Trade-offs in the production and end-use of biochar and bio-oil from the solid waste generated from the olive oil industry in Australia

The olive oil industry in Australia has been growing at a rapid rate over the past decade. This growth brings along with it new challenges. The solid waste, produced from the olive oil mills, is particularly difficult to manage. Pyrolysis is a process which may be employed to generate biochar, bio-oil and gas from biomass. The proportions and in fact the quality of the different products depend on the process parameters such as final temperature, heating rate, particle size and pyrolysis method. The change in the products quantities and qualities affect the potential revenue from the sale of these products as well as the potential environmental credits due to the altered use and or product properties. This paper investigates some of the economic and environmental trade-offs in the production and end-use of the biochar and bio-oil from the olive-oil solid waste in Australia. Special attention is paid to the impact of policies such as renewable energy targets, carbon tax and carbon sequestration credits on agricultural lands. Under the current government policies, the optimal utilisation of the pyrolysis products is limited due to the lack of incentives for the use of bio-char as a soil amendment on agricultural soils.