Quantum Computing for Vapor-Liquid and Liquid-Liquid Equilibrium Calculations

Abstract

A Quantum Computing (QC) environment was implemented to perform calculations for Vapor-Liquid Equilibrium for the system Ethanol – Water at 1.013 bar, and ternary Liquid-Liquid Equilibrium for the system N-Octane – 1-Octene – Nitroethane at 273.15 K. In addition to the common adjustable parameters for the success in simulations, the number of qubits for each case was critical, being required 14 and 24 Toffoli qubits for VLE and LLE respectively. Time required for calculating phase equilibria was about 30s for VLE, and about 20 minutes for LLE in a conventional computer emulating a quantum computer, with codes that must remain unchanged whether a real or emulating machines are used. Measurements and calculations performed in QC will not necessarily replace classical computing, but can work together in order make the hard work easier. Considering the results obtained, the time required, and availability of the software, it may be said that QC must be considered now as another available alternative for engineering calculations.