Oilseed pressing and vegetable oil properties and upgrading in decentralised small scale plants for biofuel production

Abstract

Vegetable oils became a very popular bioliquid for renewable power and transport applications. At local level, the short chain production of vegetable oils is currently important in terms of sustainability and use of rural area. This present work investigates the development of vegetable oils production chain in the Tuscany territory, focusing also to valorisation of the co-products (i.e., oil cake). The work is based on the study of the cultivation of rapeseed and sunflower, and the creation of an extraction plant based on cold-screw pressing technology, in order to obtain a raw vegetable oil suitable as biofuel. The German DIN 51623 standard was adopted to investigate the quality of vegetable oils obtained from different oil crops. Vegetable oils quality was evaluated by comparing the oil produced by a bench press at lab scale, comparing the results in terms of process yields and lipid fraction recovered. Due to the high phosphorous content of rapeseed oil, out of the DIN limits, an experimental procedure to remove P content and restore the oxidation stability of the oils was performed. The results showed a substantial P reduction by adding 2 wt% of P-removing additive. The oil cake properties were evaluated in view of its potential use for bioenergy production, in particular in terms of metals content. [Received: December 5, 2015; Accepted: September 20, 2016]