Tequila Still Distillation Fractioned Residual Streams for Use in Biorefinery

Edna Rosalba Meza-Escalante,Ruth Gabriela Ulloa-Mercado,Edgardo Martinez-Orozco,Pablo Gortares-Moroyoqui,Celia De la Mora-Orozco,Juan Napoles-Armenta,Luis Humberto Alvarez-Valencia,Luis Alonso Leyva-Soto,Norberto Santiago-Olivares

doi:10.3390/en13236222

Abstract

Tequila vinasses is a mixture made from up to six still distillation two-stage process residual effluents. First stage fractions: residual must (60%), heads (0.9%) and tails (20.0%); second stage fractions: non-evaporated (8.0%), heads (0.1%) and tails (1.0%); the result is a more complex effluent for its treatment or biorefining. The objectives of this study were to: (a) characterize the five still distillation volatile streams in the Tequila 100% Agave processing; compounds: methanol, ethanol, acetaldehyde, ethyl acetate, sec-butanol, n-propanol, iso-butanol, n-butanol, iso-amyl, n-amyl, and ethyl lactate were detected by gas chromatography; calculated chemical oxygen demand from chemical composition had very high values (53,760–1,239,220 mg/L); measurement of pH (3.24–4.80), color (38.6 UC Pt-Co max), turbidity (46.1 max), electrical conductivity (3.30–172.20 μS/cm), and solid content (0 mg/L) was also made; (b) report an energy analysis (2.02 × 109 KWh) and CO2 production (429 × 106 kg) in the Tequila industry during 2019; (c) up to date residues (365.2 × 106 kg agave bagasse, 1146.1 × 106 kg agave leaves and 3300.0 × 106 L agave vinasse) in 2019; (d) economic analysis, current tequila vinasses treatment price is 16.00 USD/m3 but could reach a considerable fraction value if is bio-refined, a break down component analysis reach for five volatile streams $51.23–$140.00 USD/m3.

Highlights

IntroductionTequila is a Mexican beverage protected by Origin Denomination, its production and commercialization are verified and certified by Tequila Regulating Council (CRT) [1,2]
Tequila vinasses are considered to be a single waste stream produced in the tequila distillation process; the six still distillation waste effluents have not been taken in consideration separately
Tequila vinasses are liquid waste from tequila distillation process that have been treated as a single stream; there are six residual streams that could be treated separately instead of conforming a single stream; this perspective will simplify their destination

Summary

Introduction

Tequila is a Mexican beverage protected by Origin Denomination, its production and commercialization are verified and certified by Tequila Regulating Council (CRT) [1,2]. The tequila production process consists of Agave tequilana Weber sugars extraction, by hydrolysis or cooking followed by milling to obtain agave juice for further fermentation, distillation, mixing, aging, and bottling. Tequila has two categories: “Tequila 100% agave” and “Tequila” Energies 2020, 13, 6222 with a minimum 51% agave reducing sugars and generally completed with cane sugar). It produces the following residues: agave leaves, agave bagasse, and tequila vinasses [1,2,3,4]

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