Reactor, Process & System Engineering

Tailor-made reactors
Development of Catalytic-Membrane-Reactor System for Efficient CO2 Hydrogenation to Methanol
A major challenge of converting CO2 to methanol through hydrogenation is the thermodynamic equilibrium limitation of the methanol yield. The thermodynamic equilibrium limitation can be overcome by continuously removing side-product (H2O) from the reaction mixture through the use of a catalytic membrane reactor. This separation of water using a catalytic membrane reactor significantly shifts reaction equilibrium towards higher methanol yield. It has been reported that by continuously removing 80% of water from the methanol at 20 bar and 200C, the equilibrium CO2 conversion and methanol yield can be able to increase from 18% to 54% and 77% to 96%, respectively, resulting in a significant increase of methanol yield from 13% to 52% (i.e. 400% increase). Since hot steam also accelerates agglomeration of catalyst (i.e. catalyst deactivation), the fast removal of water from product stream can also enhance catalyst stability. In this project, we aim to couple CO2 hydrogenation reaction with continuous pervaporative separation of produced steam through hydroxyl sodalite hollow fiber membranes. The thermo-chemical compatibility between the catalyst and membrane and the membrane permeability and selectivity under the reaction conditions will be explored in detail to obtain higher methanol yield.

Process design and optimization
The ultimate success and/or adoption of a green fuel depends solely on its cost/energy effectiveness. A material invention may seem very attractive based on specific property metrics, but the excellent properties may not necessarily translate into success at the process/system level. Catalysts and reactors, the first line of research focus for green fuels, form a critical but just one part of a process. A large majority of the equipment in a green fuel process will involve operations other than reactions. Significant interactions exist between the reactor and other process conditions, which can make or break a green fuel invention ordinary or ineffective at the system level. In other words, one must synthesize, synergize, scale up, and optimize a process fully, quickly, and reliably to firmly assess the real potential of any given green fuel technology option. This requires that we develop the full process for each catalyst invention, identify appropriate methods for feed preparations and product purifications, find the best reactor and process conditions, manage all side products and wastes responsibly and economically, perform a thorough heat and power integration to exploit all inherent synergies, size and scale up the process safely and efficiently, and estimate the overall cost and energy requirements for each green fuel candidate. To this end, we will develop and employ the state-of-the-art techniques and tools for the reliable synthesis, simulation, screening, integration, and optimization of process alternatives to quickly assess and guide the development of successful green energy technologies.

[1] A. Dutta, I.A. Karimi, and S. Farooq. "Heating Value Reduction of LNG (Liquefied Natural Gas) by Recovering Heavy Hydrocarbons: Technoeconomic Analyses Using Simulation-Based Optimization." Industrial & Engineering Chemistry Research (2018).
[2] A. Jagannath, C.M.R. Madhuranthakam, A. Elkamel, I.A. Karimi, and A. Almansoori. "Retrofit Design of Hydrogen Network in Refineries: Mathematical Model and Global Optimization." Industrial & Engineering Chemistry Research (2018).
[3] H. Hamedi, I.A. Karimi, and T. Gundersen. "Optimal Cryogenic Processes for Nitrogen Rejection from Natural Gas." Computers & Chemical Engineering 112 (2018): 101.
[4] T. He, I.A. Karimi, and Y. Ju. "Review on the Design and Optimization of Natural Gas Liquefaction Processes for Onshore and Offshore Applications." Chemical Engineering Research and Design 132 (2018): 89.
[5] S.K. Nair, H. Nagesh Rao, and I.A. Karimi. "Framework for Work‐Heat Exchange Network Synthesis (WHENS)." AIChE Journal (2018).
[6] Z. Liu, and I.A. Karimi. "Simulation and optimization of a combined cycle gas turbine power plant for part-load operation." Chemical Engineering Research and Design (2017).
[7] C.C.E. Christopher, A. Dutta, S. Farooq, and I.A. Karimi. "Process Synthesis and Optimization of Propylene/Propane Separation Using Vapor Recompression and Self-Heat Recuperation." Industrial & Engineering Chemistry Research 56 (2017): 14557.
[8] H. Nagesh Rao, and I.A. Karimi. "A superstructure‐based model for multistream heat exchanger design within flow sheet optimization." AIChE Journal 63 (2017): 3764.
[9] A. Dutta, S. Farooq, I.A. Karimi, and S.A. Khan. “Assessing the potential of CO2 utilization with an integrated framework for producing power and chemicals.” Journal of CO2 Utilization 19 (2017): 49.

Life cycle analysis and economic analysis
To bring the promising green energy technologies into pilot and industrial scale applications, cost-benefit and life cycle analysis over the whole system plays an important role to provide a comprehensive understanding of the developed process and drive long-term sustainability.

The techno-economic and life cycle sustainability analysis will benchmark the optimized design against existing processes and evaluate the novel process performance in a quantified approach [1-5]. A set of whole system metrics (e.g. CAPEX, OPEX and revenues, energy efficiency, and carbon balance) is built and evaluated along the life cycle. More advanced technologies in energy integration, waste treatment, and real-time operation are also in scope. Several tailored scenarios to the green fuels including the co-location with facilities such as hydrogen production and capture and storage (CCS) plants will be further studied, which is expected to result energy self-sufficiency and bring significant environmental benefits. The methanol produced will also be linked to the chemical industry and transportation systems for additional benefits, considering it can serve as either a fundamental building-block chemical, or an alternative to petroleum-based transportation fuel. The novel pathways are promising to realize a hydrogen economy and carbon reduction at the same time.

[1] X. Wang, M. Guo, R.H.E.M. Koppelaar, K.H. van Dam, C. Triantafyllidis, and N. Shah "A nexus approach for sustainable urban Energy-Water-Waste systems planning and operation", Environmental Science & Technology 52 (2018): 3257.
[2] N. Bieber, J. Ker, X. Wang, K. H. van Dam, C. Triantafyllidis, R. H.E.M. Koppelaar, and N. Shah. “Sustainable planning of the Energy-Water-Food nexus using decision making tools”, Energy Policy 113 (2018): 584.
[3] X. Wang, A. Palazoglu, and N. H. El-Farra. "Optimal scheduling of responsive industrial production with hybrid renewable energy systems". Renewable Energy, 100 (2017): 53.
[4] X. Wang, A. Palazoglu, and N. H. El-Farra. "Operational optimization and demand response of hybrid renewable energy systems." Applied Energy 143 (2015): 324.
[5] X. Wang, N.H. El-Farra, and A. Palazoglu. "Proactive reconfiguration of heat-exchanger super networks." Industrial & Engineering Chemistry Research 54, no. 37 (2015): 9178.