Process manufacturing produces co-products and by-products. A co-product is a saleable end item that results from a process. A by-product is a material of value that is produced incidental to or as a residual of the process.
D. a rock with metamorphic minerals but no foliation or lineation. A shale is metamorphosed into three rock types: (1) a banded gneissic rock; (2) a rock with small mica crystals with a shiny aspect; (3) a very shiny rock with large mica crystals; and (4) a dull slate with cleavage. Which of the following lists these rocks in order of increasing metamorphic grade?
There is no debate that U.S. shales produce predominantly light sweet grades. Those are premium grades that are easier to process than heavy sour grades (and cleaner in terms of environmental impact). Shale oil's value is reflected in the solid pricing these crudes receive in the global market. Claims that U.S. production mix is getting increasingly skewed towards super-light and ultra-light grades are not supported by the production data for the last three years.