An overview of fibre crop cultivation and multi-product value chains for post-mining industrial development CENTRE FOR BIOPROCESS ENGINEERING RESEARCH STL Harrison, S Rumjeet, X Mabasa, M Solomon, B Verster MINERALS TO METALS INITIATIVE JL Broadhurst, T Chimbganda, G Hangone
Over 300, Over 5900 Significant 000 job Problem lem abandoned loss of losses since mines in SA biodiversity statem emen ent 1987
Exploring the potential of fibrous plants Met etal Land and Fibre- reco covery remedia ediatio ion Fibre c Fib crop p deriv ived ed pote tenti tial pote tenti tial product ucts potent po ential
? ? ? Ke Key fibre-rich plant ques questions ns? Can fibre-rich plants serve the joint role of remediation of degraded mine land and fuelling of a multi-product value chain? What are the downstream processing options for the recovery of value from fibre plants?
Phytoremediation & Phyto-mining Proposed ed solut lution Explo lorin ing g the he poten entia ial o l of fibrous fibr pla plants Metal ions Land d remedia ediatio ion n and m nd met etal re recovery
thermoplastics fabric Proposed ed solut lution Fibre re Fibre cordage bio- composites Addi dditional pr produ ducts Woody tissue piping Explo lorin ing g shives the he Chemicals oils pharmaceuticals poten entia ial o l of fibr fibrous bio-char plants pla Energy Fib Fibre- deri derived d produ pr ducts
Water Seed Proces essing ng Manufa fact cturin ring Pre- Product Plant Fibrous- Fibrous- Harvest Conversion Cultivation treatment Part Part recovery Lead biomass products Potent ntia ial l Syste Sy tem m Manufa fact cturin ring Conversion Additional Flo Flowshe heet Non-Fibrous- products part Conversion Bioref efin iner ery Biorefinery High-end By-products by-products
Platinum Example site selection Coal Gold Average rainfall: 100 – 200 mm per Scopi ping g study dy annum and an d investiga gation Average temperature: in n 7 – 32 ℃ Carle letonvill ille, Rustenbu burg g & Wi Witba bank minin ing areas Soil pH: 5.5 - 7 Topsoil texture: Clay- sandy-loamy
Overview and selection of fibrous plants in South Africa Fibre re plants ts Bast st Leaf af Wood ood Grass ss Seed eed Flax • Fruit it Hemp Sisal Pinewood Bamboo Cotton • • • • • Coconut Scopi ping g study dy • Jute Palm Baobab Kapok • • • • Kenaf • and an d investiga gation in n Sout uth h Crit iter eria ia f for plant nt selec lectio ion f for e example s le sites es Afric frican • Non-invasive and/or indigenous minin ing areas • Preferred soil type • T emperature tolerance • pH tolerance • Multi-product possibility
Fibrous plants selection Bamboo balcooa, flax, hemp, kenaf and sisal Higher metal concentration ability • Metal selectivity • More specific metal bioconcentration sites • Plan Pl ant selec ectio ion n Wider range of fibre and seed based products • crit iteri eria Grow in warmer temperatures • Relatively easier to cultivate •
Kenaf Bambusa balcooa Hemp Sisal Flax 500 – 1500 mm 400 – 5400 mm 450 – 750 mm 500 – 700 mm 240 – 490 mm 9 – 35 ° C 10 – 27 ° C 19 – 23 ° C 15 – 27 ° C 10 – 32 ° C 12 – 18 tons/ha 1 – 4 tons/ha ~ 2 tons/ha 2.2 – 8 tons/ha 5 – 7 tons/ha 5 – 6 years 120 days 2 – 4 years 100 days 90 – 125 days Pb, Zn, Cd M Zn, Cd, Cu Ni, Pb, Cd, Zn, Cu Pb, Zn, Cr, Fe Pb, Zn, Cd
Selected fibrous plants for detailed study Bamboo Kenaf Hemp • A wider range of products • Stronger fibre (tensile strength) • Fibre type : Hemp & Kenaf – Bast fibres Bamboo – Woody grass
Limitations and challenges • Lack of top soil, organic matter and good microbial dynamics on degraded land Scopi ping g study dy an and d • Metal accumulation in fibrous plants tend to inves esti tigati tion be low in So n Sout uth Afri frican minin mi ing ar g areas eas • Metals can accumulate in harvestable parts of plants • Product quality & safety would be an issue • Return on investment may take long for some of the crops
Water Seed Proces essing ng Manufa fact cturin ring Pre- Product Plant Fibrous- Fibrous- Harvest Conversion Cultivation treatment Part Part recovery Lead biomass products Potent ntia ial l Sy Syste tem m Manufa fact cturin ring Conversion Additional Flo Flowshe heet Non-Fibrous- products part (twigs, leaves, Conversion Bioref efin iner ery seeds etc) Biorefinery High-end By-products by-products
Bast fibre crop-to-product profile SEEDS ENTIRE PLANT Energy or Seeds Oil Bast fibr Bas ibre Example - Bioethanol pla plant proces essing ing LEAVES STEM Fibre + Woody tissue Leaves or Medicine Example: Hemp
End-products Intermediates Conventional textiles Long Fibre Bast fibre Bio-composites stem cross-section Bast Fibre & Cordage Short Fibre Paper Pulp & Shives Woody tissue Hurd Construction materials
Bast fibre multi-product flowsheet options Textiles Spinning Spinning Long Composites Conversion Conversion Pre- Product Plant Stem Fibre Stem Fibre Harvest treatment recovery products Cordage Carding Carding Short Paper Pulping Pulping Shives Sorting Woody Woody tissue Paper Pulping tissue products Construction materials Conversion Whole seeds Cleaning Seeds By- Seed oil Compression By- products products Whole leaves Cleaning Leaves Medicine Conversion
Bamboo crop-to-product profile ENTIRE PLANT BRANCHES Household wood Energy products Bamboo Bam pla plants Example - Biochar and nd proces essing ing SHOOTS STEM/CULM Wood or Fibre or Pulp Vegetable
End-products Intermediates Poles Wood Wood products OR Cardboard Bamboo culm/stem Pulp Paper Pulp OR Natural Fibre Rayon
Bamboo multi-product processing scenarios Opti ption 1 1a Natural fibre Fibre recovery Plant High quality Culm (80%) High- Splitting Harvest stems end Opti ption 1 1b products Board-making Plybamboo/ Strand woven T op of culm boards Opti ption 2 2a Bamboo Weaving Pre-treatment Medium quality stems mats Medium -value Opti ption 2 2b products Board making MDF boards/ Poles Bamboo mat boards Low quality stems/wastes from Opti ption 3 3a options 1 and 2 Paper pulp Pulping Whole plant (100%) Low- Particle board Opti ption 3 3b End or Board making bulk products Opti ption 3 3c Energy Burning
Potential integrated metal recovery process Water Soil (metals) Pre- Fibre- Harvest Manufacturing Cultivation treatment recovery Plant Fibrous- Lead Fibrous- Fibre Part products Part Leachate Non-fibrous parts Manufacturing (metals) Additional products Hydrometallurgical/ Plant-synthesised Ashing pyrometallurgical nano-catalysts extraction Bio-ore Metals
Summary • All the fibre-producing plants can generate multiple products however, the range of products differ for the different plant types. • Selection of product recovery and treatment processes is highly dependent on desired lead and additional product types. Summar mmary o of f fi fibr bre e • Exploitation of fibre-based plants and industry development will also depend on the pr proces essing g socio-economic and environmental drivers. an and pr d produ duct sel elec ectio ion • Integrating metal recovery may limit product quality and the capability of the fibre products.
Acknowledgements
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