INTRODUCTION TO SUBCOAL, THE RECENT SUBCOAL TRIALS AND THE FUTURE

Neville Roberts - Managing director N+P Alternative Fuels LtdDr. Iakovos Skourides – Production Process Manager – Vassiliko Cement

February 2018

WHAT IS SUBCOAL?

• An N+P patented waste derived pelletised fuel.

• High CV, low moisture, high bulk density.

• Subcoal® is odourless, dust free and hydrophobic.

• Subcoal® can be co-milled on a vertical Loesche fuel mill and now it is felt it can be milled on a conventional horizontal mill.

• Alternatively Subcoal® can be milled using a dedicated millto achieve very high substitution rates (up to 99%)

• Subcoal® is also fed direct into the pre calciner or riser ductin a similar way to tyre chips

• Used in various forms at different applications, includingcement, lime, power and steel industries

LABORATORY WORK WITH LOESCHE• In December 2015 laboratory trials carried out at the

Loesche Dusseldorf R&D plant.

• Managed to co-mill coal and Subcoal easily up to a mixture of 30% Subcoal.

• Loesche predicted that we could easily achieve 50% substitution and that even 100% is achievable.

• The finished Subcoal product was 99% less than 5mm.

• Clearly this would burn very well on a cement kiln especially when considering a volatiles in excess of 60%.

• By this time we had “sold out “ the Dutch production plant but we were still looking for a good client to carry out full commercial trials.

THE SEARCH FOR A COMMERCIAL PARTNER TO BURN CO-MILLED SUBCOAL WAS OVER

• Together with Loesche we searched for an appropriate partner.

• Eventually we decided upon the partly owned Heidelberg plant at Vassiliko in Cyprus.

• The factory has a history of being innovative and had burnt up to 45% alternative fuels.

• N+P carried out a technical audit of the plant and concluded that following some improvements the plant would be a suitable site to carry out trials.

• The plans were therefore agreed upon to undertake the trials in the first half of 2017 depending upon clinker stocks.

Industrial trials of Subcoal® co-grinding and utilization in a 6000 tpdprecalciner kiln

Dr. Iakovos Skourides

February 2018

Presentation outline

– Brief description of VCW history and clinker production line.

– Major challenges of co-grinding petcoke with Subcoal®- results of preliminary trials.

– Grinding results after process and mechanical modifications.

– Results from 1 week trial in the kiln- impact on pyro process and clinker quality

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Vassiliko Cement Works at a Glance

• Established in 1963– First production in 1967

– 2nd Lepol Kiln line in 1969

– 3rd Lepol Kiln line in 1975

– 4th Lepol Kiln line in 1985

– New BAD 2-string 5 stage Pre-Calciner Kiln 2011

• Cement Plant– Location : Vassiliko, Cyprus

– Raw materials : Main quarry 7 km from plant

– Kiln capacity : 2 m tpa clinker

– Grinding capacity : 2,4 m tpa cement

– Other infrastructure : Vassiliko port

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Milestones since year 2000

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

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Loesche vertical cement mill

installation 60 tph

New cement silo 25,000 tns.

New clinker production line

Dedicated system for feeding alternative

fuels

Debailing system for RDF

90k tons Clinker Silo

Loesche vertical cement mill

installation 200 tph

Clinker production Line at Vassiliko Cement Works Ltd

• Commenced operation on 2011• Raw Mill (LM 60.4)- capacity 520 t/h• Rotary kiln- 2 string 5 stage precalciner kiln- capacity 6000

t/day• Coal Mill (L.M 30.3)• In 2017 thermal substitution with alternative fuels was

higher than 30 %.• Main fuels RDF/SRF, chopped tyres, sewage sludge, MBM• Substitution rates with AF up to 50 % have been tested

successfully. • However, substitution with AF is maintained at lower level

to ensure optimum clinker quality.

Coal mill- off gasses to thermal oxidation during subcoal

grinding

Co grinding Subcoal® in a Loesche Mill (LM 30.3)-Major challenges during first trials

• Petcoke requires fine grinding- fine grinding of Subcoal® is not feasible since it is a fibrous material.

• Ignition point of Subcoal® is considerably lower compared to petcoke (due to high volatiles content)- risk of fire.

• Mill capacity reduced significantly during the initial grinding tests.• The residue of the final product was very high (R90 >20 %) with

8-10% Subcoal® grinding.• Two weeks of trials grinding only calciner fuel since the final product

was not suitable for the main burner.

Co grinding Subcoal® in a Loesche Mill (LM 30.3) after process modifications

• Dual control loop for mill inlet temperature and mill outlet temperature minimized risk of fire.

• Adjustment of piston accumulators to enable grinding with lower counter pressure-higher grinding force.

• Tuning of PXP expert system for sub-coal operation (efficient ΔP control of the mill)• Efficient ΔP control improved mill productivity and fineness of the final product• Mill operation with increased speed on the main drive• Increased speed normally results in high vibrations, subcoal reduces vibration

levels enabling operation with higher grinding force and main drive speed.

• Grinding 10-15% in the main burner for 1 week• Grinding 15-20% on the calciner for 1 week

Co grinding subcoal in a Loesche Mill (LM 30.3)

Preliminary

trials

Trials after

mechanical

and process

modifications

Preliminary

trials

Trials after

miil and

process

modifications

Preliminary

trials

Trials after

mechanical

and process

modifications

Petcoke (100 %) 30 30 2 2 26 25

Subcoal 5 % 18 25 20 3 30 28

Subcoal 10 % 15 23 24 5 34 30

Subcoal 15 % 12 22 26 8 37 32

Subcoal 20 % Not tested 20 Not tested 10 Not tested 36* Residue of petcoke above 90 after substracting subcoal %

Mill capacity (t/h) R90* (%) kwh/t

Table 1. Effect of Subcoal® on coal mill performance

Effect of sub-coal on pyro-process- results from 1 week trial at VCW 6000 tpd kiln

• Subcoal was utilized in the calciner during the first two weeks of trials.• Other alternative fuels were fed to the calciner through a dedicated feeding

system (see table 2).• In the last week of trials subcoal was utilized both on the main burner and the

calciner.• No negative impact was observed on kiln capacity or on clinker quality

(according to XRD analysis and clinker microscopy- results are summarized on table 2 and table 3)

Effect of Subcoal® on pyro-process- results from 1 week trial at VCW 6000 tpd kiln

% Subcoal

Calciner *

% Thermal

substitution

calciner

% Main

burner

% Thermal

substitution

main burner

% Thermal

substitution

with subcoal

Total

% Thermal

substitution

with AF total

Average

C3S content

in clinker

Average

free lime

(fCaO)

Kiln daily capacity

(tpd)

0 0 0 0 0 35 68.5 0.8 6100

10 2.5 5 3 3.8 38 69 0.7 6050

15 3.8 10 7.24 5.2 42 68.5 0.6 6080

* % compared to petcoke fed on calciner

Table 2. Effect of Subcoal® on the pyro process and clinker quality

*Clinker with 0 % subcoal 19.59 0.0083 25.19 Clear-Faint Yellow

Clinker with 3.8 % subcoal 21.27 0.0089 23.88 Clear-Faint Yellow

Clinke with 5.2 % subcoal 22.13 0.0106 25.25 Clear-Faint Yellow

Typical Quality of CLOP 19.92 0.0082 24.64 Clear-Faint Yellow

* % subcoal is % thermal substitution

Sample Name

Alite Size - Heating

Rate

Alite Birefringence -

Max Temperature

Belite Size -

Burning time

Belite Colour -

Cooling rate

Fast=15-20μm

Moderate=20-30μm

Slow=30-40μm

Very slow=40-60μm

Overburning>40μm

Long=25-40μm

Medium=20-25μm

Short=15-20μm

Very short=5-10μm

Fast=Clear

Moderate=Faint

Yellow

Slow=Yellow

Very slow=Amber

High=0.01-0.008

Good=0.007-0.006

Average=0.006-0.005

Low=0.005-0.002

Table 3. Effect of Subcoal® on clinker microscopy

NEW TRIALS USING A HORIZONTALL BALL MILL

• Initial trials have now taken place in milling Subcoal® on a conventional horizontal ball mill in Greece.Achieved milling 10-15%.

• Inlet temperature of 3800C but no indication of CO in the milling system.

• No evidence of fouling or blockages in the milling system.

• Bottleneck was related to separator operation. This now needs further optimization work.

• Now preparing for the second trial.

NEW SUBCOAL FLUFF QUALITY

• N+P have successfully produced 6mm diameterpellets

• Very low moisture levels <3%

• Developed for usage in the steel industry

• Very short pellets have proven to be very usefulas a cement kiln main burner fuel

• Up to 75% substitution was realized at a kilnin Europe

• Loose transport using sea containers, no debalingis required

• Density typically 250-300 kg/m³

SUBCOAL USAGE IN THE STEEL INDUSTRY

• N+P have been trialing the use of Subcoal® pellets at an Austrian steel plant blast furnace for some 12 months.

• Supply by train is being developed throughout Europe

• The utilization of Subcoal® in blast furnaces is beingfollowed by various universities in Europe

• We are also in discussion with various other steel producers in the world

• Patents are now pending for this application.

• So far the use of Subcoal® on steel blast furnaces has been very successful with potential high volumes

SUBCOAL® USAGE AT POWER STATIONS

• Subcoal® has been used on coal fired power stations in the Netherlands and Germany but only at low levels of substitution.

• A major investor into the coal fired power industry sector is now looking to convert coal fired power stations to biomass with Subcoal® being the sole fuel.

• This will be another major development for Subcoal® with potential volumes of well over 1 million tonnes per year

NEW SUBCOAL PRODUCTION FACILITY:Subcoal Production TSP Ltd

• Currently N+P have one production facility in the north of Holland.

• The plant is running at maximum production and is now fully “sold out”.

• N+P are therefore building the second production facility in North East England at Teesside.

• The plant will supply domestic need and can be used for exporting purposes.

• The plant will produce circa 180kt/yr of Subcoal® pellets and highquality SRF (all over 20 GJ/ton).

• Commissioning will be completed in Q4 of 2018.

• It is believed that this will be the first of many Subcoal® plants that will be built in the UK and elsewhere.

CONCLUSIONS

• The development of the various applications of Subcoal® are moving at some pace.

• Trial at Vassiliko was well prepared, and after some modifications the results were very positive

• The cement applications are well developed and the steel and coal fired power station applications are progressing with great speed.

• These developments further underline the view that N+P is now an energy supply company and not just a waste management company.

• In addition, as can be seen from the presentation, N+P are also advising consumers on the use of their fuel and so providing more added value to their offering.