43. Symposium "Actual Tasks on Agricultural Engineering", Opatija, Croatia, 2015. 667 43. SIMPOZIJ AKTUALNI ZADACI MEHANIZACIJE POLJOPRIVREDE UDC 004.42:582.542.2 Stručni rad Expert paper COMPACTING PROCESS AND MATHEMATICAL ANALYSIS OF MISCANTHUS BRIQUETTES EXPANSION I. VOICEA 1 , V. VLĂDUğ 1 , P. CÂRDEI 1 , M. MATACHE 1 , I. GĂGEANU 1 , GH. VOICU 2 , C. POPESCU 3 , G. PARASCHIV 2 , O. KABAS 4 1 INMA Bucharest / Romania 2 UPB Bucharest / Romania 3 SC HOFIGAL SA / Romania; 4 Batı Akdeniz Agricultural Research Institute / Turkey SUMMARY In the last hundred years, man intensively exploited the primary energy sour- ces (coal, petroleum and natural gases), which led to a major contribution of CO 2 in the atmosphere, much above the possibilities of the “planet’s lungs” (plants and trees in the terrestrial ecosystem) to consume during their growing period. That is why, scientists recommend more and more, in the last period, the use of renewable bio-fuels coming from vegetal biomass. In this category falls the plant Miscanthus x giganteus which becomes a viable energy alternative to the conventional energy sources. The paper presents the compaction study of Misca- nthus x giganteus plant by means of an experimental installation in laboratory conditions. At the same time, the asymptotic behavior of the expansion (the dimensional evolution in a chosen period of time) of the briquettes made through a densification process, the data being processed using specialized mathematical programs in order to obtain an adequate mathematical equation. Key words: Miscanthus x giganteus, densification, briquettes, relaxation in time, mathematical model INTRODUCTION Biomass, in its original form, is hard to be successfully used as fuel in large dimension applications, because it is rather voluminous, damp and dispersed. Biomass densification represents a technological solution for factories converting residues into fuel Tumuluru et al