Oxygen-Deficient Thermmally Produced Processed Biogas from Beneficiated Organic-Carbon-Containing Feedstock

Abstract

A processed biogas composition made with an oxygen-deficient thermal 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 an oxygen-deficient thermal sub-system to result in processed biogas having an energy density of at least 700 BTU/cubic ft (26 MJ/cubic meter), a carbon monoxide concentration of less than 20 vol %, and a carbon dioxide concentration of less than 15 vol %.

What is claimed is: 
     
         1 . A process of making processed biogas, a gaseous fuel, composition, comprising the steps of:
 inputting into a system comprising a first and a second subsystem, an unprocessed organic-carbon-containing feedstock that is renewable and 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;   passing the 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   passing the processed organic-carbon-containing feedstock through the second sub-system, an oxygen-deprived thermal sub-system process, to result in processed biogas, a gaseous fuel composition having an energy density of at least 700 BTU/cubic ft (26 MJ/cubic meter), a carbon monoxide concentration of less than 20 vol %, and a carbon dioxide concentration of less than 15 vol %.   
     
     
         2 . The process of  claim 1  wherein the beneficiation sub-system process comprises the steps of:
 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; 
 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 penetratable by water-soluble salts without dissolving more than 25 percent of the lignin and hemicellulose; 
 removing the pressure so as to penetrate the more penetratable 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 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 oxygen-deprived thermal sub-system process, further comprises the step of: 
 inputting processed organic-carbon-containing feedstock into an oxygen-deprived reaction chamber configured to heat the processed organic-carbon-containing feedstock in an atmosphere that contains less than 5 percent oxygen to a temperature sufficient to convert at least some processed organic-carbon-containing feedstock into processed biogas and processed biochar. 
 
     
     
         3 . The process of  claim 1  wherein the oxygen-deprived thermal sub-system process, further comprises the steps of:
 inputting processed organic-carbon-containing feedstock into a substantially horizontal sublimating reaction chamber largely contained within a hot box and configured to be able to heat from an ambient temperature to an operating sublimation temperature, operate at a sublimation temperature, and cool from a operating sublimation temperature to an ambient temperature without leaking any hot product gas fuel from the reaction chamber into the hot box or atmosphere, or leaking any oxygen from outside the hot box into the hot box; 
 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. 
 
     
     
         4 . The process of  claim 1  wherein the oxygen-deprived thermal sub-system process, further comprises the steps of:
 inputting processed organic-carbon-containing feedstock into a substantially vertical sublimating reaction chamber; 
 heating 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 1  wherein the beneficiation sub-system process and the oxygen-deficient thermal sub-system process, further comprise the steps of:
 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; 
 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 penetratable by water-soluble salts without dissolving more than 25 percent of the lignin and hemicellulose; 
 removing the pressure so as to penetrate the more penetratable 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 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 oxygen-deprived thermal sub-system process, further comprises the step of: 
 inputting processed organic-carbon-containing feedstock into an oxygen-deprived reaction chamber configured to heat the processed organic-carbon-containing feedstock in an atmosphere that contains less than 5 percent oxygen to a temperature sufficient to convert at least some processed organic-carbon-containing feedstock into processed biogas and processed biochar.