i want to enroll in phd in india. i am interested in the topic "reduction in emissions in diesel engine by fuel blending". may i know the new fuel name for my research work that has not been used anywhere and can be easily available? i went through many research papers, they have used various fuels with diesel like CNG,LPG,Biogas,Methane,Hydrogen etc. so almost research have been done using different fuels with diesel. i want to reduce emissions by using some fuel that has not been used till now for research work and can get positive results. thanks