Re: GAS-L: Engines for Producer Gas

[Prof P P Parikh <parikh@me.iitb.ernet.in>]

Dear Dr. Peacocke
I will try to reply to part of your querry about Tar and Particulates in
Producer-gas and its suitability for I C Engines. I have the following
experimental experience:
1.	We operated a small single cylinder DI diesel engine under
Producer-gas cum diesel dual-fuel operation following a 16 hour standard
load cycle [0, 20, 40, 60, 80, 100 percent loadings for specified periods
of time, most of the operation being at 100% load and at the end reducing
the load in the same manner and noting down all possible observations.] 20
such cycles amounting to 320 hours were logged. At the end of each cycle a
sample of lubricating oil was drawn for analysis including particulate
accumulation, metal contents and the total base number. The engine was
stripped at the end and wear of different parts; piston, piston
rings, liner, crank and cam shafts and bearings, small and big end
bearings etc was measured. The following conclusions were drawn:
	a) The wear rate of certain parts definitely incresed, but
	   the increase was alarming!! Compression Ratio did not at all
           change and the bearing condition was satisfactory.
	b) Rate of lubricating oil deterioration did increase, but the
           oil consumption remained fairly unchanged. Rescheduling of the
           oil change by about 30 to 40% less time could easily take care
           of this effect.
	c) The main problem arose due to over heating of the fuel
           injection nozzle tip and the resultant clogging and coaking of
	   the nozzle holes. Much more frequent cleaning was warrented.
	   
	   It is important to mention that this excercise was carried out
           on a naturally aspirated engine and therefore the problems
	   associated with TAR and PARTICULATES and turbocharger were not
	   encountered.

	   It was concluded that if the engine is started and warmed up on
	   diesel mode and stopped also on diesel mode, the problems will
	   get further reduced.
	   Tar and Particulates through out this excercise were noted to
	   be TAR <100mg/cubic meter and Particulate < 50 mg/cubic meter.

	   WHILE STATING THE VALUES OF TAR AND PARTICULATES IT IS
	   IMPORTANT TO STATE THAT THE SAME WERE MEASURED USING AN
	   IMPROVISED THT-APPARATUS WITH ISOKINETIC SAMPLING AND ACETONE
	   AS THE SOLVENT. METHOD OF MEASUREMENT OF TAR AND PARTUCULATES
	   IS IMPORTANT TO THE EXTENT THAT IT PROVIDES A DEFINITION OF
	   TAR. THESE VALUES MIGHT BE VERY DIFFERENT IF SOME OTHER METHOD
	   IS USED. THERE ARE CASES WHERE MORE OR LESS ALL CONDENSIBLES
	   ARE TAKEN AS TAR. ACTUALLY WHATEVER CAN BE CONSUMED BY THE
	   ENGINE WITHOUT HARMING ITS PERFORMANCE; POWER, EMISSIONS,
	   MAINTENANCE AND LIFE SHOULD NOT BE TERMED AS TAR.
2. One twin cylinder diesel engine has been rebuild as a spark ignition
engine and has been operated on producer gas for over 1000 hours with all 
similar monitoring. Results are not very different in this case too.
Details  can be provided if required.    

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Prof. (Mrs.) P.P.Parikh          Phone  Office : 5783496, 5767548 
Dept. of Mechanical Engg.                        5782545 Ext. 7548 / 8385 
I.I.T. Bombay				Home   : 5704646 	
Mumbai 400 076 INDIA		 Fax	Office : 5783496, 5783480
		
                    email : parikh@me.iitb.ernet.in    			   
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

On Mon, 31 Jan 2000, Dr. C. Peacocke wrote:

> Dear Group,
> 
> I am trying to find an engine manufacturer who has a sympathethic ear to
> the needs of companies and organisations who are looking to buy a few
> small-scale engines [up to 1MWe] to run on producer gas, but it appears to
> be very difficult, based on stories and comments that I have heard.  My own
> experience is that a company will happily sell you an engine and leave the
> rest to you if anything goes wrong.
> 
> Interest by major companies, e.g Dale, Caterpillar etc., can be varied and
> I do not wish to go down paths many others have trodden.
> 
> Can anyone recommend an engine manufacturer who will provide the required
> level of technical backup in the modification and operation of an engine?
> Does anyone  have a detailed, requirement for the gas quality from an
> engine manufacturer?  I have seen several ''theoretical'' or "postualted"
> values for tars and particulates in the gas for an engine, but has anyone
> assessed the exact requirements based on long term operational experience?
> 
> I am aware of the limited range of interest on behalf of most engine
> manufacturers in Europe.  Can anyone in North America or elsewhere assist
> in pointing me to a suitable company?
> 
> Thanks,
> 
> Cordner
> 
> Conversion And Resource Evaluation Ltd.
> 9 Myrtle House
> 5 Cassowary Road
> Birmingham
> B20 1NE.
> Tel: (44) 121 551 0344 or  (44) 1232 687774
> Fax: (44) 870 0542981 or  (44) 121 359 6814 
> Internet:  http://www.care.demon.co.uk/
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