When a chemical reaction occurs, the rate at which it proceeds is a function of the temperature and the concentrations of the chemicals involved in the reaction. Other variables, such as pressure and the presence of catalysts, may also have important effects on the reaction rate. Chemical reactions also often release heat (exothermic reactions) or absorb heat (endothermic reactions). To get the desired reaction to occur at the desired rate, chemical reactions are usually carried out in vessels called chemical reactors. Reactors are designed to facilitate the desired reaction conditions, and the chemical reaction system often includes a heat exchanger or other means of adding heat to or removing heat from the reacting mixture. The chemical reaction system usually includes instrumentation and controls (such as temperature sensors, flowmeters, control valves, and controllers) to adjust variables (such as flow rate) to maintain process variables at the desired values.
This chapter describes several common chemical reactor configurations, provides a brief introduction to process dynamics and control, and outlines the hazardous properties of materials.