This chapter examines the production and biorefining of biocrude oil, highlighting the differences and potentials between traditional petroleum refineries and biomass biorefineries. Biorefineries utilize renewable sources, such as biomass, to produce fuels and chemicals, unlike petroleum refineries that rely on non-renewable fossil sources. This transition to biorefineries faces significant challenges, including high operational costs, technological needs for efficient biomass processing, and integration of new processes. However, biorefineries offer promising possibilities to reduce dependence on fossil fuels, lower carbon emissions, and generate sustainable products, marking a crucial evolution in the search for greener energy alternatives. Therefore, the biorefinery industry represents a vibrant technological development and innovation field, requiring supportive policies and continuous advancements to achieve its full potential.