Techno-economic analysis of the olive oil mill wastewater steam reforming process: A case-study

Abstract

Steam reforming of olive oil mill wastewater (OMW) has been object of study in several works; however, there are no references to industrial installations to treat and valorize this effluent until now. In this way, to understand the economic impact of applying this technology in the olive oil industry, techno-economic analyses of this process in a traditional reactor (TR) or in a sorption-enhanced reactor (SER - with in situ CO2 removal) were performed. This study focused on key aspects of the process units, such as the reaction and heating/cooling zones. These analyses also considered the effect of different water contents in the OMW composition (60-90 wt.%) and the impact of the operating pressure (1-4 bar), at 400 C. To determine the outlet stream composition of the process and the heat released or required in the reaction, the software Aspen Plus V.10 (R) was used. The investment cost of the heat exchanger was estimated by the Aspen Exchanger Design & Rating software tool. It was observed that the content of water in the feed, the operating pressure, the mode of operation (6 or 12 months) and the reactor configuration used affect the economic benefit of the project over time: lower content of water in the feed, lower operating pressure, operating throughout the whole year and the utilization of a SER allows to obtain a most profitable scenario.