Difference between calcination and pyrolysis
Essentially calcination is decomposition at high temperature with inorganic reactants such as calcium carbonate in making cement.
$$\ce{CaCO3 -&gt;[\Delta ] CaO + CO2}$$
Pyrolysis is decomposition or oxidation at high temperatures of organic materials such as cellulose in making charcoal.
$$\ce{(C6H12O6)_{n} -&gt;[\Delta] C7H4O + C_{x}H_{y} + H2O}$$
where $\ce{ C_{x}H_{y}}$ is volatilized byproducts.