Biogas & digestion

Enviro-Chem METHA

Name: Enviro-Chem METHA
Brand: Enviro-Chem

Reducing H₂S at the source: less iron, less activated carbon

Enviro-Chem METHA is a low-dose liquid solution applied to the feedstock before it enters the digester. It acts on the sulphur carried by the proteins in the ration and limits its release: this sulphur stays bound to the material instead of becoming H₂S in the biogas.

Where iron and activated carbon treat H₂S once it has formed, METHA acts upstream. It is used on its own or alongside iron, whose consumption it allows to be greatly reduced.

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H₂S reduction

Action on the feedstock

Less iron and activated carbon

Simple liquid dosing

Enviro-Chem METHA container for H₂S control in biogas and anaerobic digestion

Action at the sourceLow doseBiogas

Mode of action

1. Two origins of H₂S

In a digester, H₂S comes from two distinct sources. Organic sulphur, carried by the proteins in the feedstock, is released enzymatically during hydrolysis. Mineral sulphur, present as sulphates, is reduced to H₂S by specialised bacteria.

2. Protein sulphur stays in the material

Enviro-Chem METHA acts on the first pathway. Its active components attach to the sulphur-containing groups of the proteins and prevent enzymes from reaching them: the sulphur stays bound to the material and does not become H₂S.

3. A contact product, applied to the feedstock

METHA must meet the material before it is diluted in the digester. It is therefore injected onto the feedstock: premix, premixing pit, hopper or buffer tank. The choice of injection point is decisive for the result.

4. Complementary to iron

Mineral sulphur is a matter for iron. By treating the protein share of the sulphur, METHA reduces the amount of H₂S that iron and then activated carbon have to absorb. The two approaches complement each other.

Scope of application

Agricultural, community-scale and industrial anaerobic digestion plants
Protein-rich rations: whey and dairy effluents, poultry droppings and manure, slaughterhouse by-products, biowaste slurries
Grass silage, cereal by-products, pulps, fruit and vegetables, slurries and manures
Sites treated with iron hydroxide or ferric chloride that wish to reduce consumption
Sites whose activated carbon saturates too quickly

We analyse your ration before any trial and tell you what share of the sulphur the product will act on.

Why a progressive action?

METHA treats the material entering the digester, not the H₂S already present. Its effect therefore builds up as the treated feedstock replaces the contents of the digester. The first results appear after a few weeks; the full effect takes in the order of two to two and a half times the hydraulic retention time.

Recommended start-up strategy

The existing iron treatment is maintained at start-up. METHA is applied at a reinforced dose during the first weeks, then brought back to the maintenance dose. Iron is only reduced gradually, based on H₂S measurements, and never according to a pre-set schedule.

Operator benefits

H₂S reduction at the source

Large reduction in iron consumption

Activated carbon less stressed, less frequent changes

Tank and dosing pump: no more bags to handle every day

No massive addition of mineral matter to the digestate

Ration qualification and technical follow-up

Useful data for an initial assessment

To evaluate dosing and injection point, SARGO can analyse the following information:

tonnage of feedstock per day
ration composition
retention time
average and maximum H₂S level
current treatment: quantity of iron, frequency of activated carbon changes
available injection point (premix, premixing pit, hopper, buffer tank…)

NewMethanAI

Techno-economic optimisation for anaerobic digestion plants

MethanAI is an application developed to help anaerobic digestion operators optimise feedstock loading, monitor biological performance and visualise key production indicators. It helps analyse field data to improve daily operation and plant profitability.

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On-site implementation

Enviro-Chem METHA integrates simply into existing installations: a tank, a dosing pump and an injection point where the product meets the feedstock before the digester. The maintenance dose is in the order of 1 litre per 10 tonnes of feedstock, adjusted to the ration.

Dilution and dosing system

Dilution and dosing installation for regular product injection.

Injection from IBC

Simple solution with IBC and dosing pump for trials or permanent installations.

Adapted injection point

Injection as close as possible to the mixing zone, for intimate contact with the feedstock before it enters the digester.

Request a METHA technical assessment

Send us your ration and your current treatment. We will tell you the dose, injection point and start-up strategy suited to your site.

Request a METHA technical assessment View product page