Abstract
Approximate analytical solutions for the overall adsorption functions based on the Fowler-Guggenheim local isotherm with a patchwise topology of adsorption centres location and four different adsorption heat distribution functions have been obtained. The Gaussian, constant, linear (as a particular case of power distribution), and exponential distribution functions have been applied. Overall adsorption functions have been analytically obtained, studied and commented. The Gaussian-related adsorption function reproduces the classic computational result nearly perfectly.