An anchor-tenant approach to the synthesis of carbon-hydrogen-oxygen symbiosis networks

Sustainable development of industrial cities and eco-industrial parks (EIPs) requires careful consideration and creation of synergistic opportunities among the participating entities. Recently, a multi-scale design approach was developed for carbon-hydrogen-oxygen symbiosis networks (CHOSYNs) with focus on the targeting, integration, and retrofitting of EIPs involving a set of existing facilities. Another important category of EIPs involves the grass-root design of industrial cities in which the participants are not originally known. Instead, ?anchor? plants are first invited followed by the consideration and invitation of supporting facilities (referred to as ?tenants?) that are to be determined according to integration opportunities with the anchors, other tenants, common infrastructure while accounting for resource limitations, market demands, and environmental regulations. The purpose of this work is to introduce a multi-scale targeting, synthesis, and optimization approach for the grass-root design of EIPs with known anchors. The CHOSYN framework is extended to tackle the case of candidate tenants with the objective of identifying industrial facilities, raw materials, byproducts, products, and wastes that can be effectively integrated with the anchors, among the participating tenants, and with the surrounding markets. Atomic-based and techno-economic targeting approaches are developed to identify benchmarks for mass integration within the EIP and to provide preliminary screening of the type and size of candidate tenants. Next, an optimization framework is developed to synthesize a highly-integrated and cost-effective cluster of anchors and tenants with sufficient design details on the individual facilities and the interaction among the participating plants. A case study is solved to demonstrate the multi-scale targeting, synthesis, and optimization approaches for the grass-root design of EIPs. ? 2018 Elsevier LtdThis paper was made possible by NPRP grant no. 6-678-2-280 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu

Optimal Scheduling of Biodiesel Plants through Property-based Integration with Oil Refineries

This paper addresses the design and scheduling problem of biodiesel plants in conjunction with typical oil refineries via blending of biodiesel and petro-diesel. The feedstocks are often seasonal and their availability and cost usually vary with time. A multi-period scheduling framework is formulated as an optimization problem to determine the optimal feedstock utilization and blending of biodiesel with petro-diesel using a property-integration framework. A case study is solved to illustrate the applicability of the devised approach. 2011 Elsevier B.V.Scopu

Flare minimization for an olefin plant shutdown via plant-wide dynamic simulation

During shutdown operations of chemical plants, significant amounts of raw materials, intermediates, and products may be flared leading to economic losses and emissions such as carbon dioxide, nitrogen oxides, and volatile organic compounds. Thus, flare minimization during plant shutdown is a desirable goal towards economic benefit and environmental sustainability. In this paper, a systematic flare minimization methodology for an olefin plant shutdown operation has been developed. It includes three iterative stages: (i) steady-state modeling and validation to build the foundation of the dynamic modeling; (ii) dynamic modeling and validation to enable plant-wide simulations under designated plant control strategies; and (iii) plant shutdown simulation and optimization to iteratively examine, validate, quantify various flare minimization opportunities so as to identify the improved shutdown strategy. Particularly, dynamic performances of the critical equipment (e.g., the cracked gas compressor) has been thoroughly investigated to ensure the operating safety associated with the developed new shutdown strategy. Compared with the conventional plant shutdown strategy, the case study has shown that the new development can significantly reduce flared raw materials and emissions by 90.23%, which result in estimated economic savings by 91.03% and the social cost of carbon saving by 90.37%. 2020 Elsevier LtdThis work was supported impart by the Qatar National Research Fund ( NPRP 5-351-2-136 ), Texas Air Research Center and President Visionary Initiative Project from Lamar University in USA .Scopu

Integrating uncertainty quantification in reliability, availability, and maintainability (RAM) analysis in the conceptual and preliminary stages of chemical process design

Traditional analysis of a proposed process design uses average input values in the performance assessment model, thereby generating single-point estimates. The resulting estimates ignore reliability, availability, and maintainability (RAM) considerations, or assume a fixed value based on prior experience. As a result, a probabilistic view of the impact of equipment unavailability on process profitability is not considered. Recent works have proposed a financial framework for incorporating safety and sustainability considerations in the analysis of proposed designs. Based on this research, we propose a framework to integrate RAM aspects during the conceptual design stage in a probabilistic manner using Monte Carlo simulation. Subsequently, full distribution profiles of key process performance indicators are generated, including system and section availability, annual net profit, and return on investment (ROI). Probabilistic characterization of equipment availability also facilitates the prediction of potential safety and sustainability issues, as more frequent process upsets may result in increased flaring and other potential negative consequences. A modified availability metric, using restoration instead of repair times, is used in this work to obtain a more accurate view of expected downtime and thus its effects on profitability. A propane dehydrogenation (PDH) process system is used to demonstrate the application and benefits of the framework. The proposed approach allows designers and decision-makers to comprehensively assess the impacts of equipment RAM characteristics on process availability and economic performance. © 2021 Institution of Chemical Engineer

A stochastic approach to evaluating the economic impact of disruptions in feedstock pipelines on downstream production

Reliability of feedstock supply is an important consideration for enhancing the safety and continuous operation of chemical plants. A critical component of the chemical and refining sectors is the extensive pipeline network which transports natural gas and hydrocarbon liquids from producing areas to refineries and chemical plants. Incidents involving spills or releases and shutdowns of those pipeline can occur due to a number of causes including corrosion, equipment malfunction, and excavation damage. These incidents involve economic, environmental, and safety consequences such as the cost of asset damage, lost commodities, cleanup requirement, and operational disruption. In this work, an appropriately developed stochastic framework is presented to determine the disruption impact of pipeline incidents on downstream chemical production. Incident data are statistically analyzed to determine meaningful distributions for incident rates, spill/release quantities, and pipeline shutdown durations. A case study on the production of propylene via three different pathways (crude oil, propane, and natural gas) is presented to illustrate the methodology and underline the variability of the process production impact due to variations in risk occurrence characteristics. Using specific process chemistry and mass balances, more precise risk profiles for the product shortfall and cost of lost sales can be generated. © 2022 The Institution of Chemical Engineer

A pinch analysis approach to environmental risk management in industrial solvent selection

Abstract: The problem of solvent selection in an industrial process has been examined in a number of different approaches, often including single- and multi-criteria optimization techniques. Traditionally, it has been addressed using techno-economic analyses and mathematical modeling techniques usually aiming at optimizing certain economic objectives such as maximizing profitability, minimizing cost and solvent usage. The proposed methodology offers an insightful environmental risk management framework for determining the optimal solvent profiles that can effectively match process requirements and at the same time ensure safe process performance. Through this approach, the risk aspects of utilizing a number of available solvents and their mixtures for particular process tasks were first examined and targets for the selection based on solvents safety characteristics, such as the permissible exposure limit, were established. This approach, when considered in conjunction with economic performance assessment, can be substantially useful, because it enables prioritization of solvent selection options based on insightfully tracking the degree of environmental risk performance in systems with complex chemical characteristics. A pinch analysis methodology enables the direct targeting of minimum solvent(s) utilization and optimal allocation of the appropriate solvents to process sinks based on their degree of environmental risk. The methodology can also provide solvent selection and design insights for enhanced usage in any industrial process system while highlighting appropriate sustainable solutions. A case study is finally presented to illustrate the applicability of the proposed methodology. Graphical abstract: Graphical representation of the solvent selection and allocation problem addressed using the risk-based pinch analysis approach (where R i is the risk index of solvent i, W i , F fr , G j are the flowrates of sources, fresh and required flowrates of the sinks, respectively)Scopu

Synthesis of Heat Integrated Resource Conservation Networks with Varying Operating Parameters

This paper presents the synthesis of heat integrated resource conservation networks (HIRCNs), covering both concentration- and property-based direct reuse/recycle systems. This newly proposed method adopts the targeting concept of the insight-based pinch approach where the minimum consumption of fresh resources and energy utilities is targeted prior to the detailed HIRCN design. Furthermore, this method is capable of handling HIRCN problems with varying operating range of process parameters (i.e., flow rates, temperatures, and properties). The proposed method is formulated as a mixed integer nonlinear program (MINLP). As the temperature of stream is uncertain, the floating pinch concept is adopted to identify hot and cold utilities. Besides, a recently developed discretization approach is also used to solve the MINLP problem. Three literature case studies are solved to illustrate the proposed method