Olive mill pomace is a by product from the olive oil

Olive oil

Olive oil is an oil obtained from the olive , a traditional tree crop of the Mediterranean Basin. It is commonly used in cooking, cosmetics, pharmaceuticals, and soaps and as a fuel for traditional oil lamps...

 mill extraction process

Olive oil extraction

Olive oil extraction is the process of extracting the oil present in the olive drupes for food use. The oil is produced in the mesocarp cells, and stored in a particular type of vacuole called a lipo vacuole, i.e., every cell contains a tiny olive oil droplet...

. Usually it is used as fuel in a cogeneration

Cogeneration

Cogeneration is the use of a heat engine or a power station to simultaneously generate both electricity and useful heat....

 system or as organic fertiliser after a composting operation.

Olive mill pomace compost

Compost

Compost is organic matter that has been decomposed and recycled as a fertilizer and soil amendment. Compost is a key ingredient in organic farming. At its most essential, the process of composting requires simply piling up waste outdoors and waiting for the materials to break down from anywhere...

 is made by a controlled biologic process that transforms that organic waste into a stable humus. Adding composted olive mill pomace as organic fertiliser in olive orchards allows its soil to get nutrients back after each olive crop.

Two-phase pomace

In crude olive oil production, the traditional system, i.e. pressing, and the three-phase system produce a press cake and a considerable amount of waste water while the two-phase system, which is mainly used in Spain, produces a paste-like waste called "alperujo" or "two-phase pomace" that has a higher water content and is more difficult to treat than traditional solid waste. The water content of the press cake, composed of crude olive cake, pomace and husk, is about 30% if it is produced by traditional pressing technology and about 45–50% using decanter

Decanter

A decanter is a vessel that is used to hold the decantation of a liquid which may contain sediment. Decanters are normally used as serving vessels for wine. Decanters vary in shape and design. They are usually made of an inert material and will hold at least one standard bottle of wine...

 centrifuge

Centrifuge

A centrifuge is a piece of equipment, generally driven by an electric motor , that puts an object in rotation around a fixed axis, applying a force perpendicular to the axis...

s. The press cake still has some oil that is normally recovered in a separate installation. The exhausted olive cake is incinerated or used as a soil conditioner on olive groves.

External links

• Does the composted olive mill pomace increase thes sustainable N use of olive oil cropping?. 2009. 16th Nitrogen workshop. Connecting different scales of Nitrogen use in agriculture. Turin Italia.