Various technologies and their combinations for production of highvalue chemicals, including liquid biofuels (bioethanol, biobutanol),from non-edible lignocellulosic biomass have been extensivelydeveloped over the years. High fermentable sugar and final productyields have been achieved with chemical and/or physical biomasspre-treatment/hydrolysis techniques. However, more and moreattention has been made on the design of environmentally friendlyand simple technologies that could generate high product yieldsand could be introduced into industrial production.Within the research activities, the selection of the most appro-priate biomass pre-treatment method that could be combined withenzymatic hydrolysis have been evaluated. In house productionof hydrolytic enzymes from fungi was introduced to minimizethe external impact and production dependency on raw chemi-cals. Fermentable sugar purification, inhibitor removal and enzymerecirculation was performed with membrane technologies. Theresults showed that for grass and hay biomass prior enzymatichydrolysis it is sufficient to perform simple mechanical milling(fractions <0.5 cm) in combination with boiling (1 atm). Fungalenzymes produced similar activities as commercially available pro-ductions. Initial assessment of enzyme recovery demonstrated upto 70%. Introduction of membrane system allowed to concentratethe produced enzymes more than 4 times to generate enough sugarfor fermentation. Overall biomass conversion rates increased 80%.Thus, it was possible to demonstrate an environmentally friendlyand efficient technology for lignocellulosic biomass conversion.