Capacity Flexibility of Chemical Plants

Abstract

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.

Real option framework for equipment wise expansion of modular plants applied to the design of a continuous multiproduct plant

“…To guarantee an adequate phase separation in the extraction a minimum set tle time has to be guaranteed. This settling time is limited by the design of the settler unit (Seifert et al, 2014). To respect the modular approach, apparatuses with dif ferent sizes are available for each unit operation.…”

“…This is done according to the method presented in Seifert et al (2014). The result of this analysis is an operating range which is set by the overlap between the operating windows of the different unit operations.…”

“…These costs are derived from cost functions available in Woods (2007). The data for calculation of operating costs can be found in Seifert et al (2012Seifert et al ( , 2014.…”

Design of equipment modules for flexibility

“…The operating window of an apparatus is determined by the minimum capacity Cap min and the maximum capacity Cap max , respectively [2]. The difference between Cap min and Cap max describes the size of the operating window and is called Cap.…”

“…To react to these challenges the time to market of a chemical production plant needs to be reduced and the flexibility needs to be increased enabling an easy production rate adjustment. The application of modular production plants consisting of predefined apparatus designs with discrete sizes, so-called equipment modules, is a promising approach in this context [2]. Such equipment modules should offer a large flexibility to enable an operation over a wide range of production rates.…”