METHOFLOW is a specially formulated anti-foaming and foam-preventative additive for anaerobic digesters. Foaming is a common and dangerous issue in AD plants – excessive foam can reduce gas production, cause blockages, affect sensors, and even lead to digester overflow or carryover into gas lines. METHOFLOW is designed to eliminate existing foam and prevent new foam formation without using silicone (which can have downsides in biogas systems).
It is a 100% biodegradable blend of fatty alcohols and ethoxylated compounds that reduce surface tension in the fermenter liquid. By doing so, it allows trapped gas bubbles to escape the liquid easily, collapsing foam and stopping froth from building up. METHOFLOW is recommended for any biogas plant experiencing foaming, especially those processing substrates prone to foaming (like acidic waste, fats, or high nitrogen feeds).
It helps maintain optimal plant operation, safety, and efficiency by keeping the digestion smooth and foam-free.
Rapid Foam Collapse: METHOFLOW quickly breaks down foam in the digester by reducing surface tension. Gas bubbles coalescence and burst, causing the foam to dissipate. This rapid action can save a plant from needing to shut down or vent gas due to foam.
Prevents Foam Recurrence: Regular use of METHOFLOW prevents new foam from forming. It is effective against all types of foam that occur in AD, whether caused by organic overload, high fat content, or high ammonia situations.
Silicone-Free and Biodegradable: Unlike silicone-based antifoams, METHOFLOW is 100% biodegradable and contains no silicones. This is important because silicones can coat gas engine parts or accumulate in digestate, whereas METHOFLOW leaves no persistent residues and is broken down by the system over time, making it safer for the microbes and downstream processes.
Versatile for Various Foam Causes: It is effective in digesters that are:
Rich in acidic wastes (which often foam when neutralising),
Rich in fats/oils/greases (which can cause sticky foam),
High in ammonia (which can cause proteinaceous foam). Essentially, whatever the cause, METHOFLOW addresses the symptom by physically controlling the foam, giving you time to also fix the underlying cause if needed.
Maintains Gas Production and Safety: By controlling foam, METHOFLOW ensures the biogas can freely escape the liquid. This maintains consistent gas production (foam can trap gas and lower output readings) and prevents dangerous pressure build-ups or foam spillovers that could necessitate emergency flaring or risk contamination of gas lines. It thus protects both the efficiency and the safety of the plant.
METHOFLOW’s mode of action is based on surface chemistry:
Surface Tension Reduction: The fatty alcohols and ethoxylated derivatives in METHOFLOW are surfactants that concentrate at the liquid-gas interface. By doing so, they lower the surface tension of the digestate liquid. Lower surface tension makes it harder for stable bubbles to form because the liquid film of a bubble becomes weak.
Bubble Coalescence: When foam is present (foam is essentially a mass of bubbles with a liquid network between them), adding METHOFLOW causes the bubble walls to thin and break. Small bubbles coalesce into larger ones and then burst, collapsing the foam structure quickly.
Foam Prevention: With a small residual of antifoam in the liquid, future gas bubbles that form are less likely to create foam because they escape easily. The gas rises unimpeded to the surface and releases, rather than being trapped in a stable foam matrix. Essentially, METHOFLOW creates conditions where gas-liquid separation is smooth and bubble dispersion is rapid.
No Silicone Film: Traditional silicone antifoams create a hydrophobic film that pops bubbles but can accumulate. METHOFLOW avoids silicone; its components are digestible and soluble enough that they get consumed or flushed with the process. That means it doesn’t interfere with biogas combustion or leave residues in the fertiliser.
An important note is that METHOFLOW must be applied correctly to work: it should be added from the top, directly onto the foam or where foam forms. This ensures it contacts the foam and spreads across it, doing its job at the gas-liquid interface. If you were to add it deep in the liquid, it might not be as effective until it comes to the surface.
Because it’s silicone-free, METHOFLOW is also often compatible with downstream processes like biogas upgrading (membranes, etc.) because it won’t foul them.
Using METHOFLOW effectively involves dosing it in response to foam levels:
Dosage Range: The recommended dose is 2 to 20 grams of METHOFLOW per cubic meter of digestate volume (or per m³ of fermentation volume). The exact amount depends on how much foam and how severe it is. For example:
If you have a mild foaming tendency, you might start with ~2 g/m³. So for a 1000 m³ digester, that’s 2 kg.
For severe foam, up to 20 g/m³ might be needed (which would be 20 kg for 1000 m³).
Initial Dosing: When foam is first noticed or as a preventative when starting a known foam-prone feed, start with a mid-range dose. If foam is already high (several feet of foam), lean towards the higher end to knock it down fast.
Maintenance Dosing: If foam is recurrent, you might do smaller daily or weekly doses to keep it at bay. For instance, add a few liters every few days as needed to maintain a foam-free surface.
Application Method: Introduce METHOFLOW from above, directly onto the foam. Many plants will pour it in through a top hatch or a special foam port. Some might rig a sprayer or use a lance to distribute it across the foam layer.
If direct pouring is difficult, dilute it with water to ~10% solution (i.e., 1 part METHOFLOW to 9 parts water) to help spread it over a wider area. Then pour or spray this solution over the foam. The water helps carry it and ensures it contacts more of the foam surface.
Timing: Act quickly when foam is observed. Also consider adding prophylactically before feeding events known to cause foam (like adding a new type of feed or a large batch of something with high FOG or protein).
Ensure mixing is gentle during and after application. You don’t want to vigorously stir a foam as it can sometimes exacerbate it; let the antifoam do its trick to reduce it first.
Because foam can surge unexpectedly, always have METHOFLOW on hand if your feedstock mix is prone to it. Plants that feed things like distillery waste, food processing waste, or many energy crops often keep an antifoam ready.
METHOFLOW is a liquid product. It’s available in:
25 L drums and IBC for larger quantities. 25 L is convenient for moderate use, whereas an IBC (~1000 L) is for large plants or central storage if foam control is frequently needed.
The liquid itself is oily (fatty alcohol-based) but also water-emulsifiable due to the ethoxylation. It may appear as a clear to slightly hazy liquid.
Storage: Store METHOFLOW in its closed container in a cool, dry place. It’s stable, but extreme cold might thicken it (as fatty components can solidify) and extreme heat isn’t ideal. Typically it’s fine in typical warehouse conditions. Always keep the bung or lid tightly closed to prevent contamination or evaporation of any volatile components.
Handling:
When handling the concentrate, wear chemical-resistant gloves and eye protection. While biodegradable, it is still a chemical mixture that could irritate skin or eyes on contact.
If you get it on your hands, it might feel oily; wash with soap and water.
Spills: It can make floors slippery due to its surfactant nature. Use absorbents (like spill pads or kitty litter) to soak it up and then wash the area with water and detergent.
Pumping: If you use an IBC, you can pump from it. Use a pump compatible with oils (usually a diaphragm or peristaltic pump is fine). The 25 L can be manhandled and poured.
Dilution if it's your preferred method (10% solution) should be done in a plastic container or bucket. Stir gently to mix; it should form a usable solution.
Compatibility: Since no silicone is present, if the product gets into the gas path or digestate, it won’t cause issues downstream. However, you still want to keep it mostly in the digester liquid phase as designed.
Environmental: If released outside, METHOFLOW will biodegrade, but it can cause some temporary foaming in water bodies or drains because of its surfactant nature. So avoid letting large amounts go into wastewater untreated.
Foam incidents can be extremely costly, so METHOFLOW’s ROI is primarily in problem mitigation and avoidance:
Preventing Downtime: A severe foam event can force you to stop feeding, vent gas, or even shut down the CHP to avoid damage. Every hour of downtime is lost revenue. METHOFLOW’s ability to quickly defuse foam keeps the plant online and producing. Avoiding even one day of downtime in a medium-size plant can pay for a lot of antifoam.
Protecting Equipment: Foam can carry over into gas lines and even into engines or gas compressors. This moisture and scum can foul equipment, leading to expensive cleaning or repairs. By preventing foam carryover, you save on maintenance costs and potential equipment damage. Engines not ingesting foam run more efficiently and last longer.
Safety and Cleanup: If foam causes a digester overflow or a PRV (pressure relief valve) to pop, you can end up with a mess of digestate foam on the roof or surrounding area, which is a biohazard and needs labour to clean. METHOFLOW stops such accidents, saving on cleanup labour and avoiding safety incidents.
Optimising Feeding: Some plants underfeed or slow down feeding to avoid foam (especially when using risky substrates). This means they’re not operating at full capacity, which is a lost opportunity. With confidence from METHOFLOW, you can feed more optimally (or at least maintain normal feeding rates) without fear of foam, allowing you to maximise biogas production from foamy substrates rather than underfeeding to stay safe.
In essence, METHOFLOW pays for itself by preventing the significant losses and costs associated with foaming events. Consider that a single severe foaming incident could force a plant offline or require emergency flaring for days, resulting in thousands of pounds of lost energy revenue and cleanup expenses – whereas routine use of METHOFLOW, at relatively low cost, avoids those incidents entirely.
Moreover, by not using silicone-based antifoams, you avoid the hidden costs of silicone accumulation (like engine fouling or catalyst damage), making METHOFLOW a reliable and cost-effective insurance for continuous, trouble-free biogas production.