TECHNOLOGY FOCUS - ENVIRONMENT - Preferred Refuse: The organic refuse is livestock dung urine which is diluted with water before mixing with turbid liquid and glycerin. The ratio of carbon component and nitrogen component of the liquid mixture is 30 or more.    TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Arrangement: The biomass circulation system is provided with: (i) crusher which crushes the organic refuse before mixing with washing waste turbid liquid and glycerin; (ii) organic-refuse compression classifier which removes foreign material from the crushed organic refuse; (iii) solid-liquid separator (60) which removes the solid substance contained in the organic refuse; (iv) compost apparatus (80) which composts the solid substance; (v) diesel engine co-generation apparatus (30) which burns the diesel fuel and methane gas, and generates electrical energy or heat energy; (vi) de-sulfurizer (40) which removes hydrogen sulfide contained in the biogas; (vii) water-removal device (70) which dehydrates the digestive liquid obtained by carrying out methane fermentation of the liquid mixture; (viii) mixing portion (50) which prepares the liquid mixture; (ix) unit for supplying the dehydrated filtrate collected by dehydrating the digestive liquid in the water-removal device to the mixing portion; (x) wastewater treatment equipment (90) which separate-recovers the water pollutant contained in the dehydrated filtrate; (xi) unit for supplying the dehydrated filtrate free of water pollutant to the mixing portion; (xii) nitrification-denitrification processing apparatus which removes nitrogen compound contained in digestive liquid; and (xiii) compost apparatus which composts the dehydrated cake obtained by dehydrating the digestive liquid with the water-removal device. The biomass fuel apparatus has an acid generation portion which produces an acid, and a methane formation portion which produces methane gas by methane fermentation of produced acid by carrying out souring of the liquid mixture.