Process Unit Operations


Choosing the correct reactor technology and equipment sizes for your process system is vital. If the reaction rate occurs to fast or too slow, too hot or cold or the proper kinetics are not achieved, your production rates and the quality of your product are at stake. Let EPIC’s chemical process experts help you select the best reactor vessel for your modular process system.

Important factors: There are many important factors that affect reactions. Vessel size, fluid velocity, reaction kinetics, these all weighReactor System into reactors design and selection. EPIC’s expert process chemical engineers will work with your specific product to specify the important factors for reaction vessel selection, including:

  • Reaction kinetics
  • Rate of reaction
    • Temperature effects
    • Concentration of moles
      • Partial pressure
      • Mole fraction
  • Stoichiometric balances
  • Diffusion between phases
  • Catalysis
  • Chemical equilibrium
  • Material and energy balances
  • Steady states
  • Direction of flow

View a gallery of some of our reactor integration experience.

Batch Reactors

Type of ReactorUses
General batch reactors

  • Relatively slow reactions

  • Include heat transfer mechanisms to maintain steady temperature range

  • Majority = liquid phase

  • Most flexible reactor type – can have wide range of reaction times for a wide-variety of reactions

Continuous Reactors

Type of ReactorUses
General continuous reactors

  • For large quantities

  • Feed rate controls reaction rate

  • Residence time and volume are relatively fixed

  • Product is more consistent in quality

  • Generate less waste than batch

Continuous stirred tank reactors (CSTR reactors)

  • Used for greater production rates with relatively short reactions

  • Can be used singularly or in-series

  • Steady state reactions in liquid phase are the most common application

  • Best for immiscible liquids


  • Gas-phase and liquid phase reactors

  • Short reaction times are typical

  • Elevated temperatures

  • Frictional pressure drop is an important factor for this type of reactor

Plug flow(PFR reactors)

  • Low and medium temperature capabilities

  • Variable residence times

  • Low cost

  • Best used with diluted reactants

Packed bed flow reactors (fixed bed reactor)

  • Similar to a plug flow reactor, but packed with catalyst beads

  • Catalyst helps maintain reaction at a level temperature

Fluid bed reactor (FBR)

  • Used for multi-phase reactions

  • Catalysts are optional

  • Medium to high velocity

  • Uniform particle mixing and uniform temperature gradients

Reactors are used in a variety of common applications that EPIC builds, including:

Contact an engineer to start designing your custom reactor system today.

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EPIC Modular Process Systems
4134 Meramec Bottom Rd
St. Louis, MO 63129, US
(314) 845-0077