A cannabidiol extraction and conversion process includes an extraction process including a sizing unit wherein raw Cannabis plant material is reduced to a uniform size, a blending unit wherein an extraction solvent is blended together with the Cannabis plant material to form an initial extract, and a primary solvent exchange rotary evaporator unit wherein an exchange solvent is added to the initial extract, and a processed extract rich in cannabidiol is obtained. A conversion process includes a conversion rotary reflux unit wherein the processed extract is combined and processed with an acidic component, a separator unit wherein a solvent is added and a separator organic effluent is obtained, a secondary solvent exchange rotary evaporator unit wherein a further solvent is added, and a fractionation unit wherein the tetrahydrocannabinol obtained is separated into a plurality of functional fractions for selective blending.

A method and a device are disclosed for converting at least one reactant into a reaction product and separating the at least one reactant. The device includes a vessel with a vessel inner volume and a confinement, submerged in the vessel inner volume, that provides a confinement inner volume in fluid connection with the vessel inner volume. First and seconds fluids, with a respective, higher first density and a lower, second density form respective lower and upper phases in the vessel inner volume. A third fluid with a third density higher than that of the second fluid forms a lower layer in the confinement inner volume, relative to an upper layer formed by the second fluid. The third fluid may be the same as or different from, and is physically separated from, the first fluid. At least one of the first, second, and third fluids is at most partly miscible with the other two, but preferably immiscible. The at least one reactant and the reaction product have different affinities for at least two of the first, second, and third fluids, and at least one of the first and third fluid contains a fourth phase which is a solid or semi solid and is capable of promoting the conversion.