Integrating Reliability, Availability and Maintainability (RAM) in Conceptual Process Design An Optimization Approach Integrating Reliability, Availability and Maintainability (RAM) in Conceptual Process Design An Optimization Approach Proefschrift ter verkrijging van de graad van doctor aan de Technische Universiteit Delft, op gezag van de Rector Magnificus prof. dr. ir. J. T. Fokkema, voorzitter van het College voor Promoties, in het openbaar te verdedigen op maandag 7 juni 2004 om 10.30 uur door Harish Devendre GOEL Master of Chemical Engineering (University of Mumbai, India) geboren te New Delhi (India) Dit proefschrift is goedgekeurd door de promotoren: Prof. dr. ir. M. P. C. Weijnen Prof. ir. J. Grievink Toegevoegd promotor: Dr. ir. P. M. Herder Samenstelling promotiecommissie: Rector Magnificus voorzitter Prof. dr. ir. M. P. C. Weijnen Technische Universiteit Delft, promotor Prof. ir. J. Grievink Technische Universiteit Delft, promotor Dr. ir. P. M. Herder Technische Universiteit Delft, toegevoegd promotor Prof. dr. J. S. Dhillon Technische Universiteit Delft Prof. U. M. Diwekar, Ph.D. University of Illinois at Chicago, Chicago, USA Prof. dr. L. Puigjaner Universitat Polit`ecnica de Catalunya, Barcelona, Spain Dr. N. S. Nathoo Shell Global Solutions, Houston, USA Published and distributed by: DUP Science DUP Science is an imprint of Delft University Press P.O.Box 98 2600 MG Delft The Netherlands Telephone: +31 15 27 85 678 Telefax: +31 15 27 85 706 E-mail: [email protected] ISBN: 90-407-2502-0 Copyright °c 2004 by Harish Devendre Goel All rights reserved. No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage and retrieval system, without writ- ten permission from the publisher: Delft University Press Printed in The Netherlands to mummy and papa Preface This thesis presents the results of four years of research on integrating reliability and maintainability aspects into the early stages of chemical process design. During the course of my time in Delft, many people have helped me directly as well as indirectly. I would like to convey my gratitude to some of them for their efforts and best wishes. Let me start with my supervisors Margot Weijnen and Johan Grievink, who, with their different areas of expertise, provided me insight in many topics and guided this research while at the same time allowing me to pursue my own research interests. I would like to thank Margot for inspiring me to take up new challenges and for introducing me to the great worlds of reading and music. I will remain grateful to Johan for our detailed technical discussions and motivating me to take up the challenge of going into new areas of mathematical programming and reliability engineering. I would like to thank Paulien Herder, my day-to-day supervisor. I always enjoyed hav- ing lengthy technical discussion with her. I would also like to thank her for her help with improving the quality of the publications and this thesis, although we could still debate on the optimal use of “articles” in writing! I had many discussions with people from both the scientific world and everyday prac- tice. I owe them much gratitude for their valuable contribution to the completion of this thesis. I would like to thank Art Westerberg for providing me time for discussion during his short visits to Delft. I would also like to thank Nazim Nathoo for his enthusiasm and interest in my work. I would like to thank my colleagues from “E&I” group who have made my time as a Ph.D. student at Delft more pleasant. My sincere gratitude goes to Adam Turk for shar- ing the highs and lows of my Ph.D. work. I also like to thank Laurens for always being helpful to me throughout my stay in Delft. Special thanks to Gerard for introducing me to AIChE NL-BE section. I enjoyed being part of AIChE as Ph.D. student officer. I am very much thankful to Miranda Aldham-Breary for her English support and Ivo for Dutch translation. I would also like to thank Austine for allowing me to use his desk during my often unannounced visits to Delft. I also acknowledge the faculty staff and the secretaries of E&I group for all their constant support during the period of my stay. I like to thank “Ex-Menno ter Braaklaan Group (Atul, Nilesh, and Rahul)” for their company during my stay in Delft. I am also thankful to Myra and Harry for being friends and making my stay in Delft much more enjoyable. I would also like to thank Ramanan for his help in producing this thesis in LATEX. A special credit for this work goes to my parents who always supported me and gave me freedom to choose the path I wanted. I cannot thank them enough for every sacrifice they have done for me. My mother taught me the most valuable lesson of life: education is the treasure that cannot to be taken away from you. I would also like to thank the “Goel Parivar” for all their best wishes and blessing. Finally, I would like to thank Lopa for al- ways being there for me to share all my most enjoyable and worst moments. Her constant support and encouragement kept me afloat and motivated me to complete this work. Harish Goel Delft, April, 2004 Contents Preface vii 1 Introduction 1 1.1 Background 1 1.1.1 The changing business environment 1 1.1.2 RAM performance measures 3 1.2 Managing plant availability during the plant life cycle 4 1.2.1 Managing plant availability at the conceptual stage of design 6 1.3 Research Objective 8 1.4 Outline of the Thesis 8 2 RAM in process design: a literature review 11 2.1 Introduction 11 2.2 Reliability-availability analysis methods 12 2.2.1 Analytical methods 13 2.2.2 Simulation methods 18 2.3 Reliability and maintenance optimization 19 2.3.1 Reliability optimization 20 2.3.2 Maintenance optimization 22 2.4 Software tools 22 2.5 Data Sources 24 2.6 Current approaches to integrate RAM in the process design 26 2.6.1 Sequential approach 27 2.6.2 Simultaneous approach 28 2.7 Summary and refined problem formulation 30 3 Integrating reliability optimization in process design/synthesis 35 3.1 Introduction 35 3.2 Background 37 3.2.1 Reliability optimization at the design stage 37 3.2.2 Process Synthesis 37 3.3 Model Development 38 3.3.1 Process model 39 3.3.2 Availability model 39 3.3.3 Objective function 41 3.3.4 Problem formulation 43 3.4 Process synthesis examples 44 3.4.1 Example 1 44 3.4.2 Example 2: HDA process synthesis 47 3.5 Summary 54 4 Optimal reliable retrofit design of multiproduct batch plants 59 4.1 Introduction 59 4.2 Illustrative example 60 4.3 Modelling framework 63 4.4 Problem formulation 64 4.4.1 Process model 64 4.4.2 Availability model 68 4.4.3 Objective function 69 4.5 Examples 69 4.5.1 Example 1 70 4.5.2 Example 2 71 4.5.3 Example 3 73 4.6 Summary 77 5 Reliability and maintainability in process design: multipurpose plants 81 5.1 Introduction 81 5.2 Modeling Framework 83 5.3 Problem Definition 85 5.4 Mathematical formulation 86 5.4.1 Design structure constraints 86 5.4.2 Time resource utilization constraints 86 5.4.3 Capacity Constraints 87 5.4.4 Material Balance constraints 87 5.4.5 Demand Constraints 87 5.4.6 Utility constraints 88 5.4.7 Reliability Allocation Constraints 88 5.4.8 Failure Rate Constraints 88 5.4.9 Uptime Definition Constraints 89 5.4.10 Objective function 89 5.5 Examples 89 5.5.1 Example 1 90 5.5.2 Example 2 94 5.6 Summary 97 6 Reliability and maintainability in process design: continuous plants 101 6.1 Introduction 101 6.2 Model development 103 6.2.1 Process model 103 6.2.2 Availability model 104 6.2.3 Objective function 106 6.3 Illustrative example 107 6.4 Summary 112 7 Conclusions and recommendations 115 7.1 Introduction 115 7.2 Conclusions 116 7.3 Recommendations and future work 119 References 123 Appendix A: capital cost estimation models 129 Appendix B: convexication of the MINLP 133 Summary 137 Samenvatting 141 Curriculum Vitae 145 1 Introduction A theoretical framework for integrating reliability, availability and maintainability (RAM) aspects during the early stages of the process design is presented in this thesis. The focus of the the thesis is the setting of quantitative RAM targets while simultaneously making crucial design decisions. 1.1 Background 1.1.1 The changing business environment In the present business environment, where profit margins are becoming slimmer and competition is increasing, the attention of the industry leaders has turned to the reliabil- ity engineering paradigm to find ways of saving costs savings and revenue improvement opportunities. According to a recent market forecast (HPI Market data book, 2003), to- tal hydrocarbon processing industry maintenance spending in 2003 is forecasted to reach $44.9 billion of which $11.4 in the United States alone, and the majority on the Gulf Coast. Spending for equipment and materials represents 40% of the maintenance budget and will reach almost $18 billion in 2003. Labor costs account for the other 60% (almost $27 billion) of the maintenance budget. Although significant these figures do not include the cost of interruption due to unplanned failures.