Solubility of menthol in pressurized carbon dioxide: Experimental data and thermodynamic modeling

Abstract

The paper reports new experimental data and the results of the thermodynamic modeling of menthol solubility in pressurized CO2. The solubility was measured using the dynamic method and modeled with the Soave-Redlich-Kwong equation of state in the temperature range 30-60?C and pressure range 66-144 bar. The results obtained were compared with the solubility data published by Maier and Stephan and by Sovov? and Jez. The agreement with Maier and Stephan was very good: The deviation of the solubilities, published by Sovov? and Jez, from the other data sources was explained and revised accordingly. The paper also presents for the first time experimental and modeling data for the melting point depression of menthol in the presence of carbon dioxide in the pressure range of interest up to 60 bars. The experimental data was obtained comparing the appearance of menthol particles before and after their exposure to pressurized carbon dioxide.U radu se navode novi eksperimentalni podaci i rezultati termodinamickog modela kojim je definisana rastvorljivost mentola u komprimovanom CO2. Rastvorljivost je merena primenom dinamicke metode, a model je razvijen na osnovu Soave-Redlich-Kwong jednacine stanja za uslove 30-60?C i 66-144 bar. Dobijeni podaci su uporedjeni sa do sada publikovanim u literaturi pri cemu su oni koje su objavili Maier i Stephan slazu sa rezultatima ovih ispitivanja ali je istovremeno ukazano i u ovom radu objasnjeno na neslaganje sa podacima koje su ranije objavili Sovova i Jez. Ovaj rad, takodje, po prvi put eksperimentalno verifikuje i teorijskim modelom objasnjava snizenje temperature topljenja mentola u prisustvu ugljen dioksida na pritiscima iznad 60 bara. Eksperimentalni podaci o temperaturi topljenja mentola su odredjeni poredjenjem stvaranja cestica mentola pre i nakon dovodjenja mentola u kontakt sa komprimovanim ugljen dioksidom.