Process Integration - Heat integration for Major Equipment

Select TWO (2) correct statement in supplying/ removing heat from a reactor

• Exothermic reaction release heat, thus a cooling medium is required to ensure the reactor is stable.

• Exothermic reaction absorb heat, thus a cooling medium is required to ensure the reactor is stable.

• Endothermic reaction absorb heat, thus a heating medium is required to keep supply energy to the reactor.

• Endothermic reaction absorb heat, thus a cooling medium is required to supply energy to the reactor.

For exothermic reaction, a cooling medium is added to capture to excess heat produce by the reaction. What is the possible explanation for the exit temperature to have lower value than the inlet temperature? (There are 2 plausible answers)

• Heat transfer from the reactor to the cooling medium is low.

• Heat transfer from the reactor to the cooling medium is high.

• Heat of reaction is lower that the rate of heat transfer from the reactor to the cooling medium.

• Heat of reaction is higher that the rate of heat transfer from the reactor to the cooling medium.

Heat integration for a reactor can be done above or below pinch according to the type of reaction. In the case of the heat transfer intermediate used for cooling/heating is fixed, which stream should be considered for the heat integration with other process streams?

• The reactor profile

• The returning stream after the heat has been captured/ released by the heating/cooling medium

• The cooling/heating medium stream to the reactor

What is the correct placement for an exothermic reactor?

• Above pinch

• Below pinch

• Across pinch

• Should not be integrated with the process stream

What is the correct placement for an endothermic reactor?

• Above pinch

• Below pinch

• Across pinch

• Should not be integrated with the process stream

These are the benefit of integrating the reactor correctly with the rest of the process streams EXCEPT:

• Reducing the demand of hot/cold utility

• Increasing the amount of steam/CW supplied to the plant.

• Capitalizing on the heat generated/absorb by the reaction

• Increasing the economic feasibility of the plant

In the case study presented, the steam generated from the reactor is produced at 10 bar. Looking at the GCC of the steam production and other process, these are the steps that can be taken into consideration when integrating the reactor streams and process stream, EXCEPT:

• Ensure the placement of reactor is well above the pinch temperature for an exothermic reactor

• Including the reactor streams and other process streams to a single GCC

• Mirroring either one of the stream to get a better representation of the utilization of the steam generated.

• Increasing the pressure of the steam to obtain it at a useful condition

Select the 3 correct statements in integrating distillation column (DC) to the GCC

• DC can be integrated across the GCC to ensure the cost saving is achieved

• Temperature of the reboiler and condenser play an important role in the placement of DC in the GCC

• temperature for condenser and reboiler can be taken as constant for preliminary design

• A box can be used to represent the integration of DC to the GCC

Select TWO (2) characteristic of DC that fits the GCC.

• For DC placement above pinch, the reboiler duty is supplied by the hot utility and the condenser is integrated with the other process stream.

• The DC is partially integrated to the GCC.

• Pinch temperature lies in between the Reboiler and Condenser temperature.

• For DC placement below pinch, the reboiler duty is integrated with other process streams and cold utility is supplied direct to the condenser

Evolving a DC is one of the method used to successfully integrate the DC to the GCC. Several type of evolution can be done such as (you may select more than 1):

• Changing the operating pressure of the condenser and reboiler to fit the GCC

• Splitting the load from a stand-alone DC to to double effect DC to reduce the reboiler and condenser duty.

• Infeasibility of double effect DC can be overcome by thermal isolation of DC units

• Absorbing and rejecting the heat for the reboiler and condenser from other process stream is favorable.