Ethanol Production from Olive Oil Extraction Residue Pretreated with Hot Water

Abstract

The olive pulp fraction contained in the residue generated in olive oil extraction by a two-step centrifugation process can be upgraded by using the cellulose fraction to produce ethanol and recovering high value phenols (tyrosol and hydroxytyrosol). Olive pulp was pretreated in a laboratory scale stirred autoclave at different temperatures (150-250°C). Pretreatment was evaluated regarding cellulose recovery, enzymatic hydrolysis effectiveness, ethanol production by a simultaneous saccharification and fermentation process (SSP), and phenols recovery in the filtrate. The pretreatment of olive pulp using water at temperatures between 200°C and 250°C enhanced enzymatic hydrolysis. Maximum ethanol production (11.9 giL) was obtained after pretreating pulp at 210°C in a SSP fed-batch procedure. Maximum hydroxytyrosol recovery was obtained in the liquid fraction when pretreated at 230°C.

Bioremediation and biovalorisation of olive-mill wastes

“…The yield of the enzymatic hydrolysis (expressed as glucose obtained in the enzymatic hydrolysis divided by potential glucose in the raw material) was in the range 38-49%, and concentrations of >10 g l −1 of glucose after the hydrolysis could be obtained (Ballesteros et al 2001). Pre-treatment of TPOMW with hot water (200-250°C) combined with the use of feed-batch procedure is another option to improve the production of ethanol (Ballesteros et al 2002). In another recent study (Georgieva and Ahring 2007), an enzymatic hydrolysis and subsequent glucose fermentation by baker's yeast were evaluated for ethanol production using dry matter of TPOMW.…”

Olive Mill By-Products Management

“…These by-products could also be used as animal food, or in biodegradative processes to produce ethanol (Ballesteros et al, 2002), or compost for agricultural utilization. Nevertheless the olive pomace, being constituted by vegetable not fermented organic matter, does not contain heavy metals, toxic pollutants or pathogens, and can be considered as a vegetable amendment (Table 3), (Alburquerque, et al 2004).…”

Valorisation of agro‐industrial by‐products, effluents and waste: concept, opportunities and the case of olive mill wastewaters

“…In contrast to the chemical approach that has attracted much attention in the last two decades with interesting and promising results, the possibility of a biotechnological approach for OMW valorisation has been given relatively less emphasis. With the exception of (a) energy generation through anaerobic digestion that couples disposal to effective methane production,17, 36–39 and (b) ethanol production,40–43 the literature concerning OMW utilisation for the fermentative production of added‐value products and/or commodities appears somewhat limited 24…”