Marco Buffi

Challenges and Solutions for Utilization of Bioliquids in Microturbines

Increased public concerns and stricter regulatory frameworks promote the role of bioliquids (liquid fuel for energy purposes other than for transport, including electricity and heating and cooling, produced from biomass). This is a driving force for development and employment of micro-gas-turbines (MGTs) due to their ability to combust bioliquids with less favorable properties in a decentralized manner. Gas turbines are characterized by relatively high combustion efficiency at relatively low concentrations of harmful emissions, relatively high effective efficiency and durability when utilizing a common portfolio of gas turbine approved fuels. It is thus desired to preserve these advantages of gas turbines also while burning bioliquids and further relying on their scalability that is crucial to efficient support of decentralized energy production at small scales. To support these objectives, MGT technology needs to allow for utilization of bioliquids with much wider spectrum of physical and chemical properties compared to common commercially available MGTs in a single MGT based plant. In this view, the present study is providing the first thorough overview of challenges and solutions encountered by researchers across the wide area of bioliquids in MGTs.

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

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]