IMPROVING THE THERMAL EFFICIENCY OF HYBRID IGCC

IMPROVING THE THERMAL EFFICIENCY OF HYBRID IGCC

Ural Federal University I Department of Thermal Power Plants Yekaterinburg I Tel.+7(343)375-47-31 I email [email protected]

Ben-Gurion University I Laboratory for Clean Combustion Tel.+972-8-6477789 I email [email protected]

6th International Freiberg Conference

on IGCC & XtL Technologies

May 2014

Dresden/Radebeul, Germany

Ryzhkov A.1, Bar Ziv E.2, Bogatova T.1, Gordeev S.1, Saveliev R.2, Osipov P.1 1UrFU, 2BGU

Cooperation between institutions

Invitation for a guest lecture for students

Ural federal university Competitiveness enhancement program

focused on efficient cooperation with international institutions

in several areas one of them - Power Engineering, Resource

Saving and Environmental Management (including coal

gasification technologies).

Cooperation throughout this research:

•The Department of Thermal Power Plant, Ural Federal

University, Yekaterinburg, Russia;

•Laboratory for Clean Combustion, Ben-Gurion University of the

Negev, Israel.

Coal technologies development and UrFU experience

R&D goals in Russia

1.Development of prospective solid fuel installations working at ultra super critical(USC) steam conditions 720-750 °C, 35 MPa. 2.Development of IGCC technology and new high-tech and reliable gasification methods with net plat efficiency 44-45% for existing turbine technology, not less than 50% - with perspective equipment. 3.Development of hybrid plants, based on integration of fuel cells with

gasification products of solid fuels.

The development level in comparison with

global benchmark for high-efficient solid fuel

installations, safe for the environment and climate.

Coal technologies development and UrFU experience

Schematic representation of the competition

between technologies

The fundamental goal of this study

Development of the technology based on the combined cycle for

heat and electricity generation. Fuel base – low-rank coals,

petcoke.

Conventional IGCC scheme

•dry / wet fuel feed •single-stage steam-oxygen gasification •medium calorific value tar free syngas •liquid / solid ash handling •cold / wet gas clean-up •500-700 MW, 1.5 GW in the development

Direction of IGCC modernization

The main problems

•Low thermal efficiency of IGCC

•Low reliability of IGCC

•Oxygen plant

Possible solutions

•Hot gas clean-up

•Gasification island unload

•Air-blown gasification

Drawback - lack of heat to complete the conversion of carbon in to the syngas, that could be eliminated by: a) partial gasification and char combustion in the reactor (MHI) or

in the external installation (FW), entrained reactor with air heater /«air boiler» (UrFU-ICEU);

b) hybrid IGCC scheme with air heater («air boiler»).

Hybrid IGCC scheme with «air boiler»

Hybrid IGCC scheme

Now we are focus on two issues: 1) Operating conditions of the reactor with high temperature air. The syngas composition handling. 2) The «air boiler» (air heater) performance. Materials for the heating surfaces. External heat exchange in a combustion chamber. Internal heating transfer intensification in heating surfaces.

Hybrid IGCC syngases and properties of experimental coals

Proximate analysis (dry coal basis), % weight Properties of AKD bituminous coal Total moisture 7.9 Residual moisture 3.0 Ash 14.95 Volatile matter 25.6 Fixed C 59.45 High heating value (HHV), MJ/kg

28.5

Elemental analysis, % weight Carbon, C 73.20 Hydrogen, H 3.90 Nitrogen, N 1.69 Sulfur, S 0.59 Oxygen, O 5.67

Properties of KPC-Melawan subbituminous coal Total moisture 22.3 Residual moisture 15.50 Ash 4.30 Volatile matter 47.10 Fixed C 48.60 High heating value (HHV), MJ/kg 28.9 Elemental analysis, % weight Carbon, C 71.38 Hydrogen, H 5.12 Nitrogen, N 1.36 Sulfur, S 0.22 Oxygen, O 17.62

Coal test facility at BGU

Burner

Coal feed system

Probe sampling

Gas composition

Heat flux layout

Test facility operation conditions for AKD coal gasification Operation parameters with

steam without steam

Total air flow, kg h-1 49.8 37.9 Primary air flow, kg h-1 13.8 8.2 Temperature – primary air and coal, oC

65 64

Secondary air flow, kg h-1 12.1 11.7 Temperature – secondary air, oC

300 300

OFAair flow, kg h-1 23.9 18 Temperature – OFA, oC 250 189 Steam flow, kg h-1 4 - Temperature – steam, oC 227 - Coal flow, kg h-1 4.6 4.6 Total heat rate, MJ h-1 base on Net C.V.

122.5 112.9

Stoichiometric ratio on the burner

0.61 0.62

Pressure, Pa 101325 101325 Coal particle size distribution, %

100 mesh 98.4 87.0 200 mesh 74.7 50.0

Test facility experimental parameters

Devolatilization model developed by Ubhayakar et al.

The char oxidation rate combines the effects of surface reactivity and pore diffusion as described by Hurt and Mitchell, where q is the combustion rate normalized by the particle external surface area, ks is the global rate coefficient [kg-Carbon/m2-s]

Combustion processes of a coal particle

A [kg-Carbon/m2-s] represents the global pre-exponential factor, E [kJ/mol] the global activation energy, R the gas constant and Tp [K] the temperature of the char particle. Ps is the partial pressure of oxygen at the particle surface and n is the global reaction order. Three of the above parameters governing char oxidation can be varied in GLACIER: n, A and E.

Kinetic model for devolatilization – combustion of coal

GLACIER-code kinetic model parameters

*Electric Power Generation, Transmission and Efficiency, 2007 Nova Science Publishers, p. 121-170

Experimental data

CFX-simulation results

GLACIER-simulation results

Air-blown steam gasification Air-blown gasification

l/d l/d

t, oC

Comparison of experimental data, CFX- and GLACIER-simulation for AKD coal

KPC-Melawan AKD

XC, %

CO

2, %

H

2, %

H2, %

C

O2, %

CO

, %

CO

, ppm

Comparison of experimental data, equilibrium calculations and GLACIER-simulation

XC, %

KPC-Melawan

AKD

Experimental data Equilibrium GLACIER

Ternary diagram for the syngas composition

Flow-sheet simulation for different air heating temperature was conducted for conversion process in entrained –flow reactor by Thermoflow software.

Ternary diagram for the syngas composition

Thermoflow simulation for carbon Raw

syngas Units

Case1

Tair= 300 °C

Case10

Tair= 1200 °C

CO

vol %

34,66 40,4

CO2 1,596 0,1661

CH4 0,0716 1,965

H2 9,328 13,52

H2S 0 0

O2 0 0

H2O 0,8995 0,1164

COS 0 0

N2 52,81 43,31

Ar 0,636 0,5216

LHV kJ/kg 4698 6693

Calculated net efficiency of hybrid IGCC

The first plant based on IGCC technology with electrical out of 200-300 MW planned to be installed in Russia by 2020, and by 2030, the installed capacity in the country can be 1 to 2 GW.

Acknowledgement

The work is partially supported by RFBR (Project No.14-08-

01226 А) and by the Ministry of Education and Science of the

Russian Federation (State Contract No. 14.516.11.0043).

Sincere appreciation is expressed to Korytnyi E. (from BGU),

Perelman M. (from BGU) and Abaimov N. (from UrFU) for helpful

discussion about this work.