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Chemical Engineering vocabulary · Reactions and Reactors

Selectivity

Meaning in chemical engineering, with examples

/səˌlɛkˈtɪvəti/nounCommon term

In chemical engineering, selectivity means: How much of the reacted feed turns into the desired product rather than into unwanted by-products, usually given as a percentage.

In Turkish: seçicilik

How it is used

Used in catalyst testing, reactor optimization and economics. Engineers say selectivity is high, drops with temperature, or improves with a new catalyst. There is often a trade-off between conversion and selectivity.

Example sentences

  1. The new catalyst gives 96% selectivity to ethylene oxide.

  2. If we push conversion higher, selectivity drops and we make more CO2.

Common collocations

  • high selectivity
  • selectivity to
  • product selectivity
  • improve selectivity
  • yieldThe amount of desired product you actually get, usually shown as a percentage of the amount you could get in theory from the raw material fed.
  • conversionThe fraction of a reactant that has reacted, usually given as a percentage of the amount fed to the reactor.
  • catalystA substance that makes a reaction go faster, or more selectively, without being used up itself. In industry it is often a solid in pellets placed in a reactor bed.
  • by-productA substance made in a process alongside the main product. It may be sold, used elsewhere in the plant, or treated as waste.

More terms: Reactions and Reactors

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