A chemical process refers to the activity in which products chemically react with each other to form new products.
A chemical process is any laboratory or industrial activity in which products chemically react with each other to form new products. The reactions change the structure of the product molecules, rather than adding them in a mixing process. Mixtures can result from these activities, but a chemical change has occurred in one or more of the reacted materials.
Process designs often involve building larger molecules from smaller molecules found in raw materials. Some reactions can break up larger molecules and rearrange them in different ways to produce a final product. Multiple reactions may be necessary to produce a desired molecule and may include additional raw materials or changes in temperature or pressure to cause different products to form. A process can be a single reaction step or an industrial operation creating finished chemicals on a large scale.
Chemicals are produced for the first time on laboratory-scale equipment, both to confirm the necessary steps and to adjust the reaction temperatures and pressures, often necessary for reactions to take place. Many industrial chemical processes take place at high temperatures and/or pressures, but less frequently, reactions can take place at very low pressures or in a vacuum, or at very low temperatures.
Catalysts can be used to aid the chemical reaction when designing a chemical process. These are products that speed up or speed up the reaction, make more of the desired end product compared to other by-products, or, in some cases, allow reactions to take place at lower temperatures or pressures to reduce costs. High pressure or temperature reaction vessels can be expensive to manufacture, so a catalyst can be important when designing chemical plants.
Testing in a pilot plant, or on a small scale, in operations can be the next step in process design. Reaction times, temperatures and pressures must be reviewed and optimized to produce the right chemicals and reduce material waste. Products must be separated and purified in additional steps, and additional reactions may be required before the final product is made. Residual materials need to be determined and ways to neutralize or dispose of them found to minimize environmental problems. Pilot plant testing is important because some lab tests do not work properly when performed on larger equipment and design changes may be required before a full-scale plant is built.
A large-scale industrial chemical process can take years to build at great expense, so it is necessary to verify all equipment and process control requirements before construction begins. Chemical plants require raw material supply by train or truck, using tanks for liquids, cylinders or high pressure vessels for gases, and storage space for bags or drums. Reaction tanks or towers are required for the production of raw or unpurified finished products, and all piping, electrical, and instrumentation must be designed to connect all parts of the process. Chemical process designs include methods to separate and recycle unused raw materials back to the front of the process to reduce waste and operating costs.
Once finished products are purified and separated from the chemical process stream, storage may be required until they are shipped to customers. This may include additional tanks for liquids, cylinders for gases, and storage for drums or bags, and some products may have specific storage temperatures or conditions to maintain quality and avoid safety issues. A manufacturer may have trucks or tank cars available to ship large quantities to customers, and these fleets may be owned or leased.
Each reaction in a chemical process is a step, and many can be combined into a complex chain of events called a chemical factory. Chemical process engineers and plant designers carefully consider the interaction of all steps to create an efficient operation. Product quality, energy efficiency and waste minimization are carefully considered in process design and are essential to producing a profitable chemical operation.