Abstract

Micro-Flow Resource Extraction: Marine Biomass, Minerals Processing, and Space

Volker Hessel, Professor, The University of Adelaide

The potential of micro-flow extraction has been investigated as early as microreactors have emerged, >30 years ago. Yet up to now no industrial use has been reported, despite the advantages being obvious, exploiting mass transfer as key advantage, and largely reported in literature. This is likely related to the fact that flow chemistry was and is largely driven by a market-pull principle from industrial side; mainly that of the pharmaceutical industry. The two potential industrial drivers in this presentation are either only cautiously testing the new frontier technology, mining industry, or are themselves a frontier market which is just developing, marine biomass market. Microreaction and flow technology has largely be developed in Europe, US, and some Asian countries; i.e. in zones that are typically poor in own resources, while resource-rich countries, in Australia, Africa, and South America, have been only slow adaptors of micro-flow technologies. This talk is given from the Australian perspective and market pull. A continent surrounded by huge ocean area has access to abundant marine biomass. The issue is to separate one compound selectively out of many dozens or even hundreds. As most marine biomass compounds are thermally labile, yet might profit from high-temperature extraction, the classical microreactor fortitude can be exploited – to do a processing job, impossible with current technology, in a very short time in a novel process window. For minerals processing, the ‘micro-flow job’ can follow manifold motivations. One is to extract all constituents (metals) from rich industrial (waste streams) and to concentrate it to a level that supports industrial post-processing. Another one is to selectively extract one metal in the presence of many others; both given for primary and waste streams. One more ‘job’ is to selectively remove several undesired compounds, leaving the right and wanted one in high purity. As these precious materials are typically given in low concentration, the extraction needs to be done at ppb-level. It will be shown how new functional materials with unseen properties can be designed via this ‘ultra-purity’. A third market with growing Australian relevance is space technology, and in the context of the presentation, lunar regolith simulant material is leached and extracted, to provide macronutrients (P, K) for plant growth in greenhouses on moon.