1. The source and price of gutter oil are important factors affecting profits. If you can get a lot of waste oil from low-priced suppliers, the profit margin may be even greater.

2. Refining process and production cost will also affect profits. Different refining processes and production costs will lead to different quality and output of final products, thus affecting sales prices and profits.

3. Market demand and sales channels are also important factors affecting profits. If the market demand for refined products is large and the price is high, then this will increase profits.