How do I know what size reactor I need?

In order to size a reactor we must first know what the reactor should do, i.e. how large conversion (omsättning) it should accomplish. Fractional amount of reactant species (A) converted into product(s) or consumed by reaction. Indicates extent of reaction. Expressed in terms of limiting reactant.

What is an ideal plug flow reactor?

In an ideal plug flow reactor, it is assumed that there is no mixing of the medium along the long axis (X-axis) of the reactor although there may be lateral mixing in the medium at any point along the long axis (ie the Y-axis).

How do you calculate the capacity of a reactor?

Popular Answers (1)

  1. Space velocity = flow rate of the reactants/ the reactor volume.
  2. GHSV =Hourly volumetric feed gas flow rate/reaction volume.
  3. LHSV= Hourly volumetric feed liquid flow rate/reaction volume.
  4. WHSV=Hourly mass feed flow rate/ Catalyst mass.

How do I choose between CSTR and PFR?

To achieve the desired conversion with smaller reactor volumes, use a combination. In this case, use a CSTR then a PFR. By doing so, the reactor volume is less than the area underneath the curve. For competing parallel reactions, selectivity for desired product can dominate the choice.

How do you choose a reactor?

General Reactor Design

  1. Step 1: Collect Required Data.
  2. Step 2: Select Reaction Conditions.
  3. Step 3: Determine Materials of Construction.
  4. Step 4: Determine Rate-Limiting Step and Critical Sizing Parameters.
  5. Step 5: Preliminary Sizing, Layout, and Costing of Reactor.
  6. Step 6: Estimate Reactor Performance.

What are the assumptions for designing a PFR?

The key assumption is that as a plug flows through a PFR, the fluid is perfectly mixed in the radial direction but not mixed at all in the axial direction (not with the element upstream or downstream).

How does reactor volume affect conversion?

Within the range of reactor volume selected for analysis, conversion increases with increase in reactor volume.

Which is more efficient PFR or CSTR?

A PFR has a higher theoretical efficiency than a CSTR of the same volume. That is, given the same space-time (or residence time), a reaction will proceed to a higher percentage completion in a PFR than in a CSTR.

Where do we use PFR?

The PFR model is used to predict the behaviour of chemical reactors of tubular design, so that key reactor variables, such as the dimensions of the reactor, can be estimated.

What are the characteristics of an ideal plug flow reactor?

In an ideal plug-flow reactor, there should not be any longitudinal mixing (i.e., mixing in the direction of flow) and thus the particles should emerge from the reactor outlet point in the same sequence in which they enter. There will only be radial mixing.

What are the limitations of plug flow reactors?

Real plug flow reactors do not satisfy the idealized flow patterns, back mix flow or plug flow deviation from ideal behavior can be due to channeling of fluid through the vessel, recycling of fluid within the vessel or due to the presence of stagnant region or dead zone of fluid in the vessel.

What is the difference between a CSTR and a plug flow reactor?

In a plug-flow reactor, on the other hand, the substrate concentration will not drop to this low level but rather decreases in the axial direction only. Thus a plug-flow reactor will have a higher rate of substrate conversion than a CSTR.

What is the differential equation for plug flow reactor?

The plug flow reactor is characterized by the differential equation for species balance (3.17) m ˙ ″ ( d σ i /d x ) = ∑ ( v ″ i j − v ′ i j ) r j and for energy conservation