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		Soap Production (CDI, 1995, 70 p.)
			(introduction...)
			1. INTRODUCTION
			2. GENERAL INFORMATION ON SOAP
			3. THE RAW MATERIALS
			4. THE MANUFACTURE OF SOAP
			5. THE TREATMENT OF OILS AND FATS
			6. SAPONIFICATION: COLD PROCESS
			7. SAPONIFICATION: SEMI-BOILED PROCESS
			8. SAPONIFICATION: FULL BOILED PROCESS
			9. SAPONIFICATION: CONTINUOUS PROCESS
			10. THE COOLING AND DRYING OF SOAP
			11. FINISHING SOAP
			12. PRODUCTION OPTIONS
			13. GENERAL CONSIDERATIONS FOR MANUFACTURING PROCESSES
			14. CDI EXPERIENCE IN SOAP FACTORY PROJECTS
			15. IMPLEMENTING A SOAP FACTORY PROJECT
			16. EQUIPMENT MANUFACTURERS
			17. TURNKEY SUPPLIERS AND ENGINEERING OFFICES
			18. THE SOAP MAKERS
			19. DEVELOPING A SOAP FACTORY PROJECT
			20. CHECKLIST: RAW MATERIALS
			21. CHECKLIST: THE SOAP MARKET
			22. CHECKLIST: DATA FOR A FEASIBILITY STUDY
			ANNEXES
			23. SERVICES OFFERED BY THE CDI
			OTHER TITLES
			BACK COVER

5. THE TREATMENT OF OILS AND FATS

BLEACHING

The majority of good quality oils and fats do not require bleaching. Only palm oil and to a lesser extent tallows require bleaching where toilet soap is manufactured from second-grade raw materials.

Bleaching of oils and fats is generally carried out:

® by hot treatment of the oil with an adsorbent earth such as bentonite, followed by filtration, OR
® by oxidation, achieved by heating the oil and passing a current of hot air through it at a high temperature (90 to 120° C).

DEODORISATION

Deodorisation is generally achieved by passing a current of superheated steam through the oil (160 - 220° C). Given the high cost of deodorisation, it is vital to confirm the relevance of this type of treatment.

REFINING

Refining oils by treating them with alkali to remove the free fatty acids is a technique commonly used in oil mills. As stated above, "soapstocks" are produced as a by-product. The technique is rarely used in pure soap manufacture.

HYDROGENATION

Hydrogenation - by catalysis or any other process - makes palm oil and tallow more resistant to oxidation and rancidity, and improves their properties. However, the production of hydrogenated fats and oils with the desired properties requires a degree of technical expertise and practical experience which is hard to justify in developing countries. This treatment may be used in the manufacture of margarines in an oleaginous-based industry.