Abstract: A process for improved methane production by anaerobic digestion of aquatic plant material at least a portion or all of which has been grown in organically polluted water. Mixtures of aquatic plant material one portion of which has been grown in non-polluted and a second portion comprising over about 10 weight percent which has been grown in organically polluted water may be used to result in a synergistic yield of methane. The liquid effluent from the digester may be advantageously returned to the aquatic plant growing pond to maintain the desired organic pollution. The process provides for improved methane production from aquatic plant material which is, by itself, recalcitrant to anaerobic digestion.

Abstract: A process for improved methane production resulting in higher yield and higher production rates by anaerobic digestion of a mixture of plant material and organic waste. The process is suitable for production of synthetic natural gas and through anaerobic digestion of a mixture of plant material and organic waste allows better matching of organic waste and plant material feed supplies for year round operation. The process of this invention results in digester effluent which is easily dewatered and has a low concentration of soluble organics, providing easy disposal and recycling to the digester. The process of this invention may be used for methane production from plant material which is, by itself, recalcitrant to anaerobic digestion.

Abstract: A process for production of methane gas in higher yields and higher rates by thermophilic or mesophilic anaerobic digestion of plant material and/or organic waste in admixture with an extract of different plant material. Increases of methane yield of greater than about 25% and up to about 500% are obtained by addition of the extract of different plant material to a normally low biodegradable plant and/or organic waste material before anaerobic digestion thereof. The resulting methane yields and production rates are higher than those obtained by the sum from anaerobic digestion of the individual components when using the extract as taught by this invention.