I am performing a biogas production experiment at home for developing home based biogas system. I would like any practical help in measuring methane conc. of the gas produced without the aid of any instrument. Do you have any old and crude method that will also do. Gas displacement is one the way I can guess. Photograph of this or any method is also required. Thanks.
Hi Mustafa,
Don't you want to use any electronic device or do you want to avoid expensive analytics? If it is just about cost, i would consider you to inform yourself about 4duino (arduino) gas sensors and if they are applicable for you. They are not that expensive, but you have to be into electronic engineering and programming (you dont have to be an expert) to use them as 4duino is an open source tool to build small electronic devices by yourself. (see the link below)
best regards
Tilman
http://www.allnet.de/en/allnet-brand/produkte/diy-doityourself/4duino-arduino/arduino00/p/arduino-sensor-gas-methan-cng/
For initial phase, i want to avoid any expensive electronic. Just need a nearby conc on methane for comparison. I am a microbiologist by nature so cant give time in building an electronic device. Thank you
I think you can use water displacement method with water contain caustic soda to react with CO2 , so the produced gas mainly is methane
By passing your produced biogas through calcium hydroxide the CO2, H2S and NH3 can be effectively removed, such that the ratio between the new volume:original biogas volume gives you the fractional % of methane.
Does any one of you have diagram of it? How should i use the gas displacement method
Gas displacement method should help still looking for a Picture to descibe
You can try downward displacement of water technique using alkaline solution to scrub CO2 and then measure methane by using methane gas sensors
Dear Mustafa, I have already placed once in the forum the diagram. Now I have modified it.
I don´t think it´s safe to do this at home, but:
What if you would use a 5 M NaOH solution instead of water in Dr. Galushko´s method? This way the initial volume should display the produced biogas after inlet of the gas. When you then close the valve towards the reactor and keep the gas inside the NaOH-solution the CO2 should solubilize in the liquid phase and the gas volume should shrink. The final volume should then display the CH4 portion of the biogas.
Of course you would need a pH indicator like bromothymol blue to know whether the NaOH can still bind CO2.
Just a quick thought. Tell me what you think!
I don´t know how quickly the CO2 in the biogas resolves in the NaOH (assumed this method could work anyway). So one would need to test, if there´s a volume change over time, that´s not accounted to anything else. One would e.g. test this with 100 % CO2 before.
Dear Philipp, thank you for adding a very good point for this!
Additional thing is that nitrate-nitrite should not be present in the reactor, otherwise N2 might be formed by denitrification.
Thank you all
Thank you Alexander, i will try it
Thank you Philips, my friends working in H2 production, used NaOH to solubilze the CO2 and thus measuring H2 gas volume but they used specialized apparatus for it. I will used same principle to dissolve CO2 but in a simpler way using pipe and measuring cylinder. If anyone had used such method, please send me a diagram/ photo.
After trial i will tell you all my observations. Again thank you
Check out my buchner flask design for water displacement method. Though i used brine u may modify this method by using any srubber solution for Co2
Thanks Yusuf, Can you give a closer view of any of flask? How does it works?
Dear Yusuf, in your last pic gas input from Bioreactor into Second Bucker Flask is shown in a not correct way: too close to the bottom (under certain conditions backward flow of brine solution into reactor Flask is possible). ON your 1st Pic gas input is correctly shown from the the top the Secind Bucker Flask.
Thanks, i could not quickly produce a sketch of the original first pic so i attached something close to it. i believe Mustafa would understand. My first pic better answer his question.
I think, using KOH solution is better option than NaOH solution. KOH is more reactive with CO2 as the main impurities of biogas, so the measurement will be better and accurate. It refer to Orsat gas analyser Methods for CO2 content measurement on gasses which using KOH solution as absorbent for CO2. About equipment, I think the design from previous answer is good option.
Hi. Just wonder if this method has a setback in terms of inconsistency of displacement volume? And what is the concentration of the brine for this method?
Water displacement and then alkaline solution ( lime water) .Percentage of methane can be obtained by obtaining percentage of CO2 using Brigon CO2 Analyser and substract from 100%.
Is there any difference between water displacement method and NaOH displacement method?
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