PROCESS FOR THE PRODUCTION OF HUMIC SUBSTANCES FROM BIOMASS

Abstract

A process for the chemical synthesis of humic substances from biomass, includes carrying out a Maillard reaction by heating a first biomass for 1 to 30 minutes to 150-250° C. The soluble impurities obtained are extracted from a second biomass by water. The remaining first solid is torrefied under a protective gas atmosphere at 180-300° C. for 0.2 to 4 hours. A torrefied second solid obtained is heated with a solution of a strong inorganic acid in excess to 120-180° C. for 0.5 to 3 hours. The first reaction mixture obtained is filtered and washed with water.

Claims

1. A process for the chemical synthesis of humic substances from a first biomass, the process comprising: carrying out a Maillard reaction by heating the first biomass for 1 to 30 minutes to 150-250° C.; extracting soluble impurities from a second biomass obtained from the carrying out the Maillard reaction by water; torrefying a first solid remaining from the extracting soluble impurities under a protective gas atmosphere at 180-300° C. for 0.2 to 4 hours; heating a torrefied second solid obtained from torrefying the first solid with a solution of a strong inorganic acid in excess; and to 120-180° C. for 0.5 to 3 hours filtering and washing with water a first reaction mixture obtained from the heating a torrefied second solid.

2. The process according to claim 1, further comprising boiling and dissolving a third solid obtained from filtering and washing with water the first reaction mixture at 120 to 160° C. with an alkaline earth hydroxide solution, neutralizing a second reaction mixture obtained from the boiling and dissolving a third solid by sulfuric acid or nitric acid and separating off precipitating solids, or precipitating a humic acid by lowering and adjusting a first mother liquor obtained from the neutralizing a second reaction mixture from pH 0 to pH 2.5.

3. The process according to claim 1, further comprising precipitating or separating calcium sulfate or magnesium sulfate or potassium sulfate from a second mother liquor obtained in the filtering and washing with water at pH 0 to pH 1 or concentrating and neutralizing the second mother liquor obtained in the filtering and washing with water is.

4. The process according to claim 1, wherein a ratio of sugars to amino acids in the first biomass is between 1:1 to 1:3, so that a high yield of karrikins is obtained as a result of the Maillard reaction.

5. The process according to claim 1, wherein in absence of sugar or amino acids in the first biomass, a content of sugar or amino acids is increased by infiltration.

6. The process according to claim 1, wherein after the Maillard reaction is carried out, reaction products are extracted from the first biomass with hot water in the extracting soluble impurities and then thickened.

7. The process according to claim 1, wherein the torrefying the first solid is carried out under an inert protective gas such as carbon dioxide, argon, nitrogen or other known protective gases.

8. The process according to claim 1, wherein the torrefying the first solid is cooled under inert gas or is supplied to an acid boiling under reflux in the heating a torrefied second solid, and the acid boiling temperature is between 110 and 180 degrees Celsius.

9. The process according to claim 1, wherein at least one acid is used in the heating a torrefied second solid.

10. The process according to claim 1, wherein the humic acid obtained by precipitating the humic acid is neutralized by adjusting a pH value of 8 to 9, and after concentration, resulting salts are separated by filtration.

11. The process according to claim 2, wherein the humic acid obtained in the precipitating the humic acid is successively oxidized to fulvic acid by adjusting a pH value of about 14.

12. The process according to claim 10, wherein the humic acid and fulvic acid are used enriched with mineral ions or concentrated after neutralization to be subsequently further processed with a spray dryer into a powdery concentrate.

13. A process for the chemical synthesis of humic substances from a first biomass, the process comprising: carrying out a Maillard reaction by heating the first biomass for 1 to 30 minutes to 150-250° C.; extracting soluble impurities from a second biomass obtained from the carrying out the Maillard reaction by water; torrefying a first solid remaining from the extracting soluble impurities under a protective gas atmosphere at 180-300° C. for 0.2 to 4 hours; oxidizing a torrefied second solid obtained from the torrefying the first solid with an oxidizing agent in a pressure vessel with the addition of oxygen, or oxidized with the addition of an oxidizing agent into the pressure vessel; and filtering and washing with water a third reaction mixture obtained from the oxidizing the torrefied second solid.

14. The process according to claim 13, further comprising boiling and dissolving a fourth solid obtained from filtering and washing with water the third reaction mixture at 120 to 160° C. with an alkaline earth hydroxide solution, neutralizing a fourth reaction mixture obtained from the boiling and dissolving a fourth solid by sulfuric acid or nitric acid and separating off precipitated solids, or precipitating a humic acid by lowering and adjusting a third mother liquor obtained from the neutralizing a fourth reaction mixture from pH 0 to pH 2.5.

15. The process according to claim 13, further comprising precipitating or separating calcium sulfate or magnesium sulfate or potassium sulfate from a fourth mother liquor obtained in the filtering and washing with water the third reaction mixture at pH 0 to pH 1 or the fourth mother liquor obtained in the filtering and washing with water the third reaction mixture is concentrated and neutralized.

16. A process for the chemical synthesis of chitosan from a third biomass, the process comprising: carrying out a Maillard reaction by heating the third biomass for 1 to 30 minutes to 150-200° C.; extracting soluble impurities from a fourth biomass obtained from the carrying out the Maillard reaction by water; and boiling a fifth solid obtained from the extracting soluble impurities at 140 to 180° C. with an alkaline earth hydroxide solution.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0116] The invention will be explained in more detail hereinafter with reference to the drawings.

[0117] FIG. 1 is an exemplary FTIR analysis using a sigma-humic acid standard.

DETAILED DESCRIPTION OF EMBODIMENTS

[0118] FIG. 1 shows an exemplary FTIR analysis by using a Sigma Humic Acid Standard 53680-10 g Charge No. NrBCBN1711V; CAS NR1415-93-6 compared to an FTIR analysis of the product of a process according to the invention. The FTIR analyses of the different humic acid samples yield almost congruent transmission curves in almost all wavelengths. As a consequence, a process according to the invention results in valuable combinations of humic acids, which largely correspond to the combinations of humic acids from the soil.

ANNEX I: TABLES

[0119]

TABLE-US-00001 TABLE 1 typical properties of humic substances Properties of humic substances Keyword Property Molecular high-molecular structures; some 100—several weight 100,000 g/mol Element Average value Fluctuation IV contents Element [%] [%] C 54 ±10  O 33 ±8   H 4.5 ±3   N 2.7 ±2.6 S ≤2 — P <1 — Basic building Aromatic and aliphatic structural elements, blocks phenolic hydroxy groups and ether bridges Acid Acid character due to —COOH and phenolic groups, ability to exchange cations Polyelectrolytes HS are polyelectrolytes Complexing due to various donor functions complexing agent agents for metal ions; traces of reversibly or in-eversibly bound metal ions are always present in HS Organic pollutants are bound by HS via hydrogen bridges or C—C— links. Agglomerates Formation of reversible agglomerates in solution, depending on the factors in the environment in dynamic equilibrium Surface Surface activity by hydrophilic and hydrophobic activity components Spectroscopic similar spectroscopic properties; UV spectra drop properties monotonously; IR spectra have wide, little characteristic bands; .sup.1H and .sup.13C NMR spectra have wide signals

TABLE-US-00002 TABLE 2 functional groups of humic substances: Origin and effect Important functional groups of HS and their effects Functional group Main origin Effect —OH Hydroxyl Phenols, lignin Acid (phenol) —OH Hydroxyl Alcohols, coniferyl alcohol Complex (alcohol) (metabolic products) formation, H-bridge formation —COOH Carboxyl Carboxylic acid, amino acids, Acid (mostly oxidation products of carbohydrates and similar compounds) ═C═O Carbonyl Oxidation of phenols Complex (quinone) formation, H-bridge formation R—O—R Ether Carbohydrates, lignins —OCH.sub.3 Methoxyl Lignins —NH.sub.2 Amino Amino acid, amino sugar, Complex proteins formation, base, H-bridge formation Heterocyclic N Heterocycles, melanins Complex formation, base, H-bridge formation

TABLE-US-00003 TABLE 3 operational definitions of humic substance fractions Operational definitions of humic substance fractions Fraction Definition Humic Organic substances precipitated from an alkaline acids humic substance extract at a pH value of ≤2 by the addition of acid. Fulvic Organic substance, which is not precipitated from an acids alkaline hurnic substance extract at a pH value of ≤2 after the addition of acid. Humins Insoluble part of humic substances in sodium hydroxide solution.

TABLE-US-00004 TABLE 4 summary of the general properties of humic substance fractions in the form of general tendencies Humic substance fractions and their properties Humic substance fraction Characteristic Fulvic acids Humic acids Humins Color yellow/yellow brown/deep black brown brown C-content 43-52 50-62 >60 [%] N-content 0.5-2   3-8 different [%] Molecular  800-9000 Increasing different weight up to 10.sup.5 Molecular More More different building polysaccharides aromatics (partly little blocks decomposed animal and plant residues) Internal Increasing from fulvic acids via humic linking acids to humins Solubility Decreasing from fulvic acids via humic acids to humins Functional Decreasing from fulvic acids via humic group acids to humins O-content Decreasing from fulvic acids via humic acids to humins Acidity Decreasing from fulvic acids via humic acids to humins