Experimental investigation of performance, emission and combustion characteristics of olive mill wastewater biofuel blends fuelled CI engine

•A biofuel was produced from olive mill wastewater by hydrothermal liquefaction.•Engine performance and emissions were investigated for diesel-biofuel blends.•B10 blend is less polluting than B20 and B30 and offers the best engine performance.•B10 is the most similar to diesel fuel in terms of performance and polluting emissions.