oil production 2 Flashcards
(30 cards)
Extraction of vegetable oil
To obtain high quality oil with minimal
undesirable components, achieve high extraction yields and high value me
3 methods to extract oil from seed nut or plant
expeller/cold/solvent
mechanical extraction
the raw material is pressed squeezed and ir crushed under high pressure until oil begins to seep out from the oil source
pressure involved in expeller pressing creates heat
in the range of 60-99 degree
high pressure extraction can cause temperature rise
above 120 degree
advantage of expeller
-can beused with almost any kind of oilseed and nuts
-relatively simple and not capita-intensice process
-no solvent residues in oil, clearer,more pure oil, higher in natural colour and falvour
diasadvantage of expeller
lower yield due to residual oil in the meal
high power requirement
wear and tear in the equipment that requires maintenance
oil meal made by mechanical pressing method
is more valuable as a livestock feed for it contains approximately 5-10 oercent or more of the original oil centent of the seed
cold pressed oils
are a fom of expeller pressed oil
in cold pressing
no chemical used and extracted by mechanicla or physical means
temperature of cold press
under 120
cold press preserves all
of the delicate phytochemicals that make the nut or seed oil truy beneficial
solvent extraction
the process of extracting oil from oil bearing materials by means of solvent
aim of solvent extraction
to remove as muhc oil as possible form the oilseed
what solvent is used in the solvent extarction
hexane
once the oil has been obtained
the solvent is removed frm the oil by heating process
solvent extraction usually
for oilseed with low oil content such as soybeans 16-18%
seed with higher oil content are
prepressed before extraction by solvent
Why hexane
- good oil solubility at low temp
-noon corrosive to metal
-stable under process condition
-easy and complete removal from residue with low energy input
-not mixable with water
-does not react chemically with oil
-appropriate boiling temp
-cheap
factors affecting extraction efficiency
flake structure/ moisture. temperature
the oil seed are rolled into thin flakes
to facilitate solvent diffusion
flake structure- if too thin/fine powder
would make the separation fo the miscella from the spent solid extremely difficult
open and porous fake structure
facilitate solvent diffusion
moisture can come from the surface of press cake
or from poor water/hexane separation after distillation