NOVELTY - The modular water-based or battlefield-based biomass treatment unit comprises a first module (610) comprising a pretreater and a first frame for transportation to and operation at a site (600) adjacent to a solid or aquatic biomass growth source or a battlefield, a solid biomass harvester, a second module comprising a reactor, a separator and a second frame for transportation to and operation at the site adjacent to the solid or aquatic biomass growth source and the battlefield, and a third module comprising a second reactor, and a second separator and a third frame.    USE - The modular water-based or battlefield-based biomass treatment unit is useful for converting algae or aquatic biomass into a fuel, chemical or biocrude at a site adjacent to an aquatic biomass source or a battlefield (all claimed) in the filed of forestry, agricultural, aquatic and military, where the biomass includes bagasse, straw, corn stover, corn husks, cellulose, hemicellulose, lignin and grown energy crops such as switch grass and saw grass.    ADVANTAGE - The modular water-based or battlefield-based biomass treatment unit is capable of economically and efficiently converting the algae or aquatic biomass into fuel, chemical or biocrude at the site adjacent to the aquatic biomass source or battlefield in less consumption of energy.    DETAILED DESCRIPTION - The modular water-based or battlefield-based biomass treatment unit comprises a first module (610) comprising a pretreater and a first frame for transportation to and operation at a site (600) adjacent to a solid or aquatic biomass growth source or a battlefield, a solid biomass harvester, a second module comprising a reactor, a separator and a second frame for transportation to and operation at the site adjacent to the solid or aquatic biomass growth source and the battlefield, and a third module comprising a second reactor, a second separator and a third frame for transportation to and operation at the site adjacent to the solid or aquatic biomass growth source or the battlefield. The pretreater is operable to process solid or aquatic biomass to produce solid or aquatic biomass particles for conversion into a fuel, chemical or biocrude. The first frame supports the pretreater during transportation to and operation at the site adjacent to the solid biomass growth source or the battlefield. The pretreater comprises: a contactor adapted for forming a mechano-chemical interaction between a portion of the solid biomass particles and a catalyst and impregnating a portion of the solid biomass particles with a catalyst; a demineralizer for removing minerals from the solid biomass; a dryer for dewatering and torrifying the solid biomass; and a vessel for roasting or toasting biomass. The first module comprises skids, and is sized to fit within shipping containers. The reactor is operable to deoxygenate the solid or aquatic biomass particles and to produce a liquefied product. The separator is operable to separate a biocrude for conversion into a fuel or chemical from the liquefied product. The second frame supports the reactor and the separator during transportation to and operation at the site adjacent to the solid or aquatic biomass growth source or the battlefield. The second module comprises skids and a coupling mechanism for detachably engaging with the first module, and is sized to fit within shipping containers. The second reactor is operable to: refine the biocrude to produce a refined product; and deoxygenate remaining solid or aquatic biomass to produce additional liquefied product. The second separator is operable to: separate a fuel or chemical from the refined product; and separate a biocrude for conversion into a fuel or chemical from the liquefied product. The third frame supports the second reactor and the second separator during transportation to and operation at the site adjacent to the solid or aquatic biomass growth source or the battlefield. The third module comprises skids and a coupling mechanism for detachably engaging with the first and second modules, and is sized to fit within shipping containers. An INDEPENDENT CLAIM is included for a method for treating solid biomass at sites adjacent to a solid biomass growth source.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a method for treating solid biomass at a site adjacent to a solid biomass growth source.    Site (600)    Solid biomass growth module (605)    First module. (610)