Romania owns large quantities of agricultural and forest wastes, which are let on agricultural fields or around villages being subjected to the action of water, wind etc. These residues (biomass), when they are inappropriately stored may pollute the environment, especially the soil and groundwater layer. The paper is studying the biomass compaction process, in order to capitalize it as pell-ets/agro-pellets, being strongly influenced by biomass physical characteristics: dimensions, granulometric shape, humidity, density, etc). Depending on these features, different types of pellets (different recipes), obtained out of different mixtures of biomass can be achieved; thus, high quality pellets will be obtained and their valorization will significantly reduce the noxious emissions in atmosphere.