A port-stream based equation oriented modelling of complex distillation column: A dividing wall column case study

Dividing wall column (DWC) offers higher degree of freedom in comparison with the conventional column. Furthermore, the different sections configurations within the column are highly interacting with several recycle loops. Facing with such complex unit operation, describing its behaviour encourages the focal point on the resolution of ideal modelling approaches. Equation oriented (EO) modelling of DWC has been studied by several researchers involving complex algorithm and methodology. In this work, a new approach for modelling of DWC is presented. The modelling methodology involves variables connectivity based on ports and streams that is admissible to equation-oriented flow sheet. To verify the functionality of the proposed method, the modelled DWC is validated with two case studies depicted from experimental literature data to separate alcohol mixture and fatty acid fractionation. The model development was performed in MOSAIC, a web-based modelling tool and run in gPROMS. The model shows good convergence and has less than 10% error when compared to the above mentioned case studies. To furthermore extend the model capability, relative gain array (RGA) analysis was conducted for the fatty acid fractionation to determine the best control configuration in DWC. Result shows that L-S-V and L-S-B configurations are the best control configurations. Our analysis also shows that reflux flowrate, side flowrate and vapor boilup are best to control distillate product, side product and bottom product, respectively.

LONG AND VERY LONG FATTY ACID FRACTIONATION IN SYSTEMIC LUPUS ERYTHEMATOSUS IN THE ACTIVE AND INACTIVE STATUS

Objective: Flare in Systemic Lupus Erythematosus (SLE) is an exacerbation of SLE clinical features that were earlier quiescent. The disease activity changes from inactive to active with an increase of several immunological profiles; the rise of immune activity induces a metabolic shift in SLE patients. The previous study aimed to investigate the long and very long fatty acid fractions (LCFA and VLCFA) in the active and inactive statuses of SLE patients and showed there were dynamic changes in fatty acid fractions in SLE patients, compared to healthy subjects. The aim of this preliminary study is to investigate LCFA and VLCFA in the active and inactive condition of SLE patients. Methods: Four serum samples of active and inactive statuses from the same SLE patients were used in this study. Serum LCFA and VLCFA fractions were analyzed by a 7890 Gas Chromatography (GC) System 5977 Mass Selective Detector (MSD). Results: All of the LCFA and VLCFA fractions were increased in the active condition, compared to SLE patients in inactive, although they were statistically not different (p>0.05). The total fatty acid fraction was 38% higher in active condition compare to inactive. The prominent increase of fatty acid fractions was alpha-linolenic acid (inactive vs. active: 23.25±17.97 vs 48.25±38.58 μmol/l), oleic acid (1300±190.4 vs 1774±866.3 μmol/l) and myristic acid (31.25±12.76 vs 59.25±40.4 μmol/l). Conclusion: The serum of LCFA and VLCFA fractions in SLE patients tend to increase in active conditions.

A post-stream based equation oriented modelling of complex distillation column: a dividing wall column case study

Dividing wall column (DWC) offers higher degree of freedom in comparison with the conventional column. Furthermore, the different sections configurations within the column are highly interacting with several recycle loops. Facing with such complex unit operation, describing its behaviour encourages the focal point on the resolution of ideal modelling approaches. Equation oriented (EO) modelling of DWC has been studied by several researchers involving complex algorithm and methodology. In this work, a new approach for modelling of DWC is presented. The modelling methodology involves variables connectivity based on ports and streams that is admissible to equation-oriented flow sheet. To verify the functionality of the proposed method, the modelled DWC is validated with two case studies depicted from experimental literature data to separate alcohol mixture and fatty acid fractionation. The model development was performed in MOSAIC, a web-based modelling tool and run in gPROMS. The model shows good convergence and has less than 10% error when compared to the abovementioned case studies. To furthermore extend the model capability, relative gain array (RGA) analysis was conducted for the fatty acid fractionation to determine the best control configuration in DWC. Result shows that L-S-V and L-S-B configurations are the best control configurations. Our analysis also shows that reflux flowrate, side flowrate and vapor boilup are best to control distillate product, side product and bottom product respectively.

FRAKSINASI KOMPLEKSASI UREA PADA MINYAK DEDAK PADI DALAM PENINGKATAN KONSENTRASI ASAM LEMAK TAK JENUH

<p>Abstract: Polyunsaturated fatty acid in rice bran oil is good for health and valuable. The aims of<br />this research were identifying influence of complexation temperature and time on the<br />enhancement of polyunsaturated fatty acid consentration. This research began with<br />saponification and extraction of rice bran oil as pretreatment process. Then, complexation<br />process was done with urea-ethanol solution ration of 35:175 (w/v). Complexation was carried<br />out by mixing 10 gram of free fatty acid of rice bran oil with 40 ml of urea-ethanol solution and<br />then followed by separation process and iod number analysis. The result of temperature<br />variation showed that the iod number of sample 0 hour, 2 hours, 12 hours, and 24 hours were<br />29.18; 32.99; 36.04; and 37.82. Then the iod number of sample with variable temperature 28<br />o<br />C, 5<br />o<br />C, -2<br />o<br />C and -7<br />C were 37.82; 39.85; 43.15; and 44.16. The longer time and the lower<br />temperature of complexation increased polyunsaturated fatty acid consentration indicated by iod<br />number rising.<br />o<br />Keywords: Rice bran oil, Polyunsaturated Fatty Acid, fractionation urea complexation, iod<br />number bixa</p>

Process Fault Detection Using Hierarchical Artificial Neural Network Diagnostic Strategy

Kertas kerja ini menerangkan mengenai kegunaan jaringan neural tiruan (ANN) untuk mengesan dan membaiki kesilapan dalam loji proses. Dalam penyelidikan ini, ANN menggunakan dua lapisan dalam strategi diagnostik hirarki. Lapisan pertama mengenal pasti nod di mana kesilapan bermula sementara lapisan kedua membahagikan kesilapan yang berlaku pada nod tertentu. Arkitek model ANN adalah berasaskan beberapa lapisan rangkaian suapan hadapan dan menggunakan algoritma luncuran belakang dalam skema latihan. Untuk mendapatkan konfigurasi ANN yang terbaik, analisis topologi dilakukan. Keberkesanan kaedah ini ditunjukkan oleh kajian kes melibatkan turus pemecahan asid lemak. Keputusan menunjukkan sistem ini berjaya mengesan kesilapan tunggal dan fana yang terdapat dalam proses tersebut. Kata kunci: Pengenalpastian dan diagnostik kesilapan proses, strategi diagnostik hirarki, jaringan neural tiruan, turus pemecahan asid lemak This paper focuses on the use of artificial neural network (ANN) to detect and diagnose fault in process plant. In this work, the ANN uses two layers of hierarchical diagnostic strategy. The first layer diagnoses the node where the fault originated and the second layer classifies the type of faults or malfunctions occurred on that particular node. The architecture of the ANN model is founded on a multilayer feed forward network and used back propagation algorithm as the training scheme. In order to find the most suitable configuration of ANN, a topology analysis is conducted. The effectiveness of the method is demonstrated by using a fatty acid fractionation column. Results show that the system is successful in detecting original single and transient fault introduced within the process plant model. Key words: Process fault detection and diagnosis, hierarchical diagnostic strategy, artificial neural network, fatty acid fractionation column