Microwave Produced Biochar from Beneficiated Organic-Carbon-Containing Feedstock

Abstract

A processed biochar composition made with an oxygen-starved microwave sub-system from a processed organic-carbon-containing feedstock made with a beneficiation sub-system is described. Renewable biomass feedstock passed through a beneficiation sub-system to reduce water content to below at least 20 wt % and water-soluble salt reduction of at least 60% from that of unprocessed organic-carbon-containing feedstock on a dry basis. The processed feedstock is introduced into a substantially microwave-transparent reaction chamber. A microwave source emits microwaves which are directed through the microwave-transparent wall of the reaction chamber to impinge on the feedstock within the reaction chamber. The microwave source may be rotated relative to the reaction chamber. The feedstock is subjected to microwaves until the desired reaction occurs to produce a solid processed biochar fuel.

What is claimed is: 
     
         1 . A composition, comprising:
 a processed biochar composition that comprises a solid renewable carbon fuel with characteristics that include an energy density of at least 17 MMBTU/ton (20 GJ/MT), a water content of less than 10 wt %, water-soluble salt that is decreased more than 60 wt % on a dry basis from that of unprocessed organic-carbon-containing feedstock, and pores that have a variance in pore size of less than 10 percent, and   the processed biochar is made from unprocessed organic-carbon-containing feedstock that is converted into the processed organic-carbon-containing feedstock with a beneficiation sub-system, and to the processed biochar with a microwave sub-system.   
     
     
         2 . The composition of  claim 1  wherein the beneficiation sub-system, comprises:
 a. a transmission device configured to convey into a reaction chamber unprocessed organic-carbon-containing feedstock comprising 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; 
 b. at least one reaction chamber comprising at least one entrance passageway, at least one exit passageway for fluid, at least one exit passageway for processed organic-carbon-containing feedstock, and at least three sections, the sections comprising,
 i. a wet fibril disruption section configured to interact with at least some of the lignin and hemicellulose between the fibrils to make at least some regions of the cell wall more susceptible to outflow by water-soluble salts, 
 ii. a vapor explosion section in communication with the wet fibril disruption section and at least configured to volatilize plant fibril permeable fluid through rapid decompression to penetrate the more susceptible regions of the cell wall so as 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 
 iii. a compaction section in communication with the vapor explosion section and configured to compress the porous organic-carbon-containing feedstock between pressure plates configured to minimize formation of water-impermeable felt so as 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 that passes out through its reaction chamber exit passageway; and 
 
 c. a collection device in communication with the reaction chamber and configured to gather the processed organic-carbon-containing feedstock having a water content of less than 20% by weight and a water-soluble salt content that is decreased by at least 60% on a dry basis from that of the unprocessed organic-carbon-containing feedstock. 
 
     
     
         3 . The composition of  claim 1  wherein the microwave sub-system, comprises:
 a. at least one reaction chamber within a microwave reflecting enclosure, the reaction chamber comprising at least one microwave-transparent chamber wall and at least one reaction cavity within the reaction chamber that is configured to hold the organic-carbon-containing feedstock in an externally supplied oxygen free atmosphere; 
 b. a microwave subsystem comprising at least one device configured to emit microwaves when energized, the microwave device positioned relative to the reaction chamber so that the microwaves are directed through the microwave-transparent chamber wall and into the reaction cavity; and 
 c. a mechanism configured to provide relative motion between the microwave device and the reaction chamber. 
 
     
     
         4 . The composition of  claim 1  further comprising pores having a number of pores per volume that is at least 10 percent more than would have been in a char made with the same feedstock but using a thermal process that creates a liquid phase during the process. 
     
     
         5 . The composition of  claim 1  further comprising pores that have a variance in pore distribution of less than 10 percent. 
     
     
         6 . The composition of  claim 1 , wherein a number of pores per volume that is at least 20 percent more than would have been in a char made with the same feedstock but using a thermal process that creates a liquid phase during the process. 
     
     
         7 . The composition of  claim 1 , wherein a number of pores per volume that is at least 30 percent more than would have been in a char made with the same feedstock but using a thermal process that creates a liquid phase during the process. 
     
     
         8 . The composition of  claim 1 , wherein a number of pores per volume that is at least 40 percent more than would have been in a char made with the same feedstock but using a thermal process that creates a liquid phase during the process. 
     
     
         9 . The composition of  claim 1  further comprising a heat content of at least 20% more than the heat content in a char made with the same feedstock but using a thermal process that creates a liquid phase during the process. 
     
     
         10 . The composition of  claim 1  wherein the processed organic-carbon-containing feedstock comprises at least 5 weight percent water. 
     
     
         11 . The composition of  claim 1  wherein the processed organic-carbon-containing feedstock comprises at least 5 weight percent volatiles. 
     
     
         12 . The composition of  claim 1 , wherein the organic-carbon-containing feedstock comprises at least two from a group consisting of a herbaceous plant material, a soft woody plant material, and a hard woody plant material, wherein each type passes in series through the at least one reaction chamber, and wherein the energy density of each plant material in the processed organic-carbon-containing feedstock is at least 17 MMBTU/ton (20 GJ/MT). 
     
     
         13 . The composition of  claim 1  wherein the unprocessed organic-carbon-containing has a water-soluble salt content of at least 4000 mg/kg on a dry basis. 
     
     
         14 . The composition of  claim 1 , wherein the organic-carbon-containing feedstock comprises at least two from a group consisting of a herbaceous plant material, a soft woody plant material, and a hard woody plant material, wherein each type passes in series through the at least one reaction chamber, and wherein the energy density of each plant material in the processed organic-carbon-containing feedstock is at least 17 MMBTU/ton (20 GJ/MT). 
     
     
         15 . The composition of  claim 2 , wherein the beneficiation system, further comprises:
 a pretreatment chamber that is configured to use for each organic-carbon-containing feedstock a particular set of conditions including time duration, temperature profile, and the chemical content of pretreatment solution to at least initiate the dissolution of contaminates that would hinder creation of the plant cell wall passageways that allow intracellular water and intracellular water-soluble salts to pass outward from the plant cells.   
     
     
         16 . The composition of  claim 2 , wherein the vapor explosion section, further comprises:
 at least one rinsing subsection configured to flush at least some of the water-soluble salt from the porous organic-carbon-containing feedstock before it is passed to the compaction section.   
     
     
         17 . A process of making processed biochar, a solid renewable fuel, composition, comprising the steps of:
 a. inputting into a system comprising a first and a second subsystem an 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,   b. passing unprocessed organic-carbon-containing feedstock through the first sub-system, a beneficiation sub-system process, to result in 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   c. passing the processed organic-carbon-containing feedstock through the second sub-system, a microwave sub-system process, to result in a solid renewable fuel composition having an energy density of at least 17 MMBTU/ton (20 GJ/MT) a water content of less than 10 wt %, water-soluble salt that is decreased by at least 60 wt % on a dry basis from that of the unprocessed organic-carbon-containing feedstock.   
     
     
         18 . The process of  claim 17  wherein the beneficiation sub-system process and the microwave sub-system process, further comprises the steps of:
 a. inputting into a beneficiation sub-system reaction chamber unprocessed organic-carbon-containing feedstock comprising 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; 
 b. exposing the 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; 
 c. removing the pressure so as to penetrate the more penetrable regions to create porous feedstock with open pores in the plant cell walls; and 
 d. 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 prevent felt from forming and blocking escape from the reaction chamber of intracellular and intercellular water, and intracellular water-soluble salts, and 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; 
 and the microwave sub-system process, further comprises the steps of: 
 e. inputting processed organic-carbon-containing feedstock into a substantially microwave-transparent reaction chamber containing no externally supplied oxygen and within a microwave reflective enclosure; 
 f. directing microwaves from a microwave source through walls of the reaction chamber to impinge on the feedstock; 
 g. providing relative motion between the microwave-transparent reaction chamber and the microwave source; and 
 h. microwaving the feedstock until the feedstock reacts to produce a solid fuel comprising less than 60 wt % on a dry basis of water-soluble salt from that of unprocessed organic-carbon-containing feedstock, a water content of less than 10 wt %, and pores that have a variance in pore size of less than 10 percent. 
 
     
     
         19 . The process of  claim 17  wherein the beneficiation sub-system process and the microwave sub-system process, further comprises the steps of:
 a. inputting into a reaction chamber unprocessed organic-carbon-containing feedstock comprising 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; 
 b. exposing the 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; 
 c. removing the pressure so as to penetrate the more penetraable regions to create porous feedstock with open pores in the plant cell walls; and 
 d. 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 prevent felt from forming and blocking escape from the reaction chamber of intracellular and intercellular water, and intracellular water-soluble salts and 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, 
 and the microwave subsystem process, further comprises the steps of: 
 e. inputting processed organic-carbon-containing feedstock into a substantially microwave-transparent reaction chamber containing no externally supplied oxygen and within a microwave reflective enclosure; 
 f. directing microwaves from a microwave source through walls of the reaction chamber to impinge on the feedstock; 
 g. providing relative motion between the microwave-transparent reaction chamber and the microwave source; and 
 h. microwaving the feedstock until the feedstock reacts to produce a solid fuel comprising a water-soluble salt content that is a decrease of more than 60 wt % on a dry basis from that of unprocessed organic-carbon-containing feedstock and a water content of less than 10 wt %.