Development of an Industrial Multitubular Fixed Bed Catalytic Reactor as Cape-open Unit Operation Model Applied to Ethene Production by Ethanol Dehydration Process
The ethene production by ethanol dehydration has been established as a promising production route. In this work a computer software simulation written in FORTRAN 95 for an industrial multitubular fixed bed reactor (MTR), applied to this production route, is embedded in process simulation environment through a C#./NET wrapper code. This wrapper code was developed in agreement with the CAPE-OPEN standards, allowing the MTR simulator to be used as a native unit operation component in any CAPEOPEN compliant simulation environment.
Activating ABO3-type coating by additive for coke inhibition in supercritical thermal cracking of endothermic hydrocarbon fuel
Abstract Coking during endothermic hydrocarbon fuel cracking is a key problem that has to be considered. In this study, anti-coking effect was systematically studied by using water, ethanol and HPW as additives on the coatings of CsOH and BaCeO3 during RP-3 cracking. The morphology, type and amount of coke deposits on the coatings were characterized by means of scanning electron microscopy (SEM), temperature programmed oxidation (TPO) and quantitative carbonization method, respectively. The results show that either the additive or the catalytic coating can effectively remove the coke deposits on the reaction tube. Remarkably, BaCeO3 coating is more effective in inhibiting the formation of fiber coke compared with CsOH coating，which is conducive to the cracking reaction. The best anti-coking effect is achieved by using 5 wt% ethanol as additive on the BaCeO3/HPW coating, and the inhibiting percentage is 97%. In addition, a possible anti-coking mechanism of carbon-steam gasification through BaCeO3/HPW coating and ethanol has been proposed.
A new tearing algorithm for process flowsheeting
Abstract In developing an object-oriented process simulator, we found that tearing algorithms that do not use a cycle matrix might give inconsistent results depending on how ties are resolved. Two recently published flowsheet tearing algorithms (Gundersen and Li) have been studied in detail and a new tearing algorithm has been proposed. These algorithms define an optimal tear set as one that has the minimum tear set weight. Our studies show that Gundersen's “close-to-optimal” tearing algorithm may produce tear sets far from optimum depending on how a tie is resolved in the tearing process. We observe that Li's algorithm fails to produce optimum tear sets for a number of classical flowsheets. We modified Li's algorithm to significantly improve its performance. Based on this modified algorithm we propose a new tearing algorithm that gives an optimum tear set for all the 13 flowsheets studied.