*3.4. Operating Cost*

The breakdown of the operating costs is summarised in Figure 8. The direct manufacturing costs include the expenses for labor, supervisory, raw materials, utilities, and equipment maintenance and repairs. Tax and overhead are the fixed charges, while the expenditures for research and development, financing, and administrative form the general expenses [33]. The coziest raw materials are castor seed, plant residues, and sodium hydroxide. The byproducts of plants are bioethanol, glycerin, potassium phosphate, heat, and carbon dioxide. The highest revenue from the byproducts is obtained from bioethanol.

**Figure 8.** The breakdown of the operating costs.
