Optimisation of bio-oil production by hydrothermal liquefaction of agro-industrial residues: Blackcurrant pomace (Ribes nigrum L.) as an example. (December 2016)

• Record Type: Journal Article
• Authors: Déniel, Maxime; Haarlemmer, Geert; Roubaud, Anne; Weiss-Hortala, Elsa; Fages, Jacques
• Is Part Of: Biomass and bioenergy. Volume 95(2016:Dec.)
• Page Start: 273
• Page End: 285
• Publication Date: 2016-12
• Subjects: Hydrothermal liquefaction -- Food processing residues -- Blackcurrant pomace -- Bio-oil -- Batch reactor; Biomass energy -- Periodicals; Biomass -- Periodicals; Energy-Generating Resources -- Periodicals; Bioénergie -- Périodiques; 333.9539
• DOI: 10.1016/j.biombioe.2016.10.012
• Languages: English
• ISSNs: 0961-9534

Abstract

Abstract: This work reports bio-oil production by hydrothermal liquefaction of blackcurrant pomace ( Ribes nigrum L.), a fruit residue obtained after berry pressing. The bio-oil has a higher heating value of 35.9 MJ kg −1 and low ash content, which makes it suitable for energy applications. We report the influence of process parameters on yields and carbon distribution between products: temperature (563–608 K), holding time (0–240 min), mass fraction of dry biomass in the slurry (0.05–0.29), and initial pH (3.1–12.8) by adding sodium hydroxide (NaOH). Depending on the experiments, the bio-oil accounts for at least 24% mass fraction of the initial dry biomass, while char yields ranges from 24 to 40%. A temperature of 583 K enhances the bio-oil yield, up to 30%, while holding time does not have a significant influence on the results. Increasing biomass concentrations decreases bio-oil yields from 29% to 24%. Adding sodium hydroxide decreases the char yield from 35% at pH = 3.1 (without NaOH) to 24% at pH = 12.8. It also increases the bio-oil yield and carbon transfer to the aqueous phase. Thermogravimetric analysis shows that a 43% mass fraction of the bio-oil boils in the medium naphtha petroleum fraction range. The bio-oil is highly acidic and unsaturated, and its dynamic viscosity is high (1.7 Pa s at 298 K), underlining the need for further upgrading before any use for fuel applications. Highlights: Bio-oil yields up to 31% mass fraction of the dry blackcurrant pomace via hydrothermal liquefaction. NaOH enhances biomass conversion, but increases ash content in the bio-oil. Volatility of the bio-oil is characterised by a large medium naphtha fraction.