Search

In model predictive control (MPC), methods of linear offset free MPC are well established such as the disturbance model, the observer method and the state disturbance observer method. However, the observer gain in those methods is difficult to define. Based on the drawbacks observed in those methods, a novel algorithm is proposed to guarantee offset-free MPC under model-plant mismatches and disturbances by combining the two proposed methods which are the proposed Recursive Kalman estimated state method and the proposed Disturbance-Kalman state method. A comparison is made from existing methods to assess the ability of providing offset-free MPC onWood-Berry distillation column. Results shows that the proposed offset free MPC algorithm has better disturbance rejection performance than the existing algorithms. [ABSTRACT FROM AUTHOR]

This study involves the development of novel mesoporous Zr-MCM-48 photocatalyst impregnated with Cu-porphyrin (CuTPP) having Si/Zr ratio of 100, 50 and 25. The synthesized materials were applied as hybrid photocatalyst affording mid-gap energy states and Zi3+ sites for reduction of CO2 into methanol selectively using UV–Visible light treatment. Interestingly, Zr-MCM-48 displayed significant photocatalytic reduction ability under UV–Vis wavelength. The bare Zr-based MCM-48(25) matrix with maximum Zr content in catalyst enhanced the photocatalytic activity with 47.5 µmol methanol formation, possessing high surface area SBET of 1324 m2 g−1, under UV–Visible light irradiation. The characterization results highlighted the influence of visible light active Cu-porphyrin interaction over Zr-MCM-48 silica frameworks due to transition of electrons from the porphyrin centres to the active Zr sites as evident from DRS analysis. Moreover, the impregnation of Cu-porphyrin over Zr-MCM-48(25) displayed methanol formation about 365.11 µmol under UV–Visible light using 0.1 M NaOH and 0.1 M Na2SO3. Also, the effect of varying reaction conditions shown that catalyst concentration, metal loading, light intensity and stirring speed pronouncedly impact the formation of methanol. [ABSTRACT FROM AUTHOR]

Summary: Cu and Mn based tetraphenyl porphyrin namely CuTPP and MnTPP were synthesized through a one pot route with a modified procedure and the reaction conditions (Temperature and time) were optimized based on the energy consumption during the synthesis of the target macrocyclic ligands. The temperature (145°C and 160°C) and time (3, 4, 8 hr) were used to study the effect on the product yield. The optimized values obtained using MATLAB routines are 3.7 hr and 145°C. [ABSTRACT FROM AUTHOR]

Various gas permeation models including Maxwell model, Bruggeman model, Lewis-Nielson model and Pal model were compared via a modelling approach with the relative permeance of CO2 against published experimental data on silica filled polysulfone/polyimide (PSF/PI) mixed matrix membranes (MMMs). However, none of the tested models were able to predict the data with good accurately. A closer look at the cross-sectional image by scanning electron microscopy (SEM) indicated that the fillers were actually prolate ellipsoids dispersed within the matrix. Maxwell-Wagner-Sillar model was then employed to investigate the prolate effect and it was observed that the optimization curves of maximum packing ( φm) and shape factor (n) showed least deviations. The percentage average absolute relative error (AARE %) value for fitted shape factor (nf) was found to be in the range of 1.12-2.17 at 2-10 bar pressure which showed its robustness. A further evaluation from SEM image showed that the shape factor along z-direction (nz) displayed a minimum deviation of 17.52 % for prolates at 0.102 ± 0.01. By using nz as upper limit and estimated shape factor ne through generalization, the error was reduced to 6.01 %. The AAR % deviation was found in the order of nf e < nz,which indicated the importance of shape factor parameter for estimating true CO2 permeance. [ABSTRACT FROM AUTHOR]