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Starting from the necessity for more substantial evidence with regard to the Occurrence of intracrystalline diffusion as the rate-limiting transport mechanism in sorption processes on zeolites, the variation of zeolite crystal size is regarded as a criterion and used in the case of the sorption system n-hexane/MgA zeolite.The experimental study has been carried out by using a constant volume variable pressure system. The uptake curves have been analysed by solution of the appropriate diffusion equation on the assumption that the uptake rate obtained is limited by intracrystalline diffusion. An additional analysis was done considering the sorption process as being limited by surmounting a transport resistance in the surface region of zeolite crystals.The experimental parameters covered the following ranges : temperature : 373-623 K, pressure : w 4 x 10-3-265 Pa, amount sorbed : m 2 x 10-4-3 x 10-1 mmol g-l, crystal size (mean edge length of cubic crystals) : 0.7-43 pm.Over the whole of the ranges of amount sorbed and crystal size the apparent diffusion coefficient

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Operative planning in gas networks with prescribed binary decisions yields large scale nonlinear programs defined on graphs.We study the structure of the KKT systems arising in interior methods and present a customized direct solution algorithm.Computational results indicate that the algorithm is suitable for optimization in small and medium-sized gas networks.