Overall, the obtained results can be useful for the development and performance
optimization of industrial installation to treat and reuse vegetable oil refinery wastewater using a hybrid CF/UF process as feasible, safer, and more environmentally
friendly alternative to other available treatment options.
3.4 Solid Wastes and By-Products
Vegetable oil processing activities also generate significant amounts of organic solid
waste and by-products, such as empty fruit bunches (EFBs) and waste palm kernels.
The amount of waste generated depends on the quality of the raw materials and the
use or reprocessing of the discarded materials into commercially viable by-products.
Other solid wastes from the vegetable oil manufacturing process include soap-stock
and spent acids from chemical refining of crude oil; spent bleaching earth containing
gums, metals, and pigments; deodorizer distillate from the steam distillation of
refined edible oils; mucilage from degumming; and spent catalysts and filtering aid
from the hardening process. Solid wastes resulting from vegetable edible oil refining
plants can be classified as follows:
• General waste
• Tin cans and scrap
• Filter cloth
• Spent bleaching earths
• Soap-stock
• Lecithin
• Spent nickel
• Deodorizer distillate
• Sludge from wastewater treatment plant
General waste includes waste pipe, angle iron, steel, cans, plastic, glass bottles,
and papers. A portion of such wastes is sold for recycling; the rest is temporarily
stored in the factory area and sent to landfills [77]. Tin cans and scrap waste, used
containers, caps, and cans are the wastes resulting from production area. Some
factories purchase cans from subcontractors so that these kinds of wastes are not
produced in such factories. These wastes are temporarily stored in the factory area
and then sold for recycling. The amount of scrap constitutes 2–10% of total amount
of tin.
Filter cloths are used in filter presses at winterization and bleaching steps during
the refining of oil. When first installed filter cloth can be used 4–6 times. Then, it has
to be removed and washed before reuse. In this way before being discarded, a filter
cloth can be reused 2–3 times [16].
Spent bleaching earths (SBE) is generated at the vegetable oil refining industry
after bleaching of crude oil. The annual world generation of SBE is between 1.5 and
2.0 million tons based on the world edible oil production of 128.2 million metric tons
in 2007 [77] and 1.2–1.6 kg of SBE generation per metric ton of edible oil
8 Vegetable Oil Refining Wastes
353
optimization of industrial installation to treat and reuse vegetable oil refinery wastewater using a hybrid CF/UF process as feasible, safer, and more environmentally
friendly alternative to other available treatment options.
3.4 Solid Wastes and By-Products
Vegetable oil processing activities also generate significant amounts of organic solid
waste and by-products, such as empty fruit bunches (EFBs) and waste palm kernels.
The amount of waste generated depends on the quality of the raw materials and the
use or reprocessing of the discarded materials into commercially viable by-products.
Other solid wastes from the vegetable oil manufacturing process include soap-stock
and spent acids from chemical refining of crude oil; spent bleaching earth containing
gums, metals, and pigments; deodorizer distillate from the steam distillation of
refined edible oils; mucilage from degumming; and spent catalysts and filtering aid
from the hardening process. Solid wastes resulting from vegetable edible oil refining
plants can be classified as follows:
• General waste
• Tin cans and scrap
• Filter cloth
• Spent bleaching earths
• Soap-stock
• Lecithin
• Spent nickel
• Deodorizer distillate
• Sludge from wastewater treatment plant
General waste includes waste pipe, angle iron, steel, cans, plastic, glass bottles,
and papers. A portion of such wastes is sold for recycling; the rest is temporarily
stored in the factory area and sent to landfills [77]. Tin cans and scrap waste, used
containers, caps, and cans are the wastes resulting from production area. Some
factories purchase cans from subcontractors so that these kinds of wastes are not
produced in such factories. These wastes are temporarily stored in the factory area
and then sold for recycling. The amount of scrap constitutes 2–10% of total amount
of tin.
Filter cloths are used in filter presses at winterization and bleaching steps during
the refining of oil. When first installed filter cloth can be used 4–6 times. Then, it has
to be removed and washed before reuse. In this way before being discarded, a filter
cloth can be reused 2–3 times [16].
Spent bleaching earths (SBE) is generated at the vegetable oil refining industry
after bleaching of crude oil. The annual world generation of SBE is between 1.5 and
2.0 million tons based on the world edible oil production of 128.2 million metric tons
in 2007 [77] and 1.2–1.6 kg of SBE generation per metric ton of edible oil
8 Vegetable Oil Refining Wastes
353