Wikandari Rachma, Nguyen Huong, Millati Ria, Niklasson Claes, Taherzadeh Mohammad J
Swedish Centre for Resource Recovery, University of Borås, Allégatan 1, 50190 Borås, Sweden.
Department Chemical and Biological Engineering, Chalmers University of Technology, 41296 Gothenburg, Sweden.
Biomed Res Int. 2015;2015:494182. doi: 10.1155/2015/494182. Epub 2015 Mar 19.
Limonene is present in orange peel wastes and is known as an antimicrobial agent, which impedes biogas production when digesting the peels. In this work, pretreatment of the peels to remove limonene under mild condition was proposed by leaching of limonene using hexane as solvent. The pretreatments were carried out with homogenized or chopped orange peel at 20-40°C with orange peel waste and hexane ratio (w/v) ranging from 1 : 2 to 1 : 12 for 10 to 300 min. The pretreated peels were then digested in batch reactors for 33 days. The highest biogas production was achieved by treating chopped orange peel waste and hexane ratio of 12 : 1 at 20°C for 10 min corresponding to more than threefold increase of biogas production from 0.061 to 0.217 m(3) methane/kg VS. The solvent recovery was 90% using vacuum filtration and needs further separation using evaporation. The hexane residue in the peel had a negative impact on biogas production as shown by 28.6% reduction of methane and lower methane production of pretreated orange peel waste in semicontinuous digestion system compared to that of untreated peel.
柠檬烯存在于橙皮废料中，是一种抗菌剂，在消化橙皮时会阻碍沼气的产生。在这项工作中，提出了在温和条件下通过用己烷作为溶剂浸出柠檬烯来对橙皮进行预处理以去除柠檬烯的方法。预处理是在20 - 40°C下用匀浆或切碎的橙皮进行的，橙皮废料与己烷的比例（w/v）为1 : 2至1 : 12，处理时间为10至300分钟。然后将预处理后的橙皮在间歇式反应器中消化33天。通过在20°C下处理切碎的橙皮废料与己烷比例为12 : 1，处理10分钟，实现了最高的沼气产量，对应的沼气产量从0.061立方米甲烷/千克挥发性固体增加到0.217立方米甲烷/千克挥发性固体，增长了三倍多。使用真空过滤溶剂回收率为90%，还需要通过蒸发进行进一步分离。与未处理的橙皮相比，在半连续消化系统中，预处理橙皮废料中残留的己烷对沼气产量有负面影响，甲烷产量降低了28.6%，且甲烷产量更低。
