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Chemical plant flare minimization via plantwide dynamic simulation / Qiang Xu in Industrial & engineering chemistry research, Vol. 48 N° 7 (Avril 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 7 (Avril 2009) . - pp. 3505–3512 Titre : Chemical plant flare minimization via plantwide dynamic simulation Type de document : texte imprimé Auteurs : Qiang Xu, Auteur ; Xiongtao Yang, Auteur ; Chaowei Liu, Auteur Année de publication : 2009 Article en page(s) : pp. 3505–3512 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Flare  minimization  Plant  start-up  operations  Plantwide  dynamic  simulation Résumé : Flaring is crucial to chemical plant safety. However, excessive flaring, especially the intensive flaring during the chemical plant start-up operation, emits huge amounts of volatile organic compounds (VOCs) and highly reactive VOCs, which meanwhile results in tremendous industrial material and energy loss. Thus, the flare emission should be minimized if at all possible. This paper presents a general methodology on flare minimization for chemical plant start-up operations via plantwide dynamic simulation. The methodology starts with setup and validation of plantwide steady-state and dynamic simulation models. The validated dynamic model is then systematically transformed to the initial state of start-up and thereafter virtually run to check the plant start-up procedures. Any infeasible or risky scenarios will be fed back to plant engineers for operation improvement. The plantwide dynamic simulation provides an insight into process dynamic behaviors, which is crucial for the plant to minimize the flaring while maintaining operational feasibility and safety. The efficacy of the developed methodology has been demonstrated by a real start-up test. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8016219 [article] Chemical plant flare minimization via plantwide dynamic simulation [texte imprimé] / Qiang Xu, Auteur ; Xiongtao Yang, Auteur ; Chaowei Liu, Auteur . - 2009 . - pp. 3505–3512. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 7 (Avril 2009) . - pp. 3505–3512 Mots-clés : Flare  minimization  Plant  start-up  operations  Plantwide  dynamic  simulation Résumé : Flaring is crucial to chemical plant safety. However, excessive flaring, especially the intensive flaring during the chemical plant start-up operation, emits huge amounts of volatile organic compounds (VOCs) and highly reactive VOCs, which meanwhile results in tremendous industrial material and energy loss. Thus, the flare emission should be minimized if at all possible. This paper presents a general methodology on flare minimization for chemical plant start-up operations via plantwide dynamic simulation. The methodology starts with setup and validation of plantwide steady-state and dynamic simulation models. The validated dynamic model is then systematically transformed to the initial state of start-up and thereafter virtually run to check the plant start-up procedures. Any infeasible or risky scenarios will be fed back to plant engineers for operation improvement. The plantwide dynamic simulation provides an insight into process dynamic behaviors, which is crucial for the plant to minimize the flaring while maintaining operational feasibility and safety. The efficacy of the developed methodology has been demonstrated by a real start-up test. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8016219

Cyclic scheduling for ethylene cracking furnace system with consideration of secondary ethane cracking / Chuanyu Zhao in Industrial & engineering chemistry research, Vol. 49 N° 12 (Juin 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5765–5774 Titre : Cyclic scheduling for ethylene cracking furnace system with consideration of secondary ethane cracking Type de document : texte imprimé Auteurs : Chuanyu Zhao, Auteur ; Chaowei Liu, Auteur ; Qiang Xu, Auteur Année de publication : 2010 Article en page(s) : pp. 5765–5774 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Cracking  furnace  systems  Mixed-integer  nonlinear  programming  Scheduling  model Résumé : Cracking furnaces of ethylene plants are capable of processing multiple feeds to produce smaller hydrocarbon molecules, such as ethylene, propylene, and ethane. The best practice for handling the produced ethane is to recycle it as an internal feed and conduct the secondary cracking in a specific furnace. As cracking furnaces have to be periodically shut down for decoking, when multiple furnaces processing different feeds under various product values and manufacturing costs are considered, the operational scheduling for the entire furnace system should be optimized to achieve the best economic performance. In this paper, a new MINLP (mixed-integer nonlinear programming) model has been developed to optimize the operation of cracking furnace systems with the consideration of secondary ethane cracking. This model is more practical than the previous study and can simultaneously identify the allocation of feeds with their quantity, time, and sequence information for each cracking furnace. A case study has demonstrated the efficacy of the developed scheduling model. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1001235 [article] Cyclic scheduling for ethylene cracking furnace system with consideration of secondary ethane cracking [texte imprimé] / Chuanyu Zhao, Auteur ; Chaowei Liu, Auteur ; Qiang Xu, Auteur . - 2010 . - pp. 5765–5774. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5765–5774 Mots-clés : Cracking  furnace  systems  Mixed-integer  nonlinear  programming  Scheduling  model Résumé : Cracking furnaces of ethylene plants are capable of processing multiple feeds to produce smaller hydrocarbon molecules, such as ethylene, propylene, and ethane. The best practice for handling the produced ethane is to recycle it as an internal feed and conduct the secondary cracking in a specific furnace. As cracking furnaces have to be periodically shut down for decoking, when multiple furnaces processing different feeds under various product values and manufacturing costs are considered, the operational scheduling for the entire furnace system should be optimized to achieve the best economic performance. In this paper, a new MINLP (mixed-integer nonlinear programming) model has been developed to optimize the operation of cracking furnace systems with the consideration of secondary ethane cracking. This model is more practical than the previous study and can simultaneously identify the allocation of feeds with their quantity, time, and sequence information for each cracking furnace. A case study has demonstrated the efficacy of the developed scheduling model. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1001235

Dynamic scheduling for ethylene cracking furnace system / Chuanyu Zhao in Industrial & engineering chemistry research, Vol. 50 N° 21 (Novembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12026-12040 Titre : Dynamic scheduling for ethylene cracking furnace system Type de document : texte imprimé Auteurs : Chuanyu Zhao, Auteur ; Chaowei Liu, Auteur ; Qiang Xu, Auteur Année de publication : 2011 Article en page(s) : pp. 12026-12040 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Cracking  Scheduling Résumé : The craking furnace system is crucial for an olefin plant. its operation needs to follow a predefined schelule to process various feeds continuously, meanwhile conducting a periodically decoking operation for each furnace when its performance apparently decreases. In practice, because the feed supply changes dynamically, the routine furnace scheduling is better performed in a dynamic and reactive way, through which the furnace operations can be smartly rescheduled with respect to any delivery of new coming feeds. Thus, the feeds from the new delivery and the leftover inventories can be timely, feasibly, and optimally allocated to different furnaces for processing to obtain the maximum average net profit per time. Facing this challenge, this paper develops a new MINLP-based reactive scheduling strategy, which can dynamically generate reschedules based on the new feed deliveries, the leftover feeds, and current furnace operating conditions. It simultaneously addresses all the major scheduling issues of a cracking furnace system, such as semicontinuous operation, nonsimultaneous decoking, secondary ethane cracking, and seamless rescheduling. The efficacy of the study and its significant economic potential are demonstrated by a comprehensive case study. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697522 [article] Dynamic scheduling for ethylene cracking furnace system [texte imprimé] / Chuanyu Zhao, Auteur ; Chaowei Liu, Auteur ; Qiang Xu, Auteur . - 2011 . - pp. 12026-12040. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12026-12040 Mots-clés : Cracking  Scheduling Résumé : The craking furnace system is crucial for an olefin plant. its operation needs to follow a predefined schelule to process various feeds continuously, meanwhile conducting a periodically decoking operation for each furnace when its performance apparently decreases. In practice, because the feed supply changes dynamically, the routine furnace scheduling is better performed in a dynamic and reactive way, through which the furnace operations can be smartly rescheduled with respect to any delivery of new coming feeds. Thus, the feeds from the new delivery and the leftover inventories can be timely, feasibly, and optimally allocated to different furnaces for processing to obtain the maximum average net profit per time. Facing this challenge, this paper develops a new MINLP-based reactive scheduling strategy, which can dynamically generate reschedules based on the new feed deliveries, the leftover feeds, and current furnace operating conditions. It simultaneously addresses all the major scheduling issues of a cracking furnace system, such as semicontinuous operation, nonsimultaneous decoking, secondary ethane cracking, and seamless rescheduling. The efficacy of the study and its significant economic potential are demonstrated by a comprehensive case study. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697522

Emission source characterization for proactive flare minimization during ethylene plant start-ups / Chaowei Liu in Industrial & engineering chemistry research, Vol. 49 N° 12 (Juin 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5734–5741 Titre : Emission source characterization for proactive flare minimization during ethylene plant start-ups Type de document : texte imprimé Auteurs : Chaowei Liu, Auteur ; Qiang Xu, Auteur Année de publication : 2010 Article en page(s) : pp. 5734–5741 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Ethylene  plant  start-ups  Plant-wide  dynamic  simulations Résumé : Ethylene plant start-ups generate huge amounts of off-spec products for flaring, which cause negative environmental and societal impacts, as well as tremendous raw material and energy losses that could be unitized to generate much more needed products. Thus, cost-effective start-up flare minimization strategies through proactive process design and operation are becoming more important and attractive to the industry. However, fundamental and quantitative studies on start-up flaring emissions are still lacking, such as (i) what kinds of emission species are contained in the flaring sources; (ii) how much of each emission source will be generated during one start-up; and (iii) what is the dynamic emission profile of each emission source with respect to the start-up time? In this paper, rigorous plant-wide dynamic simulations are employed to characterize flaring emission sources under different flare minimization strategies for an ethylene plant start-up. Deep insights of the emission source distribution and simulated dynamic emission profiles are provided. The study enriches the emission inventory with details for industry point sources, which have never been compiled previously. It also provides detailed technical support for both the industry and environmental agencies on evaluating and developing cost-effective flare minimization strategies in the future. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902002c [article] Emission source characterization for proactive flare minimization during ethylene plant start-ups [texte imprimé] / Chaowei Liu, Auteur ; Qiang Xu, Auteur . - 2010 . - pp. 5734–5741. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5734–5741 Mots-clés : Ethylene  plant  start-ups  Plant-wide  dynamic  simulations Résumé : Ethylene plant start-ups generate huge amounts of off-spec products for flaring, which cause negative environmental and societal impacts, as well as tremendous raw material and energy losses that could be unitized to generate much more needed products. Thus, cost-effective start-up flare minimization strategies through proactive process design and operation are becoming more important and attractive to the industry. However, fundamental and quantitative studies on start-up flaring emissions are still lacking, such as (i) what kinds of emission species are contained in the flaring sources; (ii) how much of each emission source will be generated during one start-up; and (iii) what is the dynamic emission profile of each emission source with respect to the start-up time? In this paper, rigorous plant-wide dynamic simulations are employed to characterize flaring emission sources under different flare minimization strategies for an ethylene plant start-up. Deep insights of the emission source distribution and simulated dynamic emission profiles are provided. The study enriches the emission inventory with details for industry point sources, which have never been compiled previously. It also provides detailed technical support for both the industry and environmental agencies on evaluating and developing cost-effective flare minimization strategies in the future. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902002c

Thermodynamic - analysis - based design and operation for boil - Off gas flare minimization at LNG receiving terminals / Chaowei Liu in Industrial & engineering chemistry research, Vol. 49 N° 16 (Août 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7412–7420 Titre : Thermodynamic - analysis - based design and operation for boil - Off gas flare minimization at LNG receiving terminals Type de document : texte imprimé Auteurs : Chaowei Liu, Auteur ; Zhang, Jian, Auteur ; Qiang Xu, Auteur Année de publication : 2010 Article en page(s) : pp. 7412–7420 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermodynamic  Gas Résumé : The LNG (liquefied natural gas) receiving terminal is an important component of the entire LNG value chain. The handling of unloading BOG (boil-off gas) during LNG regasification at LNG receiving terminals significantly influences the BOG flare emission and energy consumption. In this work, thermodynamic-analysis-based design and operations are simultaneously considered to recover BOG with the minimum total energy consumption, a goal of which is to provide a cost-effective flare minimization strategy at LNG receiving terminals. A rigorous simulation-based optimization model and its solution algorithm are developed based on an LNG regasification superstructure. Case studies are used to demonstrate the efficacy of the developed methodology. The presented general optimization model and thermodynamic analysis also provide fundamental understandings of the LNG regasification process that are valuable for industrial applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1008426 [article] Thermodynamic - analysis - based design and operation for boil - Off gas flare minimization at LNG receiving terminals [texte imprimé] / Chaowei Liu, Auteur ; Zhang, Jian, Auteur ; Qiang Xu, Auteur . - 2010 . - pp. 7412–7420. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7412–7420 Mots-clés : Thermodynamic  Gas Résumé : The LNG (liquefied natural gas) receiving terminal is an important component of the entire LNG value chain. The handling of unloading BOG (boil-off gas) during LNG regasification at LNG receiving terminals significantly influences the BOG flare emission and energy consumption. In this work, thermodynamic-analysis-based design and operations are simultaneously considered to recover BOG with the minimum total energy consumption, a goal of which is to provide a cost-effective flare minimization strategy at LNG receiving terminals. A rigorous simulation-based optimization model and its solution algorithm are developed based on an LNG regasification superstructure. Case studies are used to demonstrate the efficacy of the developed methodology. The presented general optimization model and thermodynamic analysis also provide fundamental understandings of the LNG regasification process that are valuable for industrial applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1008426