ASPEN methodology

Several authors have already developed methodologies for the simulation of hybrid distillation-pervaporation processes. Short-cut methods were developed by Moganti et al. [95] and Stephan et al. [96]. Due to simplifications such as the use of constant relative volatility, one-phase sidestreams, perfect mixing on feed and permeate sides of the membrane, and simple membrane transport models, the results obtained should only be considered qualitative in nature. Verhoef et al. [97] used a quantitative approach for simulation, based on simplified calculations in Aspen Plus/Excel VBA. Hommerich and Rautenbach [98] describe the design and optimization of combined pervaporation-distillation processes, incorporating a user-written routine for pervaporation into the Aspen Plus simulation software. This is an improvement over most approaches with respect to accuracy, although the membrane model itself is still quite... 

A detailed discussion of the cost estimation methodology or system structure is beyond the scope of this paper and can be found in the ASPEN quarterly reports (2). 

Researchers in Korea, in 1997, announced the development of a biodegradable plastic made from fibers in genetically engineered aspen trees. Their methodology included the use of chemical catalysts as well as modification of the genetic content of the tree. ... 

Srinivas S, Mahajani SM, Malik RK. Reactive distillation for Fischer-Tropsch synthesis simulation-based design methodology using Aspen Plus. Ind. Eng. Chem. Res. 2010 49 9673-9692. 

The mass- and energy-based indicators help to identify process alternatives for which sustainability metrics, environmental impact factors, as well as inherent safety indices can be estimated. The goal here is to optimize the process so that there is improvement in all these metrics with respect to the base case design. The application of the methodology requires a combination of tools ranging from databases to process simulation software (such as Aspen , Hypro , Sim Sci , etc.), to computational routines for various types of indicators and process synthesis/design tools. 

To meet this challenge, we developed a multiple-component optimization methodology that fully accounts for the behaviour of individual components within the process reactors, separators and the recycle gas loop. While in the binary pinch approach the composition and flows of reactor feed and separator gas are fixed, our multiple-component approach allows these compositions to float, so long as constraints such as minimum hydrogen partial pressure and minimiun gas-to-oil ratio are met. Simulation models for reactors, high-pressure and low-pressure separators are used to correctly model overall process behaviour. We also developed a network simulation tool based on AspenTech s Aspen Custom Modeler (ACM) software. 

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