Efficient methanol synthesis: Perspectives, technologies and optimization strategies

Abstract In economy nowadays, methanol is already a key compound widely employed as building block for producing intermediates or synthetic hydrocarbons, solvent, energy storage medium, and fuel. This status is expected to last in the near future or even improve to the point of making this compound a central participant in the worldwide economic landscape. For these reasons, every improvement to its production process, in terms of energy savings, optimization, etc., has potential to promote relevant economic benefits. Methanol production comprises three main steps: preparation of syngas, methanol synthesis and downstream separation. This paper aims at reviewing technologies and procedures for modeling and optimizing the second aforementioned phase: the synthesis reactor. Specifically, we focus on packed-bed units, which represent the most widespread technology. In the manuscript, we are going to describe and compare both steady-state and dynamic reactor models as well as analyze typical assumptions and implementation schemes. The kinetics of methanol synthesis is also reported in detail due to a long debate, present in the literature, concerning the real carbon source for methanol, the nature of the active sites and the effect of their morphology and oxidation state.

[1]  K. C. Waugh,et al.  The measurement of copper surface areas by reactive frontal chromatography , 1987 .

[2]  Giuseppe Barbieri,et al.  Simulation of the methane steam re-forming process in a catalytic Pd-membrane reactor , 1997 .

[3]  C. H. Bartholomew,et al.  Heterogeneous Catalyst Deactivation and Regeneration: A Review , 2015 .

[4]  L. Biegler.  An overview of simultaneous strategies for dynamic optimization , 2007 .

[5]  Peter L. Silveston,et al.  Influence of forced feed composition cycling on catalytic methanol synthesis , 1985 .

[6]  Flavio Manenti,et al.  Outlier detection in large data sets , 2011, Comput. Chem. Eng..

[7]  Flavio Manenti,et al.  Differential and Differential-Algebraic Systems for the Chemical Engineer: Solving Numerical Problems , 2015 .

[8]  Masahiro Saito,et al.  Development of high performance Cu/ZnO-based catalysts for methanol synthesis and the water-gas shift reaction , 2004 .

[9]  Kyoung‐Su Ha,et al.  Modeling and analysis of a methanol synthesis process using a mixed reforming reactor: Perspective on methanol production and CO2 utilization , 2014 .

[10]  J. Ladebeck.  Improve methanol synthesis , 1993 .

[11]  C. R. Cutler,et al.  Dynamic matrix control¿A computer control algorithm , 1979 .

[12]  Kyoung‐Su Ha,et al.  Kinetic modeling of methanol synthesis over commercial catalysts based on three-site adsorption , 2014 .

[13]  H. Kordabadi,et al.  A pseudo-dynamic optimization of a dual-stage methanol synthesis reactor in the face of catalyst deactivation , 2007 .

[14]  Dale E. Seborg,et al.  Nonlinear Process Control , 1996 .

[15]  Rufino M. Navarro,et al.  Hydrogen production from renewable sources: biomass and photocatalytic opportunities , 2009 .

[16]  A. R. Galletti,et al.  Synthesizing methanol at lower temperatures , 1997 .

[17]  S. Joe Qin,et al.  A survey of industrial model predictive control technology , 2003 .

[18]  Jens K. Nørskov,et al.  A Kinetic Model of Methanol Synthesis , 1995 .

[19]  Mohammad Reza Rahimpour,et al.  Selective kinetic deactivation model for methanol synthesis from simultaneous reaction of CO2 and CO with H2 on a commercial copper/zinc oxide catalyst , 1998 .

[20]  R. Krishna,et al.  The Maxwell-Stefan approach to mass transfer , 1997 .

[21]  Mohammad Reza Rahimpour,et al.  A two-stage catalyst bed concept for conversion of carbon dioxide into methanol , 2008 .

[22]  A. Beenackers,et al.  Mathematical modeling of internal mass transport limitations in methanol synthesis , 2000 .

[23]  Richard G. Herman,et al.  Catalytic synthesis of methanol from COH2: IV. The effects of carbon dioxide , 1982 .

[24]  Antonello Barresi,et al.  Methanol synthesis in a forced unsteady-state reactor network , 2002 .

[25]  F. J. Waller,et al.  Methanol technology developments for the new millennium , 2001 .

[26]  M. Muhler,et al.  Detailed kinetic modeling of methanol synthesis over a ternary copper catalyst , 2012 .

[27]  H. Bakemeier,et al.  Development and application of a mathematical model of the methanol synthesis , 1970 .

[28]  Flavio Manenti,et al.  Nonlinear Model Predictive Control: A Self-Adaptive Approach , 2010 .

[29]  Marko Šetinc,et al.  Dynamics of a mixed slurry reactor for the three-phase methanol synthesis , 2001 .

[30]  Peter Glavič,et al.  Multi-criteria optimization in a methanol process , 2009 .

[31]  Tracy J. Benson,et al.  Process simulation and optimization of methanol production coupled to tri-reforming process , 2013 .

[32]  Magne Hillestad.  A systematic generation of reactor designs: I. Isothermal conditions , 2004, Comput. Chem. Eng..

[33]  Raquel De María,et al.  Industrial Methanol from Syngas: Kinetic Study and Process Simulation , 2013 .

[34]  T. H. Hsiung,et al.  Deactivation of methanol synthesis catalysts , 1993 .

[35]  R. Feidenhans'l,et al.  In situ cell for combined XRD and on-line catalysis tests : studies of Cu-based water gas shift and methanol catalysts , 1991 .

[36]  Mohamed Azlan Hussain,et al.  Optimization strategy for long-term catalyst deactivation in a fixed-bed reactor for methanol synthesis process , 2012, Comput. Chem. Eng..

[37]  Aacm Beenackers,et al.  Intra-particle diffusion limitations in low-pressure methanol synthesis , 1990 .

[38]  William L. Luyben,et al.  Essentials of Process Control , 1996 .

[39]  L. Pino,et al.  Syngas production by methane oxy-steam reforming on Me/CeO2 (Me = Rh, Pt, Ni) catalyst lined on cordierite monoliths , 2015 .

[40]  Giulia Bozzano,et al.  Energy-process Integration of the Gas-cooled/water-cooled Fixed-bed Reactor Network for Methanol Synthesis , 2013 .

[41]  F. Larachi,et al.  Dimethyl Ether Synthesis with in situ H2O Removal in Fixed-Bed Membrane Reactor: Model and Simulations† , 2010 .

[42]  M. Mekala,et al.  Comparative kinetics of esterification of methanol–acetic acid in the presence of liquid and solid catalysts , 2014 .

[43]  Antonio Vita,et al.  Hydrogen from biogas: Catalytic tri-reforming process with Ni/LaCeO mixed oxides , 2014 .

[44]  J. Limtrakul,et al.  Reaction mechanism of methanol to formaldehyde over Fe- and FeO-modified graphene. , 2015, Chemphyschem : a European journal of chemical physics and physical chemistry.

[45]  Zhongmin Liu,et al.  Methanol to Olefins (MTO): From Fundamentals to Commercialization , 2015 .

[46]  R. Bardet,et al.  Hydrocondensation des oxydes de carbone, à la pression atmosphérique, sur des catalyseurs Cu-ZnO-Al2O3. Influence de l'eau sur la formation du méthanol , 1984 .

[47]  K. Tohji,et al.  The structure of the copper/zinc oxide catalyst by an in-situ EXAFS study , 1985 .

[48]  Melanie A. McNeil,et al.  Methanol synthesis from hydrogen, carbon monoxide, and carbon dioxide over a CuO/ZnO/Al2O3 catalyst: I. Steady-state kinetics experiments , 1989 .

[49]  Wei Feng,et al.  Analysis of Methanol Production from Biomass Gasification , 2011 .

[50]  Giulia Bozzano,et al.  Optimal Control of Methanol Synthesis Fixed-Bed Reactor , 2013 .

[51]  Flavio Manenti,et al.  Considerations on nonlinear model predictive control techniques , 2011, Comput. Chem. Eng..

[52]  Magne Hillestad.  A systematic generation of reactor designs: II. Non-isothermal conditions , 2005, Comput. Chem. Eng..

[53]  F. Manenti,et al.  Process for reducing CO2 and producing syngas , 2014 .

[54]  K. Cen,et al.  Experimental study of improved two step synthesis for DME production , 2010 .

[55]  Flavio Manenti,et al.  Online Data Reconciliation with Poor Redundancy Systems , 2011 .

[56]  Payam Parvasi,et al.  Dynamic modeling and optimization of a novel methanol synthesis loop with hydrogen-permselective membrane reactor , 2009 .

[57]  J. Monnier,et al.  Effect of CO2 on the conversion of H2/CO to methanol over copper-chromia catalysts , 1984 .

[58]  Pio Forzatti,et al.  Synthesis of alcohols from carbon oxides and hydrogen. 1. Kinetics of the low-pressure methanol synthesis , 1985 .

[59]  Jesper Ahrenfeldt,et al.  Biomass gasification cogeneration – A review of state of the art technology and near future perspectives , 2013 .

[60]  V. Ostrovskii.  Mechanisms of methanol synthesis from hydrogen and carbon oxides at Cu–Zn-containing catalysts in the context of some fundamental problems of heterogeneous catalysis , 2002 .

[61]  K. C. Waugh,et al.  Synthesis of Methanol , 1988 .

[62]  B. Moghtaderi,et al.  Hydrogen looping approach in optimized methanol thermally coupled membrane reactor , 2012 .

[63]  Flavio Manenti,et al.  Dynamic Simulation of Lurgi-type Reactor for Methanol Synthesis , 2011 .

[64]  Kyoung‐Su Ha,et al.  Optimization of methanol synthesis reaction on Cu/ZnO/Al2O3/ZrO2 catalyst using genetic algorithm: Maximization of the synergetic effect by the optimal CO2 fraction , 2010 .

[65]  Harold H. Kung,et al.  Deactivation of methanol synthesis catalysts - a review , 1992 .

[66]  L. Tagliabue,et al.  A review of low temperature methanol synthesis , 1998 .

[67]  C. Bouallou,et al.  Design and simulation of a methanol production plant from CO2 hydrogenation , 2013 .

[68]  K. Lammertsma,et al.  Electrophilic reactions at single bonds. 20. Selective monohalogenation of methane over supported acidic or platinum metal catalysts and hydrolysis of methyl halides over .gamma.-alumina-supported metal oxide/hydroxide catalysts. A feasible path for the oxidative conversion of methane into methyl al , 1985 .

[69]  Ingvild Løvik,et al.  Modelling, estimation and optimization of the methanol synthesis with catalyst deactivation , 2001 .

[70]  Melanie A. McNeil,et al.  Methanol synthesis from hydrogen, carbon monoxide and carbon dioxide over a CuO/ZnO/Al2O3 catalyst: II. Development of a phenomenological rate expression , 1989 .

[71]  Flavio Manenti,et al.  CO2 as feedstock: a new pathway to syngas , 2015 .

[72]  K. McBride,et al.  Direct dimethyl ether synthesis by spatial patterned catalyst arrangement: A modeling and simulation study , 2012 .

[73]  Flavio Manenti,et al.  Unified modeling and feasibility study of novel green pathway of biomass to methanol/dimethylether , 2015 .

[74]  Andrzej Cybulski,et al.  Liquid-Phase Methanol Synthesis: Catalysts, Mechanism, Kinetics, Chemical Equilibria, Vapor-Liquid Equilibria, and Modeling—A Review , 1994 .

[75]  Giulia Bozzano,et al.  Dynamic modeling of the methanol synthesis fixed-bed reactor , 2013, Comput. Chem. Eng..

[76]  Hugo A. Jakobsen,et al.  Modeling of multicomponent mass diffusion in porous spherical pellets: Application to steam methane reforming and methanol synthesis , 2011 .

[77]  N. Itoh,et al.  A membrane reactor using palladium , 1987 .

[78]  R. Periana,et al.  High yield conversion of methane to methyl bisulfate catalyzed by iodine cations. , 2002, Chemical communications.

[79]  Bernard P. A. Grandjean,et al.  Methane steam reforming in asymmetric Pd- and Pd-Ag/porous SS membrane reactors , 1994 .

[80]  Laurent Falk,et al.  Methanol synthesis from CO2 and H2 in multi-tubular fixed-bed reactor and multi-tubular reactor filled with monoliths , 2014 .

[81]  I. Chorkendorff,et al.  Methanol synthesis on Cu(100) from a binary gas mixture of CO2 and H2 , 1994 .

[82]  Edward S. Cassedy,et al.  Prospects for Sustainable Energy: A Critical Assessment , 2006 .

[83]  Mohammad Reza Rahimpour,et al.  A comparison of co-current and counter-current modes of operation for a dual-type industrial methanol reactor , 2008 .

[84]  Payam Parvasi,et al.  Incorporation of Dynamic Flexibility in the Design of a Methanol Synthesis Loop in the Presence of Catalyst Deactivation , 2008 .

[85]  Eize Stamhuis,et al.  ON CHEMICAL-EQUILIBRIA IN METHANOL SYNTHESIS , 1990 .

[86]  H. Jakobsen,et al.  A numerical study of pellet model consistency with respect to molar and mass average velocities, pressure gradients and porosity models for methanol synthesis process: Effects of flux models on reactor performance , 2013 .

[87]  M. Takagawa,et al.  Study on reaction rates for methanol synthesis from carbon monoxide, carbon dioxide, and hydrogen , 1987 .

[88]  J. Levec,et al.  Intrinsic and global reaction rate of methanol dehydration over .gamma.-alumina pellets , 1992 .

[89]  M. Thring.  World Energy Outlook , 1977 .

[90]  M. Garland,et al.  The role of CO2 in methanol synthesis on CuZn oxide: An isotope labeling study , 1985 .

[91]  A. Basile,et al.  An experimental study of CO2 hydrogenation into methanol involving a zeolite membrane reactor , 2004 .

[92]  E. Stamhuis,et al.  Kinetics of low-pressure methanol synthesis , 1988 .

[93]  Mohammad Shahrokhi,et al.  Modeling, simulation and control of a methanol synthesis fixed-bed reactor , 2005 .

[94]  R. L. Mieville,et al.  Studies on the chemical state of Cu during methanol synthesis , 1984 .

[95]  Carlo Pirola,et al.  Acid Gas to Syngas (AG2S™) technology applied to solid fuel gasification: Cutting H2S and CO2 emissions by improving syngas production , 2016 .

[96]  J. Solsvik,et al.  Multicomponent mass diffusion in porous pellets: Effects of flux models on the pellet level and impacts on the reactor level. Application to methanol synthesis , 2013 .

[97]  Jürgen Haid,et al.  Lurgi’s Mega-Methanol technology opens the door for a new era in down-stream applications , 2001 .

[98]  G. Luft,et al.  Untersuchungen zur Methanol-Synthese im Mitteldruckbereich† , 1985 .

[99]  S. Prachayawarakorn,et al.  Effects of pore assembly architecture on catalyst particle tortuosity and reaction effectiveness , 2007 .

[100]  R. Periana,et al.  Platinum catalysts for the high-yield oxidation of methane to a methanol derivative , 1998, Science.

[101]  C. Takoudis,et al.  Synthesis of methanol from carbon monoxide and hydrogen over a copper-zinc oxide-alumina catalyst , 1985 .

[102]  Mohammad Farsi,et al.  Dynamic modeling and operability analysis of a dual-membrane fixed bed reactor to produce methanol considering catalyst deactivation , 2014 .

[103]  Hsuan Chang,et al.  Multi-objective optimization for two catalytic membrane reactors—Methanol synthesis and hydrogen production , 2008 .

[104]  K. C. Waugh,et al.  The activity and state of the copper surface in methanol synthesis catalysts , 1986 .

[105]  G. Froment,et al.  Chemical Reactor Analysis and Design , 1979 .

[106]  Miguel J. Bagajewicz,et al.  Gross error modeling and detection in plant linear dynamic reconciliation , 1998 .

[107]  Magne Hillestad,et al.  Modeling and optimization of a reactor system with deactivating catalyst , 1999 .

[108]  Payam Parvasi,et al.  Dynamic optimization of a novel radial-flow, spherical-bed methanol synthesis reactor in the presence of catalyst deactivation using Differential Evolution (DE) algorithm , 2009 .

[109]  Ulrich Hoffmann,et al.  Investigation of simultaneous reaction of carbon monoxide and carbon dioxide with hydrogen on a commercial copper/zinc oxide catalyst , 1993 .

[110]  G. Olah.  Beyond oil and gas: the methanol economy. , 2006, Angewandte Chemie.

[111]  Jacob A. Moulijn,et al.  Chemical Process Technology , 2001 .

[112]  K. Westerterp,et al.  Methanol adsorption by amorphous silica alumina in the critical temperature range , 1986 .

[113]  R. Jackson,et al.  Transport in porous catalysts , 1977 .

[114]  Ignacio E. Grossmann,et al.  Part II. Future perspective on optimization , 2004, Comput. Chem. Eng..

[115]  H. S. Fogler,et al.  Elements of Chemical Reaction Engineering , 1986 .

[116]  I. B. Dybkjær,et al.  Design of Ammonia and Methanol Synthesis Reactors , 1986 .

[117]  Charles T. Campbell,et al.  A kinetic model of the water gas shift reaction , 1992 .

[118]  I. Metcalfe,et al.  Deactivation of Cu/ZnO/Al2O3 Methanol Synthesis Catalyst by Sintering , 1999 .

[119]  S. Joe Qin,et al.  An Overview of Nonlinear Model Predictive Control Applications , 2000 .

[120]  Mohammad Reza Rahimpour,et al.  Dynamic optimization of membrane dual-type methanol reactor in the presence of catalyst deactivation using genetic algorithm , 2009 .

[121]  K. Lammertsma,et al.  Selective monohalogenation of methane over supported acid or platinum metal catalysts and hydrolysis of methyl halides over γ-alumina-supported metal oxide/hydroxide catalysts: a feasible path for the oxidative conversion of methane into methyl alcohol/dimethyl ether , 1985 .

[122]  Jean-Paul Lange,et al.  Methanol synthesis: a short review of technology improvements , 2001 .

[123]  Mohammad Reza Rahimpour,et al.  Contribution to emission reduction of CO2 by a fluidized-bed membrane dual-type reactor in methanol synthesis process , 2010 .

[124]  Suk-Hwan Kang,et al.  Modeling of the Kinetics for Methanol Synthesis using Cu/ZnO/Al2O3/ZrO2 Catalyst: Influence of Carbon Dioxide during Hydrogenation , 2009 .

[125]  M. Rahimpour,et al.  Enhancement of methanol production in a novel fluidized-bed hydrogen-permselective membrane reactor in the presence of catalyst deactivation , 2009 .

[126]  C. H. Bartholomew.  Sintering kinetics of supported metals: new perspectives from a unifying GPLE treatment , 1993 .

[127]  A. Burghardt,et al.  Pressure changes during diffusion with chemical reaction in a porous pellet , 1988 .

[128]  H. Zabiri,et al.  A SIMULATION STUDY OF AN INDUSTRIAL METHANOL REACTOR BASED ON SIMPLIFIED STEADY-STATE MODEL , 2010 .

[129]  Jacob A. Moulijn,et al.  Mitigation of CO2 by Chemical Conversion: Plausible Chemical Reactions and Promising Products , 1996 .

[130]  Dae Ryook Yang,et al.  The process design and simulation for the methanol production on the FPSO (floating production, storage and off-loading) system , 2014 .

[131]  Gilbert F. Froment,et al.  A Steady-State Kinetic Model for Methanol Synthesis and the Water Gas Shift Reaction on a Commercial Cu/ZnO/Al2O3 Catalyst , 1996 .

[132]  Dimitri Gidaspow,et al.  Hydrodynamic simulation of methanol synthesis in gas–liquid slurry bubble column reactors , 2000 .

[133]  Carlo Pirola,et al.  First-principles models and sensitivity analysis for the lignocellulosic biomass-to-methanol conversion process , 2016, Comput. Chem. Eng..

[134]  W. Luyben.  Design and Control of a Methanol Reactor/Column Process , 2010 .

[135]  M. Saito,et al.  Kinetic study of methanol synthesis from carbon dioxide and hydrogen , 2001 .

[136]  Jay H. Lee,et al.  Model predictive control: past, present and future , 1999 .

[137]  Carlo Pirola,et al.  Water gas shift membrane reactors , 2015 .

[138]  J. Maxwell,et al.  The Dynamical Theory of Gases , 1905, Nature.

[139]  Giulia Bozzano,et al.  Online Feasibility and Effectiveness of a Spatio-temporal Nonlinear Model Predictive Control. The Case of Methanol Synthesis Reactor , 2012 .

[140]  A. Jahanmiri,et al.  Application of water vapor and hydrogen-permselective membranes in an industrial fixed-bed reactor for large scale methanol production , 2011 .

[141]  S. Ledakowicz,et al.  New numerical algorithm for solving multidimensional heterogeneous model of the fixed bed reactor , 2013 .

[142]  Marco Restelli,et al.  Considerations on the steady-state modeling of methanol synthesis fixed-bed reactor , 2011 .

[143]  P. Spath,et al.  Preliminary screening: Technical and economic assessment of synthesis gas to fuels and chemicals with emphasis on the potential for biomass-derived syngas , 2003 .

[144]  Sidharth Abrol,et al.  Modeling, simulation and advanced control of methanol production from variable synthesis gas feed , 2012, Comput. Chem. Eng..

[145]  Behdad Moghtaderi,et al.  A comparison of homogeneous and heterogeneous dynamic models for industrial methanol reactors in the presence of catalyst deactivation , 2005 .

[146]  E. Supp,et al.  IMPROVED METHANOL PROCESS , 1981 .

[147]  Carlo Pirola,et al.  Systematic staging design applied to the fixed-bed reactor series for methanol and one-step methanol/dimethyl ether synthesis , 2014 .

[148]  Carlo Pirola,et al.  Assessing thermal energy storage technologies of concentrating solar plants for the direct coupling with chemical processes. The case of solar-driven biomass gasification , 2014 .

[149]  G. Groppi,et al.  Optimization of compact multitubular fixed-bed reactors for the methanol synthesis loaded with highly conductive structured catalysts , 2014 .

[150]  Manos Mavrikakis,et al.  Mechanism of Methanol Synthesis on Cu through CO2 and CO Hydrogenation , 2011 .

[151]  Mohammad Farsi,et al.  Dynamic modeling of a H2O-permselective membrane reactor to enhance methanol synthesis from syngas considering catalyst deactivation , 2012 .

[152]  Flavio Manenti.  Natural gas operations: considerations on process transients, design, and control. , 2012, ISA transactions.

[153]  Junji Nakamura,et al.  The chemical modification seen in the Cu/ZnO methanol synthesis catalysts , 2000 .

[154]  Sunggyu Lee,et al.  Methanol Synthesis Technology , 1989 .

[155]  Ehsan Javadi Shokroo,et al.  REAL TIME OPTIMIZATION OF SHELL AND TUBE METHANOL REACTOR USING EVOLUTIONARY AND GENETIC ALGORITHMS , 2013 .

[156]  J. Nørskov,et al.  Kinetic Implications of Dynamical Changes in Catalyst Morphology during Methanol Synthesis over Cu/ZnO Catalysts , 1997 .

[157]  Lorenz T. Biegler,et al.  Technology Advances for Dynamic Real-Time Optimization , 2009 .

[158]  O. Levenspiel.  Chemical Reaction Engineering , 1972 .

[159]  Jianhua Wang,et al.  Mathematical simulations of the performance of trickle bed and slurry reactors for methanol synthesis , 2005, Comput. Chem. Eng..

[160]  Jerzy Skrzypek,et al.  Kinetics of methanol synthesis over commercial copper/zinc oxide/alumina catalysts , 1991 .

[161]  Victor M. Zavala,et al.  Large-scale nonlinear programming using IPOPT: An integrating framework for enterprise-wide dynamic optimization , 2009, Comput. Chem. Eng..

[162]  Richard G. Herman,et al.  Catalytic synthesis of methanol from COH2: I. Phase composition, electronic properties, and activities of the Cu/ZnO/M2O3 catalysts , 1979 .

[163]  Graeme J. Millar,et al.  An in situ high pressure FT-IR study of CO2/H2 interactions with model ZnO/SiO2, Cu/SiO2 and Cu/ZnO/SiO2 methanol synthesis catalysts , 1992 .

[164]  Jiří Jaromír Klemeš,et al.  A review of cleaner production methods for the manufacture of methanol , 2013 .

[165]  R. Herman,et al.  Chemical trapping of surface intermediates in methanol synthesis by amines , 1985 .

[166]  George Stephanopoulos,et al.  Chemical Process Control: An Introduction to Theory and Practice , 1983 .

[167]  J. Bart,et al.  Copper-Zinc Oxide-Alumina Methanol Catalysts Revisited , 1987 .

[168]  G. I. Lin,et al.  Fundamentals of Methanol Synthesis and Decomposition , 2003 .

[169]  Magne Hillestad.  Systematic staging in chemical reactor design , 2010 .