Project 2 was led by Jennifer Broadhurst, Deputy Director of the Minerals to Metals Initiative in the Department of Chemical Engineering at the University of Cape Town. 

This team was responsible for the Identification and Evaluation of Downstream Options for the Recovery of Value and/or Products from Fibre Producing Plants, and included: Ms Tapiwa Chimbganda (PhD candidate), Mr Gregory Hangone, Mr Prince Destiny Ugo, Adjunct Professor Mike Solomon, and Professor Jochen Petersen, SARChI Chair for Minerals Beneficiation. The team brought the following specific skills and expertise of direct relevance to this project:

  • Development of metal and material value chains from both a fundamental technology and systemic performance perspective.
  • Complex, multi-criteria decision-making in the context of engineering design.
  • Sustainability issues of relevance to the mining and mineral beneficiation sector, post-closure land use and impacts, environmental pollution, mine waste characteristics and management, and mine-community conflict.
  • Processes and technologies for the recovery of metals from secondary sources (urban mining).

Their brief was to conduct a first-order performance assessment and comparison of processing routes for recovering metals, products from plant biomass. An anticipated outcome was a policy brief guide on the feasibility and consequences of processing alternatives for the conversion of fibre-producing plant into valuable outputs.

In terms of their approach, the team used the generic process systems design and technology selection framework. This can be broken down into three steps:

  1. Firstly, the generation of alternatives in the form of process flow diagrams and input-output data. The data enables quantitative understanding of material and energy flows over a whole array of unit operations as a function of technology efficiencies.
  2. Analysis of alternatives: • micro-economic • environmental • socio-technical • technical. The information allows for measures of process performance against objectives/targets. 
  3. Informed decision-making and selection of preferred alternative(s). 

This project was developed in close collaboration with SARChI: Bioprocess Engineering (CeBER/Future Water).

Downstream options and inputs were informed to a lesser or greater extend by the choice of fibres and the opportunities for metal recovery i.e. upstream scenarios.

Outcomes form the basis for the development of extended material value chains and socio-economic linkages, as well as inform legislative barriers and drivers.

March 2019 Update:

The Minerals to Metals (MtM) team (Associate Professor Jennifer Broadhurst, Tapiwa Chimbganda, Gregory Hangone and Prince Destiny Ugo) have completed a review and assessment of the various processing routes for recovering value from plant biomass, such as kenaf, hemp and bamboo, through the conversion into useful products.

This review, which has been based on published literature and interviews with relevant professionals, has indicated that kenaf and hemp provide opportunities for a more diverse range of products and greater flexibility than bamboo. The targeted product will, however, dictate the selection of fibre plants and plant-product processing options, and will be dependent on various external factors relating to the local socio-economy and geography.

Preliminary findings have been presented at CoP workshops in May 2018 and January 2019. The outcomes of this review will also be summarized in a working paper (expected to be completed end of October 2019) and presented at an international mine closure conference in September 2019 - abstract accepted). These findings will form the basis of a more detailed analysis of the performance of selected process routes for fibre plants in accordance with environmental, technical, socio-technical and economic criteria.