Firing of 100% Pulverized Biomass in a 250 KWFiring of 100% Pulverized Biomass in a 250 KW Combustion Test Facility

Effect of Particle Size on Combustion Performance– Effect of Particle Size on Combustion Performance

Presented by:yDr Janos Szuhanszki

Co-authors: K. Finney, B. Nimmo and M. Pourkashanian

11th European Conference on Coal Research and its Applications, 5-9 September, Sheffield, UK

The Case for BECCSLarge scale use of Bio-Energy with CCS (BECCS) inevitable due to Paris Agreement:

The Paris Agreement requires a stricter energy savings policy, large scale use of solar, wind and geothermal energy, and application of BECCS.

There is a growing and significant dependence on BECCS in future emission scenarios that do not exceed 2°C warming;

Over 100 of the 116 scenarios associated with concentrations between 430–480 ppm CO2 depend on BECCS to deliver global net negative emissions in the IPCC Fifth Assessment Report (AR5).

The feasibility of this dependence on BECCS is coming under increased scrutiny, (interconnected issues of food production, energy provision, energy system capacity and environmental impacts of large scale bioenergy coupled with large scale BECCS.

BECCS artificial “get out of jail” card in IAMs forced into a 2C world

Potential net negative CO2 emissions:Potential net negative CO2 emissions:BECCS is vital for meeting legally binding and increasingly stringent emission targets and carbon budgets. Bio-CCS has a large and distinct potential for significantly lowering CO2 emissions from energy production; thus the key messages from thelowering CO2 emissions from energy production; thus the key messages from the Bio-CAP-UK programme (UKCCSRC grant number: UKCCSRC-C1-38) will have clear policy implications on decarbonisation strategies.

Technical Challenges Case Study: Didcot Power Station ACase Study: Didcot Power Station A

Air Oxy25 Oxy30

Coal Biomass

Air Oxy25 Oxy30

Using Biomass is Ch ll i

M ld d i Heterogeneity and

Challenging

Mould during storage Heterogeneity and particle size reduction

Fire and explosion risk Deposition

Research Challenges

S f h k h ll i h bi ili iSome of the key challenges with biomass utilisation:

Sourcing and availability

Storage and handling: degradation fire Storage and handling: degradation, fire

Biomass types and its impacts on milling and combustion

Consistency of supply in terms of properties and characteristics y pp y p p

Acidic components, which can initiate corrosion of boiler tubes and other vulnerable surfaces

Ash related impact: alkali metals, which can increase the propensity for deposition within the furnace and heat recovery systems (slagging and fouling)

Environmental impact: total particulate emissions control, NOx emission control, trace metal release (impurities)

Milling Challenges

Milled WoodMilled Wood

Bit i l

Miscanthus Large particles – effect on heating up

Bituminous coal

Miscanthus

Irregular shape – aerodynamic and combustion effects

Biomass Particle Combustion

Pollutant FormationBiomass Char Combustion Steps

Source: Pollutants Generated by the Combustion of Solid Biomass Fuels (JM Jones, AR Lea-Langton, L Ma, A. Williams and M. Pourkashanian (2015).

Milling ChallengesSize

(mm)

Hammer mill

(wt%)

Hammer mill -

fine screen (wt%)

Impact mill

(wt%)

<0.5 24.17 33.38 58.76

0.5-1 39.28 38.42 40.80

1-2 34 67 26 62 0 091-2 34.67 26.62 0.09

>2 1.67 0.95 0.00

Losses 0.20 0.62 0.35

Hammer mill

Hammer mill /Hammer mill - fine scrn. /Impact mill Impact millFuel characterisation undertaken by the University of Leeds (L. Darvell, B. Dooley, J.M. Jones, A Williams)

Pilot-Scale Integrated Experimental Facilities for Bio-CAP Project j

O2/CO2/N2Gas Mixing Facilities

250kW Air/Oxy CTF

ICP-OES & DMS 500Post Combustiontrace metals &

particle aerosolsPost Combustion Carbon Capture Plant

250 kW CTF Layout

Fuel Handling Capabilities

100% coal firing

100% biomass firing

Williams, A. Dr J. M. Jones, Professor M. Pourkashanian. 2007. Co-firing Coal/Biomass and the Estimation of Burnout and NOx Formation. BCURA Agreement Number B 79.

Fuel types: El Cerrejon high volatile bituminous coal Biomasses used by power generators Biomasses used by power generators

• milled wood• recycled wood

t fi d bi• torrefied biomassJones JM, Williams A, Waldron DJ. An investigation of the grindability of two torrefied energy crops. Fuel (89); 3911–18

Current Fuels Tested at PACT

El Cerrejon coalWWP El Cerrejon

Elemental

White wood pellets (WWP)

ElementalOxide (%)SiO2 13.6 39.9Al2O3 1.9 16.6Fe2O3 1 3 10 8

Recycled wood

Wt% (AR) WWP El Cerrejon

Fe2O3 1.3 10.8TiO2 0.1 0.6CaO 27 14.4MgO 5.5 1.9Na2O 1.3 1.9

Moisture 6.69 5.07Volatiles 78.10 35.46Fixed Carbon 14.51 55.07Ash 0 70 4 40

K2O 10.1 1.6Mn3O4 2.2 0.1P2O5 3.1 0.8SO3 2.4 11.4Trace MetalsAsh 0.70 4.40

N 0.15 1.32C 48.44 69.44H 6 34 4 55

Trace Metals mg/kgArsenic 0.3 2.4Cadmium 0.1 <0.1Chromium 2 2 4 7H 6.34 4.55

S <0.02 0.07Cl <0.01 0.03O 37.69 15.15GCV (kJ/kg) 19 41 28 70

Chromium 2.2 4.7Copper 2.6 11.7Nickel 0.7 3.6Mercury <0.1 <0.1Lead 0.7 3.8

Fuel characterisation undertaken by the University of Leeds (L. Darvell, B. Dooley, J.M. Jones, A Williams)

GCV (kJ/kg) 19.41 28.70NCV (kJ/kg) 18.10 27.68

Vanadium <0.6 5.1Zinc 10.2 14.9

Flame Imaging System

Imaging system has been developed by the University of Kent (Dr Gang Lu & Prof Yong Yan)

Coal Firing Tests

200 kW coal flame –200 kW coal flame –firing El Cerrejon high bituminous coal

Biomass Firing Tests

Course milled particles(27% > 1mm)

Fine milled particlesFine milled particles(0.5% > 1mm)

Summary and key steps

Biomass combustion and in particular BECCS is vital in meeting CO2 emissions reduction targets

A number of challenges are associated with burning biomass A number of challenges are associated with burning biomass

Existing coal plants can be converted to co-fire or 100% biomass using for example white wood pellets (the preferred choice of fuel by operators)example white wood pellets (the preferred choice of fuel by operators)

Fuel preparation, quality control and blending is needed to mitigate problemsproblems.

The Bio-CAP-UK project aims to accelerate progress towards achieving l ll f fl bl ff ll bloperational excellence for flexible, efficient and environmentally sustainable

bio-CCS thermal power plants by developing and assessing fundamental knowledge.

Thank you!

Contact: Janos Szuhanszki (J.Szuhanszki@sheffield.ac.uk)

Th h k l d h h UKCCSRC PACT F ili i f d d b hThe authors acknowledge that the UKCCSRC PACT Facilities, funded by the Department of Energy and Climate Change and the Engineering and Physical Sciences Research Council, have been used for experimental and modelling work reported in this publication.