Kinetics

Mathematical Modeling and Process Simulation of Packed Bed Reactor for Methanol Synthesis from Carbon Dioxide Hydrogenation (Published)

Due to increase in carbon footprint, and demands for effective sequestration of carbon dioxide for clean environment, this work focused on the kinetic and thermodynamic modeling of a packed bed reactor (PBR), for methanol production from CO₂ hydrogenation. The system kinetics and thermodynamics are being modelled via application of the fundamental principles of mass, energy and momentum at steady state with negligible catalytic effects, such that the space time, reactor’s length, volume, and heat transfer are structured as function of the concentration gradient of the system feed (CO₂ and H₂), such that depletion of the feed concentration into methanol act at proportionate bases to changes at the reactor performance parameters. Sensitivity of the mathematical models over the studied system were was achieved using MATLAB, and results depicts that increase in the fractional conversion of methanol production system promotes the depletion rate of CO₂ concentration from 87.3452 mol/m³ to 39.2105 mol/m³ with a change in the packed bed reactor (PBR) volume to 13.5155m³ at 99% fractional conversion of the system with a 1.4452m reactor’s length attained over 1.6413 min space time, yielding 94.29% methanol (MeOH) of 103.0486 mol/m³ concentration at exothermic (heat loss) bases. Results achieved from the sensitivity assessment of the developed kinetic and thermodynamic models were in agreement with most presented by other researchers on similar system though using different modeling techniques, which proves the accuracy of the developed models achieved in this work for methanol synthesis from CO₂ hydration in a PBR system.

Keywords: Daltons law of partial pressures, Environmental Pollution, Kinetics, Matlab., greenhouse gases (GHGs), material balance, methanol additive, rate law, reactor performance, space time

Mathematical Modeling of Fluidized Bed Reactor for CO2 Capture in a Typical Cement Producing Plant Existing in Nigeria (Published)

Calcium looping technology has a high potential for capturing CO₂ in Typical Cement Producing Plant Existing in Nigeria Power Generation Plant. This work modelled the calcium looping process utilizing a twin fluidized bed reactor. Incorporating the technology into the plant required the carbonator to operate under a flow rate of 0.55 m³/s and the regenerator at 0.85 m³/s to capture 181,175 metric tonnes of CO₂ in 724,000 metric tonnes of flue gas produced from the power plant annually. The model equations developed were solved numerically using the Runge-Kutta Fourth Order method. Math Works was used to analyze the impact of performance parameters such as temperature, reactor height, residence time, and particle size. The result showed promise for capturing 81.8% of CO₂ from the flue gas in the carbonator at a temperature of 450^oC, and recovering 61.7% of highly concentrated CO₂ in the regenerator at a temperature 1200^oC and a residence time of 30 mins.

Keywords: Cement Industry, Fossil Fuel, Kinetics, Matlab., Runge-Kutta approach; calcium looping process, capturing and sequestration (CCS), greenhouse gases (GHGs)