From GT School of ChBE website:
"Chemical engineering is a broad and versatile discipline in which chemical engineers work on the development and application of processes that change materials either chemically or physically. This branch of engineering was originally based on the applications of chemistry, combined with the principles of physics and mathematics. Over time, and with increasing speed, it has evolved so that biological sciences and chemistry now fill the position once uniquely held by chemistry. This evolution led the School to add “biomolecular” to its official name in 2003. Chemical engineers use their knowledge to manipulate molecular properties of matter, and in this process, they integrate product and process design, process control, and optimization. Economics and business principles also play an important role in chemical engineering, for it is the chemical engineer who develops economical and environmentally safe applications of discoveries made in the laboratory."