[Stoves] Rice husk stove and rice husk gasifier

Mon Oct 17 12:30:36 CDT 2016

Hi Christopher

One thing I forgot to mention is that the frequent tending (every 3-5 minutes) was not that problematic for countries  that had fairly quick (eg 25-30 minute) cooking cycles like the Philippines. In West Africa, households were often 15 in number and they had much larger pots and longer cooking cycles (1hr+). The West African women already were overburdened so the rice hull stove just added another job to the day.  In West Africa the MTS was mostly used for food reheating and short cooking cycle foods.  In Senegal and Gambia we ended up inventing the REAP clay brick stove where it reduced cooking cycles and womens labour burden. It is my preferred stove for that region of West Africa as it is so cheap to build with local materials, very safe with the large pots, safes fuel and reduces cooking cycles. You can also use it outdoors in rural areas with a roof (taking stoves outdoors is the most profoundly simple and effective strategy to solve the indoor air quality problem).   

http://www.reap-canada.com/online_library/IntDev/Brochure%20-%20REAP%20Noflay%20Clay%20Brick%20Stove.pdf

We had quite a bit of time to work on designing the MTS in the field in the rural Philippines as we had a fairly large grant on climate change mitigation using household cookstoves as a mitigation strategy in 2000. We also had 6 engineering student interns periodically work on the stove after that initial project. They were especially helpful in streamlining manufacturing methods.   Several other outside stove engineers have tried to make improvements by adding features to marginally improve the combustion/convenience but what we ended up with was a more expensive and difficult stove to build and operate.  In the end we just left the stove as is,  as adding new features didn't appear viable for the rural market. A marginal efficiency improvement is not worthwhile if it comes at a cost as the stove largely has a free fuel. We can produce a blue flame from the rice hull with no fan for about $15-$20 depending on the region.  The main point is that rice hull is not a rich mans fuel as its such a low quality bulky fuel that is full of ash. You can't over design stoves for poor people. The main problem we had is that workshops that had the capacity to build the stove often dropped it because it wasn't lucrative enough. Lower capacity workshops often had problems building it to the design specifications so we ended up making jigs to help improve quality control.  Making  a more complication version of the MTS  is just going to make it more out of reach for the poor and the ability to find viable workshops to build it. Our goal in our stove designs for poor folks is to aim for profound simplicity and keep the stove affordable. 

If anyone is interested to buy the MTS stove rights from us, REAP-Canada we would be open to that.  We aren't working as much on stoves at the moment as donors seem to have lost their way by focusing on household cookstoves with confusing complexity of design that are unaffordable for the rural poor.  We presently sell the stove design patterns through a  manufacturing stove production licence for $200.

Most recently REAP-Canada has been working on biomass grass breeding in Canada and our agroecological village international development programs. Internationally I really like the idea of growing grasses and shredding them and using the stems as fuel and the leaves as fodder. Grass stems when properly sized can create a rice hull like porosity to make a really nice fuel for the MTS. Grass stems  have about 2% ash versus 25% for rice hull. I would like to work on that project further.   

best regards

Roger Samson
Executive Director

REAP-CANADA
www.reap-canada.com

--------------------------------------------
On Mon, 10/17/16, Christopher Bradnum <Christopher.Bradnum at nottingham.ac.uk> wrote:

 Subject: Re: [Stoves] Rice husk stove and rice husk gasifier
 To: "Discussion of biomass cooking stoves" <stoves at lists.bioenergylists.org>
 Received: Monday, October 17, 2016, 10:23 AM

 #yiv4886705283
 #yiv4886705283 --

  _filtered #yiv4886705283 {panose-1:2 4 5 3 5 4 6 3 2 4;}
  _filtered #yiv4886705283 {font-family:Calibri;panose-1:2 15
 5 2 2 2 4 3 2 4;}
 #yiv4886705283  
 #yiv4886705283 p.yiv4886705283MsoNormal, #yiv4886705283
 li.yiv4886705283MsoNormal, #yiv4886705283
 div.yiv4886705283MsoNormal
 	{margin:0cm;margin-bottom:.0001pt;font-size:12.0pt;}
 #yiv4886705283 a:link, #yiv4886705283
 span.yiv4886705283MsoHyperlink
 	{color:blue;text-decoration:underline;}
 #yiv4886705283 a:visited, #yiv4886705283
 span.yiv4886705283MsoHyperlinkFollowed
 	{color:purple;text-decoration:underline;}
 #yiv4886705283 span.yiv4886705283EmailStyle17
 	{color:#1F497D;}
 #yiv4886705283 .yiv4886705283MsoChpDefault
 	{font-size:10.0pt;}
  _filtered #yiv4886705283 {margin:72.0pt 72.0pt 72.0pt
 72.0pt;}
 #yiv4886705283 div.yiv4886705283WordSection1
 	{}
 #yiv4886705283 

 Dear Ken, Paul, Ronal and
 Roger, 

 Thank you for the links and
 details. I will ask the student to get on with the research.
 I too will start looking at the literature
  available and be in a better position to advise
 her. 
 I don’t expect any major
 breakthroughs as she is a third year student, but as with
 all work in this area, an incremental improvement
  can move the conversation forward. 
 Roger, the Mayon Turbo Stove looks
 really impressive, she will definitely need to start her
 investigations there. 
 Excluding the fan was her
 suggestion, but this really is the earliest possible stage
 of the project and we will need to be more open
  minded about what needs to be included or excluded, thanks
 Paul. 
 As we get on with the development
 work I will ask her to show her results to this
 forum. 

 Thank you all again, kind
 regards 

 Chris 

 From: Stoves
 [mailto:stoves-bounces at lists.bioenergylists.org]
 On Behalf Of Ken Boak

 Sent: 14 October 2016 14:28

 To: Discussion of biomass cooking stoves
 <stoves at lists.bioenergylists.org>

 Subject: Re: [Stoves] Rice husk stove and rice husk
 gasifier 

 Chris & List 

 modern experience of rice
 husk gasification  - a paper from 2014 

 https://halshs.archives-ouvertes.fr/hal-01107615/document

 plus a  link to an old
 paper with some information on rice husk gasification 

 https://books.google.co.uk/books?id=JKty_OlU8bEC&pg=PA12&dq=gemcor+rice+husk+gasifiers&hl=en&sa=X&ved=0ahUKEwjYr8bAsdrPAhVBKsAKHbnhBbIQ6AEIHjAA#v=onepage&q=gemcor%20rice%20husk%20gasifiers&f=false

 On 14 October 2016 at
 13:05, Christopher Bradnum <Christopher.Bradnum at nottingham.ac.uk>
 wrote: 

 Dear List Member

 I am looking for some help on a project one of my students
 is starting.

 I have a Taiwanese student who would like to develop a
 passive (not electric fan) rice husk stove for her home as
 her major project for the BEng in Mechanical Engineering at
 the University of Nottingham. Depending on the success of
 the project, her family may
  consider starting a business manufacturing such stoves
 within their community. Her family own a rice farm and they
 have a lot of material that they can convert into energy.
 They already have a stove (sorry I don't have the
 photographs of this) which they use
  for some of their cooking needs. It has a deep central
 'pot like' component (+/- 750mm tall X 300mm
 diameter) with a grid at its base which holds the burning
 rice husk. This 'pot' is located inside a larger
 vessel. At the base a fan directs air in below the
  central rice burning 'pot'. A separate pot holder
 unit is placed on top of the whole configuration. This has,
 what looks like, an inverted colander at its centre through
 which the flame reaches the cooking pot. The stove complete
 is around 1,000mm tall. The
  rice husk is top lit inside the central pot and I assume
 the air pushed in from underneath helps to fuel the fire.
 The stove produces a reddish / purple flame and I am told a
 pot filled with fuel lasts for 5 hours. Although I can't
 quite work out what needs
  to be cooked for that long.

 The student returns home in December and will complete some
 rudimentary tests to get a baseline for the efficiency and
 emissions given off by the stove. I will also get her to
 complete the heterogeneous cooking test developed by SeTAR
 under Prof Harold Annegarn
  and Crispin Pemberton-Piggots' supervision at the
 University of Johannesburg.

 Leading up to that testing I want her to get on with a bit
 of research, so I thought to turn to this very excellent
 group and ask for some help (standing on the shoulders of
 giants...).

 Has anyone on the list worked with rice husk as a fuel
 source and does anyone have any research work we can look at
 as a starting point? Particularly using rice husks as a fuel
 for cooking.

 It seems to me, through superficial online perusing, that a
 rice husk gasifier might be a better utilisation of the raw
 material. If it is a good system to convert rice husk into
 energy I would like to make and test one of these too. Does
 anyone have research
  around rice husk gasifiers that I could start
 investigating? Is this a good or not so good use of the
 fuel?

 Kind regards

 Chris

 This message and any attachment are intended solely for the
 addressee

 and may contain confidential information. If you have
 received this

 message in error, please send it back to me, and immediately
 delete it.

 Please do not use, copy or disclose the information
 contained in this

 message or in any attachment.  Any views or opinions
 expressed by the

 author of this email do not necessarily reflect the views of
 the

 University of Nottingham.

 This message has been checked for viruses but the contents
 of an

 attachment may still contain software viruses which could
 damage your

 computer system, you are advised to perform your own checks.
 Email

 communications with the University of Nottingham may be
 monitored as

 permitted by UK legislation.

 _______________________________________________

 Stoves mailing list

 to Send a Message to the list, use the email address

 stoves at lists.bioenergylists.org

 to UNSUBSCRIBE or Change your List Settings use the web
 page

 http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org

 for more Biomass Cooking Stoves,  News and Information see
 our web site:

 http://stoves.bioenergylists.org/

 This message and any attachment are intended solely for the
 addressee
 and may contain confidential information. If you have
 received this
 message in error, please send it back to me, and immediately
 delete it. 

 Please do not use, copy or disclose the information
 contained in this
 message or in any attachment.  Any views or opinions
 expressed by the
 author of this email do not necessarily reflect the views of
 the
 University of Nottingham.

 This message has been checked for viruses but the contents
 of an
 attachment may still contain software viruses which could
 damage your
 computer system, you are advised to perform your own checks.
 Email
 communications with the University of Nottingham may be
 monitored as
 permitted by UK legislation.

 -----Inline Attachment Follows-----

 _______________________________________________
 Stoves mailing list

 to Send a Message to the list, use the email
 address
 stoves at lists.bioenergylists.org

 to UNSUBSCRIBE or Change your
 List Settings use the web page
 http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org

 for more Biomass Cooking
 Stoves,  News and Information see our web site:
 http://stoves.bioenergylists.org/