Experienceswith

Refining Processes

Dr.-Ing. Ernst W. MünchOctober 9, 2003

Dr.-Ing. Ernst W. MünchLipPro Consulting

What does it mean?Why refining?

Summary

Alkali vs. Physical refiningDegumming processBleachingDeodorizationQuality control storage and loading

Dr.-Ing. Ernst W. MünchLipPro Consulting

Palm

Olive

Coconut

Corn

Groundnut

Soybean

Rapeseed

Sunflower seed

Cottonseed

Palm Kernel

Oil recources for vegetable oil

Dr.-Ing. Ernst W. MünchLipPro Consulting

Soybean -Field – damaged, wetharvest condition, mold, etc. can produce oil high in chlorophyll

Drying -Rapid drying couldactivate phospholipase D as well as lipoxygenase

Storage -Storage temperature > 40°C or a moisture content > 11% can activate enzymes

Cracking -

DehullingTempering -

The seeds are mostvulnerable to cracking

Enzyme activitycontinues duringthis process

Flaking -

Hexaneextraction

-

Desolventisation

Crude oil -

Extreme exposure of surfaceoccursExtended exposure to air cancause reactions from lipoxy-genase and phospholipase D

Can extract some of theproducts of reaction intothe oil

Peroxidation can occurduring storage

Dr.-Ing. Ernst W. MünchLipPro Consulting

Persistant organic pollution (POP)

- Chlorinated pesticides (Aldrin, DDT, etc.)

- Industrial chemicals (PCB, HCB, etc.)

- Flame retardants (bromine compounds, etc.)

- Unwanted by-products (dioxins, furans, PAH, etc.)

Heavy metals (cadmium, lead, mercury, etc.)

Mineral oil

Dr.-Ing. Ernst W. MünchLipPro Consulting

chemicalphysical

Advantage / Disadvantageof physical or chemical refining process

advantages advantagesdisadvantages disadvantages

Higher yields

Less of chemicals

Less of waste

Runs not stablewith poor crude oilqualityHigher consump-tion of bleachingearthStable and low costdegumming processnot for all kind of oilavailable

Lower concentra-tion of tocophe-rols in the destillat

Less consumptionof bleaching earth

Stable processalso for poor oilqualityProcess is easierto run for notqualified workers

Lower yields

Waste

Waste water(sodium sulfat solution)

Use of destillat

Dr.-Ing. Ernst W. MünchLipPro Consulting

Dearation

Degumming or conditioning (acid treatment)

Neutralisation (first alkali treatment)

Rerefining (second alkali treatment)

Washing

Vacuum drying

Cooling

The alkali neutralization process

Dr.-Ing. Ernst W. MünchLipPro Consulting

Phospholipids

Carbohydrates

Proteins

Traces of metals

Soap

Undesirable components in crude oil

Free fatty acid

Colour pigments

Oxidation products of fatty acids

Volatile components of the crude oil

Dr.-Ing. Ernst W. MünchLipPro Consulting

Process of miscella-ultrafiltrationCrude miscella

Filtration

UF

UF

DestillationDestillationHexane Hexane

Full degummed oil Lecithin

Dr.-Ing. Ernst W. MünchLipPro Consulting

Heating

Mixing

Holding

Separation

Soft degumming process

Full degummed oil

Crude oil

EDTA and water

Gums

Dr.-Ing. Ernst W. MünchLipPro Consulting

Enzymax process

Adjusting of the pH-buffer

Separation of the gums

Enzyme reaction in the holding tanks

Dr.-Ing. Ernst W. MünchLipPro Consulting

Waterdegumming

Heating 70°C

Holding 5 minutes

Mixing

Drying

Adjusting of the pH-buffer

Crude oil

Lecithin (crude)

Citric-acid solution

NaOH solution

Dr.-Ing. Ernst W. MünchLipPro Consulting

Cooling 60°C

Intensive mixing

Holding4 – 6 hours

Enzyme reaction in the holding tanks

Enzyme solutionRecycled gums

Dr.-Ing. Ernst W. MünchLipPro Consulting

Heating 70°C

Separation

Separation of gums

80% of gums back to thedegumming-process

Full degummed oil

20% of the gumsto the toaster

Dr.-Ing. Ernst W. MünchLipPro Consulting

Separation

Heating70°C

Holding4 – 6 hours

Intensive mixing

Cooling45°C

Enzymax-process without recycling

Enzyme solution

Fully degummed oil

Gums to the toaster

Dr.-Ing. Ernst W. MünchLipPro Consulting

DryingCooling

WaterdegummingDrying

DesolventizingDestillation

Extracting

Prepressing

Heating 110°C

BreakingFlaking

Seed

Heat treatment process

Lecithin Crude oilp<10mg/kg

Meal

Dr.-Ing. Ernst W. MünchLipPro Consulting

Conclusion

Acid degumming processes options for normal crude oil quality

Soft degumming an option for proper predegummed oil

Enzymax process a very good option if the availability of the enzyme is given

Heat treatment of seed should be a good option, the results with normal seedquality are excellent

Ultrafiltration process needs development work

Dr.-Ing. Ernst W. MünchLipPro Consulting

Continuous bleaching unit

Dr.-Ing. Ernst W. MünchLipPro Consulting

Continuous bleaching unit with first stage of wetbleaching

Dr.-Ing. Ernst W. MünchLipPro Consulting

Continuous bleaching unit with trysil-treatment

Dr.-Ing. Ernst W. MünchLipPro Consulting

Counter current bleaching ÖHMI bleach

Dr.-Ing. Ernst W. MünchLipPro Consulting

Counter current bleaching with Trysil-treatment

Dr.-Ing. Ernst W. MünchLipPro Consulting

Bleaching earth consumption depends on:

Kind of oil

Quality of the crude oil

Specification of finished oil

Physical or chemical refining

Bleaching earth quality

Dr.-Ing. Ernst W. MünchLipPro Consulting

Process – and plant – design is determined by:

Plant capacity

Shut-down and start-up operation

Product changes

Environmental and local conditions

Dr.-Ing. Ernst W. MünchLipPro Consulting

Continuous Bleacher

Dr.-Ing. Ernst W. MünchLipPro Consulting

Filter cycle

Filling of the filter

Precoating by turbid flow

Clear filtration

Emptying of the filter

Blowing of the filter cake

Removal of the filter cake

Dr.-Ing. Ernst W. MünchLipPro Consulting

Process control

Peroxide value

Absorbance at 232 nm and 270 nm

Colour (Lovibond)

Chlorophyll < 30 ppb

Metals

Phosphorus

Soap

Residual bleaching earth

Dr.-Ing. Ernst W. MünchLipPro Consulting

Deodorization process

Dr.-Ing. Ernst W. MünchLipPro Consulting

Deodorization process with stripper

Dr.-Ing. Ernst W. MünchLipPro Consulting

+

Possible reaction mechanisms for development of fishy flavor

Formaldehyde

Hydroperoxide (oxidized oil or fatty acid)

Trimethylamine oxideTrimethylamine

+

secondary amine (source of fishy odor)

Dr.-Ing. Ernst W. MünchLipPro Consulting

Process control for refined oil

Waxes

PAH (heavy and light)

Pesticides

Heavy metals

Tocopherols

Soap

Dirt

Taste

Colour

Chlorophyl

Free fatty acid

Peroxid number

Water content

Content of waxes

Phosphorus

Dr.-Ing. Ernst W. MünchLipPro Consulting

Conclusion

The oil after a proper process is stable and safe

- free of pesticides, PAH, etc.- free of heavy metals- no odor, neutral taste- low chlorophyll content- high tocopherol content- meet the specifications

We need for the process:

- bleaching earth- steam- water- for poor qualities of crude oils in addition chemicals, enzymes