The palm oil agroindustry produces the most consumed vegetable oil in the world but also a significant quantity of residual biomass waste (e.g. empty fruit bunch, shell, palm oil mill effluent). The importance of using some of these residues for energy production is widely understood. However, the palm oil mill effluent (POME), which is responsible for the highest share of GHG emissions in palm oil production, is still conventionally treated in an unsustainable way. This research aims at investigating alternatives to retrofit Indonesian palm oil mills into biorefineries that could efficiently use POME to produce value-added products (e.g. electricity, compost and pellet). We present a literature review of mature treatments for biomass residues highlighting the most promising ones. Subsequently, biorefinery concepts are proposed comprising conversion technologies and the use of POME with other palm residues aimed at maximizing revenues while reducing environmental impact. The results are then evaluated through a multi-criteria analysis accounting for techno-economic, environmental and social impacts. The study demonstrates that POME treatment can be done in a profitable way resulting in significant reduction of methane emissions. The most interesting option is to generate electricity from biogas and use it on site to produce high-value products such as pellets and crude palm kernel oil. Biorefinery concepts are an opportunity for mill owners to comply with strict environmental regulations while generating extra profits.