Abstract: Apparatus and method for delinting cottonseed using hydrogen chloride gas derived from hydrogen chloride stored at high pressure. The hydrogen chloride gas is expanded and reduced to a pressure in the range of but above atmospheric pressure, then heated in a heat exchanger, passed through a flow meter for regulating the flow rate and controlling the amount hydrogen gas introduced for processing a batch of fuzzy cottonseed, and then introduced into a rotating drum reaction chamber along with a measured quantity of fuzzy seed to be delinted. The expansion process and heat exchange processes are controlled to produce a gas pressure and temperature range at the inlet to the drum reaction chamber which substantially increases yields over the prior art systems, provides substantially complete absorption of the gas by the seed thereby avoiding gas leakage from the system when the treated seed is removed from the reaction chamber and further avoids the need for further treatment of the seed with anhydrous ammonia.