The great thing about engineering is that once you graduate, the disciplines end up overlapping greatly. It's interdisciplinary in the field and you can find a job or company or industry when you graduate that covers multiple areas instead of just one. I would recommend you learn more about what engineers are actually doing in these fields so you can better understand how you can make a difference in our world as an engineer. Check out the profiles on www.engineeryourlife.org and at www.fabfems.org. And yes, grad school in another discipline is something that students oftentimes do, again because of the interdisciplinary aspect of the world of engineering.
Just to give you a bit more on ChE, here's some info I'd shared when someone asked me about the greatest thing about being a ChE:
Chemical engineering is an extremely broad field where you can impact our world, create products and process that improve lives, and work in just about any industry out there. I went into the chemical industry and then ended up in higher education. My career path included working in process design where I designed the processes to manufacture various chemicals, to research where I worked on developing new testing methods for chemical products, to new business development where I worked with customers testing out our products in their systems and in their products to see if our product would work better in the market. I have friends in environmental or patent law, consulting, personal care products, automotive industries, chemical processing, oil & gas, energy, government and more.
Focusing on my Product Development Engineer role, one of my jobs was to work on the development of a process and formula for using a Dow epoxy (plastic/polymer) in biodegradable packaging peanuts. I worked on pilot testing various formulations, testing the product, researching options on manufacturing the peanuts (made on the same machine as Cheetos’s by the way), and interacting with the potential customers to test our product on their machines and assess their needs. I traveled to customer sites, conducted research at various universities where they had the equipment we needed to use (Dow didn’t have the equipment in house), and worked with a team of chemists, engineers, manufacturing specialists, technicians, equipment fabricators, customers, etc.
I love the flexibility and creativity involved in being a chemical engineer. With a degree in chemical engineering, I’m ready to tackle a challenge in a variety of fields and have the creativity to come up with a number of solutions. I could head to the food industry to design healthier potato chips or soda bottles that keep the fizz forever. I could work in the oil and gas arena, designing looking at ways to harness energy in environmentally and economical ways. I could explore the plastics industry, seeking to reduce waste, develop applications for biodegradable plastics and come up with the latest and greatest new gadget. I could work for a consumer product company, figuring out how to make a toothbrush that has bristles that never wear out or new household cleaners or never-chip fingernail polish. Chemical engineers are everywhere you find paints, plastics, food, packaging, medicine and so many other things we interact with in our daily lives.
Chemical engineers work in a variety of environments and it can vary based on your interests. I have worked in an office setting, a corporate lab setting and a university lab setting, and a production environment where I was often out in the chemical plant. Depending on what environment best suits you, you can find a chemical engineering job to fit. I have worked on projects where I was the sole person seeking a solution with input from a variety of customers. I have worked on small teams of 2-5 people to seek a solution. I have also worked on large teams of 20+ where each person or small group of people had specific responsibilities that tied in together to provide the overall design or solution.
Chemical engineering is one of the most diverse engineering fields. With chemical engineering, you really can make a world of difference!