NPRP-7 Cycle

Funding Agency

Project No

NPRP-7-843-2-321

Project Duration

January 2015-June 2018

Total funding

US$892,392; Prof. Nimir portion – US$560,000

Project Title

Maximizing the Effectiveness of Fischer-Tropsch Fixed-bed Reactor: Tailoring Reaction Media, Catalyst Geometry and Pore Structure

Project Description

Natural gas is the world’s fastest growing energy resource, with global production increasing by 3.1% in 2011. Against this backdrop, the State of Qatar’s abundant gas reserves see it strategically placed to lead the way in developing new gas processing technologies. Qatar is currently the world leader in Gas-to-Liquids (GTL) production, and is uniquely poised to immediately benefit from advances in GTL technology. The Fischer-Tropsch synthesis (FTS) reaction chemistry forms the core component of the GTL process. FTS is a classical heterogeneous reaction whereby syngas (a mixture of CO and H2 obtained from reforming methane or from coal/biomass gasification) is converted into a range of hydrocarbon products such as paraffins, olefins and oxygenates of varying chain lengths by reaction over an active metal catalyst (e.g. Co, Fe, Ni, Ru).

Advancing the catalyzed Fischer-Tropsch synthesis (FTS) reaction remains at the heart of the rapidly expanding gas-to-liquids (GTL) industry. However, existing commercial FTS reactor designs (fixed-bed; fluidized bed, and slurry) remain practically unchanged since the initial development of FTS technologies in the 1920s. Likewise, the development of cobalt- and iron-based FTS catalysts has stagnated, owing to reliance upon conventional alumina and silica supports. Heat and mass transport limitations arising from the presence of significant reaction enthalpy and both gas and liquid-phase reactants require transformative solutions to achieve the breakthroughs in FTS technology necessary to ensure the continued growth of the GTL industry.

The main objective of the current proposal is to investigate a non-conventional approach in solving the major challenges facing this complex chemistry via a series of experimental and modeling studies with the ultimate goal of realizing new reactor and catalyst technologies uniquely tailored to FTS process, thus providing the critical breakthroughs in reaction selectivity, catalyst lifetime and therefore process economy needed to ensure continued development in the GTL industry. This novel catalyst/bed for the FTS technology will be designed to facilitate significant enhancement of catalyst bed thermal conductivity, reduction of hot sport formation on catalyst surface, and improvement in process selectivity to provide selective control of the hydrocarbon product distribution while operating at higher catalyst activity and reactor bed efficiency. Specifically, the project has the following aims:

Design novel and high thermal conductivity metal microfibrous entrapped cobalt (MFEC) catalytic systems for FTS of controlled catalyst structure and with an assortment of high surface area entrapped catalyst particulates of diameters at or below 100 micron to all but eliminate intraparticle mass transport limitations and greatly accelerate external transport limitations.
Conduct detailed investigations on the performance of the novel catalyst structures under both conventional reaction media (gas phase and liquid phase) and non-conventional media (subcritical, near critical and supercritical phase conditions). MFECC will be compared and contrasted with packed beds and slurry phase reactors under approximately the same set of reaction conditions and reactor volumes compared to the resultant balance of plant requirements and annualized operating costs.

Investigate the temperature profile (both radial and axial) inside the abovementioned reactors. The maximum temperature gradient and operational temperature window at different reactor sizes and tube diameters will be established for each case by heat transfer analysis, simulations and multipoint thermocouple investigation on experimental reactor beds.
Determine the product selectivity and product distribution for each reactor configuration and provide an optimization strategy to improve the selectivity to one or two product fractions of interest (i.e. adding a unique feature to this reactor technology compared to others, of selective control of FTS product distribution).
Model the heat and mass transfer occurring within catalyst particles in order to tailor catalyst pore structure and surface wettability to facilitate wax stripping from pores, maximize catalyst activity and achieve a stable dry (gas-solid) catalytic regime for maximizing conversion under the regime where fully-developed trickling flow is present in conventional fixed-bed reactor.

Major Accomplishments

Journal Papers

1. Hussain R., Blank J., Elbashir N. (2015) “Modeling the Fixed-Bed Fischer-Tropsch Reactor in Different Reaction Media.” Computer Aided Chemical Engineering. 37: 143-148.

2. Challiwala, M. S., Wilhite, B. A., Ghouri, M., Elbashir, N. O., ” Multidimensional Modeling of a microfibrous entrapped cobalt catalyst Fischer-Tropsch reactor bed. ” AIChE Journal (2017). doi:10.1002/aic.16053.

3. Choudhury. H.A., et al. “Understanding the Deactivation Process of a Microfibrous Entrapped Cobalt Catalyst in Supercritical Fluid Fischer Tropsch Synthesis.” (Under review in Cat. Today)

4. Ghouri M. M., Afzal S., Hussain R., Blank J., Bukur D. B., Elbashir N. O. (2016) “Multi-scale modeling of fixed-bed Fischer Tropsch reactor.” Computers and Chemical Engineering. 91; 38–48.

Book Chapters

1. Tala Katbeh, Nimir Elbashir, and Mahmoud El-Halwagi, “An energy integrated approach to design supercritical Fischer-Tropsch synthesis products separation and solvent recovery system” Chapter 17 in Elbashir, N. O.; El-Halwagi M. E.; Hall, K.; I. Economou (2018) “Natural Gas Processing from Midstream to Downstream” Wiley. West Sussex, UK. ISBN: 978-1-119-27025-6; pp. 439-462.

2. M Shahin, S Afzal, and Nimir O. Elbashir, “Fractionation of the Gas-to-Liquid Diesel Fuels for Production of On-Specification Diesel and Value-Added Chemicals” Chapter 16 in Elbashir, N. O.; El-Halwagi M. E.; Hall, K.; I. Economou (2018) “Natural Gas Processing from Midstream to Downstream” Wiley. West Sussex, UK. ISBN: 978-1-119-27025-6; pp. 439-462.

Journal Papers under Preparation

1. Abusrafa, A., Challiwala, M. S., Choudhury, H. A., Wilhite, B. A., Elbashir, N. O., “Multi-Dimensional Modeling of Packed Bed Reactor: A Comparison Between Supercritical and Gas Phase Fischer Tropsch Process” to be submitted to Catalysis Today-Special issue of Dr. Bukur.

2. Abusrafa, A., Challiwala, M. S., Choudhury, H. A., Wilhite, B. A., Elbashir, N. O., “Multi-Dimensional Modeling of Fischer Tropsch reactor using detailed kinetics model”. To be submitted to AIChE Journal

3. Mohammed, Nosaiba., Choudhury, H. A, Challiwala, M. S., Choudhury, H. A, Elbashir, N. O., Detailed Kinetics of Supercritical Fischer Tropsch Reaction on Cobalt catalyst using Genetic Algorithm.” To be submitted to Industrial & Engineering Chemistry Research

Conference Presentations

1. M.S. Challiwala, H.A. Choudhury, A. Abusrafa, B. A. Wilhite, M. M Ghouri, N. O. Elbashir, “ 2-D Pseudohomogeneous reactor bed Modeling of Fischer Tropsch Process in COMSOL® Multiphysics”, Bukur Reaction Engineering and Catalysis Symposium, December 2017, Doha, Qatar.

2. M.S. Challiwala, B. A. Wilhite, M. M Ghouri, N. O. Elbashir, “ 2D Reactor Modeling of Fischer Tropsch reactor in COMSOL® Multiphysics”, AIChE Annual Meeting, November 2017, Minneapolis, MN, USA.

3. M.S. Challiwala, B. A. Wilhite, M. M Ghouri, N. O. Elbashir, “ 2D Modeling of Fischer Tropsch reactor in COMSOL® Multiphysics”, 2nd International Supercomputing conference, October 2017, Doha, Qatar.

4. M.S. Challiwala, B. A. Wilhite, M. M Ghouri, N. O. Elbashir, “ Multiscale Modeling of supercritical Fischer-Tropsch Synthesis Fixed-Bed Reactor”, The 5th International Gas Processing Symposium, Qatar University, November 2016, Doha, Qatar

5. H.A. Choudhury & N. O. Elbashira, “Microfibrous Entrapped Cobalt Catalyst (MFECC) Reactor Bed in Fischer Tropsch Synthesis (FTS) Under Different Reaction Media: A Catalyst Deactivation Study” Bukur Reaction Engineering and Catalysis Symposium, December 2017, Doha, Qatar.

6. M.S. Challiwala, H.A. Choudhury, B. A. Wilhite, N. O. Elbashir, “Experimental Verification of COMSOL® 2-D Modeling of Fischer Tropsch Reactors and Media” Syngas convention 2018, Cape Town, South Africa

7. M.S. Challiwala, H.A. Choudhury, B. A. Wilhite, N. O. Elbashir , “Experiment Supported 2-D COMSOL® Modeling of Fischer Tropsch Synthesis using Non-conventional Media and Non-conventional Catalyst.” ARC-18, Doha, Qatar

8*. Xinquan Cheng and Bruce J. Tatarchuk. Microfibrous Entrapped Catalyst Structure for Highly Exothermic Reactions: Fischer-Tropsch Synthesis, 2017 AIChE Annual Meeting, Minneapolis, MN, United States, Nov. 2017.

9*. S. Afzal, A. Kasht, R. Hussain, J. Blank, N. Elbashir, “Modeling Fischer-Tropsch Product Distribution of a Cobalt-based Catalyst in Different Reaction Media December 2017, TAMUQ Research Forum 2017, Doha, Qatar

10*. S. Afzal, R. Hussain, N. Elbashir, “Modeling Fischer-Tropsch Product Distribution of a Cobalt-based Catalyst in Different Reaction Media” GPC-2014, Doha, Qatar.

11*. J. Blank, S. Warag, S. Afzal, L.B. Nasser, R. Hussain, N. Elbashir,” Syngas Utilization through High Pressure Solvent Assisted Fischer-Tropsch Synthesis, 14th AIChE Spring Meeting, New Orleans, LA.USA

12*. M. Ghouri, R. Hussain, S. Challiwala, N. Elbashir, “Systematic Multi-scale Modeling for Supercritical Fischer-Tropsch Fixed Bed Reactor”, The 11th International Symposium on Supercritical fluids, Seoul, Korea, October 11-14, 2015.

13*. M. Noureldin, M. Ghouri, S. Challiwala, B. Bao, M. El-Halwagi, N. Elbashir, “An Energy Integrated Solvent Recovery Setup for Supercritical Fluids”, The 11th International Symposium on Supercritical fluids, Seoul, Korea, October 11-14, 2015.

*The presentations listed above (8-13) were prepared from our previous work on Fischer Tropsch process during NPRP 4 project. However, their applications were realized during current project.

Human Development

Ph.D. and Master Thesis

1. Amro Kasht (MSc): “Experimental Validations of Supercritical Phase Fischer Tropsch Models” graduated Spring 2015 Texas A&M University at Qatar (currently working in RasGas-Qatar).

2. Abdullah Abdulmajeed (M.Eng.) “Hazob Study on High Pressure Reactor Unit in Fuel Characterization Lab at TAMUQ” graduated Fall 2016 Texas A&M University at Qatar (currently at Qatargas),

3. Tala Katbeh “An Energy Integrated Approach To Design Supercritical Fischer-Tropsch Synthesis Products Separation And Solvent Recovery System” graduated summer 2017

4. Mohamedsufiyan Challiwala “Modeling gas processing reactors” Ph.D. dissertation in progress expected Fall 2019 Texas A&M University

5. Aya Abusrafa “2-D Modeling of Fischer Tropsch and Reformer reactors” to be graduated Spring 2019 Texas A&M University at Qatar.

6. Nosaiba Mohamed “Hydrocarbon Product Distribution of Fischer Tropsch” Texas A&M University to be graduated Spring 2019 Texas A&M University at Qatar.

7. Xinquan Cheng “Microfiborus Entrapped Catalysts” Ph.D. dissertation Auburn University

Research team

1. Aya Abusrafa (Graduate Student at Texas A&M University at Qatar)

2. Nosaiba Mohamed (Graduate Student at Texas A&M University at Qatar, 2019)

3. Mohammed Sufiyan Challiwala (Ph.D. Student at Texas A&M University CS, 2019)

4. Shaik Afzal (Ph.D. Student at Texas A&M University CS, 2019)

5. Amro Kasht (MSc): (currently working in RasGas-Qatar).

6. Anjaneyulu Chatla (Postdoc, Texas A&M University at Qatar 2018)

7. Abdullah Abdulmajeed (M.Eng.) currently at Qatargas

8. Saad Intikhab (Ph.D. Student at Drexel University, USA, 2019)

Graduate and undergraduate students

1. Wajdi Ahmed (currently researcher at the Petroleum Engineering Program, Texas A&M Qatar)

2. Ahmad AlRchid (Engineer in Qatar)

3. Marwan ElWahsh (currently a master student at Texas A&M Qatar)

4. Mohamed Omer (currently a master student at Texas A&M Qatar)

5. Muhammad Yoosufani (Engineer in Qatar)

Summary Slide

Project_Summary-Slide_NPRP_7