`Sustainable EVOO Production Reuses All Byproducts - Olive Oil Times

Sustainable EVOO Production Reuses All Byproducts

By Ylenia Granitto
Dec. 10, 2015 14:45 UTC

During this sea­son’s last days of activ­ity for many Italian mills, we met the direc­tor of the Associated Tuscan Olive Growers (Olivicoltori Toscani Associati ), to talk about recent improve­ments in sus­tain­able olive oil extrac­tion meth­ods.

In 2012 we decided to adopt a new pro­duc­tion sys­tem, as we under­stood to have the pos­si­bil­ity to take a sus­tain­able approach, reusing the by-prod­ucts of the olive oil extrac­tion,” Giampiero Cresti explained. We started con­vert­ing the three-phase method we have been using for years in the two-phase tech­nol­ogy.”

Usually in areas like Tuscany, in the three-phase mill, between 30 and 40 per­cent of water is added to the olive paste for dilu­tion. In the two-phase process, water is not nec­es­sary any­more, and this means both cost sav­ings for the com­pany and preser­va­tion of fresh water. Without the added water, olive oil is richer in polyphe­nols that are hydrosol­u­ble com­pounds.

During this process, olives are crushed and, after malax­a­tion, the paste is sent to decanter and sep­a­rated into two phases: olive oil and a very wet pomace.

At this point, the frag­ments of olive pits are sep­a­rated from the rest of the olives, to be used as a bio­mass com­pa­ra­ble in qual­ity to high-qual­ity pel­lets, Cresti explained. We use a part directly in the mill and we sell the rest to com­pa­nies that trade it as a mate­r­ial for heat­ing sys­tems.”

Olive pits, in addi­tion to offer­ing a lower price and a higher calorific value than aver­age pel­lets (accord­ing to some pro­duc­ers 7,78 kWh/kg), greatly reduce the for­ma­tion of smoke and ash.
Moreover, Cresti pointed out, the humid pomace, through con­trolled anaer­o­bic fer­men­ta­tion in spe­cific digesters, pro­duce a bio­gas con­tain­ing methane, that is used for the pro­duc­tion of elec­tri­cal energy.

Giampiero Cresti

This man­u­fac­tur­ing cycle ends up deliv­er­ing all of the byprod­ucts for renew­able ener­gies: the process con­cludes with no gen­er­ated waste.

We have been among the first to sys­tem­atize the process to re-use the humid pomace in Italy, now sev­eral mills use this sys­tem,” Cresti said. From a tech­ni­cal point of view the process was well known and prac­ti­ca­ble, but the real prob­lem was logis­tic, when the mill gen­er­ated so much and dif­fi­cult to man­age mate­r­ial in a few hours, the risk was to have a sub­stance that no one knew how to use.”

But the evo­lu­tion of the sec­ond part of the pro­ce­dure was the key fac­tor to finally re-use all the man­u­fac­tur­ing residues. Thanks to the great devel­op­ment of digesters for renew­able energy dur­ing recent years, this path became pos­si­ble and this mate­r­ial can be used for the pro­duc­tion of bio­gas.

The improve­ment of this kind of sys­tem — renew­able ener­gies sources which reduce the emis­sion of land­fill gas and, in gen­eral, exerts a very small car­bon foot­print into the atmos­phere — seems to be essen­tial for an eco-friendly olive oil pro­duc­tion with reduced man­age­ment costs.



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