[Stoves] Charcoal from waste - home cooking or other markets? (Re: Crispin, Anand Karve)

Crispin Pemberton-Pigott crispinpigott at outlook.com
Thu Oct 6 08:59:28 CDT 2016


Interesting details, Ken and All

Something to keep in mind re the developing of the EU market for these products: I understand from a Senegalese supplier of charred 'tiffa' (bullrush) logs is that there is an EU certification required before importing is allowed. The two criteria I recall are that the yield has to be >35% on a dry mass basis and the source has to be sustainable.

To meet the 35% target requires leaving a fair % of volatiles in‎ the product. With greater control the target is easier to achieve while keeping the carbon content up.

There is a very large, long term market for this type of sustainable biomass‎ energy carrier.

Crispin

Tom, Anand, & stoves list

Regarding charcoal in general

There appears to be a lot of activity in commercial production of a
recently introduced form of charcoal briquettes, especially in the Ukraine,
with aims of supplying Europe with a high quality "Pini & Kay" extruded
charcoal briquette.

These are now being offered from several suppliers in the UK, as a
non-charcoal version under the generic name of "heat logs".  They are made
from high pressure extrusion of sawdust and other wood chip wastes.

They are between 50 and 90mm across - often with a central hole, and
between 200 and 300mm long.

There are several companies creating these briquettes from sustainable or
recycled wood waste and then converting them to charcoal in large kilns.

The kilns are designed to recuperate the volatiles driven off by pyrolysis
thus making a much cleaner, low emission charcoal production - which is
often seen as a major polluter and source of de-forestation.

Here's one such company in the Ukraine

http://ecodgy.com/proisvodstvo.htm

The charcoal product has about a 35 to 38% mass of the original dry
biomass, low ash and high carbon content - approaching 90%.  It sells in
western Europe and US for an eye-watering $550 - $650 per tonne!

Whilst this is a "high-tech" product requiring investment in an extruder
($3500) and kiln, I am sure that a more appropriate solution could be
applied to village scale production of charcoal briquettes from agri-waste
using a low tech shredder,  hand press and simple kiln.

Crispin's "Holey" briquettes - made with a simple press, from a wide
variety of biomass and agri-waste would possibly be  a good choice for
converting to charcoal.

Alternatively the Karve's method of converting agri-waste to charcoal in
low cost kilns and running the charcoal powder plus binding agent through a
simple extruder  would make a product that would run a charcoal gasifier
and engine - for electrical and mechanical power production.



Ken

On 6 October 2016 at 07:02, Anand Karve <adkarve at gmail.com> wrote:

> Dear Tom,
> people who make charcoal in mud kilns, generally use wood as the raw
> material. Our kiln, made of mild steel sheets, does not cost all that much,
> and it can convert agricultural waste, leaf litter from avenues and
> forests, nut shells, and even cardboard into charcoal. The char is powdery
> and therefore it has to be briquetted (spending additional money) before it
> can be used as fuel. The wood charcoal vendors generally wet their charcoal
> in order to increase its weight. Owing to this, and also because of the
> unscientific manner in which the charcoal is produced, it produces smoke
> while burning. Although our briquettes are 20% costlier than the
> commercially available wood charcoal, our customers prefer to buy them,
> because our briquettes do not have any water added to them and because they
> burn absolutely without any smoke.
> Yours
> A.D.Karve
>
> ***
> Dr. A.D. Karve
>
> Chairman, Samuchit Enviro Tech Pvt Ltd (www.samuchit.com)
>
> Trustee & Founder President, Appropriate Rural Technology Institute (ARTI)
>
> On Wed, Oct 5, 2016 at 8:13 PM, Tom Miles <tmiles at trmiles.com> wrote:
>
>> Ken,
>>
>>
>>
>> Good thoughts. We looked at generating power from charcoal makers for the
>> world bank a few years ago. There is one company that makes charcoal and
>> power through a clever combination of pyrolysis and gasification. The
>> problem is usually a socio-economic on. People make charcoal in earth kilns
>> because they are not capital intensive. They can build them with “sweat
>> equity”. All alternatives are capital intensive.
>>
>>
>>
>> Tom
>>
>>
>>
>> *From:* Stoves [mailto:stoves-bounces at lists.bioenergylists.org] *On
>> Behalf Of *Ken Boak
>> *Sent:* Wednesday, October 05, 2016 1:09 AM
>> *To:* Discussion of biomass cooking stoves <stoves at lists.bioenergylists.o
>> rg>
>> *Subject:* SPAM: Re: [Stoves] Charcoal from waste - home cooking or
>> other markets? (Re: Crispin, Anand Karve)
>>
>>
>>
>>
>>
>> Dear Crispin, Anand, and stoves list,
>>
>>
>>
>> Regarding waste charcoal and other uses of charcoal fuel:
>>
>>
>>
>> I have recently restarted a project I was first involved in back in 2010,
>> which is the production of a biomass gasifier for village scale power
>> generation.
>>
>>
>>
>> This involved the conversion of a Lister 6hp engine to spark ignition to
>> allow it to run on syn-gas from a wood chip gasifier.
>>
>>
>>
>> My experiments were conducted at a workshop held at All Power Labs, of
>> Berkeley, California,  in February of 2010 and later in Spring of 2012 -
>> when I was fortunate enough to be working at APL for six months of 2012.
>>
>>
>>
>> During that time myself and a team of fellow enthusiasts converted the
>> Lister to spark ignition and proved that it would run at the elevated
>> compression ratio of 17:1 - as common in small diesel engines. This allowed
>> the Lister to perform well on syn-gas without the usual loss of performance
>> associated with running a standard low compression engine on gas.
>>
>>
>>
>> Since the initial experimental phase, I have come to believe that the
>> woodchip gasifier is a hard beast to tame, and that a charcoal gasifier is
>> a much simpler and forgiving technology and better suited to construction
>> and operation and repair - particularly in the rural setting.
>>
>>
>>
>> So this opens up the question of supplying charcoal in a form that is
>> compatible with the gasifier and in a quantity that satisfies the demand of
>> village scale distributed heat and power systems.
>>
>>
>>
>> The solution that I am currently researching is a charcoal gasifier that
>> has a pre-pyrolyser - as a means of producing the charcoal as an
>> intermediate fuel from assorted biomass.  The pyrolyser is initially driven
>> from the waste heat of the diesel exhaust and supplemented by the heat from
>> burning the pyrolysis gases, volatiles and tars - which otherwise would
>> potentially cause a problem later in the valve gear of the diesel engine.
>>
>>
>>
>> Whilst some say that converting biomass to char is wasteful in terms of
>> energy, and also prone to generating high levels of noxious pollutants,
>>  the solution of having a closed torrefier, closely coupled to the charcoal
>> gasifier, that consumes all pyrolysis gases - and makes the associated heat
>> available for other purposes - such as water heating, drying, roasting,
>> cooking, boiling etc  reduces the pollution to a minimum.
>>
>>
>>
>> It also allows a wide range of otherwise "difficult" agricultural waste
>> products to the converted to charcoal fuel in a form that can be used for
>> running the converted engine.  This includes the leaves, tree trimmings,
>> nut shells, husks, stones/pits, sawdust etc and any other wide variety of
>> waste products to be converted and used effectively as fuel for heat and
>> electrical and/or mechanical  power for running small agri-processing
>> machines
>>
>>
>>
>> In my estimation somewhere between 1.5 and 2kg of dry biomass will be
>> needed to produce 1kWh of electricity using a charcoal gasifier.
>>
>>
>>
>> For every kWh of electrical power produced about 4kWh of high grade waste
>> heat either as hot air for drying or hot water at 60C + will be available.
>>
>>
>>
>> For those requiring a refresher on the design of the charcoal gasifier -
>> I recommend a paper from 1942 "The Making of the Kalle Gasifier"  submitted
>> to the list by Tom Miles nearly 10 years ago
>>
>>
>>
>> http://gasifiers.bioenergylists.org/kallegas
>>
>>
>>
>> Additionally for small scale charcoal gasifiers made from scrap materials
>> - I suggest Gary Gilmore's design from 2010/11 - which is described in a 3
>> part YouTube series
>>
>>
>>
>> https://www.youtube.com/watch?v=srLETKDrwto
>>
>>
>>
>>
>>
>> And from 2013 - his Simple-Fire gasifier
>>
>>
>>
>> https://www.youtube.com/watch?v=KAJXdaCQ6uQ
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> regards
>>
>>
>>
>>
>>
>> Ken
>>
>>
>>
>> London
>>
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>
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