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Sustainable Industrial Design and Waste Management
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system. The evaporated hexane is recovered within the system and
reused.
• Purification of oil: During this stage oil is purified by removing all
impurities such as color, odor, fatty acids, gums, and residual soap. This
step takes place in the following stages:
– Degumming to remove about 0.15% gums.
– Neutralization using caustic soda to remove fatty acids to generate
soap stock 5%.
– Washing and separation by centrifuge.
– Drying and bleaching to remove the color.
– Deodorization of the bleached oil by vacuum distillation.
• Packaging of the final product: A brine chiller is used to cool the
refined, bleached, deodorized oil in a buffer tank. Then the final product
is transferred to 0.75 liter or 2.0 liter bottles, capped, labeled and cased.

CP opportunity assessment
Cleaner production opportunities were identified during the industrial audit
of the factory in order to achieve maximum conservation of raw materials
and energy. The following are some of the identified cleaner production
opportunities (SEAM 1999c):

• High amounts of steam losses due to the bad condition of the steam
lines regarding insulations and valves. These losses were estimated
to be 34 ton/day.
• In the seed receiving unit, broken seeds and hulls are treated as wastes,
rather than being reused in the oil extraction process.
• Heavy oil leaks and spills occurring during delivery and transfer in the
receiving area account for 2–5% of total fuel consumption.

CP techniques implemented
• Good housekeeping: This technique of cleaner production was uti-
lized in this case study in the form of a preventive maintenance pro-
gram with a total implementation cost of $2,630. The preventive
maintenance program included in-factory servicing of the expeller
and modification of the packing of the cooling tower, and it has
resulted in annual savings of $4,386 and $880 respectively.
• Process modification: Process modification was implemented in this
case study via modifying and redesigning the production process to
allow for the more fresh seeds to be fed into the expeller with a total
implementation cost of $1,750. This was achieved by converting the
path of the recycled sunflower seed fines from the expeller (original
design) to the extraction plant (modified design). As a result, the capac-
ity of the expeller has been increased by 40 ton/day of sunflower lead-
ing to an annual saving of $21,050.