Yes there is GC technique for measure Methane and other green hose gasses. But it may be expensive

It depends on the scale. For a 1-10 L experiment, the simplest way is to use water displacement to measure the volume of gas produced (communicating vessels principle): the gas line is connected to the top of a reservoir (let’s say 2 L) containing water. At the bottom of this reservoir, a plastic tubing must be connected to a L-shaped glass tube through which the water will flow as the gas is filling the reservoir. Then collect the water and measure the volume. Important note: the L-shaped glass tube must be placed in line with the water level inside the reservoir so that it will only flow out as the biogas will be produced. Check out the right side of this picture to have an idea: http://sweet.ua.pt/flavio.silva/instalacao.jpg

Industrial applications use IR-spectroscopy, if you look around you will find many devices that will also log the gas composition over time and do automated measurements. Producers that com to mind are Dräger, Severin, Awite, Union ... there are more. Tere's also portable (cheaper) measurement devices, but aotmation may be an issue here.

If you have your students doing batch tests, I think in the first few days you will have significant H2, CO2 will always be relevant.

P.s. Maybe you can have your students measure total Sulphur input and H2S output . H2S is very relevant in industrial biogas applications, but IMHO underresearched.

Dr Kani,

It rather depends on the level of accuracy desired and the nature of the environment that the methane is being measured in.

If you are in a laboratory, and seek high quality answers, then I would recommend a mass-spectrometer. I used a second-hand quadrupole (pumped with a turbo and a rotary, to evacuate a small volume connected to the source) to detect low levels of methane (ppm levels) with good results.

If you are in a sewer, looking for combustible gasses, I'd probably use a solid-state pyrolytic sensor.

etc.

All good answers for the initial charicterization of an unknown gas. However, should it be identified that the majority if the gas is methane, then an organic vapor analyzer (OVA) or other inexpensive Flame Ionizing Detector (FID) is sufficient for monitoring. FID technology is very inexpensive and can be used for constant monitoring.

A simple search for FIDs will provide a long list. No need for anything fancy. Methane is flamable at relatively low levels. Decomposing matter shows a strong methane signal as do any amounts that evolve when well waters reach surface.

Besides GC-FID, Cavity Ring-Down Spectroscopy (CRDS) can also quantify methane gas automatically and continously. It enables methane to be monitored in seconds or less at the parts per billion level.

I have the similar problem... i want to determine methane gas dissolved in water samples.... but plx guide... if I use GC technique, then I need head space equilibrium.... i don't have this instrument in my college.... neither i have FTIR for near infra red range because methane is detected at 125 nm wavelength (near IR) as per literature.... can anybody suggest me what should i do..?

Can any one tell me how much time it may take for complete dissolution of CO2 into a strong basic solution during methane measurement in biogas (In water displacement method)?

what are the different methods in measuring methane and Nitrogen oxide which one is best.......

I'm doing research project base on Biogas generation from abattoir wastes. But, my problem is how to analyse the gases. Is there any method used to analyse gases that formed   without using GC-MS machine analysis?  Pls. I need your help and contribution. Thanks.

Hi Nazir. I'm just about to start a masters with the same project. How did you get on and do you have any advise for me??

Hi Nazir and Susie,

You can use the liquid displacement devise for volume of biogas measurement and also for volume of bio-methane measurement. But for the first one you use the acidified liquid and for the second one you use concentrate KOH solution.

Good Luck

Dr. K. Derbal

we use acidic solution, because our biogas is composed of (CH4 and CO2) and in low pH (pH=2) the solubility of the two component is verry low.

Concerning the solution you can use HCl as exemple.

Hi!

In my lab, we use CSTR (8L, Dolly Belach) to half-auto measure the total biogas production. For the batch test, we now use the "BPC" system (http://www.bioprocesscontrol.com/applications/biogas/). then we use GC to measure the CH4 content.

there are many etheorical methods and also you can use GC methods

please have a look on this paper that can describe all methods

DOI: 10.18331/BRJ2017.4.2.3

regards

I want ask when we calculate the dialy displaced liquid .do we measure the headspace wolume as 1st prodoction or not. as the liquid will not displaced only when the headspace is saturated.

If you want something incredibly simple, you can always try Drager tubes. Not the most accurate thing, but it works for basic lab work.

For this answer, I suggest reading this article:

Article Optimization of methane production parameters during anaerob...

Optimization of methane production parameters during anaerobic co-digestion of food waste and garden waste.

DOI: 10.1016/j.jclepro.2020.123130.

The below links shall gie you an idea about measuring methane emissions

Article A Comparison of Methodologies for Measuring Methane Emission...

https://www.nap.edu/read/24987/chapter/5

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4494326/

Thanks and regards

Srinivas Kasulla

Hi guys. This is a great topic to discuss, in that way, to answer this question, I suggest reading the following articles:

Article Biochemical methane potential of food and garden waste co-di...

and...

Article Optimization of methane production parameters during anaerob...

Let me know if they were helpful to you folks doing a recommendation and citation of them.

Best Regards.