[Bioconversion] Online Briquetting Book

[andrew]

On Friday 25 November 2005 18:41, Jeff Davis wrote:

> If I may quote the book; "it is doubtful if the high capital cost and power
> consumption of this process makes it a viable proposition" I think the book
> was covering densification for small operations. I worked at a place that
> had a ring palleter and I must say that it was a pricey piece of equipment.
> Not some thing for Mom and Dad operation.

I note the point but we have a number of people asking about small scale 
pelleting and whilst the book points out the pros and cons of other methods 
it skips ring die pelleters without mentioning why they are so expensive to 
operate.

I would be interested in your stories about the one you worked with. I have 
little practical knowledge but did see that the GBP80k cost of a pelletter 
rose to ten times that for a full factory and that was only rated at 15k 
tonnes/annum!

One thing does seem clear is that the large scale device benefits better from 
heat in the die. Even the quoted book indicates the advantage of heating the 
die in a screw extruder, at the larger scale the input horsepower is 
sufficient to match heat losses.

Again it is a capital cost issue rather than emebedded energy in the pellet, 
as the total electrical requirement for pellet making appears to be less than 
2.5% of the thermal energy in the pellet.

AJH