Abstract
This paper describes a Stantec-developed design tool for sizing of continuous stirred tank reactors (CSTRs) and evaluating alternative configurations of CSTRs. This tool allows a quick and straightforward approach to the CSTR design, by inserting kinetic, water chemistry, reactor loading, and temperature data to calculate and compare the volumes for single versus multiple reactor networks. The tool is used to predict pseudo zero-order, first-order, pseudo first-order, and second-order reaction kinetics, and complete the CSTR designs. Outputs include conversion rates, residence times, reactor volumes, and reactant effluent concentrations for each reactor in a network of up to four CSTRs in series. This tool standardizes the calculation of CSTR sizing information in single and multiple reactor network cases, allowing designers to effortlessly assess the CAPEX (capital expenditure), OPEX (operating expenditure), and footprint of various reactor configuration scenarios, ultimately defining the chemical process design envelope. We demonstrate the tool’s application through a case study of designing a temporary water treatment system for a Canadian mine to treat ammonia via the breakpoint chlorination process. Following the standardized procedure described herein, Stantec engineers determined an optimal reactor design configuration based solely on process reaction kinetics obtained from literature and confirmatory laboratory experiments. The proposed process consisted of three CSTRs in series to treat a process side stream followed by re-blending prior to discharge. Through this lens, we discuss the practical application of this standardized tool and describe benefits due to improved engineering effort efficiencies and mitigation of quality control issues.