Energy recovery number

Definition 6.1. The energy recovery number is the ratio of the rate at which energy is recovered from the process effluent stream(s) to the rate at which energy is input to the process through the material feed streams ... 

Remark 6.1. The definition of the energy recovery number follows the same principle as that of the recycle number Rc (Definition 3.1). Both numbers characterize the intensity of recycling/recovery of a process inventory (see, e.g., Farschman et al. 1998) - that is, energy and mass, respectively. From the perspective of inventory recycling, the two numbers Ere and Rc are, in effect, particular cases of the same dimensionless quantity. 

Clearly, this very simple process belongs to the class considered in Section 6.2. From the defining assumptions, we can expect that the enthalpy in the second tank will not differ significantly from the enthalpy of the feed stream. Thus, the energy recovery number of the process,... 

On the basis of this representation, we can define the energy recovery number ... 

In practice, the integer number of shells is evaluated from Eq. (7.18) for each side of the pinch. This maintains consistency between achieving maximum energy recovery and the corresponding minimum number of units target Nu- ixs- In summary, the number of shells target can be calculated from the basic stream data and an assumed value of Xp (or equivalently,... 

Example 16.1 The process stream data for a heat recovery network problem are given in Table 16.1. A problem table analysis on these data reveals that the minimum hot utility requirement for the process is 15 MW and the minimum cold utility requirement is 26 MW for a minimum allowable temperature diflFerence of 20°C. The analysis also reveals that the pinch is located at a temperature of 120°C for hot streams and 100°C for cold streams. Design a heat exchanger network for maximum energy recovery in the minimum number of units. 

The pinch design method developed earlier followed several rules and guidelines to allow design for minimum utility (or maximum energy recovery) in the minimum number of units. Occasionally, it appears not to be possible to create the appropriate matches because one or other of the design criteria cannot be satisfied. 

In the past, the use of the turboexpander as an energy recovery device was limited for a number of reasons ... 

Incineration with energy recovery is examined as a means for the disposal of plastics waste, and data are presented for the calorific values of a number of materials. Chemical recycling techniques are also briefly reviewed. 

The origins and composition of plastics wastes and factors affecting their recycling are discussed. Partieular attention is paid to chemical recycling and incineration, with and without energy recovery, and a number of developments in chemical recycling techniques are examined. 19 refs. 

Start with the design for maximum heat recovery. The number of exchangers needed will be equal to or less than the number for maximum energy recovery. 

Landfill and surface impoundment disposal are most often used for wastewater treatment sludge, but a significant number of mills dispose of sludge through land application, conversion to sludge-derived products (e.g., compost and animal bedding), or combustion for energy recovery.25... 

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