Researchers Transform Olive Grove Waste Into Bioplastic

Summary

Researchers from the University of Jaén and the Andaltec Foundation have devel­oped biopoly­mers from olive grove prun­ing waste suit­able for food pack­ag­ing and indus­trial uses, with high heat resis­tance up to 300 ºC or 400 ºC. The researchers argue that trans­form­ing olive grove waste into bio­plas­tic could pro­vide eco­nomic ben­e­fits for farm­ers, reduce envi­ron­men­tal impact, and cre­ate new busi­ness oppor­tu­ni­ties in Andalusia.

Researchers from the University of Jaén and the Andaltec Foundation have man­u­fac­tured plas­tic suit­able for food pack­ag­ing and indus­trial uses from olive grove prun­ing waste.

The researchers refined bio­mass obtained from olive leaves and branches into biopoly­mers that can resist tem­per­a­tures up to 300 ºC or 400 ºC, depend­ing on the type of treat­ment.

As a result of their high heat resis­tance, the sci­en­tists said the biopoymers are an excel­lent can­di­date for use as biofilm in food pack­ag­ing appli­ca­tions.

The com­pound of inter­est in any type of bio­plas­tic man­u­fac­tur­ing is the cel­lu­lose in lig­no­cel­lu­lose, which is also com­posed of hemi­cel­lu­lose and lignin. Olive tree bio­mass con­tains between 30 and 40 per­cent cel­lu­lose.

“[Lignocellulose’s] appeal as a sus­tain­able source of bio­ma­te­ri­als is largely attrib­uted to dif­fer­ent fac­tors such as [its] low cost, wide­spread avail­abil­ity and chem­i­cal com­po­si­tion,” the researchers wrote in the study pub­lished in the sci­en­tific jour­nal Biofuels, Bioproducts and Biorefining.

During their inves­ti­ga­tion, the researchers refined the bio­mass fibers into cel­lu­lose pulp and then chem­i­cally trans­formed this into cel­lu­lose acetate. ​“The pro­duc­tion of cel­lu­lose acetate using this approach presents some advan­tages from dif­fer­ent per­spec­tives,” they wrote.

The researchers argued that trans­form­ing olive grove waste into bio­plas­tic pro­vides supe­rior eco­nomic ben­e­fits for farm­ers than using the waste for com­post­ing, energy gen­er­a­tion or soil cover.

“The eco­nomic advan­tage is that it con­sti­tutes a new way of revalu­ing olive tree prun­ing bio­mass that allows poly­mers to be obtained that have high added value and are in great demand in the mar­ket,” the researchers wrote.

According to María Dolores La Rubia, a co-author of the study and researcher at the University of Jaén’s depart­ment of chem­i­cal, envi­ron­men­tal and mate­ri­als engi­neer­ing, olive grove waste would also be a cheaper alter­na­tive for plas­tic man­u­fac­tur­ers. Synthetic plas­tics are made from refin­ing crude oil, nat­ural gas or coal.

“The Andalusian olive grove could thus become the main sup­plier of raw mate­ri­als for the man­u­fac­ture of bio­plas­tics in Spain,” she said.

Additionally, the researchers argued that the new appli­ca­tion of the olive farm­ing byprod­uct could reduce its envi­ron­men­tal impact. By some esti­mates, high-den­sity and super-high-den­sity farms in Spain yield 30 tons of olive tree prun­ing bio­mass per hectare each year.

“Traditionally, this residue is used in situ as a soil amend­ment, or in most cases it is incin­er­ated, sig­nif­i­cantly increas­ing the car­bon foot­print of the olive oil indus­try,” the researchers wrote.

They added that fur­ther research into using olive tree prun­ing bio­mass as an ingre­di­ent in plas­tic could help cre­ate new busi­ness oppor­tu­ni­ties in Andalusia.

“There are social advan­tages, given that it has strong poten­tial to gen­er­ate new busi­ness mod­els, based on the prin­ci­ples of the cir­cu­lar econ­omy, in agri­cul­tural areas of south­ern Spain where olive grove cul­ti­va­tion is con­cen­trated and which are, in many cases, at high risk of depop­u­la­tion,” they added.

• Junta de Andalucía