the energy consumption data of the customer. Based on the actual customer’s consumption pattern, the user sets up a model of dissatisfaction that enables aggressive energy cost reduction. In the proposed Home Energy Management System (HEMS) model, the efficient use of jointly invested offsite photovoltaic (PV) power generation is also considered. The optimal HEMS scheduling result considering the dissatisfaction, cost, and PV curtailment was obtained. The findings of this study indicate, that incentives are required above a certain EV battery capacity to induce EV charging for minimizing PV curtailment.

A design approach towards sustainable buildings in Algeria

2019 ◽  
Vol 9 (3) ◽  
pp. 229-245
Author(s):  
Sofiane Rahmouni ◽  
Rachid Smail
Keyword(s):  
Energy Consumption ◽  
Simulation Software ◽  
Cold Climate ◽  
Design Approach ◽  
Office Building ◽  
Design Stage ◽  
Building Performance ◽  
Sustainable Buildings ◽  
Content Type ◽  
Efficiency Measures

Purpose The purpose of this paper is to achieve the national strategic agenda’s criteria that aim for accomplishing sustainable buildings by estimating the effects of energy efficiency measures in order to reduce energy consumption and CO2 emission. Design/methodology/approach A design approach has been developed based on simulation software and a modeled building. Therefore, a typical office building is considered for testing five efficiency measures in three climatic conditions in Algeria. This approach is conducted in two phases: first, the analysis of each measure’s effect is independently carried out in terms of cooling energy and heating energy intensities. Then, a combination of optimal measures for each climate zone is measured in terms of three sustainable indicators: final energy consumption, energy cost saving and CO2 emission. Findings The results reveal that a combination of optimal measures has a substantial impact on building energy saving and CO2 emission. This saving can rise to 41 and 31 percent in a hot and cold climate, respectively. Furthermore, it is concluded that obtaining higher building performance, different design alternatives should be adapted to the climate proprieties and the local construction materials must be applied. Originality/value This study is considered as an opportunity for achieving the national strategy, as it may contribute in improving office building performance and demonstrating a suitable tool to assist stakeholders in the decision making of most important parameters in the design stage for new or retrofit buildings.

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