Membrane System Performance Research Articles

Cost Optimization of Nanofiltration with Fouling by Natural Organic Matter

An artificial neural network and genetic algorithm routine has been developed for predicting and optimizing membrane system performance. The model predicted system behavior in response to operating conditions of applied pressure and crossflow velocity. Artificial neural networks accurately modeled mechanisms involved in fouling of membranes by natural organic matter. The model correctly predicted the effects of calcium within the solution in exacerbating fouling, binding of the divalent calcium ions to the natural organic matter macromolecules, and the formation of complexes. The model also correctly predicted the role of increased pressure in inducing fouling and the reverse scenario of mitigating fouling with increased crossflow velocity. The model was applied to membrane plant design for determining cost-effective operations. The genetic algorithm routine searched the predictions of the system model to determine the optimal operating conditions. Fouling conditions induced by the presence of calcium resulted in escalating costs with increases in calcium concentration. Membrane-related cost components were shown to be a significant cost factor that is sensitive to operating conditions and represents a prime target for optimization.

Membrane technology applied to the n-butane oxidation in maleic anhydride production

The influence of membrane gas separation in the maleic anhydride production cycle by direct oxidation of n-C 4H 10 was analysed. The CO 2/CO ratio in the purge stream can be controlled by a two-stage system equipped with polymeric membranes in order to improve the reaction yield and the plant productivity, reducing, at the same time, the n-C 4H 10 loss in the purge stream. The recovery of the not reacted n-C 4H 10 and the reduction of the CO 2 release are further advantages due to the introduction of membrane unit in the production cycle with consequential economic and environmental benefits. The effect of driving force on the membrane system performance was investigated by a simulation study and by experimental tests on three different types of commercial and semi-commercial membranes. For its general character, the concept developed in this work can be extended to other selective oxidative processes.

Industrial Use of Reverse Osmosis

The use of reverse osmosis (RO) as a water treatment process in private industry has dramatically increased over the past five years because of increased product quality and membrane system performance. Design of RO systems must include a thorough examination of each unit process to determine the effect on preceding and succeeding units. Properly designed RO systems will provide effective industrial wastewater treatment, waste management, and recycling—all of which add up to higher quality product water at a reasonable cost.