It depend on what resource you have to purify, how much methane content you want to increase, and what purposes you will utilize the biogas for. The common technologies which using biogas purification/CO2 Capture in industry are Amine absorbtion coloumn and pressure swing adsorbtion. However for household scale, you can use water absorbtion on bubble or coloumn as simple way to purify. The more advance technology you can use adsorption material such as carbon active, silica gell, zeolite, etc.

You can use iron oxide (Fe2O3) pellets to remove H2S and silica beads (SiO2) to remove water vapors. For CO2 you can use soda (NaOH) to reduce your carbon dioxide (CO2). All the above are related to the scale of your experimental/engineering endeavour. Calculate how much you need based on the quantity of the gases you want to remove and see how often you would have to re activate.

Hope this helps a bit

Evangelos

In my lab-scale experiment,The acidified brine solution was used which makes the biogas insoluble in the water.

also,alkaline solution( 2% NaOH solution) can be used in lab scale for decreasing CO2  content in biogas

Small tip: A relatively high water content (low solids AD) in the digester can help increase CH4 content. The reason behind is that since there is a lot of water in the system which is also operating at an alkaline pH, the CO2 and H2S formed get absorbed within the substrates solution, resulting in a higher content CH4 in the biogas.

Techniques for removing H2S include the use of activated carbon, alkaline solution or use of Zn or Fe oxides.   

Quite alot of the CO2 can be removed using bottom ashes from biomass. It might be an option to consider to reduce total costs for the upgrading step.

http://www.hallbarconsulting.com/low-cost-biogas-to-biomethane-upgrading-system/

My suggestion is based on the  use of biogas scrubbing system that can help to remove different gas such as hydrogen sulfide,Carbon dioxide,moisture trapping and so on..

You can find lots of information in this paper "Progress and perspectives in converting biogas to transportation fuels"

Thanks to all the contributors. I find most of them useful. Dr. Fuqing Xu please can you give me further details about the paper you referred me to.

Yes. Attached please find the paper. 

Thanks Dr. Xu.

Pass the biogas through lime water to reduce or remove CO2 but may run the risk of affecting the calorific value of the biogas. You may try using CO2 Monitor (M90) as used in natural gas. Secondly, use iron fillings or feric oxide to remove HS2. Remember that biogas contains 65 per cent methane & 35 per cent CO2.

nice appropriate answer for biogas purification, thanks to all

there is an patent of pyrolysis gas to enrich biogas , the hydrogen and the gas CO , as this can be done insitu of external excitu , several recent paper also uploaded in research gate

This route is known as pyrobiomethan , the problem are mass tranfser limitation , can be better way the pyrogas, syngas biomethane bette fuel than combined hydrogen and methane called biohythane

Dear Dr. Pagndai V Pannir Selvam. Can you supply me with the source where I can read more about this?

Thanks

Dr. Emmanuel Echiegu

we have made biological post doctorate researchh 10 years before

https://cleanbiogas.wordpress.com/article/chapter-1-introduction-clean-fuel-from-1uq13eg5o82ex-3/

, the recent updated one is

Biogas upgrading – a technical review

www.sgc.se/ckfinder/userfiles/.../BAPF2016Hoyer+Energiforsk.p...

Traduzir esta página26 de mai de 2016 - Water, biogas upgrading and water treatment. 2014-2016 ... IEA Task 37, stajsjcs on operajonal biogas upgrading plants among IEA. Task 37 ...

[PDF]Upgrading Technologies for Biogas Production Plants - Munin - UiT

https://munin.uit.no/bitstream/handle/10037/9636/thesis.pdf?...2

Traduzir esta páginade HW Brendeløkken - ‎2016 - ‎Artigos relacionados1 de jun de 2016 - The International Energy Agency (IEA) and the World Energy Council estimates that ... commercially used biogas upgrading technologies.

[PDF]

Dear Dr. Pannirselvam

Thanks a million for the link supplied. I will study them and, if I still have some questions, I hope you don't mind my getting back to you. Once again, thanks.

Dr. Emmanuel Echiegu

i am working om biogas production from algae so i want to purify the gas to pure methane gas and absorbed co2 gas so any research paper have plezz give me

Dear Rakesh

Find below some of the responses i received when i posed the question. I hope you find the responses useful.

https://www.researchgate.net/deref/https%3A%2F%2Fcleanbiogas.wordpress.com%2Farticle%2Fchapter-1-introduction-clean-fuel-from-1uq13eg5o82ex-3%2F

Pass the biogas through lime water to reduce or remove CO2 but may run the risk of affecting the calorific value of the biogas. You may try using CO2 Monitor (M90) as used in natural gas. Secondly, use iron fillings or feric oxide to remove HS2. Remember that biogas contains 65 per cent methane & 35 per cent CO2.

https://www.researchgate.net/profile/Fuqing_Xu/post/How_do_you_purify_biogas_to_increase_the_methane_content2/attachment/59d63eb6c49f478072ea9376/AS%3A273771888349184%401442283712222/download/Yang_2014_Progress+and+perspectives+in+converting+biogas+to+transportation+fuels.pdf

thanks bro Emmanuel Amagu Echiegu

You're welcome Rakesh

Thanks