3 replies to this topic

[tjsegan]

Hi all,

 

This is my first time posting in this forum, so I apologise if I commit any forum sins! I am a young chemical engineer who has spent the first 3 years of my career cycling through various roles in the foods and detergents business. I'm currently working in a waste treatment company with strong ties to an NPO that provides sanitation. My current responsibility is to facilitate the design, construction and operation of a small-to-medium scale biogas plant.

 

My predecessors focused on rather high level approaches to this problem, looking to outsource the entire plant to a vendor that would supply a package plant as a turnkey solution. Fundamental drivers to this decision were the fact that there was (and still is, admittedly) a lack of deep technical understanding to properly design and run a biogas plant, but also that the plant is to be based in rural Kenya, just outside of Nairobi, pushing my predecessors to look for simpler processes in the hopes to mitigate operational risk. (This assumption may be flawed, but is the assumption with which they had worked.) Previously, the organisation has conducted lab scale studies (1m³ - 10m³ plug flow type digesters), but these looked primarily at gross yield of biogas and didn't focus on any operational aspects. On the bright side, I have at least a rough indication of yields based on feedstock mixes.

 

It's safe to say I am a little rusty when it comes to my Chemical Engineering fundamentals and that I have had at best limited exposure to biological processes. I'd like to approach this design problem in a logical way so at the very least I can vet some of these package plants and at best design a simple biogas plant based on the very well-described literature out there. 

 

I'm hoping that the forum could advise on how best to handle this design problem. The questions I have been asking at  this early stage of design are:

• What is the best way to handle process streams? My feeling from literature surveys is to us TSS and VS as fundamental basis, since most papers describe biogas yields relative to VS. However, I'm not sure if there is a way to look at this more fundamentally, or more pragmatically, that allows me make better process design decisions (for example - whether to use certain types of reactors, what type of feed mix to best use, temperatures of operation to maintain, whether to use upstream hydrolysis etc)
   
• Which parameters should I be looking to measure or trial at this stage to help inform me of better design choices? I still have 9 small scale digesters at my disposal - are there further trials that might be worthwhile running?
   

I will not bother you with other queries at this point since there is still quite a bit of research and review I need to do myself. However, in every industry and design niche there are typically fundamental gospels of design - could you advise where I should be looking?

Please let me know if there is more information you think I should add at this point in time.

 

Regards,

 

Tim

[breizh]

Hi Tim ,

let you try to get this book :

Biogas from waste and renewable resources  by Deiter Deublein and Angelika Steinhauser -Wiley -VCH.

 

Breizh

[tjsegan]

Thanks Breizh, I'll have a look - seems promising!

[manojkaila]

Dear Tj,

 

From your long description I can understanding that you want to design bio gas plant. As per my under standing you are going to re invent the wheel. There is already lot of work done. Specially as per my understanding in India many Govt institute done lot of research and they are very well willing to share the knowledge. One of the not for profit group I know is as follow and there are many company who are ready to offer help on turn key basis.

 

If you are doing this purely for academic interest then things are different.

 

http://www.iaemp.in/ 

 

Good Luck