My favorite way of discussing the more traditional chemical engineering careers is to look at them in terms of the product development cycle. Biography of a Product Invention Conception .
Someone decides a new product is needed.
A laboratory research chemist devises a way to make it. Typically, the initial process involves very small amounts of impure product and produces large amounts of unwanted by-products. Development Profitability . A chemist performs experiments and collects data for a preliminary estimation of yields. Marketing people develop estimates of demand and target sales prices.