NOVELTY - A water and water-soluble salts-removal system comprises a transmission device to convey unprocessed organic-carbon-containing feedstock comprising free water, intercellular water, intracellular water, intracellular water-soluble salts and plant cells comprising cell walls which comprises lignin, hemicellulose and microfibrils within fibrils, into a reaction chamber comprising entrance passageway, exit passageway(s) for fluid, exit passageway(s) for processed organic-carbon-containing feedstock and 3 or more sections.    USE - System is used for removing water and water-soluble salts from organic-carbon-containing feedstock (claimed) during synthesis of petroleum and natural gas used as fuel for boiler.    ADVANTAGE - The system efficiently removes removing water and water-soluble salts from organic-carbon-containing feedstock in short period of time without corroding, fouling or slagging the equipment during combustion.    DETAILED DESCRIPTION - A water and water-soluble salts-removal system comprises a transmission device to convey unprocessed organic-carbon-containing feedstock comprising free water, intercellular water, intracellular water, intracellular water-soluble salts and plant cells comprising cell walls which comprises lignin, hemicellulose and microfibrils within fibrils, into a reaction chamber comprising entrance passageway, exit passageway(s) for fluid, exit passageway(s) for processed organic-carbon-containing feedstock and 3 or more sections. The section comprises a wet fibril disruption section to interact with lignin and/or hemicellulose between the fibrils to make region(s) of the cell wall more susceptible to outflow by water-soluble salts, a vapor explosion section in communication with the wet fibril disruption section, to volatilize plant fibril permeable fluid through rapid decompression to penetrate more susceptible regions of the cell wall and to create a porous organic-carbon-containing feedstock with plant cell wall passageways for intracellular water and intracellular water-soluble salts to pass from the plant cell, and a compaction section in communication with the vapor explosion section, to compress the porous organic-carbon-containing feedstock between pressure plates configured to minimize formation of water-impermeable felt and to permit the escape of intracellular water and intracellular water-soluble salt from the reaction chamber fluid exit passageway and to create processed organic-carbon-containing feedstock which passes out through its reaction chamber exit passageway, and a collection device in communication with the reaction chamber and to gather the processed organic-carbon-containing feedstock having a water content of less than 40 wt.% and a water-soluble intracellular salt content which is decreased by 50% or more on a dry basis from that of the unprocessed organic-carbon-containing feedstock. An INDEPENDENT CLAIM is included for process for removing water and water-soluble salts from organic-carbon-containing feedstock.