Search

[Display omitted] • Pre-allocation of raw gases by means of split-mixing operation and multi-feeding. • Analysis for the effect of parameters on multiple gas feeds absorption. • Mass transfer of H 2 S strengthened through optimizing column profiles. • Simultaneous energy saving and purity improvement compared with conventional process. Sweetening process is essential in removing H 2 S and CO 2 from refinery gases for environmental and safety concerns. In industrial production, owing to the investment cost, multiple sour gases with various compositions are premixed and sent to a single sweetening plant, leading to unnecessary energy consumption caused by ignoring characteristics of each sour gas. Therefore, the multiple gas feeds absorption was analyzed through orthogonal test method and sensitivity analysis. Moreover, a pre-allocation of raw gases along with multi-feeding operation was proposed to optimize the temperature and concentration distribution in the absorber, so that the mass transfer was significantly strengthened. Based on this, a sweetening process with multiple gas feeds was developed to realize the simultaneous optimization of mass and energy. The rigorous simulation was carried out and the model validity had been verified with experimental and industrial data. Finally, a refinery in Shandong, China was taken as an example. With the proposed process, the purity of H 2 S in acid gas was increased by 2.55%, while the energy consumption and the overall exergy loss were reduced by 6.5% and 18.75%, respectively. [ABSTRACT FROM AUTHOR]

• State-Task Network representation for distillation sequence with sidestream column • Nonsharp distillation design through modified Fenske-Underwood-Gilliland method • Four-component case with mass interaction between reaction and separation systems • 14.11% and 5.70% reduction in operational cost and TAC for reference case In this work, a comprehensive design method for three-section sidestream columns along with a novel State Task Network representation including both conventional and sidestream distillation sequence configurations is present. The distillation network is embedded in the superstructure-based framework for reaction-separation-recycle process synthesis to explore the mass interaction in different sub-systems. In the superstructure, complete interconnections among reactor modules as well as necessary connections between reactor modules and distillation columns are involved to guarantee opportune coupled degree. Based on this, component distribution in distillation through Underwood equations is introduced to provide desired products with required purity and multiple component mixtures as feedback to the reactor network, achieving the optimization of mass interaction in the whole flowsheet. Furthermore, Fenske-Underwood-Gilliland shortcut method to design columns with and without sidestream, and finite element with orthogonal collocation approach to design PFRs are employed, so that reasonable tradeoff between model accuracy and solution difficulty is achieved. Finally, two literature examples are performed to demonstrate the feasibility and validity of the proposed methodology. [ABSTRACT FROM AUTHOR]