Closed-loop control of a hydrocarbon process is provided by an analyzer including an instrument configured for measuring a property of the liquid mixture, and having responsivities to concentrations of one of the components, independent of concentrations of others of the components. A temperature detector generates temperature data for the liquid mixture, and a processor captures data generated by the temperature detector and the instrument, and uses the data in combination with a model of responsivities to various concentrations of the components at various temperatures, to determine a temperature compensated concentration of the components while the liquid mixture flows continuously through the analyzer. A process control module including a process model of the hydrocarbon process, is coupled to the analyzer and is couplable to the hydrocarbon process, to receive the temperature compensated concentration and to generate at least one output configured to affect operation of the hydrocarbon process.