Abstract: A body of liquid, such as an aqueous fertilizer mixture, in a tank is stirred and mixed by apparatus which produces a pattern of recirculating flow including a zone of rapid streamline flow in the tank, preferably an upwardly diverging conical pattern and preferably at an eccentric point in the tank. An addition component in fluid state, such as anhydrous liquid ammonia, is injected into the rapidly flowing liquid in a plurality of fine streams from a stationary injection manifold so as to produce an intimate dispersion of finely divided addition fluid at spaced points in the mixture which is immediately carried away from the injection area and widely dispersed in the liquid mixture. When anhydrous ammonia is thus dispersed in a fertilizer mixture containing a suitable reactant, such as phosphoric acid (H.sub.3 PO.sub.

Abstract: A process for extracting methane gas and ammonia from raw material, such as organic waste. The process is carried out in a closed container or digester by anaerobic bacteria. The yield of the conventional anaerobic bacteria digestion process is greatly increased by the novel step of maintaining the space in the digester above the level of the raw material at a pressure below atmospheric during the digestion process.