Recovery versus incineration

FIGUEROA PAREDES, DANILO A.; AMELIO, ANTONIO; SÁNCHEZ, RAMIRO J.; ESPINOSA, JOSÉ

Handbook of Solvents, Volume Two: Use, Health, and Environment, Fourth Edition

Chemtec Publishing

Lugar: Torinto; Año: 2024; p. 1695 - 1735

In this chapter, the comparison between solvent recovery and incineration will be addressed through two case studies:Firstly, the economic and environmental performance of the alternatives distillation/incineration and distillation/pervaporation for the treatment of the azeotropic mixture iso¬propyl alcohol-water, whose separation by distillation is characterized by an energy demand controlled by tangent pinch points, is thoroughly analyzed.11 The incineration alternative, either in a conventional waste solvent incineration plant or in a cement kiln, resorts to a pre-concentration step by distillation. The recovery alternative, on the other hand, considers a hybrid process consisting of a distillation column followed by a per-vaporation unit. Quasi-optimal designs taking into account both operating and investment costs for each technological alternative were obtained by resorting to conceptual models of the units involved.12,13 Optimal values for the operation variables obtained at the conceptual design level were used as input data of the life cycle analysis to consider all impacts on humans and the environment during the entire life cycle of the solvent.5,14,15Secondly, the analysis of the recovery of different low-volume waste streams generated from multiple production campaigns with the same recovery system is presented.5 In this case, the recovery system carried out through a distillation skid considers not only sharp but also sloppy splits giving rise to a partial recovery of solvents. Therefore, the non-recovered fractions must be subjected to incineration. In this way, the implementation of the recovery system will become economically feasible while reducing the environ¬mental impact of the actual pharmaceutical processes. Partial or total recovery of solvents like acetone, acetonitrile, isopropyl alcohol (IPA), tetrahydrofuran (THF), and toluene involved in the production of three different active pharmaceutical ingredients (APIs) carried out in the same facility is considered.