Abstract: A method for converting delta-9 THC and or delta-9 THC-A to delta-8 THC includes adding at least one of delta-9 THC and delta-9 THC-A to a reaction vessel, streaming an inert gas through the reaction vessel, heating to melt at least one of delta-9 THC and delta-9 THC-A while stirring, converting any delta-9 THC-A into delta-9 THC upon heating to initiate decarboxylation of the delta-9 THC-A, stirring the melting delta-9 THC and adding one of concentrated HCl and diluted HCl to the liquefied delta-9 THC, increasing the temperature over time to not exceed the boiling point of reactants and products, holding the reaction vessel at a temperature less than the boiling point temperature for the reactants and products for an amount of time to allow the conversion of the delta-9 THC into delta-8 THC, and bubbling an inert gas into the reaction products to remove free ions of hydrogen and chloride.

Abstract: A solvent-free method for converting CBD or delta-9 THC-A to delta-9 THC and delta-8 THC includes adding CBD to a reaction vessel, streaming an inert gas through the reaction vessel, heating the CBD while stirring to melt the CBD, stirring the melting CBD, adding concentrated hydrochloric acid as a catalyst to the melting CBD while stirring, increasing the temperature over time to a temperature not to exceed the boiling point of reactants and products in the reaction vessel, holding the reaction vessel at a temperature less than the boiling point temperature for the reactants and products in the reaction vessel for an amount of time to allow the complete conversion of the CBD, and bubbling an inert gas into the reaction products to remove free ions of hydrogen and chloride. The CBD can be replaced in whole or in part by delta-9 THC-A as the reactant.