PLASMA PROCESSING OF URANIUN-

CONTAINING SOLID FUELSV.E. Messerle

Combustion Problems Institute, Almaty, Kazakhstan Institute of Thermophysics of SB RAS, Novosibirsk, Russia

O.A. Lavrichshev, A.B. UstimenkoPlasmatechnics R&D LLP, Institute of Experimental and Theoretical Physics of

Kazakhstan National University, Almaty, KazakhstanE-mail: ust@physics.kz

Generation of electricity in the world

1 – natural gas, 2 – nuclear power, 3 – hydroelectric, 4 – renewable energy sources, including waste,5 – coal, including lignite and shale,6 - oil fuel

2Key World Energy Statistics 2017: International Energy Agency.

THE MOTIVATION FOR THE DEVELOPMENT OF PLASMA PROCESSING OF URANIUM-BEARING COAL

Balance reserves of coal in Kazakhstan – 33

billion tons

Uranium-bearing coal(0,06% U) -

14 billion tons

Plasma processing of uranium-bearing coal would increase the fuel base of the Republic of Kazakhstan by 42%, while the existing uranium base – fivefold, up to 5 million tons

The Economic Effect of plasma processing of

uranium-bearing coal will exceed $ 550 billion3

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COAL UTILIZATION

SiO2Fe2O3Al 2O3CaOMgO

UO2U2C3

COMPREHINSIVE PLASMA PROCESSING OF COAL

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С+H2O=CO+H2

MenOm + C = nMe +mCO

МеnOm+2mC=MenCm+mCO

PLASMA U, UO, UO2, UO3

For computation of the solid fuels comprehensive processing thermodynamic code TERRA was used. The calculations were performed over a range of temperatures from 300 to 4000 K and pressure 0.1 MPa.

THERMODYNAMIC COMPUTATION

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Chemical analysis of SFs, Wt. % dry mass basis

С О Н N S Si Al Fe Ca Mg Ti K Na U

Nizhneilli brown coal (Kazakhstan), Аsh=12%, HHV=20,400 kJ/kg, Vdaf=39%

67.01 19.82 3.08 0.50 2.10 1.0 0.74 1.12 3.14 0.92 - 0.14 0.38 0.05

Dictyonema shale (Estonia), Аsh=88%, HHV=6,275 kJ/kg, Vdaf=50%

8.33 41.87 0.90 0.30 3.59 28.51 6.36 2.78 1.64 - 1.05 4.65 - 0.02

Temperature dependence of coal gasification degree at comprehensive processing of the brow coal (1, 3) and shale (2, 4) and specific power consumption for the processes

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The mixture composition is: 1, 2 – plasma pyrolysis of brown coal and shale, resp.3 – 100% of coal + 85% of steam4 – 100% of shale + 10% of steam

Temperature dependence of concentrations of components in gas phase at comprehensive processing of brown coal and shale

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100% of brown coal + 85% of steam 100% of shale + 10% of steam

Temperature dependence of concentrations of mineral components in condensed phase and Uranium containing components in gaseous

phase at complex processing of the brown coal10

100% of brown coal + 85% of steam

Temperature dependence of concentrations of mineral components in condensed phase and Uranium containing components in gaseous

phase at complex processing of the shale11

100% of shale + 10% of steam

BLOCK DIAGRAM OF PLASMA PROCESS FOR URANIUM EXTRACTING FROM COAL

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С+H2O=CO+H2

UnOm+mC=mCO+nU

plasma gasifier

Off-gas cooling section –heat exchanger

solid fuel dust hopper

Layout of Plasma Installation for Processing of Coal

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EXPERIMENTAL REACTOR FOR PLASMA GASIFICATION AND COMPREHENSIVE PROCESSING OF COAL

1 – rode graphite cathode; 2 – cathode insulator; 3 – water cooled cover;4 – electromagnetic coil; 5 – ring graphite anode; 6 – graphite orifice

Scheme of Plasma Reactor

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Plasmochemical installation

Material balance of the installation

G2+G3+G4+G5=G6+G1+G7, [kg/h]

Heat balance of the installation

Parc+P1=P2+P3+P4+P5+P6, [kW]

PLASMA GASIFICATION AND COMPLEX PROCESSING OF COAL

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0 1 0 2 0 3 0 4 0 5 00

5 0 0

1 0 0 0

1 5 0 0

2 0 0 0

T, 0 C

τ , m in

2

1

Temperature dependence of the reactor wall (1) and exiting gases (2) on duration of the experiment

PLASMA GASIFICATION AND COMPLEX PROCESSING OF COAL

RESULTS OF THE EXPERIMENTS ON PLASMA PROCESSING FOR URANIUM EXTRACTING FROM COAL

Gf, kg/h Gsteam, kg/h Тav, К Qsp, kW h/kg XU, % XС, %

5.82 0 2900 6.87 48.0 56.28.40 0 2500 4.65 25.7 54.66.60 0.60 2700 5.55 78.6 66.44.33 0.40 3150 8.46 23.6 70.4

ComputationPyrolysis 2900 3.1 100 100

6.60 0.60 2700 2.23 100 100

INTEGRAL PARAMETERS OF URANIUM-BEARING SHALE PLASMA PROCESSING

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PLASMA STEAM GASIFICATION OF SHALE

Flame of syngas from uranium-bearing shale

Gas composition vol.%:CO = 35H2 = 51

CO2 = 10N2 = 4

NOx < 15 ppmSOx < 20 ppm

CONCLUSIONS• Thermodynamic analysis showed that the gaseous phase of the SF plasma pyrolysis and

steam gasification products consists, basically, of synthesis gas witha concentration of

up to 95.2 vol.% at 1,800 K. At this temperature, uranium-containing compounds

completely pass into the gas phase in the form of uranium oxides.

• Plasma-steam gasification of the shale allowed producing the synthesisgas yield of

86 %, the carbon gasification degree of 70.4%, and degree of uranium release to the

gaseous phase of 83.6%.

• The results of the research testify to the insensitivity of the plasma processing

technology to the quality of the SF used.

• The study showed that the integrated indices of plasma gasification of uranium-

containing SF are higher than those of plasma pyrolysis.

Thanks !