Universität Stuttgart Production of bioplastic on a municipal waste water treatment plant Dipl . -Ing. Timo Pittmann Prof. Dr. -Ing. Heidrun Steinmetz Many thanks to the WILLY-HAGER-STIFTUNG for funding the research project 1 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Outline 1. Motivation - exploitation of natural resources - waste problems 2. Bioplastic 3. Material & Methods 4. Results - raw material - boundary conditions - mass balance 5. Conclusion 2 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Motivation Major environmental challenges are • resource consumption • waste production 3 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Resource Consumption • gas • petrol • aircraft fuel • havy fuel oil • bitumen from gas and petrol • cosmetics • medicine • isolation • ect. 4 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Resource Consumption The daily crude oil consumption in the year 2012 : 83,477 million barrel. Global reserve : 1652600 million barrel Sufficient for how long? 1652.600.000.000 barrel / 83.477.295 barrel/day =19.797 days Equals: 54.2 years OPEC: about 64 years Attention: Consumption and global reserve may fluctuate significantly Source: BP Statistical Review of World Energy, 2012 5 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Waste Production 6 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Waste Production Source: www.infohow.org 7 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Waste Production 8 Source: Algalita Marine Research Foundation Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Waste Production Paranaque, Philippines on August 25, 2012. Quelle: Romeo Ranoco, Reuters 9 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Waste Production Skeleton of an Albatros 10 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Waste Production Skeleton of an Albatros 11 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Bioplastic What can we do? We need to solve both problems: Resource consumption Waste problem How about a biodegradable plastic, a Bioplastic! Definition: There is no universal definition. What do we understand by „Bioplastic“? 12 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Bioplastic - Definition Renewable raw material Biodegradable and based upon renewable raw material Bioplastic Bioplastic Non biodegradable biodegradable conventional Bioplastic plastic Petrochemical raw material 13 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Bioplastic Source: http://www.technewsdaily.com 14 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Bioplastic – Production costs Raw material: starchy plants like maize Problems: 11,92% • high costs Raw material 36,56% • ethical problem General works 21,08% Supplies Labor Waste Treatment Utilities Depreciation 4,34% 8,94% 13,06% 3,21% Source: Lee a.Y., Choi C.Y.: Biosynthesis and Biotechnological Production of Degradable Polyhydroxyalkanoic Acid , Biotechnol. Bioprocess Eng. Solution: Substitution of raw material 15 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Material and Methods 16 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Results – 1 Step Degree of Acetic- Temp. HRT ΣVFA ∆VFA Acidification /propionic- Carbon source pH [°°°C] [d] [mg/l] [mg/l] [gCSB/l]/[gCSB/l] /butyric acid [%] [%] Primary sludge 6 30 9 3880 3424 31 52/48/0 Primary sludge 6 20 7 1754 1298 14 56/44/0 Primary sludge 4,6 30 10 1920 1599 14 41/59/0 Primary-/digested sludge 7 20 14 1719 1551 14 79/21/0 Primary sludge 4,5 20 15 1796 1475 13 42/58/0 Primary-/digested sludge 7,5 30 14 1561 1393 12 84/16/0 Excess sludge 7 30 5 610 463 10 59/20/21 Excess sludge 6,5 20 4 541 394 8 60/20/20 Primary-/digested sludge 6 30 5 1068 923 7 75/25/0 Excess sludge 6 20 7 397 299 6 24/76/07 Excess sludge 6 30 5 467 369 6 67/33/0 Primary-/digested sludge 6 20 2 413 268 3 57/43/0 Excess-/digested sludge 6 30 4 280 231 3 100/0/0 Excess-/digested sludge 8 30 3 278 180 3 76/0/24 Excess-/digested sludge 7,5 20 7 207 158 2 100/0/0 Excess-/digested sludge 6 20 2 80 31 1 100/0/0 17 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Results – 1 Step After raw material selection: Find the best boundary conditions: • Temperature • pH • Retention time (RT) and withdrawal (WD) 18 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Results – 1 Step • In 6 out of 8 tested combinations 30 °C yields better results than 20 °C • 30 °C is considered as reasonable Degree of Acidification Acetic-/ propionic- Temp. HRT ΣVFA ∆VFA Carbon source pH [gCSB/l]/[gCSB/l] /butyric acid [°°°C] [d] [mg/l] [mg/l] [%] [%] Primary sludge 6 30 9 3880 3424 31 52/48/0 Primary sludge 6 20 7 1754 1298 14 56/44/0 Primary sludge 4,6 30 10 1920 1599 14 41/59/0 Primary-/digested sludge 7 20 14 1719 1551 14 79/21/0 Primary sludge 4,5 20 15 1796 1475 13 42/58/0 Primary-/digested sludge 7,5 30 14 1561 1393 12 84/16/0 Excess sludge 7 30 5 610 463 10 59/20/21 Excess sludge 6,5 20 4 541 394 8 59,7/19,6/20,7 Primary-/digested sludge 6 30 5 1068 923 7 75/25/0 Excess sludge 6 20 7 397 299 6 24/76/07 Excess sludge 6 30 5 467 369 6 67/33/0 Primary-/digested sludge 6 20 2 413 268 3 57/43/0 Excess-/digested sludge 6 30 4 280 231 3 100/0/0 Excess-/digested sludge 8 30 3 278 180 3 76/0/24 Excess-/digested sludge 7,5 20 7 207 158 2 100/0/0 Excess-/digested sludge 6 20 2 80 31 1 100/0/0 19 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Results – 1 Step 20000 18000 pH = 6 16000 pH = 6,5 14000 pH = 7 mg/L pH = 8 12000 pH = 10 10000 8000 concentrationconcentrationinin VFA- 6000 4000 2000 0 0 2 4 6 8 10 12 14 16 18 20 time in days pH 7 yields best results 20 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Results – 1 Step 10000 9000 8000 7000 6000 5000 4000 3000 2000 1000 Average VFA concentraion in mg/L in concentraion VFA Average 0 RT = 4d; RT = 4d ; RT = 4d ; RT = 6d ; RT = 6d ; RT = 8d ; RT = 8d ; WD = 25% WD = 50% WD = 75% WD = 25% WD = 50% WD = 25% WD = 50% 2000 1800 1600 1400 1200 1000 800 600 VFA mass flow in in mg/(Ld) flow mass VFA 400 200 0 RT = 4d; RT = 4d ; RT = 4d ; RT = 6d ; RT = 6d ; RT = 8d ; RT = 8d ; WD = 25% WD = 50% WD = 75% WD = 25% WD = 50% WD = 25% WD = 50% 21 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Results – 1 Step VFA-composition at RT = 4 d, WD = 50 % 22 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Results – 2 Step • Using VFAs from first step • Using excess sludge for selection • Find the best boundary conditions: • Temperature • pH • VFA-concentration • feast/famine cycle • selection time 23 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Results – 2 Step Start selection End selection Feast/famine-phase Day 1 Day 2 Day 3 Day 4 Day 5 Oxigen in mg/L Day 6 Day 7 Time in h 24 Institute for Sanitary Engineering, Water Quality and Solid Waste Management Chair of Sanitary Engineering and Water Recycling Universität Stuttgart Results – 2 Step operation conditions PHA-production Temp. pH cycle time substrate conc. in % cell dry weight 30 unregulated 24 h 2000 mgVFA/L 5,8 30 unregulated 24 h 1200 mgVFA/L 3,4 20 unregulated 24 h 1200 mgVFA/L 13,2 20 unregulated 24 h 2000 mgVFA/L 4,8 30 7 24 h 1200 mgVFA /L 0,6 20 7 24 h 1200 mgVFA/L 25,9 15 7 24 h/48 h 1200 mgVFA/L 4,2 15 8 24 h/48 h 1200 mgVFA/L 3,9 20 8 24 h 1200 mgVFA/L 30,2 20 9 24 h 1200 mgVFA/L 4,4 20 6 24 h 1200 mgVFA/L n.n.