This paper repor
ts rea
ctive dynami
cs (RD) simula
tions of a ma
cro-model of Morwell Brown
coal using
the ReaxFF rea
ctive for
ce field. We find
tha
t these rea
ctive MD simula
tions su
ccessfully reprodu
ce
thermal de
composi
tion pro
cesses of defun
ctionaliza
tion, depolymeriza
tion and rearrangemen
t of
the residual s
tru
cture observed in various experimen
tal s
tudies. For example, our simula
tions indi
ca
te
tha
t the de
carboxyla
tion and dehydroxyla
tion of
the lignin side
chain of
the Morwell model involves
the forma
tion of double bonds
conjuga
ted wi
th
the aroma
ti
c rings. The pro
cess of defun
ctionaliza
tion of
the me
thoxy fun
ctions involving
the forma
tion of phenoli
c s
tru
ctures in
the residue has been
confirmed. We also observe
tha
t gaseous hydro
carbons are genera
ted by
cleavage of C–C bonds of
the lignin side
chain.
The success in using ReaxFF RD to describe the molecular processes underlying the kinetics in pyrolysis of this model of coal plus the success of a similar previous study on the algaenan of Botryococcus braunii race L biopolymer model of kerogens suggests that such computation can be useful in providing molecular based kinetic models for other pyrolysis processes underlying the organic transformations in sedimentary materials.