Nowadays, the concept of sustainable production and consumption is a key lever towards bio-based economy, which has biomass conversion into bio-products and bio-energy production as essential elements. In this study, a two-step bio-refinery process fed with kitchen waste was investigated for the sequential fermentative production of two added-value products: lactic acid (LA) and biogas. Organic waste, representing a massive social, economic and environmental problem, could be employed in bio-refinery processes with three important benefits: production of added value products (LA and biogas), decrease of bio-refinery process costs and reduction of waste amount. LA and biogas production through biological pathways is based on mature technologies, already implemented on pilot and full scale. The aim of this research is the evaluation of technical, economic and environmental feasibility and sustainability of the proposed bio-refinery system, which is coherent with EU strategy on Circular Economy. The novelty of the approach consists of taking into account the conversion of kitchen waste into LA and biogas through two biological fermentative processes performed in sequence and combined into a value chain. The consistency of this study is verified by the implementation of the proposed value chain in areas with 2000 to 1 million inhabitants.