Pinch Analysis Research Articles

Пинчанализ – как инструмент повышения энергетической эффективности НПЗ

The article is devoted to the problem of reserves and opportunities for further improvement of oil refineries in the field of energy efficiency and energy conservation. The results of rational use of energy resources and their savings, as well as improvement of the process of energy consumption management in the implementation of all typesof the company’s activities are shown on the example of the production activities of PJSC «NK «Rosneft».The assessment of the existing methods and approaches used to analyze the energy efficiency of technological processes and aggregates in terms of their functionality is given. From the considered set of methods, the Pinch method is singled out as the most promising for a comprehensive analysis of production in order to optimizethe consumption of various energy resources when designing new enterprises or production units, as well as modernization of production facilities. It is presented the methodology of using Pinch analysis to improvethe operational efficiency of a number of specific refinery facilities. In conclusion economic results are shown and promising directions are outlined for the development of energy saving works using the new method.

The use of pinch analysis technology to assess the energy efficiency of oil refining technologies

The use of pinch analysis technology to assess the energy efficiency of oil refining technologies

Remodelling of heat exchanger networks integrating the temperature dependence of the calorific flows of the streams: Application to the hydrodesulphurization unit of a refinery

The fight against global warming and the reduction of greenhouse gas emissions is now a major challenge for society and industry. In this context of decarbonization, combined with a rise in energy prices, the latter are seeking to equip themselves with energy diagnosis and decision support tools to redesign existing processes and thus contribute to greater efficiency. energy of their production site. Generally based on the principles of pinch analysis (Linnhoff and Sahdev, 2000), different approaches and resolution techniques are proposed in the literature to address this issue. Review articles such as (Klemeš et al., 2018), (Čuček et al., 2019) summarize them and highlight the advantages and limitations of each of them. The RREflex software, developed at the LGC for several years and tested on other processes including a crude oil preheating train (Payet et al., 2018), is one of the tools for carrying out the initial synthesis as well as the remodelling of networks of heat exchangers with the aim of improving the energy performance of existing processes.

A systemic model predictive control based on adaptive power pinch analysis for load shifting and shedding in an isolated hybrid energy storage system

This paper presents a novel systemic algorithm based on conservative power pinch analysis principles using a computationally efficient insight-based binary linear programming optimization technique in a model predictive framework for integrated load shifting and shedding in an isolated hybrid energy storage system. In a receding 24-hour predictive horizon, the energy demand and supply are integrated via an adaptive power grand composite curve tool to form a diagonal matrix of predicted hourly minimum and maximum energy constraints. The intgrated energy constraints must be satisfied recursively by the binary optimisation to ensure the energy storage’s state of charge only operates within 30% and 90%. Hence, the control command to shift or shed load is contingent on the energy storage state of the charge violating the operating constraints. The controllable load demand is shifted and/or shed to prevent any violations while ensuring energy supply to the most critical load without sacrificing the consumers' comfort. The proposed approach enhances efficient energy use from renewable energy supply as well as limits the use of the Hydrogen resources by a fuel cell to satisfy controllable load demands which can be shifted to periods in the day with excess renewable energy supply.

How to effectively produce value-added products from microalgae?

Microalgae are the third generation of biomasses that have received lots of attention due to their high energy content and ability to capture carbon dioxide from the air. However, there are some techno-economic challenges for their world commercialization. A variety of fuels can be extracted from microalgae, and in addition to these fuels, algae by-products can be used to commercialize this industry. Various processes will be performed on microalgae to finally desired products can be extracted. In this research, an integrated system has been designed for the simultaneous production of ethanol, methane, and hydrogen from Chlorella vulgaris microalgae. The results showed that after culturing, harvesting, and increasing the concentration of the solution in addition to the main products such as ethanol, methane, and hydrogen, by-products including acetic acid, methyl acetate, ethyl acetate, furfural and etc. can be utilized for commercializing microalgae industry. Also, another purpose of this study is to apply Pinch Analysis to the mentioned system, which will ultimately improve the concentration of microalgae in the photobioreactor. The results of Pinch Analysis show that by increasing the concentrations of microalgae, carbon dioxide, and nutrients in the photobioreactor inlet up to 2.35 gr/l, the desired amount of demands can be met by the new supplies.

An insight-based approach for batch water network with flexible production scheduling framework

Batch chemical plants play an important role in the chemical and pharmacy industry. Efficient water management is becoming increasingly important in batch production systems because of the stricter environmental regulations and rising costs of water utilization activities. In this work, an insight-based method is proposed to effectively utilize the water in batch chemical plant with flexible scheduling framework. First, Pinch Analysis for continuous process is extended to targeting the freshwater requirement of batch processes. Second, a matrix of source-sink matches is constructed based on insight from Pinch Analysis. Some heuristic rules are defined to select the matches of water sinks and sources in order to reduce the connections and meet the time constraints. Thirdly, initial water network is designed based on the chosen matches and the timing of batch operations is determined based on the water reuse. Four illustrative examples adopted from the literature are investigated based on the proposed method. Results show that flexible product scheduling is useful to reduce freshwater consumption and batch operation time. The proposed method could be used to assist wastewater recovery in flexible batch plant.

A generic algorithm-based application for pinch-exergy prediction in process industries: A case study

In the industrial sector, efficient production and optimal use of thermal energy are primary concerns for managers and engineers. Considerable research has been devoted to improving and promoting thermal energy efficiency, especially energy recovery in the context of sustainability. Pinch analysis is one of the most powerful methods in this regard. To maximise the energy recovery (MER), the pinch method is well-established in designing an optimal heat exchange network (HEN). Exergy analysis is combined with the pinch method to minimise the work potential loss (exergy loss) while ensuring maximum heat recovery. This study presents a generic algorithm built using Python language to predict and quantify energy and exergy targets in industrial processes. It provides a framework to guide experts and planners in efficiently using the combined analysis tools. The generic algorithm is based on advanced numerical and graphical tools. It provides exergy problem table algorithm (Ex–PTA) and grand composite curve (EHR and HRP) tools. For Δ T min = 10°C, the generic algorithm is implemented in a building complex case study. The energy targets for heating and cooling requirements are 316.2625 kW and 0 kW, respectively. The obtained exergy targets are less attractive given an improvement from advanced utility integration; this is due to the treated system (medium-temperature system) and not to the reliability and efficiency of the generic algorithm. To evaluate the generic algorithm calculations, they are executed in a low-temperature process in which pinch exergy analysis (PExA) has already been performed. The simulated and generated results are identical, demonstrating the reliability and effectiveness of the developed generic algorithm.

Technology Focus: Production and Facilities (December 2022)

The COVID-19 pandemic has caused unprecedented circumstances affecting production and facilities. Restrictions in mobility between sites and reduction in manpower challenged the business continuity of several operations. This accelerated the development and implementation of various technological solutions. We can see many examples in the works submitted this year: drone surveillance, inspection robots, digital twins, and automated systems. The digitalization tendency brought by the fourth industrial revolution continues to be the dominant topic of the works submitted. Approximately 28% were on simulation and modeling, of which one-third used machine learning. A total of 9% addressed intelligent management systems, 5% robotics and drones, 3% 3D printing, and 1.5% digital twins and augmented reality. The main topics addressed were inspection and maintenance (20%), flow assurance (7%), corrosion (6%), drilling (6%), nonmetallic materials (3%), and debottlenecking (2%). A few papers were on clean energy subjects, such as hydrogen energy and wind turbines (2%). I would like to highlight the following works as promising technological developments for production and facilities: innovative measurement techniques, such as the development of a new adjustable cone meter that adapts automatically to flow conditions of wet and dry gas (paper SPE 207505); improvements to drilling safety, such as the design of a new casing connector that significantly reduces rig time and health, safety, and environmental exposure risks (paper OTC 31075); new developments in piping inspection, such as the combination of direct-response spectroscopy with microwave for inspection of hard-to-inspect piping with coatings and overwraps (paper IPTC 21799); and a very interesting study of triangular vs. circular cross-sectional pipes, which shows that triangular pipes and elbows have significant less erosion, better heat transfer properties, and reduced slug frequencies for multiphase flow (paper SPE 208101). In the matter of optimizing production, debottlenecking continues to be a challenge. Whether it is for increase of production needs or for handling greater water cuts from aging wells, new technological solutions are arising to make production facilities increasingly efficient. Paper IPTC 22365 discusses dual-frequency AC/DC desalting technology. It shows a reduction in costs and energy requirements while achieving superior basic sediment and water removal. One of the topics becoming more relevant is the reduction of CO2 emissions. At least 5% of the abstracts I reviewed addressed lowering CO2 emissions as their main topic. Energy harvesting is an economically interesting way to reduce emissions because the energy consumption of the facility is reduced. The study shown in paper OTC 31724 describes energy harvesting from hydraulic pressure drops as an example of the circular economy applied to oil-production facilities. In this study, the energy and costs savings were evaluated at different pressure-drop points of a gas/oil separation plant. Paper SPE 207096 uses pinch analysis to perform a detailed heat-exchange-network retrofitting study of a crude distillation unit, predicting 8% of energy savings. I sincerely hope that we can see more developments in this area in coming years. Recommended additional reading at OnePetro: www.onepetro.org. IPTC 21799 Effectiveness of Dynamic-Response Spectroscopy and Microwave-Inspection Technology for Substrate Pipe and Composite Wraps by Rehan Ahmed, Petronas, et al. OTC 31075 Premium Antirotation Casing Connector With Metal-to-Metal Seal Optimized for High-Fatigue Performance To Meet Market Needs by Reducing Operational Expenditure and Risk Exposure by Scott Patrick Ellisor, Dril-Quip, et al. SPE 207096 A Practical Approach to Energy Optimization Using Pinch Analysis: A Case Study of an Oil Refinery by Paschal Uzoma Ndunagu, Honeywell, et al. OTC 31724 Circular Economy Initiatives at Upstream Surface Facilities by Ahmed Khalid Bu Ali, Aramco, et al.

Graphical Prediction of Optimum Pinch Point Value with AEA Software Simulation and Validation Applied in Closed Cycle Gas Power Plant

Studying industries energy saving is very important prospect for many researchers in the last four decades. In this respect, better process heat transfer can be achieved to improve process operating and capital cost. Thereafter, obtaining higher amount of heat recovery, which will help to reach system optimum heat exchanger network design. Application of Pinch analysis (PA) in our current study, was found to be as an effective method towards economic solution and assessment for all system thermal processes. Whereby, minimizing energy losses, and thus, prediction of maximum energy saving. In addition, application of "Aspen Energy Analyzer (AEA)" simulation software assist our effort to optimize Heat Exchanger Network design (HEN), with various application scenario towards best design. This study represents a "Case study" as a Brayton closed cycle gas turbine power plant in Al-khairat district, which is one of a number of sites used to generate electricity for Iraq national grid. However, the plant original design is open cycle. This study, represent an attempt to apply (PA) in system closed cycle model with the same working conditions. The results predicted, on the contrary of open cycle, that using closed cycle (PA) with temperature difference ∆Tmin can be acceptable with several design propositions. The optimum (∆Tmin = 15℃) were evaluated in the closed cycle system pinch analysis, thereby the maximum Qrec. process that minimize the QHmin & QCmin requirement were identified by the software simulation for the best HEN design. These results were found as Qrec. = 318.330 MW, QHmin = 88.607 MW and QCmin =39.564 MW.

Study of Energy Integration in Chlorobenzene Production Process Using Pinch Technology

In this paper, the industrial application of detailed heat integration in the chlorobenzene production plant has been solved by using the Pinch design method. Designing a Heat Exchanger Network (HEN) through pinch analysis is an effective energy integration technology. In addition, minimizing unit and cost, operability and process control are essential parameters for selecting a suitable HEN design. In this research, the HEN of the existing process has been designed and analyzed using HINT software to minimize energy consumption and cost, thereby achieving maximum energy recovery. The analysis shows that the existing plant has been well integrated, and sound energy-saving effects and minimum energy requirements have been observed through the energy integration between processes. The total energy saving has been 91.80 %, while the energy recovery for heating and cooling have been 86.99 % and 96.23 %, respectively. Based on the economic analysis, the total annual cost of the proposed HEN design has been calculated to be 80912.5 $.

Energy Integration of Crude Distillation Unit of a Refining and Petrochemical Company in Northern Nigeria

Most Nigerian refineries were constructed before pinch technology was developed, hence, the design were not optimal, leading to high energy loss. The objective of this work is to evaluate energy integration of crude distillation unit (CDU) of a refining and petrochemical company in Northern Nigeria using pinch analysis by utilising HINT software. Minimum heating and cooling demand of 32251.1 kW and 29637.9 kW at the pinch point of 506.5 K was evaluated from the composite curve, grand composite curve and the cascade diagram. The region of overlap in the composite curve indicates a total of 108,945 kW as the possible energy that can be recovered in the process. Existing utility demand of the unit was 96,873.5 kW, after heat integration it reduces to 61,889 kW, this showed 36.11 % energy saving with a total operating cost of US$4,560,766.5 that could be saved (annually). Minimum approach temperature (DTmin) analysis results showed an optimum DTmin of 15 K which resulted in a total annual cost of US$6,715,700. Furthermore, the analysis showed the effect of DTmin on energy, area, minimum number of units and cost targets. The design objective of the retrofit heat exchanger network (HEN) was set toward maximum energy recovery. A total of twenty (20) heat exchangers made up the new network, which comprises of twelve (12) process to process heat exchangers, two (2) heaters and six (6) coolers.

Novel circularity and sustainability assessment of symbiosis networks through the Energy Quality Pinch concept

Circular Economy is a well-known concept to mitigate global resource depletion issues. The sustainability of a system is closely related to its environmental performance, which is directly linked to energy consumption. This work provides a circularity assessment tool by determining the minimum system energy requirements, according to the Energy Quality Factor, as it indicates the useful energy that can be extracted from material and energy flows. The proposed tool is Energy Quality Pinch Analysis which identifies the minimum energy requirements for a circular system and shows the system's sustainability. The analysis considers cascades of the energy used and released by recycling and symbiosis processes, evaluating the minimal external energy flows: high-quality energy input and waste energy output. The method is applied to case studies, including Total Site Heat and Power Integration, chemical energy reuse in wastewater systems, and Municipal Solid Waste management. Practical energy conversion technologies in each study are proposed as well. The results of the case studies indicate that the degree of energy recovery rate can be as high as 60% for the case of the utility system and higher for the cases of wastewater and municipal waste treatment, providing potentially valuable guidance to system designers.

Energy–Water–Carbon Nexus Study for the Optimal Design of Integrated Energy–Water Systems Considering Process Losses

Integrated energy–water systems have been explored using different process integration techniques considering the energy–water–carbon nexus to minimize the carbon footprint, e.g., pinch analysis techniques (power cascade table, water cascade table, and energy planning pinch diagram). However, the power and water losses while considering the energy–water–carbon nexus have not been explored in detail in the previous works. This work focuses on the modifications of the existing pinch analysis methods for energy–water–carbon nexus study while considering power and water losses, for an optimized energy–water system. Power and water losses should not be neglected in the analysis as they have a significant impact on the carbon emissions and overall capacities of energy and water. The effect of losses on energy storage capacity, outsourced electricity, water supply volume and water storage capacity were evaluated on an industrial case study. Results from the case study demonstrate that, while considering power losses during power allocation can lower storage capacity, it tends to raise the needed outsourced electricity supply. As water supply volume tends to increase, the water storage capacity tends to decline when losses are considered. The results were compared to the data without losses, and it was observed that the storage capacity of energy decreases by 4% while outsourced energy increases by 6%. Water supply volume increases by 20% but water storage capacity decreases by 13.7%. The emissions from energy system remains same while from the water system the emissions rise significantly by 20%. It is expected that consumers that takes power and water losses into account will produce more realistic and reliable energy, water, and carbon reduction targets and prevent under-sizing issues in designing integrated energy–water systems.

A heat integration case study for the dehydration and condensate stabilization units in LNG plants for economic and energy savings

Liquefied Natural Gas, derived from natural gas is the cleanest fossil fuel, and it plays a critical role in global energy markets, although its production is costly. To partially reduce the cost, this study considers the hot section (pre-separation) of LNG process and integrates the Tri-Ethylene Glycol Dehydration and Condensate stabilization units for maximum energy savings using the Pinch Analysis technique, which is conducted through Aspen Energy Analyser V10. Plant simulations are used to verify the feasibility and functionality of the whole heat integration design. The energy analysis reveals ten heat exchange networks (HEN) comprising of two heaters and five coolers and one process heat exchanger for the base case simulation. Whereas the total energy required for the base case is 80.86 MW and indirect carbon emissions are 395.3 tonne/d. After integrating the units, the energy consumption for heating and cooling are reduced by 18.83% and 21.37%, respectively, while carbon emissions are reduced by 316.2 tonne/d.

Investigation of process stream systems for targeting energy-capital trade-offs of a heat recovery network

The process industries consume a huge amount of heat energy contributing to environmental impact. Energy recovery is a key instrument of energy-saving that can be implemented via a heat exchanger network. Pinch-based approaches presume analysis of energy targets of industrial processes to find the optimal ΔTmin for heat exchanger network design. Classical Pinch Analysis do not account for the stream splitting in the super targeting procedure while parallel branches are usually needed. The splitters and mixers contribute a lot to the capital cost of the heat exchanger network. Current work proposes the update of super targeting procedure accounting stream splitting and mixing in a Pinch problem. The original algorithm of Composite Curves construction is proposed to analyse the distribution of process streams and stream splitting in subsystems above/below the Pinch before the design of the heat exchanger network. It was then used in a super targeting procedure to precise the capital cost and, as a result, the optimal ΔTmin. The process stream distribution and stream splitting are analysed in a whole range of ΔTmin. Identifying all possible starting points for heat exchanger network design. Two new criteria were proposed to estimate the topological complexity of network pre-design and the specific ratio of stream splitting. The case study analyses the ethylene oxide process and calculation of trade-off between capital and energy costs were performed and optimal ΔTmin = 16 °C. The result was compared with two known approaches, which account for the number of heat exchangers without stream splitting. Total annual costs and optimal ΔTmin was also calculated for different energy prices to show a possible deviation of starting point for heat exchanger network design. The range of optimal ΔTmin from 9 to 54 °C resulted in the range of hot utility prices from 42 to 291 $/kWy, and the emission targets will be from 14,380 to 77,919 tCO2/y. The methodology can be used for the pre-design of the heat exchanger network to better precise the optimal ΔTmin, capital cost targets, and check the optimum changing for different energy prices.

Analysis of an energy storage system using reversible calcium hydroxide in fluidised-bed reactors

• Conceptual study of new CSP-TCES layouts based on calcium hydroxide reaction. • Single fluidised bed reactor designs simplify plant integration and reduce costs. • Design and operation challenges with different requirements in charge and discharge. • Novel insights for reactor design and thermal integration of the systems. • Competitive round-trip efficiency values of 68% and LCOE values of 67–83 $/MWhe. The widespread use of renewable energy requires the support of high-capacity energy storage systems. This work proposes a thermochemical energy storage system for concentrated solar power plants based on the reversible hydration/dehydration process of the calcium hydroxide. It is a single fluidised bed reactor concept with alternating dehydration-hydration processes, charging and discharging alternating reactions, with superheated steam as fluidising agent. The system has been modelled using Aspen Plus™, including equilibrium data and hydrodynamic performance of the reactor. The model has been used to evaluate the effect of different parameters of the reactor, such as geometry, average particle size, or inlet streams conditions, on the performance of the reactor and the system. The thermal integration of the system was optimised using pinch analysis. For the proposed layouts, round-trip efficiencies values of 68 % are obtained. The economic analyses show specific investment costs between 4170 $/kWe and 3250 $/kWe for plants in the range of 31 MW to 45 MW, which are competitive with those expected for plants with storage of molten salts in this power range. LCOE values between 67 $/MWh and 83 $/MWh were obtained. The analyses show how these values highly depend on the fresh material replacement requirements related to the deactivation of the material and operational strategies. The results show the interest in further developments of this concept for concentrated solar power plants.

Greenhouse gas reduction through optimal breeding policy and diet configuration targeting via Carbon Emission Pinch Analysis

Carbon emission neutralisation is the future target in many countries. Many sectors including the breeding industry, are contributing to achieve this target. Carbon emissions can be reduced by adjusting breeding and dietary structures. This study develops a Food-Carbon Emission Pinch Analysis tool for diet configuration optimisation to target possible greenhouse gas reduction. Several scenarios with different aims are considered to adjust the diet configuration in China and Zhejiang province. Results show that from the perspective of nutrition, replacing meat with equal protein mass of fish is more reasonable. 8.42 kg fish consumption should be increased, and 10.16 kg poultry and livestock meat consumption should be reduced annual per capita to reduce 10% food-carbon emission in Zhejiang province. For China as a whole, 9.88 Mt of poultry and livestock meat consumption should be reduced to achieve the 10% reduction target. If the reduced meat consumption is fully borne by the domestic breeding industry, the income of the domestic breeding industry would be reduced by 202,724 M CNY. It is recommended to reduce meat consumption by reducing meat imports and to increase the breeding and consumption of low-carbon fish rather than shellfish because of its extremely low carbon emission factor.

Economic Analysis of Separation Unit of Methanol to Propylene Production Based on Optimization of Refrigeration Cycles Using Pinch and Exergy Analysis

In this study, optimization and economic analysis of the separation of light gases in the methanol to propylene, MTP, process along with refrigeration cycles design are performed, by using pinch and exergy analysis. In the course of the separation process optimization and refrigeration cycles design, by using a Visual Basic, VB, program and genetic algorithm, GA, rigorous distillation simulation is carried out, then streams information is employed to find optimum temperature levels, corresponding to tower condenser temperature, by minimizing the areas between the Exergy Grand Composite Curve, EGCC, and constant temperature levels of refrigeration cycles. Economic calculations were performed to obtain the lowest total annual cost, TAC, for refrigeration cycles, towers and other equipment. Two cases of the direct and indirect sequences are examined through the developed framework, inspection of their results represents that the operational cost has a significant contribution to the TAC. As a result, heat integration would reduce it by nearly 60%. Also, scrutinized analysis of the optimization results, especially by considering the TAC and its contributions, for the direct and indirect sequences, leads to the conclusion that indirect sequence would exhibit lower cost for light gas separation. The framework represented herein paves a way to the systematic design of integrated low-temperature separation processes with refrigeration cycles.

Heat Integration and Heat Exchanger Network Design with Aspen Energy Analyze

The considerable amount of energy used in industrial processes is typically used for heating and cooling. The synthesis of heat ex-changer networks (HEN) is a critical topic in this industry in order to reduce energy and capital costs in chemical plants. Heating and cooling systems in industry must be designed efficiently, which can be done using technologies like pinch analysis to create an optimal heat recovery network. Heat pinch analysis is a systematic method for designing thermally efficient systems. A designer can determine the minimum heating and cooling requirements as well as the maximum heat recovery (MHR) potential by locating a thermodynamic bottleneck, or the pinch point for heat recovery. This Paper uses Aspen Energy Analyzer for HEN Design.Heat integration network design is a cost-effective strategy that helps industries to cut costs by reducing the number of external utilities needed and increase profitability by lowering energy consumption. The HENs’ composite curves, grand composite curves, grid representation, and target reports were created using the Aspen Energy Analyzer. The software suggested ten designs, which were then optimized based on total annualized cost. By comparing it to other optimized designs, the best design is determined.

Pinch Analysis for Heat Integration of Pulverized Coke Chemical Looping Gasification Coupled with Coke-Oven Gas to Methanol and Ammonia

Methanol and ammonia are important chemical materials in the chemical industry. During the production of methanol and ammonia, a large amount of waste heat is released. The waste heat can be used to save energy and reduce CO2 emissions. In this study, pinch analysis is used to design the heat exchanger network (HEN) of pulverized coke (PC) chemical looping gasification coupled with coke-oven gas (COG) to methanol and ammonia (PCCLHG-CGTMA). The heat integration process is accomplished in two ways, as mentioned below. (1) The HENs in each of the three heat exchange units are designed individually; (2) the HENs of the three heat exchange units are treated as a whole and designed simultaneously. Compared to the HEN designed individually, when the HENs are designed as a whole, a total of 112.12 MW of hot and cold utilities are saved. In the HENs designed as a whole, the reduction in operating cost is sufficient to offset the increase in capital cost; the total annual cost (TAC) is reduced by 10.9%. These results reveal that the HENs designed as a whole have more scope for energy saving, which can be a reference for new HEN design and modification to realize more heat recovery and lower investment.