(In The Name of God)

Process Oil Neutralization

Presented By: Ehsan Moradi11 April 2016

Headlines:IntroductionChemical DeacidificationPhysical RefiningOther Refining MethodsConclusionReferences

Introduction:Terminology:Neutralization/ DeacidificationChemical refining/Caustic refiningAlkali refining

Refining : In Europe and America

Introduction:Objectives of Neutralization:In addition to the removal of FFA other undesirable non-glyceride materials are also removed. These are mainly:Phospholipids (gums)Oxidized productsMetal ions (e.g. iron, copper)Color pigments (e.g. gossypol)Insoluble impurities (e.g. meal fines)

Chemical Refining:

The most commonly used methodThe process is widely known as caustic deacidification.The main purpose of chemical refining is to saponify the FFA by an alkaline solution.The addition of an alkali solution to a crude oil brings about a number of reactions. These soaps are removed by separators either by static separation or centrifugal separation.

Process steps:

Chemical RefiningAdvantages of chemical refining: Successful reduction of FFA up to the desired level irrespective of FFA content in raw/crude oil.Can be used for reliably refining virtually all crude oils, including oils of low qualitySoaps formed during deacidification have the combined effects of purifying, degumming and partially decolouring the oils.

Chemical refining:

Disadvantages:considerable oil loss due to: the hydrolysis of neutral oil by caustic in the form of occlusion in soapstock.FFA content in the crude oil has a direct

bearing on the neutral oil lossGenerates more waste which is difficult and

expensive treat

Chemical VS Physical Refining:

Physical refining:

Physical deacidification uses steam stripping under vacuum, that removes FFA, unsaponifiable substances, and pungent compounds.

Steam stripping can convert the carotenoids and remove FFAs, most off-flavors, and pesticides, but the other impurities must be handled before the distillation step.

To obtain good-quality fats and oils with physical refining, it is essential to have a phosphorus content lower than 5 ppm before steam stripping.

Advantages of physical refining:

Physical deacidification offers many advantages over alkali neutralization such as:Oil losses are reduced, the quality of FFA is

improved, and the operation is simplified. It consumes less steam, water and power. Improved product yield, elimination of

soapstock as well as reduced effluent quantity.

Disadvantages of physical refining:

Certain oils contain impurities that cannot be adequately removed by the pretreatment process to enable them to be physically refined.

It has been reported that physical deacidification reduces the tocopherol content and destroys all carotenes present in palm oil.

Physical refining requires high temperature and high vacuum, and often forms side reaction products.

Miscella refining:

The refining of crude oil in the solvent extraction plant, prior to solvent stripping, is termed miscella refining.

Miscella refining has been applied to a variety of oils, including cottonseed, soybean, sunflower, palm, coconut and tallow.

Miscella refining:

Miscella refining:

Advantages:Higher oil yield due to less occluded neutral

oil in the soapstock.Elimination of the water-wash and vacuum

drying step Extraction of the color pigments before

solvent stripping has set the colorMiscella does not easily emulsify and the soap

tends not to entrain oil.Reduction in energy requirements due to

physical properties of miscella.

Miscella refining:

Disadvantages: Equipment — All equipment and facilities must be

explosion proof for solvent handling. Maintenance — The equipment and facilities must

be well maintained to avoid excessive solvent losses and accidents.

Laboratory — More elaborate laboratory facilities and staffing are necessary to control this process.

The soapstock can be sticky and awkward to handle.Its being tied to a running solvent extraction plant.

Zenith Process:The Zenith process was developed in Sweden in 1960 to enable better refining of the only oilseed crop grown in that country: rapeseed. The stainless steel continuous process consists of three main refining steps, two of which are semicontinuous to maintain the desired reaction times.Zenith plants are designed for crude oil capacities in the range of 20-200 tons per 24 hrs.

Zenith Process:

Conclusion:These conventional deacidification methods

are notbest suited for oils that contain more than 8–10% FFA.The basic unit operations in vegetable oil

processing have remained relatively unchanged for the past 5–6 decades. There are several drawbacks to today's technology, and so alternative approaches are needed to overcome these drawbacks.

References:Wolf Hamm Richard J. Hamilton and Gijs

Calliauw Edible Oil Processing, Second Edition , 2013,

Richard D. O’Brien. Fats and oils: formulating and processing for applications, 2008

Albert J. Dijkstra , Edible Oil Processing from a Patent Perspective,, 2013

Frank D. Gunstone, The Lipid Handbook,third edition,2007

Fereidoon Shahidi, Bailey’s Industrial Oil and Fat Products,2005