[Digestion] Biogas volume measurements

Tue May 24 08:44:19 CDT 2011

Dear Jos,

I have pasted in a post I made back in January on the subject as it may be
of relevance. The monitoring units that we are developing are suitable for
small-scale biodigester production rates. If you are interested please get
in contact with me - perhaps off list would be more appropriate. An update
on the post below is that we are targeting the $150-$200 mark per monitoring
unit with an accuracy of around 5%, and that we are currently working on a
second round of prototypes which should be tried and tested in 1-2 months -
after which we should be able to publish a sale price and technical
specification.

However, I feel that I am off the mark with what you are looking for. If you
are looking for something to use for experimentation on a single
biodigester, as opposed to logging the performance of a large number of
small-scale biodigesters over a long period of time, I can recommend the
Elster diaphragm gas flow meter that we use in our laboratory (
<http://www.elster-instromet.com/en/309.html>
http://www.elster-instromet.com/en/309.html), the main benefits being its
affordable cost and the fact that it has an electronic output that can be
logged on a data logger or similar - so you can easily calculate flow rate.
Its main disadvantage is that it is probably not resistant to corrosion. The
approach that we have taken is to ensure the input has a H2S filter on it,
and to purge it of biogas by blowing down the inlet pipe when we have
finished the experiment. We also regularly check it with a standard volume
to make sure that it reads the same values as when we first bought it. The
day that it goes off we can just buy another!

Hope this helps,

Ed

_______________________________________
Edward Matos
MEng (Hons.), AMIMechE, Hon.MSEE

Director

Shamba Technologies Ltd.

Email: edward.matos at shambatechnologies.com
Web: http://www.shambatechnologies.com <http://www.shambatechnologies.com/> 
Mobile UK: +44(0) 755 2811 646

Mobile TZ: +255(0) 686 128 037

Shamba Technologies Limited is a company registered in England and Wales

Company Registration No:  7094993

Registered Office: 2nd Floor, 145-157 St John Street, London, EC1V 4PY,
England

From: digestion-bounces at lists.bioenergylists.org
[mailto:digestion-bounces at lists.bioenergylists.org] On Behalf Of Edward
Matos
Sent: 21 January 2011 18:25
To: 'For Discussion of Anaerobic Digestion'
Subject: Re: [Digestion] Small Scale Remote Biogas Monitoring

Hi Alex,

We have developed this exact device for use in monitoring and testing the
performance of a small-scale biodigesters.

We use a physical computing platform called the "Seeeduino Stalker", that
detects up to 6 analog voltage readings and logs these onto an SD card. It
is also fairly simple to attach the components to send out the data via GSM,
though admittedly we haven't actually tried this yet. Our prototypes run off
a rechargeable battery making them a suitable solution for remote testing in
rural environments.

You can attach whatever low cost sensors you like to the analog readers,
including temperature sensors, solar intensity sensors, proximity sensors
(great for measuring gas reserve volume in floating drum designs), pressure
sensors (great for measuring gas reserve volume in expansion chamber
designs), and flow rate sensors. As you pointed out, there are no low cost
flow meters available on the market, much less ones which are compatible
with dirty biogas, which is why we developed our own! Our prototype uses a
super low cost solution to get a biogas flow rate reading every 5 seconds -
consistently accurate to within 5%.

We are currently making final improvements to the module before implementing
them on 100 Tanzanian small-scale biodigesters later this year. Initially we
did not intend to scale up our manufacturing capability to supply anything
other than our own needs as we did not think there would be much market
demand for such a product. However if we can be persuaded otherwise then we
would be happy to put the effort in to cater for this market need. If you
(and/or anyone else on this forum) would be interested in such a product
then please let me know (off this mailing list would probably be most
appropriate) how many units you would need and by when and we can see how we
might be able to help you. I cannot say anything of the cost (except that it
will be "low-cost"!) but if your order quantity would vary depending on the
cost then please include this for us to be able to gauge feasibility
effectively. Also, please specify whether you would just be interested in
the flow rate sensor (requires some C++ and electronics knowledge to
implement) or whether you would prefer a whole user-friendly package with
all the above sensors included.

Feel free to contact me on any of the details below.

Best regards,

Ed

_______________________________________
Edward Matos
MEng (Hons.), AMIMechE, Hon.MSEE

Director

Shamba Technologies Ltd.

Email: edward.matos at shambatechnologies.com
Web: http://www.shambatechnologies.com <http://www.shambatechnologies.com/> 
Mobile UK: +44(0) 755 2811 646

Mobile TZ: +255(0) 686 128 037

Skype: shamba_technologies

Shamba Technologies Limited is a company registered in England and Wales

Company Registration No:  7094993

Registered Office: 2nd Floor, 145-157 St John Street, London, EC1V 4PY,
England

From: digestion-bounces at lists.bioenergylists.org
[mailto:digestion-bounces at lists.bioenergylists.org] On Behalf Of Alexander
Eaton
Sent: 21 January 2011 00:31
To: For Discussion of Anaerobic Digestion
Subject: [Digestion] Small Scale Remote Biogas Monitoring

If you could only monitor two or three things in a small scale system in
order to determine gas flow and methane destruction from a small
biodigester, what would it be?  Keep in mind low (ish) cost, and remote
locations.  

We are considering data logging thermocouples that would show
presence/absence of a biogas flame across a time period.  We would then
compare that to measured flow rates.  We have also considered monitoring
internal digester temperature, so that with known waste input, we could
calculate biogas production.  We are testing so low cost flow meters, but
they are still relatively expensive, and have yet to pass the durability
test with biogas at this setting.  We are also looking a difference
platforms, from data loggers to GSM remote monitoring systems that transmit
data.  Does anyone have any low cost systems like this that could be
used/adjusted for biogas?  Something fro remote monitroing of efficient wood
stoves, for example, may translate.  The goal is monitoring sample systems
in a larger population to improve carbon reduction estimates.  We would be
using very conservative multipliers to incorporate a large population, so
the accuracy could be slightly sacrificed for robust measurements from a low
cost system.    

Best,

A

-- 
Alexander Eaton
Sistema Biobolsa
IRRI-Mexico
RedBioLAC

Mex cel: (55) 11522786
US cel: 970 275 4505

alex at irrimexico.org
alex at sistemabiobolsa.com

sistemabiobolsa.com
www.irrimexico.org
www.redbiolac.org

From: digestion-bounces at lists.bioenergylists.org
[mailto:digestion-bounces at lists.bioenergylists.org] On Behalf Of Jos van der
Ent | Safi Sana
Sent: 24 May 2011 16:13
To: For Discussion of Anaerobic Digestion
Subject: [Digestion] Biogas volume measurements

Hi All,

I know there are more than one companies offering advanced measuring tools
for gas(mass) flow meters. These are probably working fine for large scale
systems, but I am wondering about methods for determining the biogas
production of small scale systems (e.g. max 5 m3 biogas a day). The
preference would go a simple meter, just like it can be done with water flow
measurements.

- I found one reference described at the biogas wiki about 'upside down
barrel' method (and useful excel sheet!). 

- Also special biogas meters are sold on internet (e.g. Puxin is offering
with Qmax 4 m3/h) 

- What would be against using a regular household flowmeter? (Would special
arrangement be needed e.g. pressure regulators?)

What accuracy would these methods have? 

Are there other options? 

What do they use in laboratories?

What are the experiences with these methods?

Thanks,

Regards, Jos

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