TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: In the method, the temperature in the reaction vessel is 50-200 degrees C, preferably 50-100 degrees C, and the temperature in the reaction vessel increases after delivery of the gaseous ammonia to the reaction vessel. The gaseous ammonia is delivered to the reaction vessel at a pressure of 100-1000, preferably 100-200 psi. In the method, the gaseous ammonia condenses on the biomass. In the method, the gaseous ammonia reacts with water in the biomass. The time for the gaseous ammonia to react with the biomass is 2-36 hours, preferably 1-120 minutes. The biomass is uniformly pretreated by the gaseous ammonia. The method is either continuous or semi-batch. The method further comprises: delivering a carrier to the reaction vessel, where the carrier is combined with the gaseous ammonia; and recycling at least a portion of the gaseous ammonia as a gas to be used in the treatment process. In the method, an inert gas and steam are combined with the gaseous ammonia before the gaseous ammonia is delivered to the reaction vessel. The carrier is added to the reaction vessel after the gaseous ammonia gas is delivered to the reaction vessel. Preferred Components: The carrier is an inert gas, steam or air. The carrier is oxidative.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The reaction vessel is a fixed bed reactor, a fluidized bed reactor or a semi-fluidized bed reactor.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The biomass comprises less than 15% or 15-233% of water on a dry weight basis. EXAMPLE - Anhydrous gaseous ammonia was transferred to a stainless steel cylinder and preheated to reach 450-900 psi. In parallel, the biomass with appropriate moisture (60%) was kept in a preheated (at 140 degrees C and 160 degrees C) stainless steel reaction vessel, and a vacuum was applied to remove air and to create negative pressure to facilitate ammonia delivery. The preheated ammonia gas was transferred to the reaction vessel, and a rapid rise in temperature from 30 degrees C initial temperature to 100-200 degrees C of the biomass was observed depending on the pressure/temperature of preheated ammonia gas.