Innovative Sulphuric Acid Production for high strength smelter off-gases using the CORE System

Transcription

1 23 27 ABRIL/APRIL 2018 Santiago, Chile INNOVACIÓN PARA EL DESARROLLO MINERO INNOVATION FOR MINING DEVELOPMENT 3 ER SEMINARIO FUNDICIÓN Y REFINERÍA 26/04/2018 Innovative Sulphuric Acid Production for high strength Rene Dijkstra Acid Technology Manager Chemetics Inc. ORGANIZA Y PRODUCE ORGANIZED AND PRODUCED BY

2 Design and Supply of Sulfuric Acid plants Equipment Fabricator

3 Chemetics Head Office in Vancouver Chemetics Fabrication Facility (Toronto) Local representatives in: Morocco Peru Tunisia Brazil Russia China Chile India

4 1. INTRODUCTION The smelting of non-ferrous metals produces off-gases containing SO 2 which typically are converted to Sulfuric Acid. Recent innovations in smelter technologies have increased the concentration of SO 2 in the off-gases. Smelter Off-gases require additional oxygen before entering the acid plant Current acid plant technologies require addition dilution of the smelter off gases to limit the SO 2 concentration to ~12.5 vol% This presentation will briefly discuss existing technologies and then focus on an Innovative approach to dealing with higher SO 2 concentrations using the Chemetics CORE System

5 Conventional Sulfuric Acid Plant Dilution Air Smelter Off-Gas 1 st Contact 3-pass 2 nd Contact 1-pass Dilution Air used to control SO 2 concentration below ~12.5 vol% Results in very large acid plants to cope with diluted gas flows Plant size increases as smelter Off-gas concentration is higher

6 Chemetics High Strength (CHS ) / MECS Pre-converter System Dilution Air Smelter Off-Gas CHS Converter 1 st Contact 3-pass 2 nd Contact 1-pass All dilution air is mixed with a portion of smelter off-gas to create ~12.5 vol% gas After the CHS converter all remaining smelter gas is added Additional Equipment is required Air/SO 2 Blower Second Drying Tower CHS Converter with single catalyst bed Not suitable for all Smelter Off-gas Possible to retro-fit to existing plant Proven and reliable equipment Can be operated as conventional plant at reduced rate

7 Outotec Lurec System Dilution Air Hot SO 3 recycle Smelter Off-Gas 1 st Contact 3-pass 2 nd Contact 2-pass Recycle of process gas after bed 3 Increased gas flow and SO 3 presence reduces peak bed temperature Additional Equipment is required SO 3 recycle Blower Tough duty! Larger Converter 5 th Catalyst Bed Typically not possible to retro-fit to existing plant SO 3 Recycle Blower failure is immediate risk to plant due to overheating Can be operated as conventional plant at reduced rate

8 Chemetics CORE System Smelter Off-Gas Air or Oxygen 1 st Contact 1-pass CORE 2 nd Contact 1 or 2-pass Smelter Off-Gas Air or Oxygen High purity SO 2 1 st Contact 1-pass CORE Regenerative TGTU SO 2 conversion in special cooled reactor Air/Oxygen only required to maintain desired O 2 :SO 2 ratio Less equipment compared to conventional plant Highest energy recovery

9 Relative Gas flow Innovative Sulphuric Acid Production for high strength Comparison of Plant Size (Gas to Converter) Conventional CORE SO2 Concentration [vol%] Plant size dependent on both SO 2 and O 2 concentrations in smelter off-gas CORE design allows use of Oxygen to reduce plant size further

10 CORE TM (Cooled Oxidation Reactor)

11 RICH SO 2 PROCESS GAS Start-up Heater LEAN SO 2 PROCESS GAS CORE REACTOR HEAT REMOVAL COOLANT CIRCULATION 1.

12 CORE TM (Cooled Oxidation Reaction) The Chemetics CORE TM Converter is the only commercially available isothermal converter system for SO 2 oxidation. Continuous removal of the reaction heat allows the process temperature to be controlled within the operating limit of the catalyst. Highly stable and easy to control (coolant control only) Standby mode keeps reactor hot during smelter interruptions Demonstration unit has over 8 yr operating record

13 Smelter upgrades Acid Plant in good condition Use CORE System in Add-On configuration CORE System handles additional SO 2 Existing acid plant continues to operate as before Dilution Air Smelter Off-Gas Existing Acid Plant CORE Add-On

14 Smelter upgrades Acid Plant in good condition Use CORE System in Add-On configuration CORE System handles additional SO 2 Existing acid plant continues to operate as before Small additional investment Additional benefit: High Purity Acid & Steam

15 Existing Double absorption Acid Plant Ambient air SO 2 -Gas Drying Main Blower HX HX SO 2 Steam Boiler HX HX Intermediate Absorber Final Absorber Stack Start-up heater Fuel (start-up) SO 2 -Blower Intermediate Absorber Gas-Gas Heat Exchanger CORE Converter Coolant circulation CORE Add-on Unit

16 Smelter upgrades Acid Plant in Bad condition OR New Smelter / Acid Plant installation Use CORE System with in-line configuration Double Absorption configuration Single Absorption with Regenerative tail gas scrubber CORE System handles all smelter Off-gas Highest Energy Recovery using single boiler Smallest plant size Highest reliability Lowest investment cost

17 CORE In-line configuration (Double Absorption) HIGH SO 2 GAS FROM DRY TOWER TO STACK SO 2 BLOWER HEAT REMOVAL COOLANT PUMP COOLANT TANK & HEATER CORE REACTOR & HOT EXCHANGER GAS / GAS EXCHANGER ABSORPTION GAS / GAS EXCHANGER FINAL CONVERTER ABSORPTION

18 CORE In-line configuration Clean Gas Dilute SO 2 Gas (<2vol%) Regenerable SO 2 Scrubbing (e.g. CANSOLV ) LP Steam STACK High Purity SO 2 Ambient Air (or Oxygen) SO 2 BLOWER Strong SO 2 Gas HEAT REMOVAL DRYING TOWER COOLANT PUMP MOLTEN SALT TANK & HEATER CORE REACTOR & HOT EXCHANGER GAS / GAS EXCHANGER ABSORPTION TOWER

19 Conventional CHS Lurec CORE SO 2 < 12.5% PP P P PP SO 2 > 12.5% O P P PP New Plant Design PP PP PP PP Expansion/Retrofit O P O PP Equipment Size O P P PP Equipment count O O P PP Oxygen Enrichment O O/P O/P PP Smelter interruptions O/P O/P O/P PP Energy Efficiency O P P PP Operability P P P PP Reliability P P O PP

20 Conclusions The CORE System allows for direct processing of high strength smelter gases without unnecessary dilution If Oxygen is available then a CORE system becomes much smaller and even more attractive Combining CORE with Regenerative Scrubbing further reduces CAPEX and improves operational flexibility and emissions Once a regenerative scrubber is installed it can easily be adapted to capture other SO 2 emissions

21 23 27 ABRIL/APRIL 2018 Santiago, Chile INNOVACIÓN PARA EL DESARROLLO MINERO INNOVATION FOR MINING DEVELOPMENT 3 ER SEMINARIO FUNDICIÓN Y REFINERÍA 26/04/2018 Questions?... Contact: Claudia Araya Bravo Business development manager for Chemetics in LatinAmerica claudia.araya@jacobs.com ORGANIZA Y PRODUCE ORGANIZED AND PRODUCED BY