Different technologies are available for the treatment of gaseous streams containing VOCs (Volatile Organic Compounds), namely catalytic or homogeneous combustion, absorption, adsorption, etc. The goal is either to recover the VOCs, or to destroy them, thus avoiding, in both cases, their emission into the atmosphere.
The treatment of “lean” streams, where the concentration of the VOCs is particularly low (e.g. lower than 1% v/v), is a particularly challenging case study as the low concentration makes the VOC recovery technically and economically impracticable. In this case, the catalytic combustion stands out as the reference technology as it allows fulfilling the constraints on the characteristics of the product released into the atmosphere …show more content…
This poses the problem of energy recovery: in fact, a large amount of energy is required to pre-heat the feed to the reaction temperature, and a fraction of this energy can be recovered from the treated gas to pre-heat the feed. In any case, a certain amount of energy has to be supplied, as the efficiency of this approach is usually not higher than about 70% [2].
In this framework, a particularly effective technology is represented by the reverse-flow reactor, firstly proposed by Cottrell [3]. The operating principle of the reverse-flow reactor is particularly simple: at first, the reactor is pre-heated to the target temperature and, then, the gaseous stream is fed to the reactor. As a consequence, the gas is heated by the solid, thus reaching the reaction temperature (and cooling the solid material close to the entrance of the reactor), and, then, it heats the solid before leaving the reactor. After a certain time interval, that has to be carefully selected, the …show more content…
tank overflowing [20, 21], risk-based design of an allyl-chloride production plant [22], analysis and optimisation of procedures for LPG tanks maintenance and testing [23]. The IDDA methodology is based on the combined use of a logical-probabilistic model of the system under analysis and its phenomenological model. The logical-probabilistic model allows identifying all potential sequences of events the system can undergo and their probability of occurrence, and it can be coupled to a phenomenological model, i.e. a mathematical description of the process plant behaviour both in case of normal condition and in case of equipment faults. The phenomenological model is used to evaluate the consequences for each sequence of events, and the overall risk value. The joint modelling allows a risk-based decision making to be performed, as discussed in Piccinini & Demichela [20] and in Demichela & Camuncoli
The treatment of “lean” streams, where the concentration of the VOCs is particularly low (e.g. lower than 1% v/v), is a particularly challenging case study as the low concentration makes the VOC recovery technically and economically impracticable. In this case, the catalytic combustion stands out as the reference technology as it allows fulfilling the constraints on the characteristics of the product released into the atmosphere …show more content…
This poses the problem of energy recovery: in fact, a large amount of energy is required to pre-heat the feed to the reaction temperature, and a fraction of this energy can be recovered from the treated gas to pre-heat the feed. In any case, a certain amount of energy has to be supplied, as the efficiency of this approach is usually not higher than about 70% [2].
In this framework, a particularly effective technology is represented by the reverse-flow reactor, firstly proposed by Cottrell [3]. The operating principle of the reverse-flow reactor is particularly simple: at first, the reactor is pre-heated to the target temperature and, then, the gaseous stream is fed to the reactor. As a consequence, the gas is heated by the solid, thus reaching the reaction temperature (and cooling the solid material close to the entrance of the reactor), and, then, it heats the solid before leaving the reactor. After a certain time interval, that has to be carefully selected, the …show more content…
tank overflowing [20, 21], risk-based design of an allyl-chloride production plant [22], analysis and optimisation of procedures for LPG tanks maintenance and testing [23]. The IDDA methodology is based on the combined use of a logical-probabilistic model of the system under analysis and its phenomenological model. The logical-probabilistic model allows identifying all potential sequences of events the system can undergo and their probability of occurrence, and it can be coupled to a phenomenological model, i.e. a mathematical description of the process plant behaviour both in case of normal condition and in case of equipment faults. The phenomenological model is used to evaluate the consequences for each sequence of events, and the overall risk value. The joint modelling allows a risk-based decision making to be performed, as discussed in Piccinini & Demichela [20] and in Demichela & Camuncoli