If you heat a piece of wood in the absences of oxygen the wood
produces combustible gas.  Wood gas I believe it is called but that
doesn't matter to me.  My question is where or how to find out the
amount of energy (BUTs) used to convert the wood molecules into char
and gas.  Also of interest is the temperature at which all the
material is converted?  I am not interested in the BTUs to change the
temperature of the wood or to drive off the moisture.  These things I
under stand well.  Also the energy to change the temperature of the
container is of no interest either.  The question is about the
endothermic part of the reactions and how to lookup or calculate the
energy input to do the conversion of the material.  I want to be able
to determine this energy input for a number of different materials
like coal, LP gas or plastic.  What is this property called and is there a
chart for this type of information.

The process you are interested in is called calorimetry.

Depending on the type of reaction(heating various materials to
decomposition will result in different products depending on
temperature, pressure etc.) you are performing, one can simply look up
the associated heats of formation of the materials you are interested
in.  Comparison of the heats of formation of the products vs. the
reactants will get you the energy you are interested in.

I am not sure if there are engineering type tables of poorly
characterized materials like wood that show the energy consummed from
the from anaerobic decomposition of wood.

Chugs,