Specific Heat Value of Cow Manure

No idea of any actual value - but I suspect that the water content will by far outweigh the solids - both in mass and thermal capacity.

IMHO, take all the water out and what's left isn't much more than straw.

The thermal properties of dairy cattle manure were measured at the different temperature and moisture content. The specific heat and thermal conductivity of dairy cattle manure increased linearly from 1.9925 to 3.606 kJ kg-1 °C-1 and from 0.0901 to 0.6814 W m-1 °C-1, respectively.
I'm looking for the source citation.

BS.

A picture is worth a thousand words:

The data cited by Lyn are found on this page:

http://www.international-agrophysics.org/en/issues.html?stan=detail&vol=23&numer=4&paper=803&i=7

This is a web page of the Institute of Agrophysics of the Polish Academy of Sciences, and the paper comes from the University of Tehran. They offer an 8-page PDF of the article without charge and in English here:

http://www.international-agrophysics.org/artykuly/international_agrophysics/IntAgr_2009_23_4_359.pdf

Unsurprisingly, the article is entitled Thermal Properties of Dairy Cattle Manure.

I doubt that there is such a "calculated value," but there might be some measured values for various samples and dilutions of cow manure.

Do you really want specific heat (slightly less than 1.00), or combustion heat (so many Btu/lb)?

Here i believe is some of the info you are looking for.

http://energymd.wordpress.com/2008/12/05/heat-free-nearly-with-a-compost-furnace/

The exact information you need is presented here:

http://www.oardc.ohio-state.edu/ocamm/images/ManureTech11_keener.pdf

in Table 1 on Page 7.

Mark Bingham
Relativity PL

I'm not the OP, but thanks! In an attempt to save us all from looking at that table, the HHV (Higher Heating Value) on a dry basis for swine is 18.80 and for cattle is 17.01 MJ/kg) (Mega Joules per kilogram)

For us metrically challenged folks, multiply those numbers by 238 to get BTU/lb., thus: swine is 4474 and cattle is 4046 BTU/lb.

Don't forget that is on a dry basis, and there is a lot of water to remove--the water content is listed, but I'm not sure of the units--it might be % by weight as received: swine is 68, cattle is 81.

IIUC, to get the HHV (i.e., to make use of the HHV), you must get rid of all the water at an energy cost of, well: "The difference is caused by the heat of evaporation of the water formed from the hydrogen in the material and the moisture. (1 kJ/kg = 0.4312 btu/lb)"

Here's a clickable link to that pdf--it looks like an interesting document--it also talks about the value of the fertilizer in the manure.

Of course, the higher value use of this manure may be as meat. Did somebody post that link here already, or did I just happen to come across it yesterday: Japan scientist synthesizes meat from human feces

I'm making plans to become a vegetarian ;-)

Here is some information that may help you.

Few years ago we used to manufacture pellet stoves. These stoves are for environmental heating and use wood pellets as combustible. We wanted to sell these stoves in India using a locally available "fuel".

It is well known that in India since ages, they use cow dung (as they call it) to run brick furnaces in rural areas.

Now there is big difference between cow dung and the excrement of any other animal except of course elephant dung.

We mixed cow dung with 20% straw, as they do in India. We then extruded the mixture in a "Spaghetti Machine" to form pellets which were eventually dried. I don't know the final water content but the pellets were pretty hard.

We then compares the heating characteristics of these pellets with the characteristics of wooden pellets and found the performance to be 20% better.

Knowing that the wooden pellets have a calorific value of 4500 W/kg we presumed that the cow dung pellets (with straw) would be about 5400 W/Kg.

There was no scientific calculation behind this, only comparison but the real calorific testing can be done in any equipped lab.

This seems to be on the right track. Combustion heating value is likely to be more useful than specific heat. GA.

I seem to remember watching my brother-in-law doing this test when he was working on his Masters Thesis (Bio-chemistry)- If I remember correctly he gathered a lot of samples, dried them, put them through a pellet processor, weighed them and then burned them and measured how much energy they produced...or something like that...sounds like a research project to me.

How much heat removed from a mix of manure and water? That's his question.

In my physics days specific heat was the amount of heat required to raise the temperature of 1 gram by 1 degree C.

Is this guy looking for composting heat from a manure slurry? He makes no mention of drying and burning. Problem would be if you cool a compost heap it will slow or stop composting.

This hybrid system, how is the other part producing heat?

Then we can all give some constructive answers.