Besides training Refining skill, you can also gain status with the station faction to reduce the 5% tax, but at first your biggest enemy is refining waste. After you get Refining 5, you can train Refinery Efficiency which shaves another 4% off of waste per level. Note that it reduces waste rather than increases return. Big difference.
Why am I homeless? Why do all you motherfuckers need homes is the real question. They called it The Prayer, its answer was law Mommy come back 'cause the water's all gone