Gas Separation by Adsorption Processes Ralph T Yang 1987 Chemical Engineering Preowned vintage copy with general wear from age, storage and previous use. Cover shows rubbing, scuffs, scratches and edge/corner wear as pictured. Pages show age-related toning. Binding is intact. Colors may vary due to lighting and screen settings. Most items are shipped with reused/recycled material. The package might not be pretty but it's helping the environment which is a win for everyone. Please ask questions prior to purchasing and thank you for looking.