TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Methods: The method includes heating of biosolids to a second temperature to evolve carbon dioxide from the biosolids and form a char slurry comprising charred ruptured biosolids cells, separating the carbon dioxide from the char slurry. The removing of portion(s) of the freed cell-bound water provides (partially) dewatered char product, reacting the char product with a gas comprising oxygen to convert its fuel value into thermal energy, and using the thermal energy and incinerating the fuel. The step of applying pressure comprises providing a pump. The step of removing comprises removing water-soluble constituents from the char slurry, removing free water from slurry and/or the partially dewatered product as steam to produce a dried product. The method includes step of washing the dewatered char product with clean water or solvent. The method includes mixing the dried char product with a fuel oil to form a coal-oil mixture, transporting the char product to a chemical plant, converting the char product to a synthesis gas, oil, oxygenated compounds, carbon fibers, and/or fertilizer additive, pretreating water removed from the char slurry, recycling portion(s) of pretreated water to the providing step, adding water, heat, and/or steam to the biosolids prior to the step of applying, adding a chelating agent to the water removed from the charred slurry, and converting the dried char product to a carbon-based product. The pretreating of the water comprises pretreating with membranes, vibrating membranes, ammonia removal, anaerobic digestion, and/or reverse osmosis. The method includes grinding and/or shearing the biosolids prior to the step of applying, screening the biosolids prior to the step of applying, cooling the slurry before depressurization and/or cooling the slurry after depressurization. The depressurizing step occurs in at least two increments. The step of cooling occurs prior to the depressurizing step. When foam interferes with the step of separating, char slurry from a lower part of a separator is pumped and sprayed toward the foam from at least one spray nozzle located above a liquid level in the separator. The method includes discharging the carbon dioxide through a flame of oxidizer and/or a process heater. The step of separating the carbon dioxide further comprises sequestering carbon dioxide into earth and/or a large body of water; purifying and using carbon dioxide for carbonizing beverages, pressurizing fire extinguishers, spray can propellant, refrigerant, and/or inert blanketing gas; and/or using the carbon dioxide as a mixable flooding agent for tertiary oil recovery. The step of heating includes providing a hot heat transfer fluid and heating the pressurized biosolids with the hot heat transfer fluid. The method includes exchanging heat in the slurry with the pressurized biosolids prior to the step of applying, using the thermal energy for process heat, using the process heat to dry the dewatered char product. The heating comprises using steam as a heating medium. The sulfur contained in the carbon dioxide gas is generated in the separating step, and including removing the sulfur with pollution control equipment. The method includes reacting the dewatered biomass char product with a gas containing oxygen to convert its fuel value into thermal energy; and using the thermal energy. The method includes discharging the carbon dioxide through a flame of oxidizer and/or process heater, pretreating portion(s) of the free water to form pretreated water and recycling the pretreated water to an adjacent wastewater treatment plant. The process water from an adjacent wastewater treatment plant is used in the slurrying step. The removing comprises removing water from biomass char slurry and/or dewatered product as steam. The method includes cooling the aqueous char slurry to a second temperature less than the first temperature. The method includes using a digester gas from an adjacent wastewater treatment plant as fuel for the heating step, using the dewatered biomass char product as fuel in a cement kiln, recycling waste heat from the cement kiln to performing and/or heating steps, using blowdown water from an adjacent cement kiln for the performing step, using the carbon dioxide for heat recovery and/or odor reduction in the adjacent cement kiln, using the dewatered biomass char product as fuel in a thermal power station, using portion(s) of the freed water for cooling an adjacent thermal power station, using heat from the adjacent thermal power station for performing and/or heating steps, using the carbon dioxide for heat recovery and/or odor reduction in the adjacent thermal power station. The step of providing includes providing and adding an agent for dissolution of polluting and/or slag-forming element in the biomass, preferably in dewatered biomass char product. The method includes reacting the dewatered char product with a gas comprising oxygen to convert fuel value into thermal energy to form char. The pressurizing includes injecting steam into the batch process to heat the biosolids. The heating step is performed by burning the fuel gas from a gasifier, and/or steam from a boiler. The fuel for the heating step is fossil fuel, digester gas, and/or product char. The removing comprises adding polymer(s) to enhance separation of the aqueous phase, using the dewatered char product as a raw material for hydrogen fuel cells through partial oxidation to a fuel gas. A portion of the char slurry is recycled back to the heated pressurized biosolids prior to depressurization. The converting of seaweeds includes suspending the ruptured biosolids cells in at least the water freed from the biosolids cells. The disposing of the char product comprises combusting the char product to generate heat with it. The disposing comprises furnishing the char product for use by a third person. Preferred Components: The booster pumps are provided downstream to reduce the required head pressure of the pump. The free water from the removing step is recirculated to the providing step in order to reduce the required head pressure of the pump. The dried product is a dried char product. The slurry is a char slurry of charred ruptured biosolids cells. The slurry is a char slurry of charred ruptured biosolids cells. The pretreating the aqueous phase renders a methane gas. The ash produced is utilized in cement kiln, building materials, compost, and/or fertilizer product. The biomass comprises paper mill sludge, sludge from paper recycling operations, agricultural and forestry wastes, peat, food waste, hog manure, chicken litter, cow manure, other animal manures, rice hulls, bagasse, green waste, municipal solid waste, palm oil residue, refuse derived fuels, Kraft Mill black liquor, and short rotation energy crops. A portion of the freed water is recycled to the adding step. The agent comprises an alkali. Preferred Parameters: The first temperature is 200-345degreesC. The second temperature is 40-90degreesC.