Dark fermentative hydrogen production method

Abstract

A method for hydrogen production by dark fermentation includes the following steps: a pretreatment process for an anaerobic sludge, wherein the anaerobic sludge is thermally dried and then inoculated into a culture environment; isolation and purification of a hydrogen-producing microorganism; and dark fermentation of the hydrogen-producing microorganism in the culture environment. The present invention utilizes carbon sources, nitrogen sources, phosphorus sources, biochar, and magnetic nanoparticles added to the culture environment, and applies an external magnetic field to the culture environment to significantly improve the hydrogen production efficiency of the hydrogen-producing microorganism and the stability of the hydrogen production system.

Claims

1. A method for hydrogen production by dark fermentation, comprising the steps of: placing a hydrogen-producing microorganism in a culture environment, wherein the hydrogen-producing microorganism comprises a strain of *Clostridium tertium*; introducing an inert gas into the culture environment to form an anaerobic atmosphere, the culture environment comprising a carbon source, a nitrogen source, a phosphorus source, biochar, and a magnetic nanoparticle; and applying an external magnetic field to the culture environment, wherein: One of the culture environments has an initial pH between 4.5 and 7.0; the culture temperature of one of the culture environments is between 37°C and 55°C; the biochar system is made from elephant dung or cassava peel as raw materials, and the concentration of the biochar in the culture environment is 10 g / L; the concentration of the magnetic nanoparticles is between 80 mg / L and 120 mg / L; and the strength of the applied magnetic field is between 150 mT and 200 mT, which acts on the magnetic nanoparticles, causing the magnetic nanoparticles to act as electron mediators to promote electron transfer between or within Clostridium tertium strains.

2. The dark fermentation hydrogen production method as described in claim 1, wherein the carbon source comprises one or a combination thereof selected from glucose, galactose, fructose, sucrose, xylose, sorbitol and cellulose.

3. The dark fermentation hydrogen production method as described in claim 1, wherein the nitrogen source comprises one or a combination thereof selected from peptone, yeast extract, ammonium chloride (NH4Cl), ammonium nitrate (NH4NO3), ammonium bicarbonate (NH4HCO3), sodium nitrate (NaNO3), and ammonium sulfate ((NH4)2SO4).

4. The dark fermentation hydrogen production method as described in claim 1, wherein the phosphorus source comprises one or a combination thereof selected from sodium dihydrogen phosphate (NaH2PO4), potassium dihydrogen phosphate (KH2PO4), disodium hydrogen phosphate (Na2HPO4), dipotassium hydrogen phosphate (K2HPO4).

5. The dark fermentation hydrogen production method as described in claim 1, wherein the magnetic nanoparticles comprise one or a combination thereof selected from iron(III) oxide (Fe3O4), iron(II) oxide (α-Fe₂O₃), iron(III) oxide (γ-Fe₂O₃), cobalt(II) oxide (CoFe₂O₄), nickel(II) oxide (NiFe₂O₄), and zinc(II) oxide (ZnFe₂O₄).

6. The dark fermentation hydrogen production method as described in claim 5, wherein the iron(III) oxide (Fe3O4) is synthesized by coprecipitation.

7. The dark fermentation hydrogen production method as described in claim 1, wherein the hydrogen-producing microorganism is obtained through a pretreatment process and purification extraction of an anaerobic sludge, wherein, The pretreatment process involves thermally drying the anaerobic sludge under preheating conditions of a preheating temperature and a preheating time.

8. The dark fermentation hydrogen production method as described in claim 7, wherein the preheating temperature is between 100°C and 120°C; and the preheating time is between 2 hours and 4 hours.

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