NOVELTY - Cultivating and/or processing of biomass, preferably algae in biomass cultivation plant (2) under utilization of carbon dioxide (CO2), comprises disposing the biomass cultivation plant in spatial proximity of at least one biomass (BM), residual biomass (RBM, RBM3.1-RBM3.3, RBM10.1-RBM10.2) or a biomass product (BMP, BMP1-BMPn; BMP3.1, BMP10.1, BMP9.1) processing, and also CO2-emitting device (3, 3.1-3.8), and at least partially supplying carbon dioxide emitted through the operation of this device, to the biomass cultivation plant.    USE - The method is useful for culturing biomass in the form of micro-algae or macro-algae and/or pure species cultures. The residual biomass and biomass product are useful to produce additives such as sizing agents, starch, hemicellulose, nanocellulose, pigments, fillers for use in the paper, and packaging-industry. The biomass is useful for: the production of fungicides, bactericides and/or other drugs; and processing into foods, preferably animal feed (all claimed).    ADVANTAGE - The method produces the biomass in a large scale, in bioreactors or open ponds, and in an economical manner.    DETAILED DESCRIPTION - Cultivating and/or processing of biomass, preferably algae in biomass cultivation plant (2) under utilization of carbon dioxide (CO2), comprises disposing the biomass cultivation plant in spatial proximity of at least one biomass (BM), residual biomass (RBM, RBM3.1-RBM3.3, RBM10.1-RBM10.2) or a biomass product (BMP, BMP1-BMPn; BMP3.1, BMP10.1, BMP9.1) processing, and also CO2-emitting device (3, 3.1-3.8), and at least partially supplying carbon dioxide emitted through the operation of this device, to the biomass cultivation plant, where the biomass cultivation plant, the biomass, residual biomass or a biomass product processing, and CO2 emitting device as CO2 recycling process unit are arranged in a subecumenical area, preferably near-desert or desert area (4). An INDEPENDENT CLAIM is included for a CO2 recovery process unit (1) for the production of biomass, preferably algae, comprising at least one CO2-consuming biomass cultivation plant and at least one biomass, or at least a residual biomass, a biomass product and/or any other material flow processing, and CO2-emitting device for the direct processing of biomass from the biomass cultivation plant or indirect processing of the biomass through processing of residual biomass or from biomass products, or by further processing of process-related material flows under: releasing of CO2, means for supply of CO2 from such biomass, residual biomass, biomass product or material flow processing and CO2-emitting device for biomass cultivation plant, where the CO2 recovery process unit is arranged at a site on subecumenical properties, preferably near-desert or desert area; and under energy demand, supply of energy requirements from a power plant, which provides the needed energy in a CO2-emission, means for the supply of CO2 from this CO2-emitting power plant for biomass cultivation plant.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of an arrangement of a paper mill as a biomass, residual biomass or biomass product processing device.    Carbon dioxide recovery process unit (1)    Biomass cultivation plant (2)    Carbon dioxide-emitting device (3, 3.1-3.8)    Desert area (4)    Means (5)    Sand leaching device (6)    Drying device (9)    Deoiling device (10)    Refinery (15)    Pulp preparation equipment (16)    Paper machine (18)    Material flow. (s1-s9, s10-s12, s13)