Adsorption processes have experienced a significant growth in the last decades. This growth was a result of scientific and technological advances which generated new adsorbents as well as new concepts for processing systems (UOP's "Sorbex" process and PSA cycles). The expectations for a continued development of adsorption are high since process engineering is deeply concerned with intensive processes using less energy. Adsorption processes are also relevant to the increasingly important area of biotechonology. The development of affinity processes is a creative synthesis of biochemistry,molecular biology and chemical engineering. This NATO Advanced Study Institute on "ADSORPTION:SCIENCE and TECHNOLOGY" had as a primary objective to provide an updated treatment of the fundamentals of adsorption and adsorption processes. The lectures presented at the Institute are collected in this volume together with a few papers presented by participants. The material is arranged in four sections.Part I deals with the characterization of adsorption and thermodynamics of adsorption,namely the correlation of equilibrium data.Part II covers the kinetics of adsorption and fixed-bed processes (equilibrium theory,design aspects, adsorptive reactors).Part III is an extensive coverage of cyclic processes (pressure swing adsorption and thermal swing adsorption) and simulated moving beds (modeling for process optimization and industrial applications).Finally Part IV deals with applications mainly in biotechnolo gy (con tin uous adsorption, affini ty chrom atography, gel permeation,chromatographic reactors,scale-up methods).