Chemical engineers work on a surprisingly wide range of projects, from designing cleaner ways to manufacture medications to building systems that pull carbon dioxide out of the air. The common thread is scaling up chemical processes so they work safely, efficiently, and economically outside the lab. If a process involves transforming raw materials into something useful, a chemical engineer probably helped design it.
Pharmaceutical Manufacturing
One of the most impactful areas for chemical engineers is figuring out how to produce drugs at scale. A chemist might develop a new molecule in a lab flask, but someone has to design the full-sized production process, and that’s where chemical engineering comes in. Projects include scaling up drug synthesis from grams to tons, designing continuous manufacturing lines that run nonstop instead of in batches, and optimizing the conditions (temperature, pressure, mixing speed) that determine whether a process yields 60% or 95% of the desired product.
A good example: a European Commission-funded project developed a new way to produce flucytosine, a drug used to treat a deadly fungal meningitis common in HIV/AIDS patients. Chemical engineers redesigned the synthesis using flow chemistry, a technique where reactions happen in a continuous stream through tubes rather than in large vats. The new process eliminated the need for expensive toxic chemicals, used fewer raw materials, and generated less waste. The result was a dramatically cheaper drug that could realistically reach patients in sub-Saharan Africa, where the disease kills an estimated 500,000 people per year.
Green Hydrogen Production
Chemical engineers are central to the push for green hydrogen, which is hydrogen made by splitting water using renewable electricity. The core technology is an electrolyzer, and optimizing these devices is a major area of active project work. Engineers focus on reducing the amount of precious metals needed in electrode design, improving efficiency at high electrical currents, and building systems that can handle intermittent operation (ramping up when solar or wind power is abundant, shutting down when it’s not) without damaging the equipment.
The economics are moving fast. Current electrolyzer systems from US and European manufacturers cost around $1,000 per kilowatt, but prices are dropping along a curve similar to solar panels and batteries, both of which fell roughly tenfold since 2010. If capital costs reach $200 per kilowatt by 2030, and electrolyzers run at about 30% capacity using electricity priced around one cent per kilowatt-hour, the resulting hydrogen could cost as little as $0.19 per kilogram to produce. Chemical engineers working on these projects tackle everything from managing gas bubble formation on electrode surfaces (which directly affects efficiency) to designing the storage tanks and pipelines that buffer hydrogen for industrial customers making fertilizer, steel, or synthetic fuels.
Carbon Capture and Storage
Removing carbon dioxide from industrial exhaust or directly from the atmosphere is one of the defining engineering challenges of the next few decades, and chemical engineers design the processes that make it work. Projects fall into two broad categories: point-source capture, where CO2 is grabbed from factory or power plant exhaust, and direct air capture, where machines pull it from the open atmosphere.
Point-source capture from concentrated streams, like those at ammonia or ethanol plants, currently costs just under $50 per ton of CO2. Capturing it from power plants or cement factories, where the CO2 concentration is lower (5 to 15%), runs $70 to $150 per ton. Direct air capture is the most expensive because the atmosphere contains only about 0.04% CO2. Some estimates put it above $500 per ton today, though engineers are working to bring that number down significantly.
The actual project work involves designing and optimizing the chemical solvents or solid materials that absorb CO2, engineering the equipment that heats those materials to release the captured gas, and planning the pipeline and geological storage systems that lock the CO2 underground permanently. These projects require chemical engineers to work alongside geologists and materials scientists.
Battery Recycling
As electric vehicles become mainstream, the question of what happens to billions of spent lithium-ion batteries is creating a new class of chemical engineering projects. The dominant approach is called hydrometallurgy, a wet chemistry process that recovers valuable metals from dead battery cells.
The process starts by shredding entire battery cells into a fine powder known as black mass. That powder is then dissolved in acid, creating a liquid containing cobalt, lithium, nickel, and manganese. Chemical engineers design the separation steps that pull each metal out of this mixture individually and convert them into sulfate salts, which are pure enough to go right back into new battery production. Companies like Northvolt have built large-scale facilities around this process. The engineering challenges include handling hazardous materials safely, maximizing how much of each metal gets recovered, and making the economics work so recycling competes with mining fresh ore.
Process Optimization With Machine Learning
A growing number of chemical engineering projects don’t involve building new plants at all. Instead, they focus on making existing operations smarter. Machine learning is now used to model the complex, nonlinear relationships between process inputs (temperature, pressure, flow rate, catalyst type) and outputs (product yield, energy consumption, waste generation). These models can predict how a reactor will respond to changes faster than traditional simulation software, which makes them useful for real-time decision making.
Practical applications include predicting coke buildup in fluid catalytic cracking units at oil refineries, optimizing which catalysts to use for a given reaction, and designing experiments more efficiently so fewer trial runs are needed. Engineers also use reinforcement learning, a technique where an algorithm learns by trial and error, to improve process scheduling and control. The biggest payoff comes in time-sensitive situations where a plant operator needs an accurate recommendation in seconds, not hours.
Food, Water, and Consumer Products
Not every chemical engineering project involves heavy industry. Engineers in the food sector design pasteurization systems, optimize fermentation processes for beer and yogurt production, and develop new methods for extracting flavors or nutrients from plant materials. In water treatment, they design the membrane filtration and chemical disinfection systems that turn wastewater or seawater into drinking water.
Consumer product companies rely on chemical engineers to formulate everything from laundry detergent to sunscreen. These projects involve selecting surfactants that clean effectively at low temperatures, designing emulsions that stay stable on store shelves for years, and scaling up production so a formula that works in a one-liter test batch still performs identically in a 10,000-liter mixing tank. The underlying challenge is always the same: controlling chemical and physical processes at industrial scale while hitting cost, safety, and quality targets.
What Ties These Projects Together
Across all these industries, chemical engineers do a few things consistently. They design and optimize processes that convert raw inputs into valuable outputs. They figure out how to do that at large scale without sacrificing quality or safety. They balance competing constraints: cost, efficiency, environmental impact, and speed. And increasingly, they use computational tools to model and predict system behavior before anything gets built. The range of industries is broader than most people expect, which is part of what makes the field flexible for people entering it.