February 1997 Gasification Archive

From 73002.1213 at CompuServe.COM Wed Feb 5 12:47:39 1997
From: 73002.1213 at CompuServe.COM (Thomas Reed)
Date: Tue Aug 31 21:07:15 2004
Subject: GAS-L: Multistage Reactors
Message-ID: <970205175022_73002.1213_FHM28-1@CompuServe.COM>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 73002.1213@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Clean gas Producers:

On my recent trip"tar" levels in gas was the prime area of concern around the
world. I was concerned that some laboratories were defining "tar" as the
condensible organics, collected as low as -50C, while others were more concerned
with the creosote varnish that can deposit on pipes and valve stems.

In Switzerland and Bangalore I saw "low tar" downdraft gas producers with tar
levels in the 10-100 ppm level (after reaching operating Temperature) developed
by Mukunda's group. This was achieved by a secondary injection of air below the
flaming pyrolysis zone.

Yesterday I received a very interesting paper from Bhattacharya, ("Multi-Stage
Reactor for Thermal Gasification of Wood", T. Bui, R. Loof and S. C. Bhata..,
Energy 19, pp 397, 1994) using a similar approach and again reporting 92 ppm
"tar" (method unspecified). There were a number of interesting measurements of
temperatures in the two zones.

This would appear to be simultaneous invention of an important principle for
downdraft: After flaming pyrolysis, add a little more air below the Fp zone to
burn up the remaining tars during final gas reduction.

I visited several gasifiers in India developed by Tata, SDC, ... For themal
cooking of silk cocoons. How low would tar have to be before we could dispense
with gas cleaning, representing more than half the cost, here?

hope that we will hear others weigh in on (a) how to measure SIGNIFICANT tars
(b) other methods of getting low enough levels for engine operation and (c) how
low the levels need to be for thermal applications.

Regards, TOM REED

From Nick.Barker at aeat.co.uk Fri Feb 7 13:57:11 1997
From: Nick.Barker at aeat.co.uk (Nick Barker)
Date: Tue Aug 31 21:07:15 2004
Subject: GAS-L: Renewables in England and Wales
Message-ID: <2FB7AC40.1268@ccgate.aeat.co.uk>

Colleagues

A short note to let you know that the results have been announced for
the latest round of bidding for the England and Wales NFFO ( the UK
premium price scheme for renewable electricity). The way it works is
that projects bid competitively, on electricity price, within their
technology sector. The government then decide on the amount of
capacity to be purchased within each sector.

Wind power has secured 341MW worth of contracts in 65 projects, small
hydro 13MW in 31 projects, Waste combustion 240MW in 16 projects,
landfill gas 174MW in 70 projects, anaerobic digestion of ag wastes
7MW in 6 projects and gasification or pyrolysis of energy
crops/forestry residue 67MW in 7 projects.

The bid prices and further details are in the press release on the UK
Department of Trade and Industry Web page

http://www.coi.gov.uk/coi/depts/GTI/coi6569c.ok

We don't know, at this stage, details of the exact technologies being
used or the names of the successful bidders. I will post any further
information that may be of interest to the group when it becomes
available.

Nick Barker
UK Biomass Programme
ETSU

From sturn at hawaii.edu Mon Feb 10 11:51:00 1997
From: sturn at hawaii.edu (Scott Turn)
Date: Tue Aug 31 21:07:15 2004
Subject: GAS-L: Multistage Reactors
In-Reply-To: <970205175022_73002.1213_FHM28-1@CompuServe.COM>
Message-ID: <Pine.GSO.3.93.970210065049.14108B-100000@uhunix3>

On Wed, 5 Feb 1997, Thomas Reed wrote:
> This would appear to be simultaneous invention of an important principle for
> downdraft: After flaming pyrolysis, add a little more air below the Fp zone to
> burn up the remaining tars during final gas reduction.

your statement on secondary air injection is interesting. based on
concentrations of "tars" and other permanent gases, and the reaction
rate kinetics, would you expect to "burn" the tars, or instead,
burn more reactive species such as hydrogen and perhaps thermally crack
tars. what temperatures resulted at the point of secondary air
injection?

From houmoller at dk-teknik.dk Tue Feb 11 08:17:55 1997
From: houmoller at dk-teknik.dk (houmoller@dk-teknik.dk)
Date: Tue Aug 31 21:07:16 2004
Subject: GAS-L: Multistage Reactors
Message-ID: <199702111324.OAA13263@ns.dknet.dk>

Hi,

Multistage gasification reactors are well known here in Denmark as they are
able to gasify straw as well as other biofuels. As straw is a larger
resource here than wood, this is important. But more important is perhaps
that the tar content in the gas is so low that it isn't necessary to clean
any tar out of the gas before feeding the gas into an internal combustion
engine (this is NOT an assertion but a proven fact).

To decompose the tar thermally, the temperature must be rather high, lets
say around a 1000 degrees Celsius. At this temperature straw ash melts and
blocks up a single-reactor gasifier.

During the last approx. ten years the Technical University of Denmark has
been working on the two stage gasifier which keeps pyrolysis and
gasification separate in two reactors. The pyrolysis takes place in a
horizontal tube at around 600 degrees Celsius, delivering char and pyrolysis
gas to the gasifier, which is vertical. Air is added on top of char layer in
the gasifier to raise the temperature here to approx. 1000 degrees Celsius
and crack the tar. Steam is also added as a gasification agent, which also
activate the char bed.

The SMART thing is that the gasification takes place at a lower temperature
than the cracking, so that the ash doesn't melt.

The tar content is very small - less than 50 mg per normal cubic meter (yes,
yes, I know - I should specify the measuring method, but I still haven't got
a standard to refer to). This is both due to the high temperature the tar
passes and the activated charcoal in the bed.

In a paper I presented in December in Trondheim I have included a
description and a sketch of this gasifier. The paper is about the fluid bed
version of the two stage process, which is being developed in cooperation
between the university and dk-TEKNIK.. I just put this paper on my homepage
- http://www.sh.dk/~cbt/sh - take a look. If you don't have www-access,
check the proceedings from Banff and Copenhagen last year. These versions
are older and not as elaborate.

Søren
________________________________________________________

Soren Houmoller, M.Sc.
dk-TEKNIK Energy & Environment
houmoller@dk-teknik.dk http://www.sh.dk/~cbt/sh
CENTRE FOR BIOMASS TECHNOLOGY http://www.sh.dk/~cbt/
________________________________________________________

****

On Wed, 5 Feb 1997, Thomas Reed wrote:
> This would appear to be simultaneous invention of an important principle
for
> downdraft: After flaming pyrolysis, add a little more air below the Fp
zone
to
> burn up the remaining tars during final gas reduction.

From 73002.1213 at CompuServe.COM Thu Feb 13 09:22:24 1997
From: 73002.1213 at CompuServe.COM (Thomas Reed)
Date: Tue Aug 31 21:07:16 2004
Subject: GAS-L: Re: Charcoal Kilns
Message-ID: <970213142611_73002.1213_FHM77-1@CompuServe.COM>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 73002.1213@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dear Greg:

I know Bhatacharya fairly well and talked to him (but was prevented from a
visit) when I was in Bangkok last November. I am currently writing to him to
get more information on the "ferrocement" gasifier/kiln construction method
pioneered by Bob Reines. I'll post whatever I find to you. I hope to use this
construction for various gasifiers. However, I believe to be most effective
that it needs to be insulating ferrocement. Dense refractories are not very good
insulators. I can't find anyone on the internet to comment on such construction.
Any ideas?

I hadn't heard of the two types of kilns you mentioned. I would say

1) that burning the "smoke" is useful for energy and necessary to suppress the
incredible pollution that charcoal making causes

2) that portability and "ferrocement" kilns probably don't go together

3) our "top burning" method of firing may bring a new dimension to charcoal
making (but requires moderately dry wood)

4) keep us posted on your progress and we'll do the same for you.

Tom Reed (and Ron Larson)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Subject: Re: Charcoal Kilns
To: Thomas Reed <73002.1213@CompuServe.COM>

Dear Tom,
I made a new contact in Bangkok who is working on a research
project funded by the Swedish Intl. Development Corp. Agency (SIDA) to
prepare state of the art reports on biomass combustion, gasification,
densification, and carbonization. His name is Prof. S.C. Bhattacharya
e-mail--- bhatta@ait.ac.th
In our communications he mentioned a research project carried out
by Natural Resources Institute of UK (NRI). That is where I originally
got my plans for the kiln etc. They did an experiment using 20 kilns
(Doing batch processing) using a staggered firing order to ensure a
constant supply of smoke to be burned. I have sent away for this
Report, and it usually takes a couple of weeks to receive. Have you
heard of this project or NRI?
The Professor also mentioned work called the Cornell Retort? are
you familiar with this project? Our goal is to keep this project as
LOW-TECH as possible, putting as many PEOPLE to work as possible. I
think it would be redundant to use a cyclone and baghouse if the end
product would still need further treatment (combustion), do you agree?
Any suggestions you can offer would be greatly appreciated. We plan to
do all our processing well away from populated areas. We also need to
make whatever process of a portable nature, just as our kilns are.
Hope to hear from you soon...
Greg Brown
<

From mheat at mha-net.org Thu Feb 13 18:20:44 1997
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:07:16 2004
Subject: GAS-L: Re: Charcoal Kilns
In-Reply-To: <970213142611_73002.1213_FHM77-1@CompuServe.COM>
Message-ID: <330395C5.3AC@mha-net.org>

Thomas Reed wrote:

(snip)
"ferrocement" gasifier/kiln construction method
> pioneered by Bob Reines. I'll post whatever I find to you. I hope to use this
> construction for various gasifiers. However, I believe to be most effective
> that it needs to be insulating ferrocement. Dense refractories are not very good
> insulators. I can't find anyone on the internet to comment on such construction.
> Any ideas?
>
(snip)
Thomas:

We've experimented quite a bit with various refractory materials for
manufacturing masonry heater components.

There's quite a range. Determining what is most suitable depends on the
relative importance of:

cost
maximum service temperature required
thermal shock resistance required
amount of long term thermal cycling

Portland cement binder starts to break down at around 600F. For higher
service, it can be replaced with calcium aluminate cement (lumnite,
ciment fondue). Another refractory binder is sodium silicate
(waterglass).

For insulation, you need an insulating aggregate. Vermiculite is the
most common. There is also expanded clay ("leca" clay), perlite, and
others.

Other options include:

- low density fired clay

- a composite wall with a non-structural insulating refractory facing. A
high tech insulator is ceramic fiber, which can be rigidized with by
painting on a zirconium rigidizer.

- A low/high tech solution would be a fired clay container (many
countries have indigenous traditions for firing fairly large appliances,
such as the Indian tandoor, etc.) with a refractory insulating lining.

Best..........Norbert Senf
--------------------------------------------------------
Norbert Senf email: mheat@mha-net.org
Masonry Stove Builders mheat@hookup.net
RR 5, Shawville website: http://mha-net.org/msb
Quebec J0X 2Y0 fax: 819.647.6082
voice: 819.647.5092

From BIOTENGP at aol.com Wed Feb 19 10:51:15 1997
From: BIOTENGP at aol.com (BIOTENGP@aol.com)
Date: Tue Aug 31 21:07:16 2004
Subject: GAS-L: BUN India Newsletter
Message-ID: <970219105756_277579820@emout05.mail.aol.com>

I would like to subcribe to the BUN India Newsletter. Could you tell me
where I might learn more about the newsletter and who to contact for a
subcription? Thank you.

Laura Blake
BIOTEN

From gayathri at aero.iisc.ernet.in Wed Feb 19 11:47:37 1997
From: gayathri at aero.iisc.ernet.in (Gayathri)
Date: Tue Aug 31 21:07:16 2004
Subject: GAS-L: BUN India Newsletter
Message-ID: <9702200321.AA24514@aero.iisc.ernet.in>

DEar MR. Blake,
Please write to us your mailing address.
we will send u the news-letter.
Feel free to contact me if u need any more info.
Regards
Gayathri

******************************************************************************
Mrs.Gayathri V BIOMASS USERS NETWORK - INDIA
Project Engineer
Combustion Gasification and Propulsion Lab.
Dept. of Aerospace Engineering
IISc . Bangalore 560 012 Phone :(off) +91-80-3092338 or 3348536
(Res) :+91-80-6632717
Fax :+91-80-3341683
E-mail : gayathri@aero.iisc.ernet.in

"There is nothing like impossible"
*****************************************************************************

From jfreeman at gamma.pair.com Mon Feb 24 16:16:08 1997
From: jfreeman at gamma.pair.com (Jon F. Freeman)
Date: Tue Aug 31 21:07:16 2004
Subject: GAS-L: Home page announcement from SUCRON, Inc.
Message-ID: <199702242123.QAA06404@gamma.pair.com>

This is an invitation to visit the SUCRON, Inc. home page at
http://www.sucron.com. SUCRON is a corporation created to
commercialize a chemical process that converts wood, grass, and
high-biomass cane to hexane, pentane, and hydrogen. We also invite
you to contact us by surface mail if you have any comments, questions,
or suggestions for improving the page.

Sincerely,

Jon F. Freeman, President

From REEDTB at CompuServe.COM Wed Feb 26 12:13:29 1997
From: REEDTB at CompuServe.COM (Thomas Reed)
Date: Tue Aug 31 21:07:16 2004
Subject: GAS-L: New Address, Tom Reed
Message-ID: <199702261156_MC2-11C5-3DC@compuserve.com>

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 ReedTB@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Hi All:

You may have noticed that I have stuck with Compuserve for many years,
despite many minor irritations, free E-mail at Mines etc. I notice that
other servers serve up minor irritations as well. So, for better or worse
I'll continue with CS.

One MAJOR irritation is the number address (which is labelled "unknown") in
many of my received messages. In 1995 they announced that they were going
to permit us to use names instead of numbers and said "please register you
name and we'll let you know when to start using it". About once I month I
write a note "where is it?" and get a response "be patient!".

Finally, this morning, under "what's new" it says I can use my NEW ADDRESS,

reedtb@compuserve.com

Nice, eh? Easy to remember? The old number still works as well.

While I have your patient ears, you may wonder why I am so prolix. In part
it is due to the fact that I took touch-typing in 8th grade and so can
type-like-talk. At that distant time it was thought that everyone would
have a secretary, so why learn typing. I did anyway.

I would be curious to know how many of you touch-type and how it correlates
with how many letters you E-mail a week.

In spite of the fact that I know how to touch-type, I have enjoyed using
the various computer Typing Tutors (ie Mavis Beacon....). I learned my
numbers and Symbols a few years ago and have never regreted it. I would
advise all the "search and sock", "Hunt and Peck" typists out there to
learn touch typing if you are younger than 80. It will pay off over your
remaining lifetimes (unless you have a "secretary" who knows all your
thoughts).

Best to all, TOM REED

From houmoller at dk-teknik.dk Wed Feb 26 12:42:46 1997
From: houmoller at dk-teknik.dk (houmoller@dk-teknik.dk)
Date: Tue Aug 31 21:07:16 2004
Subject: GAS-L: New Address, Tom Reed - and t
Message-ID: <199702261749.SAA17973@ns.dknet.dk>

Hi list,

Just before finishing my M.Sc. studies I reasoned that replacing the
biblical typing system (search and you shall find) with the 10-finger system
would improve speed a lot.

So, I went to the public library, borrowed a book called something like "How
to Typewrite" from around 1968, placed myself comfortably in front of the
computer and started from page 1. Starting with "jjjjjjjjjjjjjjjj" I soon
moved onto "ffffffffffffff", continueing with "jkjkjkjkjkjkjk" and
proceeding further with "fdfdfdfdfdfdf" I soon picked up type-writing.

After this Saturday in Hell I knew where all the keys were and after some
day's practise I could type-write! The main advantage of these couple of
days with hard work is that I can write boring, uninteresting and off-topic
mail like this in an instance.

Søren
________________________________________________________

Subject: GAS-L: New Address, Tom Reed
Date: 26. February 1997 18.35

Thomas B. Reed 303 278 0558 V Colorado School of Mines
1810 Smith Rd., 303 278 0560 FX Department Chem Eng
Golden, CO 80401 ReedTB@Compuserve.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Hi All:

Finally, this morning, under "what's new" it says I can use my NEW ADDRESS,

reedtb@compuserve.com

Nice, eh? Easy to remember? The old number still works as well.

I would be curious to know how many of you touch-type and how it correlates
with how many letters you E-mail a week.

Best to all, TOM REED

From rolittge at ucdavis.edu Wed Feb 26 19:02:50 1997
From: rolittge at ucdavis.edu (Roger Littge)
Date: Tue Aug 31 21:07:16 2004
Subject: GAS-L: Re: New Address, Tom Reed
In-Reply-To: <199702261156_MC2-11C5-3DC@compuserve.com>
Message-ID: <Pine.GSO.3.95.970226160226.12097A-100000@rocky.ucdavis.edu>

Please forgive this brief tangental comment, but since Tom Reed suggested
that we all learn to touch type, and since I harbor a hope that we can
replace the standard keyboard, called qwerty, with an ergonomic key layout
as well as shape, I am bringing one example of such a keyboard to your
attention--the Maltron. For information, please check the "typing injury
FAQ" site at Princeton:

http://www.cs.princeton.edu/~dwallach/tifaq/keyboards.html

or the company which sells the Maltron in the USA (lower cost than that
sold in the UK):

http://www.teleprint.com

Thanks for your attention, and, again, sorry for the digression.

Roger

-----------------------------------------------------------------------------
Roger Littge, M.D. 916-752-7420
Biological and Agricultural Engineering fax:754-8129
Bainer Hall
U.C., Davis email: rolittge@ucdavis.edu
Davis, CA 95616

BioEnergy Lists: Gasifiers & Gasification

February 1997 Gasification Archive