Process design for Silicon projects Downstream effects for the photovoltaic supply chain

Transcription

1 Process design for Silicon projects Downstream effects for the photovoltaic supply chain Dipl.. Eng. Valdiney Domingos Dipl.. Eng. Lou Parous Dipl. Eng. Gabriel Esteves Viridis.iQ Metal Bulletin 30 th International Ferroalloy Conference 9-11 November 2014, Barcelona, Spain

2 Topics Introduction Viridis.iQ GmbH Process Design Divergences CAPEX: turnkey versus package based projects (Greenfield plants) Downstream effects caused by the mistakes in the project engineering phases Summary

3 Experience and knowhow Viridis.iQ GmbH is a German engineering, project development, operations and consulting firm with unique technical, business and financial experience on each step of the photovoltaic value chain including metallurgical silicon, polysilicon, ingoting, wafering, solar cell and modules, along with proficiency in thin film technologies and innovative process engineering. Crossover expertise in ferroalloy production and engineering (FeCr, FeMn, FeSi) Selected services: Engineering (FEL, FEED, etc) Project Management Knowhow Transfer Interim Operations Teams Management Teams Learning Curve Support Technology Audits Process Design and Upgrades Lean Six Sigma Optimization Electrode Technology conversion Furnaces Conversion Feasibility Studies Start Up/ Ram Ups Cold/Hot Commissioning

4 Publications and Appearances

5 Ferroalloy and Silicon Production Metrics Facts and Figures > tons managed 70 years of accumulated silicon production experience in-house 8150 furnace ramp ups, warm and cold and start ups 231 furnace tap hole reformations 1029 Electrode Burn Downs 121 Södeberg electrode transitions 13 furnace optimization programs 6 development programs on silicon and ferroalloy casting 120 Lean Six Sigma specialists trained 24 furnace reformations 48 Distinct Lean Six Sigma projects 4 system developments for silicon milling and grinding.

6 Topics Introduction Viridis.iQ GmbH Process Design Divergences CAPEX: turnkey versus package based projects (Greenfield plants) Downstream effects caused by the mistakes in the project engineering phases Summary

7 Process Design Divergences greenfield,, brownfield and conversions of Silicon furnaces Raw Materials Source: Myrvågnes, 2008 and V. Domingos, 2013 Reductant Mix Pre-treatment design (quartz, woodchip, reductant)

8 Process Design Divergences greenfield,, brownfield and conversions of Silicon furnaces Lay Out Wind direction De dusting system Plant organization flow Source: ELPION - OCI Substation (electrical system) Logistics aspects Efluents disposal Source: Google Maps

9 Process Design Divergences greenfield,, brownfield and conversions of Silicon furnaces Casting Process Z cm X cm Y cm Source: SINTEF PhD thesis of Moll, Maria Casting process definition Casting molds design Cross contamination (i.e. slag and Iron) Process Time (Lead Time) calculations

10 Process Design Divergences greenfield,, brownfield and conversions of Silicon furnaces Refining Process Raw Material Handling System SAF Furnace Refining Process Casting Process Milling Process Final Product mgsi Refining Process design Gas supply design Refractory Plug and ladle design

11 Process Design Divergences greenfield,, brownfield and conversions of Silicon furnaces Sizing and Classification Milling system design Process modeling Sievings definition Neutralization components Product flexibility 1min Source: Metso BR

12 Process Design Divergences greenfield,, brownfield and conversions of Silicon furnaces Furnace Dimensions Active Power (MW) ,000 6,000 7,000 8,000 9,000 10,000 11,000 12,000 Shell Diameter (m) Active Power (MW) ,750 2,250 2,750 3,250 3,750 4,250 Crucible Height (m) Active Power MW Lineal (Active Power MW) Active Power MW Lineal (Active Power MW) Shell Diameter Crucible Diameter Residence Time Reaction Zone (furnace lining) Source: Tenova and Viridis.iQ GmbH

13 Process Design Divergences greenfield,, brownfield and conversions of Silicon furnaces Furnace Dimensions Electrode Spacing Equipment Flexibility Electrode Column Design

14 Process Design Divergences conversions of Silicon and Ferro alloy furnaces f Difference between the processes The focus on conversion should be restricted to the process technology equipment. Important points : Raw material Contaminants level Pre treatment Post treatment process Energy system Plant design Off gas (PCP)

15 Process Design Divergences conversions of Silicon and Ferro alloy furnaces f Difference between the processes Thermal gradient in the reaction zones Refractory Lining Handling of the product

16 Process Design Divergences conversions of Silicon and Ferro alloy furnaces f Submerged Arc Furnace Conversion

17 Topics Introduction Viridis.iQ GmbH Process Design Divergences CAPEX: turnkey versus package based projects (Greenfield plants) Downstream effects caused by the mistakes in the project engineering phases Summary

18 CAPEX: Turnkey versus Package Based Package Based Divisions Recent Projects Methodology Turnkey vs Packaged Based The CAPEX TKP refers to Turnkey Project CAPEX. The CAPEX PB2 refers to Package Based following the subdivision of the project in areas so far. Comparison: CAPEX TKP / CAPEX PB2 Turnkey Project (MES) Silicon/Ferroalloy Project Package Based Equipment Supply SYSTEMS Division AREAS Division CAPEX TKP CAPEX PB1 CAPEX PB2

19 CAPEX: Turnkey versus Package Based Package Based Divisions Mud Gun and Drilling Machine Ladle and Pre Heater Stocking Machines Package Based Breakdown Structure Poluction Control Plant (PCP) Submerged Arc Furnace Power Transformers System Sub divisions (example example) Main diferences between the plants

20 CAPEX: Turnkey versus Package Based Package Based Divisions 120% 100% 80% 60% Turn Key TK% B1-BP B2-PS -Y1% -Y3% B3-RMHS -Y2% -Y9% B9-FMS B5-SAF -Y5% B10-MRP -Y10% B8-U&WT -Y8% B4-TRF -Y4% -Y7% B7-PCP B6-C&M -Y6% -Y11% B11-HSP Estimates on Potential CAPEX Reduction Greenfield Plant CAPEX Reduction is function of: Engineering maturity Assumptions, Risk Assessment, Radar Staff competence Company history Commercial conditions Warranties, etc. 40% 20% 0% TurnkeyAreas WBD System WBD ME WBD Components WBD CAPEX Efforts Warranties Interfaces Number Operational Risk

21 CAPEX: Turnkey versus Package Based Package Based Divisions Calculated difference between Turnkey and Package Based Projects (Greenfield)

22 Topics Introduction Viridis.iQ GmbH Process Design Divergences CAPEX: turnkey versus package based projects (Greenfield plants) Downstream effects caused by the mistakes in the project engineering phases Summary

23 Downstream Effects Risks during the Engineering phases Equipment Supplier must have this contaminants map in mind

24 Downstream Effects Risks during the Engineering phases Category Element/Comp. Risks area Downstream Effect Metals more noble than Silicon Fe Casting and Milling Minimize the accumulation rate in the contact mass and to reduce the silicon metal wastes Ti Refining Minimize formation of TiCl 4 Metals less noble than Silicon Mn, Ni, Cu, Co, V NA In the case of Mn, should be low metal content to avoid undesired catalytical effects and formation of byproducts (disilanes or dichlorosilanes) Al Refining Reduce the expenses with maintenance (AlCl 3 removal). Reduce the waste disposal Stabilize the selectivity and reactivity in TCS Systhesis. Ca Refining Lower impact on the intermetallic phases formation. Mg ND ND Carbon SiC (or dissolved in Si) Process Minimize contents of hydrocarbons and methylsilantes in chlorosilanes Reduce the expenses in the distillation system Oxygen SiO 2 Refining, Casting, Milling Minimize the accumulation rate in the contact mass and to reduce the silicon metal wastes Dopants P SAF (process), Refining Avoid fluctuation dopant concentration in TCS semiconductor grade. Reduce the expenses in the B SAF (process), Refining distillation system. Source: CT USA and Viridis.iQ GmbH

25 Downstream Effects Risks during the Engineering phases Fe Casting and Milling Ca, Al Refining design P Furnace design Source: CT photovoltaics USA

26 Downstream Effects Risks during the Engineering phases Fe Casting and Milling Iron increase will result in more waste/spent mass. In case of high pressure hydro chlorination of mgsi + STC + H2 iron (Fe) acts as a catalyst. Refining Al acts as a promoter through Al2Cl6 (or AlCl3) which is easily volatized and extremely aggressive. Consumes the native layer of SiO2 on Si and helps the reaction to initiate. Some Al is therefore suitable. But too much Al causes a lot of problem because AlCl3 is also very aggressive with respect to chemical hardware, vessels, tubes, valves and pumps. Fouling is a major operational issue in TCS synthesis. Ca could bring to the process more risk for intermetallic phases formation (silicides with Si, Fe and Al) and may bind these elements in inactive (not reactive phases). Furnace design Phosphorous is a kind of dopants, their elimination through distillation is the main aim of the TCS/polysilicon process. High level of P request high level of distillation.

27 Topics Introduction Viridis.iQ GmbH Process Design Divergences CAPEX: turnkey versus package based projects (Greenfield plants) Downstream effects caused by the mistakes in the project engineering phases Summary

28 Summary For Greenfield Silicon Plants, the definition of turnkey or packaged based is a high strategic decision based on the company characteristics and FEL. Although for the brownfield plants upgrade/expansion looks that the package based is the better choice, a turnkey supplier with enough flexibility could be considered as a reasonable option. The level of difficulty of furnace conversion is a function of the technology, process and production parameters. Process Design divergences in the Engineering phase are very common and should be avoided during the Front End Loading (FEL). Most dangerous downstream effects on the Polysilicon process are related with the post treatment process, like Refining, Casting and Milling.

29 Thanks for the attention!