  The aim of the presented work is to analyze the impact of experimentally
evaluated reactions of hydrogen abstraction on surfaces of interstellar grains
on the chemical evolution of methanol and its precursors on grains and in the
gas phase under conditions of cold dark cloud and during the collapse of the
translucent cloud into the dark cloud. Analysis of simulation results shows
that those reactions are highly efficient destruction channels for HCO and H2CO
on grain surfaces, and significantly impact the abundances of almost all
molecules participating in the formation of CH3OH. Next, in models with those
reactions maximum abundances of methanol in gas and on grain surface decrease
by more than 2-3 orders of magnitude in comparison to models without surface
abstraction reactions of hydrogen. Finally, we study the impact of binding
energies of CH2OH and CH3O radicals on methanol chemistry.
