Department of Civil, Environmental and Mechanical Engineering, University of Trento, via Mesiano 77, 38123 Trento, Italy.
Department of Civil, Environmental and Mechanical Engineering, University of Trento, via Mesiano 77, 38123 Trento, Italy; University of Hohenheim, Institute of Agricultural Engineering, Department of Conversion Technologies and of Biobased Resources, Garbenstrasse 9, 70599 Stuttgart, Germany.
Waste Manag. 2018 Oct;80:224-234. doi: 10.1016/j.wasman.2018.09.021. Epub 2018 Sep 18.
An olive waste stream mixture, coming from a three phase-continuous centrifugation olive oil mill industry, with a typical wet basis mass composition of olive pulp 39 wt%, kernels 5 wt% and olive mill waste water 56 wt%, was subjected to hydrothermal carbonisation (HTC) at 180, 220 and 250 °C for a 3-hour residence time in a 2-litre stainless steel electrically heated batch reactor. The raw feedstock and corresponding hydrochars were characterised in terms of proximate and ultimate analyses, higher heating values and energy properties. Results showed an increase in carbonisation of samples with increasing HTC severity and an energy densification ratio up to 142% (at 250 °C). Hydrochar obtained at 250 °C was successfully pelletised using a lab scale pelletiser without binders or expensive drying procedures. Energy characterisation (HHV, TGA), ATR-FTIR analysis, fouling index evaluation and pelletisation results suggested that olive mill waste hydrochars could be used as energy dense and mechanical stable bio-fuels. Characterisation of HTC residues in terms of mineral content via induced coupled plasma optical emission spectroscopy (ICP-OES) as well as Total and Dissolved Organic Carbon enabled to evaluate their potential use as soil improvers. Nutrients and polyphenolic compounds in HTC liquid fractions were evaluated for the estimation of their potential use as liquid fertilisers. Results showed that HTC could represent a viable route for the valorisation of olive mill industry waste streams.
一种来自三相连续离心橄榄石油磨坊工业的橄榄废物混合物，以典型的湿基质量组成为橄榄果肉 39wt%、橄榄核 5wt%和橄榄磨废水 56wt%，在 180、220 和 250°C 下进行水热碳化 (HTC) 3 小时停留时间在 2 升不锈钢电加热分批式反应器中。对原料和相应的水炭进行了近似和最终分析、高热值和能量特性的表征。结果表明，随着 HTC 严重程度的增加，样品的碳化程度增加，能量致密化比高达 142%（在 250°C 下）。在 250°C 下获得的水炭在没有粘结剂或昂贵干燥程序的实验室规模制粒机中成功制粒。能量特性（HHV、TGA）、ATR-FTIR 分析、结垢指数评估和制粒结果表明，橄榄磨废水水炭可作为能量密集型和机械稳定的生物燃料使用。通过电感耦合等离子体发射光谱 (ICP-OES) 对 HTC 残渣的矿物含量进行了表征，以及总有机碳和溶解有机碳，评估了它们作为土壤改良剂的潜在用途。评估了 HTC 液体馏分中的营养物质和多酚化合物，以估计它们作为液体肥料的潜在用途。结果表明，HTC 可能是橄榄磨坊工业废物资源化的可行途径。
