Process Analysis - Input / output

Question 1

When choosing process design and concepts, what are the four main factors considered?

Answer 1

Level of confidence
Economic / performance factors
Sustainability/Environmental performance
Hazards

Question 2

What are production goals?

Answer 2

Production goals mainly refer to input and output goals. This may be in reference to volume of material process, ratio of inflow to outflow, composition of output.

Question 3

Describe the operation / technical goals

Answer 3

Operational goals consider the four types of units. This may include operational temperature, pressure, reactor efficiency or yield. Also, residual time, separation extent or purge fraction.

Question 4

What basic ANALysis can be performed initially within a process to determine rough profits and what’s it equation

Answer 4

Economic potential produces a rough estimate of system profitability.
It is the sum of primary and secondary products. subtracting all raw materials and any associated waste.

If the EP is found to be negative at this stage. The investigation can be terminated as consideration of extra costs will only reduce profitability.

Question 5

Efficiency indicators are a good way of measuring how close a process is operating to ideal conditions. What are some factors that we can measure?

Answer 5

Chemical loss
Physical loss
Energy loss
Water loss
Time loss

Question 6

What do we use to measure the efficiency of a reactor or plant and what is the associated equation?

Answer 6

The indicator is yield and is measured by the moles of the B formed divide the moles of A supplied x the stoichiometric factor.

Question 7

Describe selectivity efficiency

Answer 7

A measure of the moles of B formed divide the ideal amount formed. An indicator of how dominating the side reactions are.

Question 8

What is the most useful indictor to describe chemical losses to side reactions?

Answer 8

Reaction Yield or

moles of A consumed over moles of A supplied.

Question 9

What plant performance indicator is most commonly used

Answer 9

plant yield = moles of product/moles of reagent * stoich factor.
a good indicator as it measures all chemical and physical losses.

when separation and recycling is used, should me greater than reactor yield. Likewise, is recovery and recycle system was 100% efficient, the plant yield would approach the reactor selectivity.

Question 10

What is the main drawback of efficiency indicators?

Answer 10

They tell you nothing about the costs or resources required to operate the process.