Emission Challenges in Cement Making due to alternative Fuels

Transcription

1 Emission Challenges in Cement Making due to alternative Fuels March 2017 / Carl-Henrik Persson Yara Environmental Technologies AB carl-henrik.persson@yara.com

2 Presentation Contents Yara s start in environmental solutions Yara at a glance Different emissions from AFR SNCR denox process and technology CAPEX and OPEX for NOx reduction

3 The start 1997 in Cement: NOx case in Sweden 3

4 Reference Case: Sweden Low NO x cement installation In operation since 1997 Base NO x mg/nm3 at 8 % O2 To achieve this the system is designed with 12 injectors and 2 process units. The residence time in cement plants are short and a large number of injectors are required The plant has been running below 200 mg/nm3 since start up and no other cement plant in the world runs continuously at this level of reduction, > 80 % 4

5 YARA s Cement Customers and experience Cement, 100 SNCR references SNCR References in Europe, USA, Australia and China More than 200 inerting cement references all over the world 5

6 YARA s Key numbers Crop nutrition products, solutions and knowledge to 20 million farmers Number of people we help feed with our crop nutrition solutions 240 million Helped our customers to reduce 1.4 million tons of NOx per year (= total annual emissions in France) Revenues and other income (2015) EUR 12 billion Number of employees > 12,900 Operations in more than 51 countries Sales to about 150 countries 23.6 million tons Crop nutrients 4.9 million tons Industrial products 1.7 million tons Environmental solutions

7 Yara has a solid global presence Yara plants Joint venture Sales offices Development programs R&D Units

8 Yara s NOxCare Product Portfolio DeNOx Reducing Agents NOxCare products: - Anhydrous ammonia - Aqueous ammonia - Solid urea - Urea solution DeNOx Technologies SNCR and HYBRID - Boilers / Cogeneration - Industrial applications - Cement Industry SCR - Boilers / Cogeneration - Industrial applications - Diesel engines - Marine Reagent Handling and Storage Urea to Ammonia DeNOx Services Technology services Testing & Optimization Upgrade & Modification Spare parts & Maintenance Catalyst Management Operation & Maintenance Training Safety Services Training Online & Customized Inspection, Audit & Advisory 8

9 Additional emissions and negative impacts on human health and the environment from AFR must be avoided Negative effects of pollution on the environment and human health must be prevented or kept at a minimum. Air emissions from cement kilns burning alternative fuels cannot be higher than those of cement kilns burning traditional fuels. International and national regulations. 27/03/2017 Page 9

10 Lots of different alternative fuels Liquid fuels Tar, chemical wastes, distillation residues, waste solvents, used oils, wax suspensions, petrochemical waste, asphalt slurry, paint waste, oil sludge Solid fuels Paper waste, rubber residues, pulp sludge, sewage sludge, used tyres, battery cases, plastics residues, wood waste, domestic refuse, rice husks, refuse derived fuel, nut shells, oil-bearing soils, diapers, meat and bone meal, etc. 27/03/2017 Page 10

11 Greenhouse gases Fuel type Net CO2 emission factor (kg CO2/GJ) Petcoke 101 Coal 96 Natural gas 54 Tyres 85 Waste oil 74 Plastic 75 MSW 9 Animal meal 0 Waste wood 0 Adapted from Albino et al. 27/03/2017 Page 11

12 Sulphur dioxide The concentration of sulphur in substitute fuels ( %) is generally much lower than the reference value in conventional fossil fuels (3 5%). In addition, the alkaline matrix of the clinker traps much of the sulphur, thus keeping sulphur emissions below critical levels. There is still the possibility that sulphur may react with different metals in raw meal, so metal and sulphur content in fuels must be monitored closely. Lawrence Berkeley Laboratory study 27/03/2017 Page 12

13 Nitrogen oxides - NOx In general, the formation of NOx is related to the amount of nitrogen in the fuel, the temperatures in the kiln, the residence times and the types of burners. Overall, alternative fuels do not lead to higher NOx emissions. Alternative fuels in the calciner has a longer combustion time resulting in higher CO and thus less NOx. Lawrence Berkeley Laboratory study 27/03/2017 Page 13

14 Chlorine Chlorine-related concerns are the same whether alternative or conventional fossil fuels are being used. These concerns include both direct and indirect impacts on cement kiln emissions and performance. Chlorine in feed materials can lead to the formation of acid gases, and there is a risk of increased corrosion if these gases build up on the kiln surface. Provided that chlorine content stays below 0.5%, these risks are minimal. If the chlorine content of the fuel rises above that level, it may be necessary to operate a bypass on the flue gas to limit the chloride concentration in clinker. Lawrence Berkeley Laboratory study 27/03/2017 Page 14

15 Heavy metals Heavy metal concerns are essentially the same for both alternative fuels and traditional fossil fuels. Non-volatile heavy metals are effectively incorporated in the clinker. Semi-volatile metals are captured in the clinker stream or dust. Highly volatile metals such as mercury and cadmium are an exception: the best approach is to limit their concentration in raw materials and fuels. Lawrence Berkeley Laboratory study 27/03/2017 Page 15

16 Dioxins and furans The formation of dioxins and furans is a recognized concern for cement manufacturing regardless of the fuel used. The high temperatures and long residence time typical of cement kilns can repress formation of these compounds, as they form more readily at lower temperatures. Limiting the concentration of organics in raw materials and quickly cooling the exhaust gases in the kilns also reduces formation. Numerous studies comparing dioxin formation rates between alternative fuels and traditional fuels in cement manufacturing have found no significant difference in emissions. Lawrence Berkeley Laboratory study 27/03/2017 Page 16

17 Other emissions For other emissions, the European Commission have summarized assumed impacts of waste co-processing as follows: Dust emissions and carbon monoxide are largely unaffected by coprocessing wastes. The alkaline kiln environment removes hydrogen chloride and hydrogen fluoride produced during firing. There is no correlation between the use of alternative fuels and total organic compound emissions levels. Lawrence Berkeley Laboratory study 27/03/2017 Page 17

18 Example of profile from a cement kiln using waste-derived fuels 27/03/2017 Page 18 Lawrence Berkeley Laboratory study

19 SNCR process NH 3 + NOx N 2 + H 2 O 850º C 1000º C 19

20 SNCR system Process control Reagent mixing & distribution Combustion chamber / Boiler Storage Tank CMM PU reagent injection PMR PMW Unloading pump PMR = Pump module for reagent PMW = Pump module for water

21 Injector Optimum location and design Impact on operational costs Find optimum location between kiln inlet and last cyclone After secondary combustion Injector designed for atomizing and cooling with compressed air and equipped with quick release coupling for easy inspection. 21

22 Modular design vs built on site - Well proven standard modules - shorter lead time Pump Module Reduction agent PMR Pump Module Reduction agent PMW Process Unit, PU Tank module Control and Management Module; CMM Injector 22

23 Fast installation and commissioning Total lead time from order to startup 4-6 months 27/03/2017 Page 23

24 Reduction agent Alternative reduction agents for SNCR Ammonium hydroxide - NH 4 OH Urea - NH 2 CONH 2 24

25 Higher performance with Ammonia solution Up to 90% reduction of NOx emission with ammonia (Urea 30 50% reduction) High efficiency = low consumption and operational costs ( Million INR / year higher cost with urea) Low emission of ammonia slip Low emission of laughing gas (N 2 O) 25

26 CAPEX and OPEX SNCR denox Example 4300 ton clinker per day Flue gas flow Nm3/h 10% O2 Average base NOx 1100 mg/nm3 10% O2 NOx with reduction 500 mg/nm3 10% O2 25% ammonia solution consumption 415 kg/h (expected) Price example in Europe 200 EUR/ton 8000 hours per year EUR/year Compressed air consumption 40 m3/h x 0,015 EUR/m hours per year EUR/year Soft water for flushing <500 EUR/year Power for the SNCR 2 kw x 0,10 EUR/kWh 8000 hour per year EUR/year Wear parts Maintenance man hours Per year TOTAL operation cost CAPEX EUR/year 20 hours per year x 25 EUR/hour 500 EUR/year EUR/year ( INR) EUR 26

27 2 commercial summary messages for NOxCare Tailored DeNOx Solutions: solving the problems before they occur Best Value DeNOx offer: Optimizing the customers DeNOx costs over time Thank you!