TY - JOUR

T1 - Kinetics of extraction and in situ transesterification of oils from spent coffee grounds

AU - Najdanovic, Vesna

AU - Yee-Lam Lee, Lee

AU - Tavares, Marcia

AU - Armstrong, Alona Barbara

N1 - This is the author’s version of a work that was accepted for publication in Journal of Environmental Chemical Engineering. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Environmental Chemical Engineering, 5, 3, 2017 DOI: 10.1016/j.jece.2017.04.041

PY - 2017/6

Y1 - 2017/6

N2 - Resource limits, environmental concerns and unstable petroleum costs have led to an increased effort to develop alternative liquid fuels. Purpose grown feedstocks are expensive and demand additional resources such as land and water. Spent coffee grounds (SCGs) are a good potential low-cost feedstock, however, processing times and costs must be lowered in order to be cost competitive with fossil fuels.In this work, we investigated the kinetics of oil extraction from SCGs to explore if current methods of oil extraction could be hastened and an integrated process which couples oil extraction and conversion to biodiesel stages in one single step (in situ transesterification) which could significantly cut down biodiesel production costs.Kinetics of oil extraction from SCGs using n-hexane as solvent was studied as a function of temperature, solvent to solid ratio and water content. We have found that oil extraction times could be significantly reduced to 10 minutes due to high diffusion coefficients. Further, we demonstrate, for the first time, the successful in situ transesterification of SCGs using different concentration of sodium hydroxide as catalyst and methanol to oil mole ratio, promising lower biodiesel production costs from a ubiquitous waste product around the world.

AB - Resource limits, environmental concerns and unstable petroleum costs have led to an increased effort to develop alternative liquid fuels. Purpose grown feedstocks are expensive and demand additional resources such as land and water. Spent coffee grounds (SCGs) are a good potential low-cost feedstock, however, processing times and costs must be lowered in order to be cost competitive with fossil fuels.In this work, we investigated the kinetics of oil extraction from SCGs to explore if current methods of oil extraction could be hastened and an integrated process which couples oil extraction and conversion to biodiesel stages in one single step (in situ transesterification) which could significantly cut down biodiesel production costs.Kinetics of oil extraction from SCGs using n-hexane as solvent was studied as a function of temperature, solvent to solid ratio and water content. We have found that oil extraction times could be significantly reduced to 10 minutes due to high diffusion coefficients. Further, we demonstrate, for the first time, the successful in situ transesterification of SCGs using different concentration of sodium hydroxide as catalyst and methanol to oil mole ratio, promising lower biodiesel production costs from a ubiquitous waste product around the world.

KW - biodiesel

KW - coffee waste

KW - coffee oil

KW - direct transesterification

KW - reactive transesterification

KW - oil extraction

U2 - 10.1016/j.jece.2017.04.041

DO - 10.1016/j.jece.2017.04.041

M3 - Journal article

VL - 5

SP - 2611

EP - 2616

JO - Journal of Environmental Chemical Engineering

JF - Journal of Environmental Chemical Engineering

SN - 2213-2929

IS - 3

ER -