Valorization of winery and distillery by-products by hydrothermal carbonization

Abstract

This work aims at finding an alternative strategy to manage the waste generated by the winemaking industry to obtain a solid biofuel and phenolic compounds. The effect of temperature (180–260 °C), residence time (1–7 h), and biomass-to-liquid ratio (0.05–0.25) on the co-hydrothermal carbonization of vine pruning and exhausted grape pomace, by using vinasse as moisture source, is studied. The effect of the variables is investigated and optimized using the Box–Behnken design of response surface methodology to maximize mass yield, fuel ratio, energy densification yield and phenols extraction yield and to minimize energy consumption. The statistical analysis shows that the carbonization temperature is a crucial parameter of the process, decreasing the product yield on one hand and improving the quality of hydrochar on the other. At the optimal conditions (246.3 °C, 1.6 h, 0.066), an hydrochar yield of 52.64% and a calorific value of 24.1 MJ/kg were obtained. Moreover, the analysis of the H/C and O/C ratios of hydrochars demonstrates that carbonisation significantly improves the fuel properties of solid biofuel. Liquid by-products obtained from the HTC process are found to contain high concentrations of organic matter but the BOD/COD ratios suggest their potential valorization by biological methods.

A Comparative Study of the Influence of Various Fungal-Based Pretreatments of Grape Pomace on Phenolic Compounds Recovery

“…GP is usually improperly disposed of in the environment or burned without a clear waste management strategy, which can have numerous negative impacts on the environment (impending the germination of plants in the soil, occurrence of undesirable odors) and economic losses [ 3 ]. It is still widely used in distilleries for alcohol production, while a smaller part is used for composting or dried and used as fertilizer or animal feed [ 4 , 5 ]. In line with sustainable development and increasing consumer demand for the use of natural rather than synthetic resources, there is great interest in the reuse of GP for various purposes, such as the production of fertilizers, animal feed, functional foods, pharmaceuticals, cosmetics, industrial enzymes, composites, biopolymers, as biomass for biofuel production, to its use for mushroom cultivation, and as an additive to improve building insulation [ 1 , 6 , 7 , 8 ].…”

An Innovative, Green Cascade Protocol for Grape Stalk Valorization with Process Intensification Technologies

“…The winemaking sector is one of the most productive worldwide, involving the generation of millions of tons of waste. As a result, several studies have focused their attention on the reuse of grape by-products in the food sector, as ingredients for making functional foods, since they are a good source of bioactive compounds [4][5][6].…”

Substitution of Fossil Coal with Hydrochar from Agricultural Waste in the Electric Arc Furnace Steel Industry: A Comprehensive Life Cycle Analysis

“…Moreover, fuels from biomass are considered carbon neutral since the carbon dioxide emitted when they are burnt is offset by the CO 2 that was absorbed by the plants during their growth [9]. A significant amount of waste, both liquid and solid, is generated by the winemaking industry, and its management causes economic and environmental burdens [10]. To address this issue from a circular economy perspective, the hydrothermal carbonization (HTC) process is a promising option for producing renewable energy from the winery and distillery waste, also enhancing the biomass characteristics.…”