DEVELOPMENT AND APPLICATION OF PROMISING TECHNOLOGIES FOR FIRING COAL-WATER FUELS Coal-Gen Europe 2008 F. Serant , K. Agapov , A. Kuzmin, Yu. Ovchinnikov, L. Pugach SibCOTES, NSTU cotes@cotes.sib.ru Novosibirsk Russian Federation Ladies and Gentlemen, I consider it a special honour to make a presentation on such a representative forum and I would like to thank the organizers of the conference for this opportunity. I will speak about technologies for coal-water fuels production & firing

CONTENTS Problems and prospects for coal-water firing at power generation installations Experience of application of coal-water fuel at Novosibirsk CHP-5 Plant & Belovskaya PP Advanced coal-water technologies developed together with Novosibirsk State Technical Institute & Novosibirskteploelectroproect My presentation covers the following issues: The first point concerns the problems and prospects for coal-water firing Experience of application of coal-water fuel The next point is Advanced coal-water technologies And in summary I will sum up the results of our study and give the main conclusions regarding coal-water fuel production and firing Main conclusions - 2 -

Power industry & coal-water fuel in Russia Tons of coal equivalent It is well-known that the development of power industry in Russia for the next 20-30 years will rely on the increased use of coal both due to economical reasons and the need to ensure energy safety. Oil and gas resources will last for several decades, while coal resources will last for centuries. The use of coal-water fuel is one of the ways for a wider application of coal in power generation along with conventional pulverized coal firing and fuel-bed firing. At present, the use of coal-water fuel instead of oil at thermal power plants is considered to be very promising. - 3 -

Advantages of coal-water fuel Coal-water slurry is a relatively new type of fuel for small- and large-scale power installations. It has a number of advantages compared to conventional fuels: Long-distance pipeline transition No explosion hazard Lower NOx and SOx emission level Coal-water slurry is a relatively new type of fuel for small- and large-scale power installations. It has a number of advantages compared to conventional fuels: Long-distance pipeline transition No explosion hazard Lower NOx and SOx emission level - 4 -

Requirements for coal-water fuel General requirements for coal-water fuels: Suitable viscosity - about 0.5–1.0 Pa·s with shear rate 100 s-1 Certain stability of properties when stored in tanks for 12-18 months Ensuring the conditions for stable direct combustion: acceptable heating value, reactivity, and good dispersing properties (drops up to 350 μm) Fired fuel should ensure efficient combustion, as well as reduced emissions Eliminate covering and slagging of heating surfaces General requirements for coal-water fuels production process: Acceptable power inputs per 1 ton of product Moderate wear and metal intensity per 1 ton of the product Long overhaul life for the elements (mills, cavitators, dispersers, fuel nozzles) Automation ensuring proper operation level To substitute gas and oil, it should meet the following requirements. Suitable viscosity Certain stability of properties Ensuring the conditions for stable direct combustion Fired fuel should ensure efficient combustion, reduced emission level without covering and slagging of heating surfaces General requirements for coal-water fuels production process are the following: Acceptable power inputs Moderate wear and metal intensity Long overhaul life for the elements Automation ensuring proper operation level - 5 -

Coal-water fuel combustion on a 200 MW unit at Belovskaya Power Plant Coal-water slurry conditions: Kuznetsky coal, grades D (long-flame coal) Kuznetsky G (gas coal) Qir =15.1 MJ/kg Wr = 39% Ar =9% Nr = 1.45% Density ρ=1180÷1220 kg/m3 Viscosity μ = 0.5÷1.2 Pa·s Russia has a wide experience of application of various technologies for coal-water fuel preparation and firing. Combustion of coal-water fuel prepared in conventional wet mills was tested on several 200 MW power units at Belovskaya Power Plant in Siberia. This slide presents the scheme of reception, storage and firing of coal-water fuel at Belovskaya Power Plant as well as coal-water fuel parameters. 6000 tons of fuel were fired at the boiler with wet slag removal sysytem. Coal-water fuel was based on Kuznetsky long-flame and gas coal. Boiler PK-40-1: Steaming capacity = 320 t/h Furnace heat release rate qv= 130 kW/m3 Furnace cross-section heat release rate qF= 3.8 MW/m2 6000 tons of coal-water fuel were fired - 6 -

Application of coal-water fuel at Novosibirsk CHP-5 Plant Pilot coal slurry pipeline Belovo – Novosibirsk 262 km-long coal slurry pipeline 4 million tons of coal-water fuel per year 3 million tons of dry coal per year Novosibirsk CHP-5 Plant has an experience of reception, storage and firing of coal-water fuel as well. This fuel produced at Belovo terminal in the Kuzbass region and transmitted through a 262 km-long coal slurry pipeline. At this slide you can see coal-water fuel preparation unit, the main and intermediary pumping stations and reception point where the fuel is heated and further forwarded to the boilers. - 7 -

Coal-water fuel handling and storage system Two tanks (20 000 m3 each) with hydro mixers Air compressor Compressed air The terminal, final point of the coal slurry pipeline, is given at the next slide. It technologically consists of three systems that receive, store and supply coal-water fuel for firing. - 8 -

Coal-water fuel combustion on boiler at Novosibirsk CHP Plant Boiler performance: Steaming capacity - 670 t/h 1 boiler was completely re-equipped for coal-water fuel firing (together with Snamprogetti) 3 boilers fired it together with conventional Kuznetsky coal (grades D (long-flame coal) and G (gas coal)). Low heat release rates - qv = 95 kW/m3 and qF = 3.4 MW/m2. Coal-water fuel conditions: Coal concentration in the coal-water fuel - 54.6 - 55.8% Coal-water fuel density – ρ=1.21 g/cm3 Ash content Ad=9.5 % Calorific value Qir =13.6-14.4 MJ/kg During the process of coal-water firing at dry-bottom furnace boilers at Novosibirsk CHP Plant one boiler was completely re-equipped with coal-water fuel firing system. 3 other boilers fired coal-water fuel together with coal. Coal quality: Qir =22,7 MJ/kg Ad=12.5 % Wr =14.6% - 9 -

Conclusions after coal-water fuel firing at Belovskaya PP and Novosibirsk CHP-5 Plant Switching of the existing PC-fired boilers to coal-water fuel without any additional reconstruction results in the following: Lower gas temperature in the flame kernel (by 100-150°С) Lower cost-efficiency of combustion (by 2.5-3.3%) Higher gas temperature at the furnace tail (by 35-45°С) and downstream the boiler by 15-20°С Lower NOx level under certain conditions (by 25-35%) To eliminate adverse effects the boilers need some re-engineering, incl.: Heat insulation of the furnace to increase gas temperature within the flame kernel Changed superheater and economizer surfaces Finer coal grinding Higher hot air temperature Transmission system for coal-water fuel (Belovo – Novosibirsk) with conventional milling and mixing with water has some disadvantages: Limited time of being in a stable condition Abrasivity of coal-water fuel, which causes considerable wear of pumps, gate valves, fuel nozzles, etc. Need to use surface-active substances Based on the experience of coal-water fuel firing we can make the following conclusions. Switching of the existing PC-fired boilers to coal-water fuel without reconstruction results in flame kernel temperature decrease and cost-efficiency reduction, but NOx level is lower. Thus, it is necessary to carry out a certain reconstruction to avoid the negative consequences. Conventional milling and mixing within the transmission system for coal-water fuel revealed a number of drawbacks. For this reason it seems very important to develop advanced technologies, which meet specific requirements. - 10 -

Cavitation of coal-water fuel Technology developed together with company NovosibirskTeploelectroproekt New technology for coal-water fuel production was developed together with Novosibirskteploelektroproekt This advanced technology is based on mechanical and chemical activation making use of cavitation technology. This cavitation technology is featured by the stability over a long period of time and plasticity without using any additives. Based on the operational experience installations with different capacities (from 5 to 300 tons per hour of source coal) were developed. Capacity from 5 to 300 t/h of sourse coal Coal-water fuel stability – more than 24 months - 11 -

Production and supply of composite liquid fuel to boiler Coal-water technologies developed by Novosibirsk State Technical University (NSTU) 1 – coal hopper 2 – crusher 3 – feeder 4 – desintegrator 5 – separator 6 – cyclone 7 – FDF 8 – PC bunker 9 – feeder 10 – cavitators 11 – raw oil tank (oil and fuel oil residue) 12 – daily tank for composite liquid fuel 13 – recirculation line of composite liquid fuel 14 – water-supply tank 15 – peat hopper 16 – screen 17 – flotation plant 18 – peat gel feed line 19 – feeding pump of composite liquid fuel 20 – feed line of composite liquid fuel 21 – FDF 22 – feed line for coal-water mixture after the first cavitation stage Another technology was developed in cooperation with NSTU. This technology is based on the use of coal dust and crushed peat using molecular decomposition in a multi-stage cavitators and disintegrators. As a result the final product – composite liquid fuel, meets the required physical-and-technical conditions of liquid fuel. Production and supply of composite liquid fuel to boiler - 12 -

Coal-water production technology features Stability of the system is more than 1 year Basic methods of stabilization: Mechanical-chemical activation of solid phase during grinding in a desintegrator Mechanical-chemical activation of liquid phase in a cavitator Creation of stable physical-chemical fuel system through profound homogenization of activated phase in a cavitator Due to mecanical & chemical activation the received fuel has an in-depth dispersed composition & long period of stability - 13 -

Main equipment for the technology Desintegrator is a high-speed mill with percussive-smashing effect. Desintegrator output is 3 t/h Activation of coal particles is realized through deformation of coal structure and through creation of micro-defects on the surface of coal particles. These processes were realized on high-speed dry milling grinders for solid phase, so-called disintegrating mills. Solid and liquid phases were mechanically and chemically activated. Coal is grinded to almost minimum size. - 14 -

Main equipment for the technology Cavitator functions: Further grinding of solid phase material Homogenization of liquid and solid particles mixture Creation of stable physical chemical liquid fuel system Major feature - Shock-thermal effect in the cavitator zone; This impact leads to: activation of liquid destruction of connections in the clusters of the liquid creation of free radicals and active molecules. Cavitator: output - 3 tons per hour ACLF A shock-wave effect in cavitator zone leads to activation of liquid, destruction of connections in the clusters of the liquid, creation of free radicals and active molecules. Activated particles of coal and activated liquid create stable physical-chemical system during homogenization process. The stability of this coal-water fuel is much higher than that of coal-water fuel received using conventional milling and mixing. - 15 -

Production of synthetic composite liquid fuel Main technical characteristics of the new technology: Specific energy consumption ~ 14-17 kW per ton of product Specific metal consumption ~ 0.45-0.50 t per ton of product in terms of the main equipment Reasonable cost of equipment Production area ~ 8 m2/t Production of synthetic composite liquid fuel: 1 – coal tank; 2 – coal feeder; 3 – crusher; 4 – disintegrator; 5 – mixer with water; 6 – cavitator; 7 – intermediate tank; 8 – tank for finished composite liquid fuel Due to the need in new equipment for a new type of fuel NSTU developed and brought to commercial application a processing plant for synthetic composite liquid fuel production. The main feature of the technology is that synthetic composite fuel includes complementary components, and as a result we can obtain a better fuel compared to the source components. The composite liquid fuel should be a homogenized system. The scheme of composite liquid fuel production is given at the slide. - 16 -

Module for synthetic composite fuel production Composite liquid fuel production lines can be developed both for the production of synthetic composite liquid fuel and for synthetic composite solid fuel. As you can see on this slide, the synthetic composite liquid fuel is an intermediate product. At this point the stage for synthetic composite liquid fuel preparation is completed. - 17 -

Received fuels & their combustion Line 1: Wr = 64 %, coal – 20 %, peat – 8 %, oil – 8 %, Ad =28 %; Line 2: Wr = 54.5 %, coal – 45.5 %, Ad =27.8 %; Line 3: Wr = 56.05 %, coal – 17 %, peat – 10 %, fuel oil – 17 %, Ad =19.5 %; In addition, coal-based fuel without any peat component was received: Line А: Wr = 35.5%, coal – 39.5%, oil - 25%, Аd = 10.3 %; Line G: Wr = 48.6%, coal – 43.4%, oil - 8%, Ad= 19.5 %. Mail results of fuel lines studies: Viscosity of the synthetic composite liquid fuel does not depend on the temperature within the operating temperature range and on the shear rate within the operating velocities, it depends on the composition and is similar to operating viscosity of fuel oils. Synthetic composite liquid fuel is a thixotropic fluid. Combustion process confirmed reliable flame ignition of sprayed synthetic composite liquid fuel and its independent stable combustion. Emissions when firing coal-water fuel are: NOx = 50-100 mg/Nm3 (with O2 = 6 %), SO2 =140-200 mg/Nm3. Using the technology several lines of synthetic composite liquid fuel were prepared making use of anthracite fines, peat and black coal. Crude oil and fuel oil were used as additives. All mentioned components and received fuel were studied and tested in the laboratories. Our studies have shown that viscosity of the synthetic composite liquid fuel does not depend on the temperature, but it significantly depends on the composition. Generally its viscosity is similar to that of fuel oil. The received experience has proved the reliable ignition, stable burning and low NOx and SO2 levels. - 18 -

Conclusions Presented technologies make it possible to produce a fundamentally new type of synthetic fuel based on coal, water and other components; Rheological, sedimentation, heat-and-power requirements for this fuel were defined; In order to burn synthetic composite fuel on existing PC-fired boilers with good efficiency, it is necessary to reconstruct such boilers; The fuel meets the requirements set for the coal-water fuels; New composite fuel can be used both for firing in various combustion chambers, and as a fuel for internal-combustion engines, gas turbine fuel and fuel for gasifiers, or instead of oil fuel for boilers and TPPs; Research works for the preparation and combustion of synthetic composite liquid fuel making use of local fuels (different grades of peat), coal treatment products, wood waste, farm and oil refinery waste are still in progress. All implemented research and development, pilot and design efforts allow us to make the following conclusions: Described technologies make it possible to produce a fundamentally new type of fuel Requirements for this fuel were defined To ensure good performance during coal-water fuel firing on the existing PC-fired boilers some reconstruction is required. Developed fuel meets the requirements set for the coal-water fuels; New composite fuels can be used for different applications: boilers, gasifiers, instead of oil fuel and coal and so on. Research works for the preparation and combustion of synthetic composite liquid fuel are still in progress. - 19 -

Thank you for your attention!