Once the facility is already built and we assume everything is mechanically going well, your goal is to keep the microbes happy. Unhappy microbes = reduced biogas production.

Common operational factors that stress out the microbes:

-Overfeeding

-Temperature swings (more common in the winter when feedstocks are fed frozen into…

Read more

The concentration of H2S in the biogas will depend on the 1) feedstocks 2) pH 3) temperature. Generally, higher protein feedstocks produce more H2S. Decreasing pH and temperature pushes more H2S in the gas phase (instead of staying in the digestate). There’s a wide range of pH and temperatures that you can operate at to minimize the H2S in…

Read more

hmmm, hearing a lot of silence here. Guess we know what points to press the technology folks on when bidding projects!

Dave,

The microbial community must be functionally adapted, not just active. I agree that using the same inoculum from a BMP test to start a plant is not practical and this is why:

1- The microbial community may not be adapted to the plant feedstock or process conditions.

2- Industrial start-up usually requires large volumes of digestate from…

Read more

Landfill biogas is much more variable and contains more nitrogen, oxygen, and trace contaminants than biogas from controlled anaerobic digestion, making it harder to upgrade and more sensitive to operational changes, and validating its composition is essential because methane levels can fluctuate significantly as well as flow rate over the…

Read more

What operational factors most commonly limit methane yield at existing RNG facilities once the digester is already built and running?

Question for all you RNG upgrading folks here, and facility operators who care to share:

What is your guaranteed % methane recovery at nameplate production levels? BUT, more importantly, what is your % recovery at lower flows, say at 50%, 75%, 90%, and 95% throughput?

Our experience with RNG upgrading plants in Canada and the USA, when operating…

Read more

Excellent point about the inoculum affecting the gas quality and quantity–that is one reason why we see full-scale food waste and SSO AD plants with own-growth biomass rarely match the results of a BMP study that uses a different inoculum, sometimes from a local domestic sewage digester and under ideal laboratory conditions.

I’ll go further…

Read more

Landfill gas is dramatically different from raw biogas produced inside engineered anaerobic digesters. In our experience across Canada and the United States we’ve seen raw landfill gas contain high percentages of air (+30% air), very high hydrogen sulfide from degrading construction waste, and VOCs from historical landfilling of paint and…

Read more

Another strategy would be to treat hydrogen sulfide production inside the digester, significantly reducing the load that the carbon is exposed to and responsible for, making it last significantly longer.

At PlanET we use a combination of micro-aeration (O2 injection into the digester), eco-net for sulfur accumulation and precipitation, and…

Read more

I would say since 2024, the discussions on CO2 capture and use are ongoing. Do you see this market develop further? What are the main trends and any concrete CO2 use examples you can share?

I can see that a lot of our members innovate within making incremental changes to their existing technology to make it more efficient. What do you think about innovations in biogas upgrading in general? Is the technology mature?

Yes Maximum ROI is not achieved by the cheapest plant.

It is achieved by the lowest cost per cubic meter of methane produced.

Hi Malek,

I think the guaranteed offtake is the first key for pushing the market. Pricing of RNG equivalent or more compared to NG since this is green product should help a lot.

YES<br data-start=”416″ data-end=”419″> Different digesters host different populations of hydrolytic bacteria, acidogens, acetogens, and methanogens. The dominance of specific methanogens (acetoclastic vs. hydrogenotrophic) influences the methane-to-CO₂ ratio in the biogas. The type of organic waste (food waste, manure, crop residues, industrial…

Read more

Long term, lower OpEx will always eventually pay for higher CapEx, but you are correct, in small flow applications with relatively clean gas, it may take a while. I’d say any landfill, and most WWTPs would be a fit for a regenerative system with payback measured in months to 1 – 2 years. Ag projects generally have little or no siloxanes, so…

Read more

Thanks @RNGinsight , What is the minimum flow and concentration where these regenerative VOC and siloxane removal systems are cost effective? How do they respond to high turpine concentrations?

As @RNGinsight says regenerative systems are the lowest operating cost long term when you are treating very contaminated gas. In some cases the biogas flows on smaller agricultural projects will never justify the upfront cost of a regenerative system. In lower flow cases carbon costs can be managed by using carbon for siloxane, turpine, and…

Read more

Agree.

The BMP test provides the ground truth on the actual methane potential and biodegradability of the feedstock. Using our analysis tool, the BMP curve is fitted to appropriate kinetic models to determine the key degradation parameters, particularly the substrate conversion and methane production rates. These calibrated kinetic parameters…

Read more

I believe we can call the current situation as adjustment period and I personally do not think we will see the numbers we had in 2023-2024 in terms of overall growth.

In 2025, the projects that went online all started in 2023-2024, but we are not tracking a lot of announcements of new projects in development in 2026.

A quick article to…

Read more

Hi Malek,

Whether we like it or not, our industry is very dependent of support programs and offtake market, so, I believe, until that is in place, it is very difficult to say what else can be done. What are you thinking?

The answer is simple – replace (or supplement) your activated carbon vessels with a regenerative system. A technology that is massively underutilized in the RNG space is the regenerative siloxane and VOC reduction system. The media is regenerated automatically, often lasting for years without replacement. For any waste water or landfill…

Read more

The report published by ICF in November 2025 titled “Near-Term Renewable Natural Gas Demand
Assessment” predicts massive growth in the RNG industry leading up to 2030. With less than 4 years to that deadline, it stands to reason that some of that growth will occur this year. While every forecast has some uncertainty, what I like about this…

Read more

Oxygen can cause corrosion in RNG pipelines, so it is tightly restricted. Most RNG projects must meet a certain O2 spec, usually much lower than what is in raw biogas. Regarding oxygen reduction / removal methods, I can’t really speak on this topic but it would be needed and I believe there are technologies out there for deoxygenation.

How is US growth expected in 2026?

What external levers you think are necessary to push the market forward substantially

N2 removal from landfill gas: Technology challenges and opportunities

Activated carbon prices have increased a lot lately. What other options could be used for biogas/biomethane contaminant removal?

What is the critical concentration of h2s and other contamination to produce RNG