"Petroleum products" means petroleum; any distillate, fraction, or derivative of petroleum; natural gas or its components; gas manufactured from a petroleum product; and any product derived from the gas or from the manufacture thereof, such as benzene, xylene, toluene, acetylene, tars, components of tars, and ammonia.
"Refiner" means any person who, in the State, engages in the business of refining petroleum products and is taxable under this chapter, upon the value or gross proceeds of sales of the petroleum products resultant from the business. A person who is engaged in business as a refiner and also in other business shall be deemed a refiner only in respect of the business that produces the products included in the measure of the tax imposed by this chapter.
"Refining" means:
HRS § 237-27