Increasing the energy yield of mechanochemical transformations: selected case studies

The products of mechanical treatment are surface atoms or molecules, substances with a crystal structure different from their initial one (another polymorph, amorphous), point or linear defects, radicals and new chemical substances. It is often assumed, that to increase the yield of the products of a mechanical treatment, it is necessary to increase the treatment time and the mechanical power input. In view of the low energy yield of many mechanochemical transformations, this leads to high power consumption and contamination of the matter under treatment with the wear products of the material of a mill or reactor, in which the mechanical treatment is carried out. As a result, the technological attractiveness of mechanochemical processes is reduced, so that many mechanochemical transformations that have been discovered recently do not reach the stage of commercialization. In the present paper we describe different examples of increasing successfully the energy yield of mechanochemical processes, by a factor of several times to several orders of magnitude, for inorganic and organic substances. An increase in the energy yield of mechanochemical transformations opens new possibilities for their practical usage. In particular, the methods of preliminary treatment and the modes of conducting enzymatic processes that may find application in the production of second-generation biofuels are discussed using lignocellulose materials as examples.