Process of Making Biochar From Beneficiated Organic-Carbon-Containing Feedstock

Abstract

A process for making a biochar composition by passing renewable organic-carbon-containing feedstock through a beneficiation sub-system to reduce water content followed by introducing beneficiated feedstock into an oxygen-deficient thermal sub-system to result in renewable processed biochar having an energy density of at least 17 MMBTU/ton (20 GJ/MT) a water content of less than 10 wt %, and water-soluble salt that is decreased by at least 60 wt % on a dry basis from that of the unprocessed organic-carbon-containing feedstock.

What is claimed is: 
     
         1 . A process of making processed biochar comprising:
 passing renewable unprocessed organic-carbon-containing feedstock that includes free water, intercellular water, intracellular water, intracellular water-soluble salts, and at least some plant cells comprising cell walls that include lignin, hemicellulose, and microfibrils within fibrils through a beneficiation sub-system to produce processed organic-carbon-containing feedstock having a water content of less than 20 wt % and a salt content that is reduced by at least 60 wt % on a dry basis from that of the unprocessed organic-carbon-containing feedstock; and   passing the processed organic-carbon-containing feedstock an oxygen-deprived thermal sub-system process to produce processed biochar having an energy density of at least 17 MMBTU/ton (20 GJ/MT) a water content of less than 10 wt %, and water-soluble salt that is decreased by at least 60 wt % on a dry basis from that of the unprocessed organic-carbon-containing feedstock.   
     
     
         2 . The process of  claim 1 , wherein the beneficiation sub-system process comprises:
 exposing the unprocessed feedstock to hot solvent under pressure for a time at conditions specific to the feedstock to make some regions of the cell walls comprising crystallized cellulosic fibrils, lignin, and hemicellulose more able to be penetrable by water-soluble salts without dissolving more than 25 percent of the lignin and hemicellulose;   removing the pressure so as to penetrate the more penetrable regions to create porous feedstock with open pores in the plant cell walls; and   pressing the porous feedstock with conditions that include an adjustable compaction pressure versus time profile and compaction time duration, and between pressure plates to create processed organic-carbon-containing feedstock that has a water content of less than 20 wt % and a water-soluble salt content that is decreased by at least 60 wt % on a dry basis from that of unprocessed organic-carbon-containing feedstock.   
     
     
         3 . The process of  claim 1 , wherein the oxygen-deprived thermal sub-system process is configured to heat the processed organic-carbon-containing feedstock in an atmosphere that contains less than 4 percent oxygen to a temperature sufficient to convert at least some processed organic-carbon-containing feedstock into processed biogas and processed biochar. 
     
     
         4 . The process of  claim 3 , wherein the oxygen-deprived thermal sub-system process, comprises:
 heating the processed organic-carbon-containing feedstock to a sublimating temperature before it is able to form a liquid phase;   maintaining the temperature at a sublimation temperature for a residence time that is as long a time as needed to convert the processed organic-carbon-containing feedstock to processed biogas and processed biochar; and   separating the processed biogas from the processed biochar.   
     
     
         5 . The process of  claim 2 , wherein the oxygen-deprived thermal sub-system process comprises:
 inputting processed organic-carbon-containing feedstock into a substantially vertical sublimating reaction chamber;   heating the processed organic-carbon-containing feedstock to a sublimating temperature before it is able to form a liquid phase;   maintaining the temperature at a sublimation temperature for a residence time that is as long a time as needed to convert the processed organic-carbon-containing feedstock to processed biogas and processed biochar; and   separating the processed biogas from the processed biochar.   
     
     
         6 . The process of  claim 1 , wherein the beneficiation sub-system process comprises:
 exposing the unprocessed feedstock to hot solvent under pressure for a time at conditions specific to the feedstock to make some regions of the cell walls comprising crystallized cellulosic fibrils, lignin, and hemicellulose more able to be penetrable by water-soluble salts without dissolving more than 25 percent of the lignin and hemicellulose;   removing the pressure so as to penetrate the more penetrable regions to create porous feedstock with open pores in the plant cell walls; and   pressing the porous feedstock with conditions that include an adjustable compaction pressure versus time profile and compaction time duration, and between pressure plates configured to to create processed organic-carbon-containing feedstock that has a water content of less than 20 wt %, a water-soluble salt content that is decreased by at least 60 wt % on a dry basis over that of unprocessed organic-carbon-containing feedstock, and a cost per weight of removing the water and water-soluble salt that is reduced to less than 60% of the cost per weight of similar water removal from known mechanical, known physiochemical, or known thermal processes.   
     
     
         7 . A process of making processed biochar comprising:
 inputting unprocessed organic-carbon-containing feedstock into a reaction chamber;   exposing the feedstock to hot solvent under pressure;   removing the pressure to for pressed feedstock; and   pressing the pressed feedstock so as to created processed organic-carbon-containing feedstock that has a water content of less than 20% by weight and a water-soluble salt contend that is decreased by at least 60% from that of unprocessed organic-carbon-containing feedstock.   
     
     
         8 . The process of  claim 7 , wherein the solvent is water heated to from about 130° C. about 215° C. and the pressure is from about 260 psig to about 650 psig,
 wherein the unprocessed feedstock is exposed to the heated water for about 15 to about 45 minutes. 
 
     
     
         9 . The process of  claim 8 , wherein the solvent is water heated to from about 130° C. to about 160° C., the pressure is from about 260 psig to about 280° C., and the exposure time of the feedstock to the heated water is from 15 to 25 minutes. 
     
     
         10 . The process of  claim 8 , wherein the solvent is water or water/methanol heated to from about 165° C. to about 205° C., the pressure is from about 280 psig to about 385 psig for water or from about 640 psig to about 650 psig for methanol, and the exposure time of the feedstock to the heated solvent is from 20 to 35 minutes. 
     
     
         11 . The process of  claim 8 , wherein the solvent is water heated to from about 180° C. to about 215° C., the pressure is from about 375 psig to about 425° C., and the exposure time of the feedstock to the heated water is from 30 to 45 minutes. 
     
     
         12 . The process of  claim 9 , wherein the pressure decreases by about 260 psig to about 250 psig in a time period of 50 milliseconds or less. 
     
     
         13 . The process of  claim 10 , wherein the pressure decreases by about 250 psig to about 350 psig in a time period of 50 milliseconds or less when water is the solvent and the pressure decreases by about 640 psig to about 650 psig when the solvent is water/methanol. 
     
     
         14 . The process of  claim 11 , wherein the pressure decreases by about 345 psig to about 400 psig in a time period of 50 milliseconds or less.