`Olive Tree Biomass a Promising Fossil Fuel Alternative - Olive Oil Times

Olive Tree Biomass a Promising Fossil Fuel Alternative

By Naomi Tupper
May. 16, 2012 10:58 UTC

Research car­ried out by the University of Jaén and pre­sented at the recent Bioptima con­fer­ence has high­lighted the great promise of olive tree bio­mass in the gen­er­a­tion of ethanol as a bio-fuel, as well as other poten­tially use­ful prod­ucts.

The research, headed by Dr. Eulogio Castro, has spanned sev­eral years, begin­ning with the first demon­stra­tion of the pro­duc­tion of ethanol from olive tree residue. Subsequent projects have expanded to the con­cept of a bio-refin­ery based on this bio­mass. Ethanol is an impor­tant bio-fuel, already added to fuel sup­plies in Spain and around the world, and a viable par­tial replace­ment to fos­sil fuels. Its pro­duc­tion is thus an area of great inter­est and sub­stan­tial research on the sub­ject is being funded around the world.

The process of pro­duc­ing ethanol from olive tree bio­mass is a sim­ple process made up of four main steps. The tree is com­posed of a num­ber of com­pounds, of which sug­ars in the form of cel­lu­lose and hemi­cel­lu­lose are the most impor­tant. These sug­ars are held together by a com­pound called lignin. The first step of the process involves the degra­da­tion of this lignin cement’, fol­lowed by the sol­u­bil­i­sa­tion of hemi­cel­lu­lose. Enzymatic hydrol­y­sis then occurs, by which cel­lu­lose is attacked by enzymes and bro­ken down into the sim­pler glu­cose units. This step is essen­tial as only sin­gle sugar mol­e­cules can be con­verted to ethanol — it is not pos­si­ble to covert cel­lu­lose directly. Fermentation of this glu­cose by yeast or other microor­gan­isms to gen­er­ate ethanol is then car­ried out. Finally, the ethanol is sep­a­rated for use as a bio-fuel.

Dr. Castro stated that the use of olive tree bio­mass in this process had a huge advan­tage over other pri­mary sources as it was a waste prod­uct pro­duced in huge amounts annu­ally (3 tons per hectare in the 2.4 mil­lion hectares of olive groves in Spain alone), with no indus­trial uses. In addi­tion to this it is essen­tial to remove this bio­mass from fields to pre­vent the spread of veg­e­tal dis­eases. Currently tree waste is burned, so rather than spend money on dis­pos­ing the waste, it makes sense to use it to con­vert the residue into a use­ful prod­uct.

Ethanol pro­duced from olive tree bio­mass is termed as a sec­ond gen­er­a­tion bio-fuel, as it is pro­duced from a source that is not viable for other uses. This makes it prefer­able to those known as first gen­er­a­tion, which are pro­duced from raw mate­r­ial that have food or feed appli­ca­tion, such as grains. It is there­fore an ideal source from which to gen­er­ate par­tial fos­sil fuel replace­ments. In addi­tion to ethanol pro­duc­tion, the gen­er­a­tion of other use­ful prod­ucts from olive tree bio­mass such as a com­pound exhibit­ing antiox­i­dant capac­ity and oligo-sac­cha­rides, which could be used in the food and phar­ma­ceu­ti­cal indus­tries respec­tively, have been demon­strated by Castro’s team.

Despite the advan­tages of this type of bio fuel pro­duc­tion, there are sev­eral bar­ri­ers still hin­der­ing fur­ther devel­op­ment. Dr. Castro explains that in the spe­cific case of olive bio­mass, which is obtained by prun­ing, logis­tics is one of the main con­cerns. A col­lec­tion sys­tem is needed that can trans­port large amounts of bio­mass from fields to trans­for­ma­tion plants, with eco­nomic effi­ciency.” He also said that the cur­rent tech­no­log­i­cal issues being addressed involved improv­ing yields in all steps of the process and that, as always, ongo­ing fund­ing from pub­lic and pri­vate orga­ni­za­tions were essen­tial to con­tin­ued research into this poten­tial fuel source.

Sources:

La Informacion
Dr Eulogio Castro Galiano

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