[Stoves] coffee grounds gasification fuel

[Thomas Reed]

Dear Jim and All:

In addition to our listing of various materials at www.woodgas.com, the 
Energy Center of the Netherlands (PHYLLIS at 
http://www.ecn.nl/phyllis/DataTable.asp) has a good database.  Here is 
what they list for coffee grounds:

Proximate analysis (wt. %) 	Ultimate analysis (wt. %)

	dry 	daf 	ar 	
	dry 	daf 	ar 	
Ash 	0.2 	
	0.1 	C 	30 	30.1 	12 	Msr
Water 	
	
	60 	H 	9.1 	9.1 	3.6 	Msr
Volatiles 	- 	- 	- 	O 	59.6 	59.7 	23.8 	Cal

	
	
	
	N 	1 	1 	0.4 	Msr
Calorific value (kJ/kg) 	S 	0.08 	0.08 	0.03 	Msr

	dry 	daf 	ar 	Cl 	0.03 	0.03 	0.012 	Msr
HHV 	12550 	12575 	5020 	F 	0.001 	0.001 	0 	Msr
LHV 	10564 	10585 	2760 	Br 	- 	- 	- 	ND
HHV_Milne 	14992 	15022 	5997 	Total: 	100 	100 	100

	
Elemental analysis (mg/kg sample (dry))
Al 	100 	Msr 	Fe 	50 	Msr 	Pb 	1 	Msr
As 	1 	Msr 	Hg 	0.1 	Msr 	Sb 	1 	Msr
B 	- 	ND 	K 	200 	Msr 	Se 	1 	Msr
Ba 	3 	Msr 	Mg 	200 	Msr 	Si 	100 	Msr
Ca 	900 	Msr 	Mn 	14 	Msr 	Sn 	1 	Msr
Cd 	1 	Msr 	Mo 	1 	Msr 	Sr 	- 	ND
Co 	10 	Msr 	Na 	- 	ND 	Te 	- 	ND
Cr 	1 	Msr 	Ni 	1 	Msr 	Ti 	- 	ND
Cu 	14 	Msr 	P 	100 	Msr 	V 	1 	Msr

	Zn 	4 	Msr


Note that their "high heating value", HHV of 12.5 or 15 MJ/kg is low 
compared to most biomass at 20 MJ/kg (Dry, ash free).   This is probably 
because it has a high content of starch or cellulose (11) and low lignin 
(27) content.

Still, it could be a great fuel and would burn very clean.

TOM REED        BEF




jim mason wrote:
> apinun, man bilong save, ken calvert . . .
>
> i'm not sure if you saw  my post on the gasification list, but i am
> curious about any info on using coffee grounds as fuel.  i know you
> have done work with coffee husks in png, but not sure if you did
> anything with waste beans.  looking through the list archives, i only
> find posts about coffee husks.
>
> i live in san francisco, and we have a tremendous amount of coffee
> grounds around here.  i've burned them in an updraft unit, and of
> course they work, but i don't yet have an adequate gasifier rig to
> make much of an assessment (other than they are hard to light and mine
> were pretty wet)
>
> i would imagine they are very energy dense, as they are the
> reproductive part of the plant.  and their form factor of coffee
> grounds if very consistent, though wet, but with high surface area so
> they should dry reasonably quickly.
>
> none of the BEF books have any analysis of coffee grounds as a fuel
> from what i can find.  any ideas on its relative energy value, gas
> compositions and likely tar content?
>
> it seems to me that this fuel would work very well in a kalle or
> fluidized bed type rig.  which is what i plan to try in the very near
> future.
>
> i am cc'ing tom reed on this, as it might jog his memory on other
> studies with coffee grounds he has might know of.
>
> tenkyu tru,
>
> jim
>
>