Environmental assessment in early process development

A short‐cut method for environmental assessment during process development is presented. The method can deal with data uncertainties in early phases, includes all relevant environmental impacts, and is simple and easy to apply. Therefore, it can be used in early phases of process development. The environmental relevance of each substance is represented by the Environmental Factors. These factors are derived from 14 impact categories, where each compound is classified using an ABC methodology. The impact categories are then grouped into six impact groups: Resources, Grey Input, Component Risk, Organisms, Air and Water/Soil. From these, input and output environmental factors are deduced. This factor is combined with mass balance data to yield a number of indices that can be used to optimize the environmental performance of a process in an integrated manner. The method is applied to three case studies: a comparison of chemical and biotechnological production of 6‐aminopenicillanic acid, a comparison of two process alternatives in the enzymatic production of α‐cyclodextrin and the development of a new process for the fermentative production of pyruvate. Copyright © 2004 Society of Chemical Industry     

Einfluß der Holzfeuchtigkeit bei der Diisocyanat-Tränkung auf physikalische und mechanische Eigenschaften von Polymerholz

European Journal of Wood and Wood Products - Die Beladung von Kiefernholz mit Diisocyanat nimmt mit steigender Holzfeuchtigkeit beim Tränken zunächst allmählich und bei Erreichen des...     

Spreading the control complexity in decentralized control of interconnected systems

The problem is considered for large scale interconnected systems of designing decentralized dynamic controllers so that the sum of the orders of the local controllers is approximately the system order, while the separate controller orders are more evenly spread than permitted by the procedure of Corfmat and Morse, which generally leads to all memoriless controllers, save one of high complexity. The paper shows that under certain circumstances, it is possible to design dynamic feedback controllers for each channel which introduce stable uncontrollable or unobservable modes to the overall system, thus lowering the effective order of that system. This result is then used to spread the controller complexity.