• Energy Research

AbstractBACKGROUNDIncreased water demand caused by population growth has forced the reuse of wastewater after treatment. Safflower is a salt‐tolerant plant that can be irrigated with moderately saline water. Cultivation of safflower plant can be achieved by irrigation with membrane bioreactor (MBR)‐treated wastewater and further utilized in oil and then biodiesel production according to standard (TS EN 14214). Irrigation water quality can impact oil and biodiesel yield and content.RESULTSIn this study, safflower plants were cultivated using different irrigation strategies in a field next to a wastewater treatment plant in Menderes‐Izmir, Turkey. These strategies were: irrigation weekly with MBR‐treated wastewater or with tap water; with MBR‐treated wastewater just three times during phenological periods; and without irrigation. Oil yields for seeds of the plants irrigated by these strategies were 103.8, 98.7, 63.7 and 57.4 (kg oil daa−1), respectively. Oil yield was found to be highest following weekly irrigation with MBR‐treated wastewater that has a high salinity of 4 mS cm−1. Safflower oil methyl ester (SOME) contents of biodiesel were 94.6 and 94.5% (g SOME:g biodiesel), and ester yields of biodiesel were 71.3 and 81.4% (g biodiesel:g oil–1) for safflower irrigated weekly with MBR‐treated wastewater and tap water, respectively.CONCLUSIONIt is concluded that SOME yields and contents of safflowers irrigated with MBR‐treated wastewater and tap water weekly are so close. © 2019 Society of Chemical Industry

In addition to examining the highest yield production of Levulinic acid (LA) from artichoke leaves by the subcritical catalytic hydrothermal decomposition, the studies were carried out on also increasing the production yields of 5-Hydroxymethylfurfural (HMF), Acetic and Formic acid from this biomass. In order to obtain the most suitable reaction conditions, the effect of different reaction conditions, including different temperature, reaction time, pH and catalyst types, on the decomposition of artichoke leaves and product yields were investigated. The subcritical thermal decomposition studies of artichoke leaves were carried out in an autoclave system at temperatures (120°C, 140°C, 160°C, and 180°C) for reaction times of 10, 20, 30, 40, and 50 min in the presence of H2SO4, HNO3, and HCL catalysts with different pH values; these reactions were realized also without adding a catalyst. As a result of the detailed research, it was seen that the most suitable experimental conditions for the production of LA with the highest yield from artichoke leaves could be achieved by adding sulfuric acid with a pH of 0.5 at a reaction temperature of 180°C and a reaction time of 50 min. The investigations were continued till achieving the highest product yields. After carrying out the experiments stated above, the optimal yields of the products produced from the artichoke biomass by the reactions were found as 209.39 g/kg biomass for LA, 117.40 g/kg biomass for formic acid, 72.27 g/kg biomass for acetic acid, and 39.04 g/kg biomass for 5-HMF.

The pyrolysis behavior of Turkish biomass samples such as hazelnut shell, almond shell, and sunflower stalk residue was studied using a thermogravimetric analysis (TGA) laboratory-scale setup. Biomass samples were characterized using the standard method of the Van Soest detergent analysis, and both the virgin biomass and fractions were investigated. The reaction temperature was increased to 900 °C with a heating rate range between 2 and 60 °C min−1 in the TGA experiments. Seven solid-state reaction models were applied to evaluate the obtained experimental TGA results. The heating rate was not the only parameter affecting the values of activation energy and the ratio of the main components such as the cellulose and lignin of the virgin biomass samples (almond shell, sunflower stalk, and hazelnut shell) also affected the value of the activated energy values. It was determined that a model fitting mechanism gives limited information to determine the exact activation energy values for the samples. The reaction order model provided straightforward and decisive results for all the biomass and lignin samples. Models of two- and three-dimensional diffusion were better suitable for the cellulose devolatilization. It was also determined that the activation energy of the lignin samples was similar regardless of the types of biomass. According to the kinetic calculations, the cellulose samples showed the highest activation energy values and the lignin samples had the lowest.