[Digestion] diesel replacement

[Zietsman, Rex]

We were talking about the level of diesel replacement possible on
biogas. Here is the replacement level with gasifier gas...

Kind regards
Rex

Date: Wed, 21 May 2008 07:24:20 +0530
From: venusengineers <venusengineers at eth.net>
Subject: Re: [Gasification] wood gasifiers
To: Discussion of biomass pyrolysis and gasification
<gasification at listserv.repp.org>

Dear Tom, 

A hectic work schedule is the cause of delay in this overdue response,
for which my apologies. Some positive developments - we recently
commissioned a 1.5 MWe dual fuel generator at a textile mill in Southern
Tamil Nadu for off grid captive power. In initial runs, the specially
designed dual fuel generator could achieve ~ 92% diesel replacement with
producer gas. This opens up a whole range of new possibilities in
developing countries in Africa, Latin America and Asia as well as the
far north in Canada/Alaska/Scandinavia, which are abundantly endowed
with a variety of low cost biomass resources and handicapped by poor
grid penetration owing to remote habitations, resulting in their needs
being serviced by imported diesel operated generators. The "fuel miles"
are typically 500 - 1500 km as most of these locations do not have
refineries close by.

As many have observed, we have so far been chary of entering into new
countries, mainly owing to additional cost implications needing
deployment of trained manpower in distant lands over extended timelines
and warranty implications under different legal regimens. Only recently
did we decide to explore specific export projects where the ruggedness,
reliability, fuel flexibility, service life and PLF>80% of our systems
could prove useful in other settings.

Your point is well taken that the target price for a power plant in USA
should be about $ 2,500 -3,000/kWe of gross power, if you sell
electricity @ $0.10/kWh from wood received @ $ 25-30/MT. Depending on
unit capacity, this range can be achieved with our systems, subject to
conditions specific to each installation, despite the recent 25-50%
increases in input costs on mild steel, stainless steel and copper, You
will appreciate that our technology is designed to operate at > 7,000
hours/year in the industrial mode for faster recovery of capital costs
and for such a punishing schedule the makeshift solutions of the DIY
kind simply won't last. The result is higher upfront capital costs but
lower lifecycle costs and therefore lower cost of generation. 

The mulch like wood waste (possibly in the form of slivers/fibres) may
need to be compacted into briquettes prior to use in our systems, which
typically use "rounds" of wood/briquettes in sizes 1" to 3" in any
direction, obtained generally by transverse cutting of wooden poles with
multi-blade saw cutters. Our limited experience with chipped wood has
not been very encouraging. The as received moist wood is dried to ~10%
mc, using part of the engine exhaust heat suitably diluted with ambient
air in a continuous process drier. 

So, yes, we are willing to export our systems to other countries after a
careful assessment of all the inputs necessary to ensure their
successful operation. We are intentionally cautious, as good news
travels at the speed of sound and bad news at the speed of light. :)}

T R Krishnaswamy