I have had the opportunity to work in both R&D and in a corporate engineering group. I will describe some of my main day-to-day activities in each area.
R&D: My work in R&D has mainly been in the development of commercial processes for specialty organic chemicals. This often involves working with synthetic organic chemists, who have defined the chemical route, and concentrating on both optimizing the synthetic conditions, and defining the means of isolating the material.
The techniques used in process development include bench-scale laboratory work, computer simulations where applicable (e.g., fractional distillation), and pilot plant work.
A specific example of a unit operation I have done considerable work on is crystallization. The bench-scale work often includes measurement of solubility curves and metastable zone widths, measurement of crystallization kinetics, and bench-scale crystallization experiments (to optimize conditions). Because crystallization affects downstream processing, evaluating the effect of crystallization conditions on filtration and drying rates is also important.
Corporate Engineering Group: This position entailed the design and implementation of large capital projects, as well as providing engineering assistance to operating plants. Day-to-day activities included generating process flow diagrams, or PFD's, which are basically material and energy balances of the process; generating piping and instrumentation diagrams, or P&ID's, which are the essential blueprints of the process, showing all equipment, piping, and instrumentation. Generating the P&ID's requires specifying all major equipment in terms of process requirements (so that equipment vendors have enough information to bid) and the sizing of all ancillary equipment such as piping, valves, and pumps. Another important task is the generation of cost estimates.
Looking back on my chemical engineering background, there are a few areas which stand out as being important in my career. I'll list them below:
Thermodynamics - Thermo. crops up all the time. An obvious example is in energy balances for processes. Also, in many process modeling applications such as fractional distillation. One interesting phenomenon which occurs frequently in crystallization work is polymorphism - the ability of a chemical compound to crystallize in more than one lattice structure. I have found basic thermodynamic principles to be invaluable in rationalizing this phenomenon, and helping to take the "black magic" out of it.
Statistics - Very important in design of experiments, and evaluation of both laboratory and production data. Signal-to-noise must always be evaluated. A common example of statistics is separating real effects from analytical (testing) noise.
Unit Operations - While most of what I know today was learned on the job, the basic college-level background in Unit Ops was the foundation on which the added knowledge was built.
Writing - Writing is an everyday activity, particularly with the growth of electronic mail. Required writing has included technical reports, status reports, cost estimates, and memos.