TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: In the process (P1 and P2), the step of contacting the metal-containing biomass-derived pyrolysis oil with the acidic ion-exchange resin involves calculating the volume capacity of the acidic ion-exchange resin to a given mass of metal-containing biomass-derived pyrolysis oil (VCr) according to the equation of VCr(ml resin/kg oil)=( Sigma i(Cix 1000 g/kg)/MWi)x Vix 1000 meq/eq/(TCrx Dr). In the process (P1 and P2), the step of contacting the metal-containing biomass-derived pyrolysis oil involves contacting the metal-containing biomass-derived pyrolysis oil with 0.1-10 times the volume capacity (VCr) of the acidic ion-exchange resin. In the process (P1 and P2), the step of contacting the metal-containing biomass-derived pyrolysis oil with the acidic ion-exchange resin involves calculating the maximum volume (Voil) of the metal-containing biomass-derived pyrolysis oil per unit volume of resin that can be ion-exchanged according to the equation of Voil=Vr/(VCrx Dfeed). In the process (P1 and P2), the step of contacting the metal-containing biomass-derived pyrolysis oil with the acidic ion-exchange resin involves mixing the acidic ion-exchange resin with the metal-containing biomass-derived pyrolysis oil. In the process (P1 and P2), the step of contacting the metal-containing biomass-derived pyrolysis oil involves contacting the metal-containing biomass-derived pyrolysis oil with the acidic ion-exchange resin at: a temperature of 10-120 degrees C and an exposure time of 0.5-24 hours. In the process (P1 and P2), the step of contacting the metal-containing biomass-derived pyrolysis oil with the acidic ion-exchange resin involves passing the metal-containing biomass-derived pyrolysis oil through a column containing the acidic ion-exchange resin. In the process (P1 and P2), the step of contacting the metal-containing biomass-derived pyrolysis oil with the acidic ion-exchange resin involves contacting at: a Liquid Hourly Space Velocity (LHSV) of 0.1-20 hours-1 and a temperature of 10-120 degrees C. In the process (P1 and P2), the step of contacting the metal-containing biomass-derived pyrolysis oil with the acidic ion-exchange resin further involves contacting at an absolute pressure greater than 0-13790 KPa (greater than 0-2000 psi). The process (P2) further involves washing the spent acidic ion-exchange resin with a solvent to remove at least a portion of residual oil from the spent acidic ion-exchange resin and to retain residual solvent in the low metal biomass-derived pyrolysis oil.Ci=concentration of metal i in the biomass-derived pyrolysis oil in gram metal/gram oil;MWi=molecular weight of metal i in g/mol;Vi=valency (charge) of metal i in solution;TCr=theoretical capacity of the acidic ion-exchange resin r expressed in milliequivalents ions/gram resin;Dr=acidic ion-exchange resin density in g/ml;Voil=volume of metal-containing biomass-derived pyrolysis oil in liters;Dfeed=density of the metal-containing biomass-derived pyrolysis oil in kilograms/liter;Vr=acidic ion-exchange resin volume in milliliters.Preferred Components: The solvent is selected from methanol, ethanol and/or acetone. EXAMPLE - No suitable example given.