A product that reduces the load of the post-stage desulfurization process by properly injecting iron hydroxide-based anaerobic digester stabilizer (DSULFER) into the anaerobic digester.



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Basic biogas plant process
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dsulfer table
Reaction process Reaction formula Microorganism
Hydrolysis step Organicsubstances → Sugars, Glycerin, Fattyacids, Aminoacids Microbial in vitro enzyme
Acid production stage Sugar → Acetic acid, Propionic acid, Butyric acid Organic acid-producing bacteria
Methane production stage CH3COOH + 2H2O → 2CO2 + 8H (Oxidation reaction) 4H2 +CO2 → CH4 + 2H2O (Reduction reaction) Methane microorganism
Hydrogen sulfide production stage SO42- + organic matter → S2- + CO2 S2- + 2H+ → H2S Sulphur-reducing bacteria(SRB)

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Iron hydroxide-iron chloride hydrogen sulfide reaction formula

FeCl2 + HS-+ H+ → FeS + 2HCl

2FeCl3 + 3HS- + 3H+ → 2FeS + 6HCl + S

2Fe(OH)3 + 3HS- + 3H+ → 2FeS + S + 6H2O

2FeOOH + 3HS- + 3H+ → 2FeS + S + 4H2O

BMP(Biochemical methane potential) Test
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Conditions for testing

  • Operation type

    Batch (Anaerobic digester at City D Sewage Process Plant)

  • Test capacity per batch


  • Concentration of injection of digestive stabilizer

    0g, 0.1g, 0.2g, 0.5g, 1.0g

  • Microbial concentration

    20.4± 0.1 g VS/L

  • Concentration of organic matter (COD)

    5.0g TCOD/L

  • Sulfur concentration

    20.0 mg/L

  • Digester temperature

    37 ± 1℃

  • pH

    7.5 (Experiments with alkalinity of 5g/L as CaCO3)

  • Medium

    BA medium

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Methane production by concentration of digestive stabilizers
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Hydrogen sulfide production by the concentration of digestive stabilizers
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Digestive stabilizer hydrogen sulfide adsorption test
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dsulfer table
Dosing amount Adsorption capacity (mg/g)
0.1 g/L Fe(OH)3 63.4
0.2 g/L Fe(OH)3 60.7
0.5 g/L Fe(OH)3 28.4
1.0 g/L Fe(OH)3 17.4
Comparative testing of hydrogen sulfide adsorption capacity of digestive stabilizers
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As a result of the experiment of evaluating the adsorption capacity of hydrogen sulfide through BMP tests, it was confirmed that Fe(OH)3 had the highest adsorption amount of hydrogen sulfide per unit mass.

Anaerobic digestive tank demonstration operation
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Fire extinguisher capacity : 2,000L

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Empirical test results
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result test image

Methane production rate : 1.47 ± 1.2 L/L/d

Hydrogen sulfide concentration : < 90 ppm(Condition : Pressure 2bar, oxide 4g/L)