Abstract
Process industry is characterized by the existence of several, usually competitive, technical solutions that can be used to achieve a certain result. In this paper competing technologies for the treatment of lean VOC-air mixtures are compared on the basis of more relevant operational parameters: the energy consumption , the out-of-service time and monetary risk. Two systems has been compared in this paper: a catalytic fixed-bed reactor in which the heat recovery is guaranteed by a heat exchanger - traditional plant, and a "intensified" plant where a catalytic reverse-flow reactor is installed, able to achieve and internal heat recovery through the periodical reversal of the flow direction. The decisions-making would require a full picture of the plant behaviour in regime conditions, but also during transients deviations following a failure and the related recovery actions. This picture can be obtained through the Integrated Dynamic Decision Analysis, that generates the full set of possible sequences of events that could result in plant unavailability, with their probability of occurrence and the effect on energy consumption. Results are expressed in terms of out-of-services times, that for operatively sake have to be minimized of energy absorbed by each piece of equipment and cost for the VOC treatment. Outcomes evidenced the pros and cons of the two plants. The traditional plant guarantees a better continuity of service, but also higher operational costs. The intensified plant shows lower operational costs, but a higher complexity, with a need of more level of protection to obtain a comparable out-of-service time. The quantification of risks and benefits allows the comparison between competing technologies to be performed on a complete picture of the behaviour of the plants, promoting a more effective decision-making process.
