The present invention relates to a process for preparing alkylate comprising the subsequent steps (a), (b) and (c): (a) an alkylation step, wherein in a reaction zone a hydrocarbon mixture comprising at least an isoparaffin and an olefin is reacted with an ionic liquid catalyst to obtain an effluent comprising alkylate and solids, which latter are formed as side products in the alkylation step; (b) a separation step, wherein at least part of the alkylate-comprising effluent coming from the reaction zone is separated in a separator unit into a hydrocarbon-rich phase and an ionic liquid catalyst-rich phase which latter phase also comprises solids formed as side products during the alkylation reaction; and (c) a solids removal step, wherein the solids in ionic liquid catalyst-rich phase are separated from the ionic liquid catalyst using a suitable separating device; wherein the process further comprises a step following the separation step (b) and prior to the solids removal step (c).