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Improvement of biogas production from orange peel waste by leaching of limonene.

Wikandari R, Nguyen H, Millati R, Niklasson C, Taherzadeh MJ - Biomed Res Int (2015)

Bottom Line: The pretreatments were carried out with homogenized or chopped orange peel at 20-40°C with orange peel waste and hexane ratio (w/v) ranging from 1 : 2 to 1 : 12 for 10 to 300 min.The highest biogas production was achieved by treating chopped orange peel waste and hexane ratio of 12 : 1 at 20°C for 10 min corresponding to more than threefold increase of biogas production from 0.061 to 0.217 m(3) methane/kg VS.The hexane residue in the peel had a negative impact on biogas production as shown by 28.6% reduction of methane and lower methane production of pretreated orange peel waste in semicontinuous digestion system compared to that of untreated peel.

View Article: PubMed Central - PubMed

Affiliation: Swedish Centre for Resource Recovery, University of Borås, Allégatan 1, 50190 Borås, Sweden.

ABSTRACT
Limonene is present in orange peel wastes and is known as an antimicrobial agent, which impedes biogas production when digesting the peels. In this work, pretreatment of the peels to remove limonene under mild condition was proposed by leaching of limonene using hexane as solvent. The pretreatments were carried out with homogenized or chopped orange peel at 20-40°C with orange peel waste and hexane ratio (w/v) ranging from 1 : 2 to 1 : 12 for 10 to 300 min. The pretreated peels were then digested in batch reactors for 33 days. The highest biogas production was achieved by treating chopped orange peel waste and hexane ratio of 12 : 1 at 20°C for 10 min corresponding to more than threefold increase of biogas production from 0.061 to 0.217 m(3) methane/kg VS. The solvent recovery was 90% using vacuum filtration and needs further separation using evaporation. The hexane residue in the peel had a negative impact on biogas production as shown by 28.6% reduction of methane and lower methane production of pretreated orange peel waste in semicontinuous digestion system compared to that of untreated peel.

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Block flow diagram of biogas production from treated orange peel waste by leaching pretreatment and limonene extraction.
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fig4: Block flow diagram of biogas production from treated orange peel waste by leaching pretreatment and limonene extraction.

Mentions: In this process (Figure 4), orange peel is fed to grinding unit using a conveyer for size reduction. The chopped peel is mixed with hexane for 10 min at 20°C with peel and solvent ratio of 1 : 2, where limonene is extracted from the peels and dissolved in the organic phase of hexane. The peel is then separated from the hexane by vacuum filtration which separates ca 90% of the hexane. Since the remaining hexane in the peel inhibits the digestion, it should be separated and recycled using normal or vacuum evaporation. The treated peel is fed into anaerobic digester to produce methane. The mixture of hexane and limonene out from filtration which has about 0.55 L limonene per m3 of hexane is fed into rotary vacuum evaporator operated at 70°C in order to evaporate the volatile hexane and separate it from the limonene. The vapor of hexane is condensed and recycled back to the pretreatment vessel for extraction of more limonene from fresh peels.


Improvement of biogas production from orange peel waste by leaching of limonene.

Wikandari R, Nguyen H, Millati R, Niklasson C, Taherzadeh MJ - Biomed Res Int (2015)

Block flow diagram of biogas production from treated orange peel waste by leaching pretreatment and limonene extraction.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4383308&req=5

fig4: Block flow diagram of biogas production from treated orange peel waste by leaching pretreatment and limonene extraction.
Mentions: In this process (Figure 4), orange peel is fed to grinding unit using a conveyer for size reduction. The chopped peel is mixed with hexane for 10 min at 20°C with peel and solvent ratio of 1 : 2, where limonene is extracted from the peels and dissolved in the organic phase of hexane. The peel is then separated from the hexane by vacuum filtration which separates ca 90% of the hexane. Since the remaining hexane in the peel inhibits the digestion, it should be separated and recycled using normal or vacuum evaporation. The treated peel is fed into anaerobic digester to produce methane. The mixture of hexane and limonene out from filtration which has about 0.55 L limonene per m3 of hexane is fed into rotary vacuum evaporator operated at 70°C in order to evaporate the volatile hexane and separate it from the limonene. The vapor of hexane is condensed and recycled back to the pretreatment vessel for extraction of more limonene from fresh peels.

Bottom Line: The pretreatments were carried out with homogenized or chopped orange peel at 20-40°C with orange peel waste and hexane ratio (w/v) ranging from 1 : 2 to 1 : 12 for 10 to 300 min.The highest biogas production was achieved by treating chopped orange peel waste and hexane ratio of 12 : 1 at 20°C for 10 min corresponding to more than threefold increase of biogas production from 0.061 to 0.217 m(3) methane/kg VS.The hexane residue in the peel had a negative impact on biogas production as shown by 28.6% reduction of methane and lower methane production of pretreated orange peel waste in semicontinuous digestion system compared to that of untreated peel.

View Article: PubMed Central - PubMed

Affiliation: Swedish Centre for Resource Recovery, University of Borås, Allégatan 1, 50190 Borås, Sweden.

ABSTRACT
Limonene is present in orange peel wastes and is known as an antimicrobial agent, which impedes biogas production when digesting the peels. In this work, pretreatment of the peels to remove limonene under mild condition was proposed by leaching of limonene using hexane as solvent. The pretreatments were carried out with homogenized or chopped orange peel at 20-40°C with orange peel waste and hexane ratio (w/v) ranging from 1 : 2 to 1 : 12 for 10 to 300 min. The pretreated peels were then digested in batch reactors for 33 days. The highest biogas production was achieved by treating chopped orange peel waste and hexane ratio of 12 : 1 at 20°C for 10 min corresponding to more than threefold increase of biogas production from 0.061 to 0.217 m(3) methane/kg VS. The solvent recovery was 90% using vacuum filtration and needs further separation using evaporation. The hexane residue in the peel had a negative impact on biogas production as shown by 28.6% reduction of methane and lower methane production of pretreated orange peel waste in semicontinuous digestion system compared to that of untreated peel.

Show MeSH
Related in: MedlinePlus