Wenkai Li

FacultyGraduate School of International Management
PositionProfessor
Last Updated: Feb. 04, 2019 at 11:47

Researcher Profile & Settings

Name

    Wenkai Li

Profile & Settings

    Profile:
    PhD from Hong Kong University of Science and Technology, 2004.
    Professor of Operations Management.
    Research Interests: Supply Chain Management, Operations Management and its Applications in Different Businesses,Life Cycle Assessment

Affiliation

  • Graduate School of International Management Professor

Education

  • Sep. 2000Jun. 2004Hong Kong University of Science and Technology PhD

Degree

  • Doctor of Philosophy(Hong Kong University of Science and Technology)

Academic & Professional Experience

  • Sep. 2015- TodayProfessor, International University of Japan
  • Apr. 2014Sep. 2015Associate Professor, International University of Japan
  • Sep. 2011Apr. 2014Assistant Professor, International University of Japan

Research Activities

Published Papers

  • Simultaneous target of HEN and columns with variable feed temperatures for a toluene disproportionation plant
    3. B.J. Zhang , X. L. Luo , K. Liu , Qinglin Chen , and Wenkai Li
    Ind. Eng. Chem. Res. 53(25) 10429-10438 2014 [Refereed]
  • Synthesis Framework of Biorefinery Systems for Lignocellulosic Biorenewables
    Wenkai Li, Ramadoss Karthik, I. A. Karimi, Wong Pui Kwan
    Computer Aided Chemical Engineering 31 245-249 Aug. 2012 [Refereed]
    In this paper, we present a mathematical framework to design an economically attractive and environmentally friendly biorefinery. We embed various biomass feedstocks, conversion technologies, and products into a novel superstructure of alternative configurations for a general biorefinery. To obtain the optimal configuration and design of the biorefinery, we model each technology block using simplified mass, resource, and energy balance equations. These form the basis for the mathematical model. © 2012 Elsevier B.V.
  • Applying marginal value analysis in refinery planning
    Wenkai Li, Chi Wai Hui
    Chemical Engineering Communications 194 962-974 Jul. 2007 [Refereed]
    Most research work and refinery decision makers mainly focus on direct planning results such as the optimal combination of raw materials, unit loads, and production rates. There exists much more useful hidden information from an LP model such as marginal values of the feed stocks, the intermediate products, and the final products than direct planning results. One of the limitations of using marginal values is that they are only applied for stream flows at the solution point. We have no idea how these marginal values are changed beyond the solution. To tackle this problem, two analytical methods, namely sensitivity analysis (SA) and parametric programming (PP), are proposed and applied in MVA (marginal value analysis). With these two analysis methods, MVA can be extended beyond the solution point and applied to process constraints. This article first uses a simple gasoline blending example to illustrate the required modeling techniques and procedures for performing these analyses. Then a multi-period refinery case study is presented to show how to interpret the results and apply the analyses to a real world refinery. The approach proposed here can be of great help for debottlenecking, retrofitting, pricing, and investment evaluation. The analytical methods proposed can also be generally applied to other chemical plants.
  • A novel CDU model for refinery planning
    Wenkai Li, Chi Wai Hui, I. A. Karimi, I. A. Karimi, Rajagopalan Srinivasan, Rajagopalan Srinivasan
    Asia-Pacific Journal of Chemical Engineering 2 282-293 Jul. 2007 [Refereed]
    Crude distillation unit (CDU) operations are often defined in several operating modes, which are still being used by quite a few refineries for their planning. However, these operational modes cannot reflect all the everchanging operating conditions of a refinery. As a result, the CDU operation condition may be sub-optimal and potential profit may be lost. This paper proposes a CDU model to decide the weight transfer ratio (WTR) ranges of CDU fractions from the operation modes. These WTR ranges are integrated into the refinery planning model to obtain the optimal CDU operation condition. Unlike the traditional linear CDU models that often omit the optimal solutions, or the rigorous simulation models that are time consuming to solve, the proposed CDU model can be easily solved with much higher accuracy than traditional linear models and better solution speed than the rigorous simulation models. © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.
  • Refinery planning under correlated and truncated price and demand uncertainties
    Wenkai Li, I. A. Karimi, R. Srinivasan
    Computer Aided Chemical Engineering 21 2123-2128 Dec. 2006 [Refereed]
    Because of the difficulty in computing the bivariate integral originated from the correlated demand and price, most research work on uncertainty assumes that the demand and price are independent. This can cause significant discrepancies in revenue calculation and hence yield sub-optimal planning strategies. This paper presents a novel approach to handle correlated and truncated demand and price uncertainties. A bivariate normal distribution is used to describe demand and price. The double integral for unintegrable standard normal cumulative distribution function in the single integrals is approximated by polynomial functions. Case studies show that, assuming independent price and demand may underestimate the revenue by up to 20%. Since the real world demands or prices vary in limited ranges, integrating over the whole range of a normal distribution, which some research has done, may give incorrect results. This paper uses a bivariate double-truncated normal distribution to describe demand and price. The influence of different degrees of truncation on plant revenue is studied. © 2006 Elsevier B.V. All rights reserved.
  • Plant-wide planning and marginal value analysis for a refinery complex
    Wenkai Li, Xige Liang, Hui Chi-Wai
    Computer Aided Chemical Engineering 21 2117-2122 Dec. 2006 [Refereed]
    Recently, besides the production of petroleum products and fuels, modern refinery complexes are being reformed to become "energy plants" that are able to export electricity and steam. The success of this reformation depends, heavily on effective integration of the production and the energy system. In view of this, this paper proposes a plant-wide multi-period planning model for a real world refinery complex. All main plants, such as the refining plant, the lubricant oil plant and the utility plant etc., are integrated into a site model enabling the model to optimize operations among the plants at different periods and scenarios. Investment strategies and retrofitting suggestions are obtained which can contribute to an increase of the total profit by 6% in case studies. It has become common practice that electricity price is charged differently at different time shifts of a day in some countries. This paper proposes a multi-period model which examines how this pricing policy affects the operation of a refinery. Case studies show that adjusting the use of electricity to suit the price variance can significantly reduce operation costs in a refinery. Marginal Value Analysis (MVA), an analytical method that provides additional economic information for refinery complex, is also proposed in this paper. From the marginal value of final or intermediated products (e.g. electricity), important insights can be gained into the identification of production bottlenecks, decision-making and intermediate products pricing. © 2006 Elsevier B.V. All rights reserved.
  • Long-term electricity contract optimization with demand uncertainties
    Pang Chan, Chi Wai Hui, Wenkai Li, Haruo Sakamoto, Kentaro Hirata, Pu Li
    Energy 31 2133-2149 Oct. 2006 [Refereed]
    This paper presents a study on selecting electricity contracts for a large-scale chemical production plant, which requires electricity importation, under demand uncertainty. Two common types of electricity contracts are considered, time zone (TZ) contract and loading curve (LC) contract. A multi-period linear probabilistic programming model is adopted for the contract selection and optimization. Hence, by using the probabilistic programming, a solution procedure is proposed that allow users to determine the best electricity contract according to their desired confident level of the uncertainties. In addition, due to the fact that the demand of product is uncertain, if one considers the overage and shortage of the products in the market as well, an interesting result can be obtained. The methodology is explained in the paper. © 2005 Elsevier Ltd. All rights reserved.
  • Integrating CDU, FCC and product blending models into refinery planning
    Wenkai Li, Chi Wai Hui, Anxue Li
    Computers and Chemical Engineering 29 2010-2028 Aug. 2005 [Refereed]
    The accuracy of using linear models for crude distillation unit (CDU), fluidize-bed catalytic cracker (FCC) and product blending in refinery planning has been debated for decades. Inaccuracy caused by nonrigorous linear models may reduce the overall profitability or sacrifice product quality. On the other hand, using rigorous process models for refinery planning imposes unnecessary complications on the problem because these models lengthen the solution time and often hide critical issues and parameters for profit improvements. To overcome these problems, this paper presents a refinery planning model that utilizes simplified empirical nonlinear process models with considerations for crude characteristics, products' yields and qualities, etc. The proposed model can be easily solved with much higher accuracy than a traditional linear model. This paper will present how the CDU, FCC and product blending models are formulated and applied to refinery planning. Several case studies are used to illustrate the features of the refinery-planning model proposed. © 2005 Elsevier Ltd. All rights reserved.
  • Refinery planning under uncertainty
    Wenkai Li, Chi Wai Hui, Pu Li, An Xue Li
    Industrial and Engineering Chemistry Research 43 6742-6755 Oct. 2004 [Refereed]
    This paper presents a novel approach to refinery planning under uncertainty. To calculate the expectation of plant revenues, which is the main difficulty of the problem, loss functions are derived and applied. Different standard loss function approximation methods are compared and integrated into the planning model. The results show that the piecewise-linear approximation of the loss function can obtain good accuracy with improved solution speed. A general formulation for revenue and cost calculations is proposed by considering uncertainty in both the raw material and the product demand. To handle possible unmet customer demands, the hard-to-specify penalty functions of the two-stage programming are avoided and replaced by two of the decision maker's service objectives, namely, confidence level and fill rate. Confidence level, which is the probability of satisfying customer demands, is commonly used in chance-constrained programming. However, fill rate, which is the proportion of demands that are met by a plant, is a greater concern of most managers. In this paper, fill rates are effectively calculated using the loss function. The maximum plant profit that satisfies certain fill rate objectives can then be obtained. Case studies show that a planning strategy that satisfies certain confidence level objectives might be overly lenient compared to a strategy that satisfies a fill rate objective. Because very few refinery planning models consider the influences of uncertainty, case studies including real-world large-scale refinery planning problems are used to illustrate the effectiveness of the proposed approach.
  • Integrating neural network models for refinery planning
    Li Weimin, Li Wenkai, Chi Wai Hui
    Computer Aided Chemical Engineering 15 1304-1309 Dec. 2003 [Refereed]
    This paper presents two artificial neural networks (ANN) to predict pour point (PP) and cold filter plugging point (CFPP) of diesel oil and octane number of gasoline respectively, using back-propagation (BP) algorithm with actual plant data. Appropriate topologies of ANNs were obtained and the training rates and momentum in ANNs were discussed. Detailed models of the most important process units such as Crude Distillation Unit (CDU) and Fluidized-bed Catalytic Cracking (FCC) in a refinery were developed. The developed ANN models and CDU, FCC models were integrated into the refinery planning model to replace the traditional linear processing unit models and the linear blending rule used in gasoline blending and diesel oil blending. With these accurate unit models and blending models, the planning model gives us much more reliable results which can be used for refinery business decision and configuration retrofitting, etc. Several case studies were used to illustrate the capabilities and effectiveness of the integrated model proposed. © 2003 Elsevier B.V. All rights reserved.
  • Debottlenecking and retrofitting for a refinery using marginal value analysis, sensitivity analysis and parametric programming
    Li Wenkai, Chi Wai Hui
    Computer Aided Chemical Engineering 15 268-273 Dec. 2003 [Refereed]
    A new analytical method called "marginal value analysis" is used in this paper to provide economic information for all stream flows inside a refinery. Three types of marginal values are defined that represent respectively the de-bottlenecking effect, production cost and product value of an intermediate material flow. Important insights are generated using the analysis to find production bottlenecks, assist in decision making and price intermediate materials, etc. Sensitivity analysis and parametric programming are studied in this paper to provide more comprehensive information for pricing, retrofitting and investment evaluation. Several case studies are used to illustrate the research on marginal value analysis, sensitivity analysis and parametric programming. © 2003 Elsevier B.V. All rights reserved.
  • Process economics/refining: New methodology enhances planning for refined products
    Li Wenkai, Chi Wai Hui, Li Anxue
    Hydrocarbon Processing 82 Oct. 2003 [Refereed]
    A discussion on marginal value (MV) analysis, a unique tool that provides economic information for all streams within a refinery covers a simplified refinery process comprising two processing units, i.e., crude distillation unit (CDU) and FCC unit; calculation of the MV of the material (crude oil) flows; and case studies, where the problem contains three production units: CDU, gasoline blending, and diesel oil blending.
  • Scheduling crude oil unloading, storage, and processing
    Li Wenkai, Chi Wai Hui, Ben Hua, Zhongxuan Tong
    Industrial and Engineering Chemistry Research 41 6723-6734 Dec. 2002 [Refereed]
    This paper presents a solution algorithm and effective mathematical formulations for short-term scheduling of crude oil unloading, storage, and processing with multiple oil types, multiple berths, and multiple processing units. The problem can be formulated as a mixed-integer nonlinear programming (MINLP) model. However, solving a MINLP model directly results in inconsistency in solution quality and time. This paper proposes a solution algorithm that iteratively solves two mixed-integer linear programming (MIP) models and a nonlinear programming (NLP) model, resulting in better quality, stability, and efficiency than solving the MINLP model directly. The proposed MIP formulations disaggregate the three-dimensional binary decision variables in traditional formulations using two-dimensional binary variables, significantly reduce the total number of binary variables required, and hence improve the overall solution time. For handling large-scale problems, heuristics are included in the formulations to further reduce the solution time. Finally, an industrial case study is used to demonstrate the effectiveness of the proposed formulation and solution algorithm.
  • Prediction of homogeneous nucleation superheat limits of pure liquids using molecular interaction model
    Wenkai Li, Lianwei Ren, Jiabin Chen
    Dalian Ligong Daxue Xuebao/Journal of Dalian University of Technology 36 439-444 Jul. 1996 [Refereed]
    The homogeneous bubble nucleation superheat limits of pure liquids are experimentally measured using the rising droplet method and it is found that the experimental results are consistent with those of literatures. The homogeneous bubble nucleation superheat limits of nine pure liquids are predicted using the molecular interaction model and found to be in good agreement with those of experiments and literatures.

Books etc

  • Planning and Scheduling for Maritime Container Yards
    Li Wenkai
    Joint Work
    Springer  Apr. 2015
  • Some perspectives on transportation landscape in China: the guide to supply chain management and logistics 2006/2007
    Robert de Souza, Mark Goh, W LI, Y WU and A Fu
    Joint Work
    ed. S Wormwell, 75-82. Hong Kong: D Tat  2006
    Book Chapter
  • Techniques and Applications of Real-Time Simulation
    You Jingyu, Li Wenkai et al.,
    Joint Work
      1997
    Book Chapter (Chapter 11)

Conference Activities & Talks

  • PROCESS SYNTHESIS OF VALUE ADDED CHEMICALS FROM BIORENEWABLES
    Karthik Ramadoss, Wenkai Li, Iftekhar Abubakar Karimi, Wong Pui Kwan
    6th International Conference on Process Systems Engineering (PSE ASIA 2013) Jun. 2013
    Karthik Ramadoss, Wenkai Li, Iftekhar Abubakar Karimi, Wong Pui Kwan, PROCESS SYNTHESIS OF VALUE ADDED CHEMICALS FROM BIORENEWABLES, 6th International Conference on Process Systems Engineering (PSE ASIA 2013), June 25-27, 2013, Kuala Lumpur, Malaysia
  • Real-Time Container Storage Location Assignment at a Seaport Container Transshipment Terminal: Dispersion Levels and Math Programming Strategies
    MEH Petering, KG Murty, Y Wu, W Li, M Goh, R de Souza
    Second INFORMS Transportation Science and Logistics Society Workshop Jun. 2013
    Real-Time Container Storage Location Assignment at a Seaport Container Transshipment Terminal: Dispersion Levels and Math Programming Strategies, MEH Petering, KG Murty, Y Wu, W Li, M Goh, R de Souza, Second INFORMS Transportation Science and Logistics Society Workshop June 16-19, 2013, 75-78
  • Synthesis of biorefinery systems for lignocellulosic biorenewables
    Karthik Ramadoss, Wenkai Li, Iftekar A. Karimi, Pui Kwan Wong
    AIChE 2012 - 2012 AIChE Annual Meeting, Conference Proceedings Dec. 2012
    Our society is actively looking for sustainable alternatives to meet the increasing energy and product demands. This is amid increasing concerns of global warming, fast depletion of petroleum resources, expected increase of the crude oil price due to rapid demand growth from China and India, and unstable oil supply due to turmoil in the Middle East. Although replacement of carbon-based economy is receiving a major research attention nowadays, mankind's reliance on carbon will continue for the foreseeable future. As the only carbon-rich material source, biorenewables processed in biorefineries is very likely to be the only viable alternative to fossil resources for the production of transportation fuels and chemicals. The attractive future prospects for biorefineries are accompanied by several unique and challenging characteristics. Such challenges mainly include supply chain design and management (decentralized raw material sources etc.), process design and development (lack of models etc.) and intelligent decision making (uncertainty in markets and prices etc.). Furthermore, in most scenarios, successful process synthesis strategies for conventional refineries do not work for biorefineries. Thus, biorefinery synthesis using advanced systems engineering approaches require substantial research to design and manage economically viable, environmentally benign, and socially beneficial biorefineries. Kamm et al. (2006) highlight existing works relevant to process, raw material, product, and technology options. However, a study that integrates all these components using a modeling and optimization approach based on mathematical programming does not exist. Here, we aim to bridge this knowledge gap by systematically and intelligently evaluating all possible alternatives. In this paper, we explore and evaluate a variety of plausible and promising options for the conversion of cellulose, lignin, and C5 sugars into a slate of potential value-added chemicals using different technologies. We propose a novel superstructure of various alternative configurations for a general biorefinery. For this, we develop a general mathematical model based on short-cut equations to obtain the optimal design of a biorefinery. In addition, we examine a number of alternatives in the superstructure and cost factors such as operation cost, utility cost, capital expenditures (investments, overheads etc.), taxes and inflation rates for the entire lifetime of the biorefinery. Then, based on market scenarios, availability of lignocellulosic biorenewables, and available technologies, we present a reduced and dedicated biorefinery superstructure for Singapore. Finally, we illustrate sensitivity analysis and debottlenecking opportunities in biorefineries using several case studies.
  • Synthesis of Biorefinery Systems for Lignocellulosic Biorenewables
    Wenkai Li, Karthik Ramadoss, Iftekhar Abubakar Karimi, Wong Pui Kwan
    2012 AIChE Annual Meeting, Pittsburgh, USA  Oct. 2012
    Wenkai Li, Karthik Ramadoss, Iftekhar Abubakar Karimi, Wong Pui Kwan, Synthesis of Biorefinery Systems for Lignocellulosic Biorenewables, 2012 AIChE Annual Meeting, Pittsburgh, USA Oct.28- Nov. 2, 2012
  • An Empirical Model for Crude Distillation Units in Petroleum Refinery Planning
    Omar J. Guerra, Galo A. C. Le Roux, Wenkai Li
    AIChE Annual Meeting, Nashville, TN, USA Nov. 2009
    Omar J. Guerra, Galo A. C. Le Roux, Wenkai Li, An Empirical Model for Crude Distillation Units in Petroleum Refinery Planning, AIChE Annual Meeting, Nashville, TN, USA, Nov. 8-13, 2009
  • Novel model and algorithm for airline disruption management
    Wenkai Li, Sophie Dickson, Olivia Smith, Mark Wallace, Natashia Boland
    Conference on Transportation Scheduling and Disruption Handling, Prato, Italy  Sep. 2009
    Wenkai Li, Sophie Dickson, Olivia Smith, Mark Wallace, Natashia Boland, Novel model and algorithm for airline disruption management, Conference on Transportation Scheduling and Disruption Handling, Prato, Italy September 17-19th 2009
  • Challenge ROADEF 2009: Disruption Management for Commercial Aviation, A Mixed Integer Programming Approach, ROADEF 2009
    Sophie Dickson, Olivia Smith, Wenkai Li
    ROADEF 2009 2009
    Sophie Dickson, Olivia Smith, Wenkai Li, Challenge ROADEF 2009: Disruption Management for Commercial Aviation, A Mixed Integer Programming Approach, ROADEF 2009, Page 401, 2009
  • Green supply chain: How does it affect current supply chain practice?
    Q. Lu, W. Li, B. Sundarakani, S. Cai, R. De Souza, M. Goh
    2008 IEEE International Conference on Industrial Engineering and Engineering Management, IEEM 2008 Dec. 2008
    With the growing awareness of human activity on global climate change, the pricing of carbon emissions would inevitably become reality in Asia as it is in Europe. This paper critically analyzes the possible environmental challenges on supply chain management at the strategic level and the possible paradigm shift. We investigate how environmental factors such as carbon emission affect the supply chain architecture and change its landscape. We predict that green supply chain would bring a paradigm shift in supply chain management. Higher level of horizontal integration is expected to see among suppliers, manufacturers and logistics service providers, and geographically the supply chain would start to contract after the ruthless expansion in past two decades. These predictions would help manufacturers, suppliers, and logistics service providers adjust their supply chain strategies in this shift. © 2008 IEEE.
  • The adoption of green supply Chain strategy: An institutional perspective
    S. Cai, R. De Souza, M. Goh, W. Li, Q. Lu, B. Sundarakani
    Proceedings of the 4th IEEE International Conference on Management of Innovation and Technology, ICMIT Dec. 2008
    Green supply chain has emerged as an important organizational strategy in modern business environment. While most of the current literature look at the green supply chain strategy adoption from economic and political perspective, we investigate the green supply chain strategy adoption from an institutional perspective because supply chain management involves cooperation and interactions among multiple stakeholders, and the decision to adopt this strategy may have more to do with the institutional environment in which a firm is situated. In this study, we identify key institutional determinants of green supply chain strategy adoption. A structured survey was designed to investigate critical driving forces of adoption of green supply chain strategy. ©2008 IEEE.
  • An efficient continuous-time model for container yard crane work schedules
    LI, W., Y. WU, M E H Petering, MarK Goh and Robert de Souza
    Proceedings of POMS international conference - Shanghai 2006  Jun. 2006
    LI, W., Y. WU, M E H Petering, MarK Goh and Robert de Souza, An efficient continuous-time model for container yard crane work schedules. proceedings of POMS international conference - Shanghai 2006 (2006). 19 - 23 Jun 2006
  • Simulation Analysis of Yard Crane Routing Systems at a Marine Container Transshipment Terminal
    Matthew E. H. Petering, Yong Wu, Wenkai Li, Mark Goh, Katta G. Murty, Robert de Souza
    International Congress on Logistics and SCM Systems, Kaohsiung, Taiwan May 2006
    Matthew E. H. Petering, Yong Wu, Wenkai Li, Mark Goh, Katta G. Murty, Robert de Souza, Simulation Analysis of Yard Crane Routing Systems at a Marine Container Transshipment Terminal, International Congress on Logistics and SCM Systems, Kaohsiung, Taiwan, May 1-2, 2006
  • Clustering-reassigning approach for scheduling multiple yard cranes at container terminals
    WU, Y., M E H Petering, W. LI, Mark Goh and Robert de Souza
    Proceedings of the 11th International Symposium on Logistics, 9 - 11 Jul 2006, Tsinghua University, Beijing, China 2006
    WU, Y., M E H Petering, W. LI, Mark Goh and Robert de Souza, Clustering-reassigning approach for scheduling multiple yard cranes at container terminals. Proceedings of the 11th International Symposium on Logistics, 9 - 11 Jul 2006, Tsinghua University, Beijing, China)
  • Planning under correlated and truncated price and demand uncertainties
    Wenkai Li, I. A. Karimi, R. Srinivasan
    AIChE Annual Meeting, Conference Proceedings Dec. 2005
    Until now, most research work on uncertainty assumes that the demand and price are independent because of the difficulty in computing the bivariate integral originated from the correlated demand and price. This can cause significant discrepancies in revenue calculation and hence yield sub-optimal planning strategies. This paper presents a novel approach to handle correlated and truncated demand and price uncertainties. To compute the expectation of plant revenue, which is the main difficulty for a planning problem under uncertainty, we use a bivariate normal distribution to describe demand and price. The double integral for revenue calculation is reduced to several single integrals after detailed derivation. The unintegrable standard normal cumulative distribution function in the single integrals is approximated by polynomial function. Case studies show that, for a large enough CV of a product, assuming independent price and demand may underestimate the revenue by up to 20%. Since the real world demands or prices vary in limited ranges, integrating over the whole range of a normal distribution, which some research has done, may give incorrect results. This paper thus approximates a bivariate double-truncated normal distribution for demand and price. The influence of degree of truncation on plant revenue is studied. To handle possible unmet customer demands, the hard-to-specify penalty functions of the two-stage programming are avoided and replaced by two of the decision maker's service objectives, namely the confidence level and fill rate objective. Confidence level or the type I service level, which is the probability of satisfying customer demands, is commonly used in chance-constrained programming. However, fill rate or the type II service level, which is the proportion of demands that are met from a plant, is a greater concern of most managers. In this paper, fill rate is efficiently calculated using the derived formulae and the maximal plant profit that satisfies certain fill rate objectives can thus be obtained. Case studies show that a planning strategy that satisfies certain confidence level objectives might be too generous compared to a strategy that satisfies a fill rate objective. Case studies including refinery planning problems were used to illustrate the proposed approach. The proposed approach can be generally applied for modeling other chemical plants under uncertainty.
  • Robust and efficient algorithm for optimizing crude oil operations
    J. Li, W. K. Li, I. A. Karimi, R. Srinivasan
    AIChE Annual Meeting, Conference Proceedings Dec. 2005
  • Robust and efficient algorithm for optimizing crude oil operations
    J. Li, W. K. Li, I. A. Karimi, R. Srinivasan
    AIChE Annual Meeting Conference Proceedings Jan. 2005
    Fifteen crude oil properties that are critical to crude distillation and downstream processing were studied. These fifteen crude properties were specific gravity, sulfur content, nitrogen content, oxygen content, carbon residue content, pour point, flash point, Ni content, Rvp, asphaltene content, aromatics content, paraffins content, naphthene content, viscosity content, and wax content. A new robust algorithm based on a backtracking strategy using an intelligent integer cut to solve the complex mixed integer nonlinear program problem. The improved algorithm was much more efficient than the other three algorithms. A partial relaxation strategy was studied to further increase solution speed and improve solution quality. The partial relaxation strategy greatly reduced the computation time and improved the solution quality for most examples simultaneously, especially for scheduling problems with horizons as long as 20 days. In addition, two constraints were imposed to make sure practically realistic schedules with limited flow rate changes to the CDU. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 10/30/2005-11/4/2005).
  • Plant-wide Scheduling and Marginal Cost Analysis For A Refinery
    Li Wenkai, Chi-Wai Hui, Ben Hua, Zhongxuan Tong
    The Foundations of Computer Aided Process Operations Conference (FOCAPO 2003), Coral Springs, Florida, USA Jan. 2003
    Li Wenkai, Chi-Wai Hui, Ben Hua, Zhongxuan Tong, Plant-wide Scheduling and Marginal Cost Analysis For A Refinery, The Foundations of Computer Aided Process Operations Conference (FOCAPO 2003), Coral Springs, Florida, USA, January 12-15, 2003
  • Universal Plant Model for Production Planning
    K.Y. Cheung, W.K. Li, C.W. Hui, H. Sakamoto, K. Hirata and L.O'Young
    5th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction (CHISA2002), Praha, Czech Republic Aug. 2002
    K.Y. Cheung, W.K. Li, C.W. Hui, H. Sakamoto, K. Hirata and L.O'Young, Universal Plant Model for Production Planning, 5th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction (CHISA2002), Praha, Czech Republic, August 25-29, 2002
  • Supply Chain Optimization of Refinery
    Li Wenkai, Chi-Wai Hui, Ben Hua
    5th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction (CHISA2002),Praha, Czech Republic Aug. 2002
    Li Wenkai, Chi-Wai Hui, Ben Hua, Supply Chain Optimization of Refinery, 5th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction (CHISA2002),Praha, Czech Republic, August 25-29, 2002
  • Automatic Modeling Generation Tool of Flownet, Symposium of Simulation and Control
    Li Wenkai, Pan Chaoxiang
    Symposium of Simulation and Control, Zhangjiajie, P.R.China 1999
    Li Wenkai, Pan Chaoxiang, Automatic Modeling Generation Tool of Flownet, Symposium of Simulation and Control, Zhangjiajie, P.R.China, 1999, 93~107
  • Modeling of Polypropylene and Separation Apparatus
    Li Wenkai, Lin Jianfen
    Symposium of Simulation and Control, Zhangjiajie, P.R.China 1999
    Li Wenkai, Lin Jianfen, Modeling of Polypropylene and Separation Apparatus, Symposium of Simulation and Control, Zhangjiajie, P.R.China,1999, 283~291
  • Simulation Model on Ethylene Cracking Furnace
    Li Huaiyang, Li Wenkai
    Symposium of Simulation and Control, Zhangjiajie, P.R.China 1999
    Li Huaiyang, Li Wenkai, Simulation Model on Ethylene Cracking Furnace, Symposium of Simulation and Control, Zhangjiajie, P.R.China,1999, 302~312
  • the full-range simulator for 300KT/Y ethylene united complex
    Li Wenkai, et al
    Symposium of China System Simulation Committee Annual Meeting 1997
    Li Wenkai, et al, the full-range simulator for 300KT/Y ethylene united complex, Symposium of China System Simulation Committee Annual Meeting,1997,637-641

Misc

  • Disruption Management for Commercial Aviation
    Wenkai Li, Mark Wallace
    Working Papers on Economics & Management Series EMS-2012-18 1-34 Nov. 2012
    0
    Wenkai Li, Mark Wallace, Disruption Management for Commercial Aviation, Working Papers on Economics & Management Series, EMS-2012-18, 1-34, 2012-11, International University of Japan, 2012
  • Planning under Correlated and Truncated Price and Demand Uncertainties
    Wenkai Li, I. A. Karimi, R. Srinivasan
    , Working Papers on Economics & Management Series EMS-2012-15 1-45 Sep. 2012
    0
    Wenkai Li, I. A. Karimi, R. Srinivasan, Planning under Correlated and Truncated Price and Demand Uncertainties, Working Papers on Economics & Management Series, EMS-2012-15, 1-45, 2012-09, International University of Japan, 2012

Educational Activities

Teaching Experience

  • Supply Chain Management (International University of Japan)
  • Operations Management (International University of Japan)
  • Applied Statistics (International University of Japan)
  • Business Ethics (International University of Japan)


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