Olive Mill by-Products Thermochemical Conversion via Hydrothermal Carbonization and Slow Pyrolysis: Detailed Comparison between the Generated Hydrochars and Biochars Characteristics

Abstract

In this research work, an ecofriendly approach was adopted for the treatment of two abundant liquid and solid agricultural wastes generated by olive mill industry: olive mill wastewater (OMWW) and raw olive pomace (ROP). It consists, firstly of the impregnation of ROP by OMWW and the conversion of the resulting impregnated sample (IROP) into hydrochars and biochars through hydrothermal carbonization (HTC) and slow pyrolysis methods, respectively. The impact of the treatment temperature on the physico-chemical properties of the derived chars was assessed by various analytical techniques. The hydrochars production yields were found to be higher than the biochars ones and associated to the lower temperature used. However, the generated biochars possess higher carbon percentage and lower volatile matter contents. In addition, the increase of the hydrothermal and pyrolysis carbonization temperatures shows an increase of macro-elements contents and a significant decrease of the O/C ratios which led to an enhancement of the high heating value for both hydrochars and biochars. The FTIR and Boehm titration analysis highlighted a significant alteration of the biochars surface chemistry compared to hydrochars evidenced by the lower amount of functional groups. The collected data emphasize on the efficient potential application of hydrochars and biochars for agricultural and environmental applications, respectively. Furthermore, it was noted that both chars have high energetic potentials and could be used for co-firing with coal in industrial boilers.

Short-term effects of olive-mill-wastes-derived biochars amendment and arbuscular mycorrhizal fungi inoculation on growth of maize (Zea mays) and mycorrhizal colonization

“…The addition of OMWW slightly enhanced the organic content in the lignocellulosic material, which was converted into additional fixed carbon content after pyrolysis [8]. A slight increase in the volatile matter content (Figure 2) was also noticed, which was set to be relatively low (17% and 18%, respectively) compared to the initial feedstocks (67% and 69% for ROP and IROP, respectively [54,58]).…”

“…Mineral composition of the biochars was performed through X-ray fluorescence (XRF) analysis. Generally, 200 mg of ROP and IROP biochar powders were mixed with 100 mg of boric acid (used as a binder), transformed into pellets then analyzed using a PHILIPS PW2540 (Amsterdam, Netherlands) [54].…”

“…Firstly, Figure 2. Proximate analysis of raw ROP and IROP and its derivative biochars (results related to the raw materials were imported from our previous publications [54,58]).…”

Thermophilic Dark Fermentation of Olive Mill Wastewater in Batch Reactors: Effect of pH and Organic Loading

“…Hydrothermal carbonization Production of hydrochars for agricultural applications. [35] Slow pyrolysis Biochar production, which can be applied as an organic fertilizer with promising results (e.g., K bioavailability).…”

Characteristics of Fishery Industry MSMEs in Takalar Regency that are Resistant to Interferences in Uncertainty Era

“…Micro, Small and Medium Enterprises (MSMEs), especially the fisheries sector, have a significant contribution to the economy, especially to employment, poverty reduction, food sources, the formation of gross domestic product (GDP), exports, investment creation and sustainable economic growth (Fatoki, 2018;Namotemo, Kour, Dilly, Akerina, & Amahorseja, 2021;Nursini, 2020;Pornparnomchai & Rajchamaha, 2021;Wahyudi, Suroso, Arifin, Syarief, & Rusli, 2021). This enterprises segment dominates the world economy, including Indonesia (Franco, Haase, & António, 2020;Utami & Nugroho, 2022) The existence of MSMEs for a long time was tested with various disturbances that emerged in the era of uncertainty (Azzaz, Matei Ghimbeu, Jellai, El-Bassi, & Jeguirim, 2022;Martin & Sunley, 2020). These disturbances are caused by turmoil that occurs in various sectors both at the local and global level such as economic, political, social and environmental crises, increasing over time (Pal, Torstensson, & Mattila, 2014;Suresh, Sanders, & Braunscheidel, 2020;Varona, 2017) including the latest incident that is Covid 19 pandemic restricted bussiness economy which has never been experienced before by (Czainska, Sus, & Thalassinos, 2021;Etemad, 2020;Lim, Morse, & Yu, 2020).…”