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The new model describing the gaseous transport through graphite gaskets is based on the assumption of a flow in the transition regime through nano-scale capillaries, using the Maxwellian wall-slip boundary condition for rarefied gases. Together with an earlier published model describing the liquid transport in graphite gaskets, it enables the characterization of fugitive emissions of volatile organic compounds from fluid-charged flange joints in chemical and petrochemical plants as a function of medium properties, pipe pressure, and gasket stress. Additionally, combination of the models allows predicting the emission rates of gases by experiments with liquids as the emitting fluid. Finally, recommendations are made to improve the gaskets with respect to their sealing performance towards gases.

In the light of market uncertainties and globalization, the capacity of fast and flexible adaption of a chemical plant to changing market conditions becomes a major necessity in future production scenarios. The capacity flexibility of a plant can be influenced by oversizing and numbering up of unit operations. The additional costs for these measures have to be compensated for by the financial benefit arising from the option to adapt to uncertain market demands. Therefore, the additional costs have to be balanced against the gain in flexibility. In this work, methods for the evaluation of capacity flexibility are adapted from the manufacturing industries to enable a cost-effective design of a modular plant. The evaluation methods are used to select modular plant setups allowing the best compromise between costs and flexibility in different market scenarios.