NOVELTY - A biomass circulation system (100) comprising biodiesel fuel apparatus (10) and biomass fuel apparatus, where vegetable oil is heated, and alcohol and alkali are added and transesterified, and the product is separated into diesel fuel and glycerin, where the washing waste turbid liquid obtained by washing diesel fuel, is recovered, the washed diesel fuel is recovered by biodiesel fuel apparatus, and methane fermentation of liquid mixture and organic refuse is carried out, and biogas containing methane gas is recovered by biomass fuel apparatus, is new.    USE - For processing biomass of organic refuse, such as livestock-dung urine and vegetable oil (all claimed), such as waste edible oil, rapeseed oil, and sunflower oil, and producing biodiesel fuel.    ADVANTAGE - The biomass circulation system enables efficient processing of glycerin generated when producing biodiesel fuel, and washing waste turbid liquid.    DETAILED DESCRIPTION - A biomass circulation system (100) comprises a biodiesel fuel apparatus (10) which recovers washed diesel fuel, and a biomass fuel apparatus which recovers biogas containing methane gas. Solid matter is removed from a vegetable oil, and the vegetable oil is heated. A primary alcohol and a caustic alkali are added to the heated vegetable oil, and transesterification is carried out. The reaction product is separated into diesel fuel and glycerin which is then recovered. The washing waste turbid liquid obtained by washing the diesel fuel with wash water, is recovered. The washed diesel fuel is recovered by the biodiesel fuel apparatus. Methane fermentation of the liquid mixture containing washing waste turbid liquid recover from the biodiesel apparatus and glycerin, and organic refuse is carried out, and biogas containing methane gas is recovered by the biomass fuel apparatus.    An INDEPENDENT CLAIM is included for processing method of biomass.    DESCRIPTION OF DRAWING(S) - The figure shows the structure of the biomass circulation system. (Drawing includes non-English language text)    Biodiesel fuel apparatus (10)    Diesel engine co-generation apparatus (30)    De-sulfurizer (40)    Mixing portion (50)    Solid-liquid separator (60)    Water-removal device (70)    Compost apparatus (80)    Wastewater treatment equipment (90)    Biomass circulation system (100)