4

MANUFACTURING AND TECHNOLOGY CONVERSION INTERNATIONAL, INC. P 0 Box 21, Columbia, Maryland 21045 (301) 982-1292 Telex 292354 I MTCI UR

January 31, 1994

Mr. Douglas Gyorke Contracting Off ices Representative U . S . Department o f Energy Pittsburgh Energy Technology Center

Pi t tsburgh, PA 15236 P.O. BOX 10940, MS 922-H

O S T I

Subject: DOE Contract No. DE-AC22-90PC90155

Dear Mr. Gyorke:

Enclosed i s a copy of the 13th Quar te r ly Technical Progress Report f o r "Development and Testing o f Commercial-Scale, Coal-Fired Combustion Systems: Phase 111" f o r the subject contract and covering the period September 27, 1993 through January 2 , 1994 (October - Decerber).

Also enclosed i s the Milestone Schedule/Status under the subject contract f o r the same period (October - December).

I f you have any quest ions, please do n o t h e s i t a t e t o c o n t a c t ' u s .

AMM/df:EROF-SOQ.PRE

Enclosures : As s t a t e d above

cc: Martin R . R . Chandran, MTCI

WEST COAST OFFICE: 13080 Park Street, Santa Fe Springs, CA 90670 (310) 944-8967

DISCLAIMER

Portions of this document may be illegible in electronic image products. Images are produced from the best available original document.

c

TECHNICAL PROGRESS REPORT

October 1993 = December 1993

For:

US. Department of Energy Pittsburgh Energy Technology Center

Under:

DOE Contract No. OE-AC22-90PC90155

Development and Testing of Commercial- Scale, Coal-Fired Combustion Systems:

Phase 111

By:

MANUFACTURING AND TECHNOLOGY CONVERSfON

P.O. Box 21, Columbia, Maryland 21045-0021 j j

PREFACE

This 13th Quar te r l y Technical Progress Report presents the r e s u l t s o f work accomplished d u r i n g t h e pe r iod September 27, 1993 through January 2, 1994 (October - December) under Contract No. DE-AC22-90PC90155 e n t i t l e d "Development and Tes t i ng o f Commercial-Scale, Coal -F i red Combustion Systems: Phase I 1 1 . ' I The f i r s t Q u a r t e r l y Report inc luded subsect ions on background and t h e Statement o f Work. These are omi t ted f rom t h i s q u a r t e r l y progress r e p o r t .

Dur ing t h i s 13th quar te r , a steam generat ion cos t model was developed t o compare t h e economics o f steam produc t ion i n the commercial -sca le, coal - f i r e d pu lse combustion system w i t h t h a t i n a na tu ra l gas- o r o i l - f i r e d system. The purpose o f t h i s model i s t o d e f i n e the compet i t i ve c a p i t a l cos t range f o r t he MTCI system under a s p e c i f i e d se t o f techn ica l and economic cond i t ions .

A c u r r e n t p r e l i m i n a r y est imate o f t h e MTCI pu lse coal combustion system c a p i t a l cos t t u r n s ou t t o be about $120,000 and t h i s i s w i t h i n t h e t a r g e t range o f t h e U.S. commercial b o i l e r market sector . European d i f f e r e n t i a l f u e l cos ts a re expected t o be more favorable.

Several conceptual arrangements f o r coal reburn and char burnout were evaluated. The arrangement was se lected based on the f o l l o w i n g cons idera t ions v i z . u t i l i z a t i o n o f t h e e x i s t i n g pu lse combustor as i s , m in im iza t i on o f f o o t p r i n t and v e r t i c a l space requirement, good mix ing o f coal , steam and combustion products i n t h e reburn sect ion, and adequate char residence t ime i n the char burnout sec t i on.

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TABLE OF CONTENTS

Pase . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.0 INTRODUCTION

1 1.1 OBJECTIVES

1.2 SUMMARY STATUS 4

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.0 TECHNICAL DISCUSSION OF WORK ACCOMPLISHED DURING THE REPORTING PERIOD . . . . . . . . . . . . . . . . . . 5

3.0 PLANS FOR NEXT PERIOD . . . . . . . . . . . . . . . . . . . . . 16

DISCLAIMER

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsi- bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Refer- ence herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recom- mendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

ii EROF-50Q. PRE

LIST OF FIGURES

Pase

FIGURE 1 COAL REBURNING CHAMBER AND CHAR BURNOUT CYCLONE CONFIGURATION . . . . . . . . . . . . . . . . . . . 6

FIGURE 2 PULSE COAL COMBUSTION SYSTEM FOR BOILER RETROFIT - NATURAL GAS BURNER REPLACEMENT . . . . . . . . . . . . . 10

FIGURE 3 PULSE COAL COMBUSTION SYSTEM FOR BOILER RETROFIT - NATURAL GAS/OIL COMBINATION BURNER REPLACEMENT . . . . . 11

FIGURE 4 PULSE COAL COMBUSTION SYSTEM FOR BOILER RETROFIT - NATURAL GAS/OIL COMBINATION BURNER REPLACEMENT (75% C a p a c i t y F a c t o r ) . . . . . . . . . . . . . . . . . . 1 2

FIGURE 5 RELATIONSHIP BETWEEN PAYBACK PERIOD AND DISCOUNTED-CASH-FLOW RATE OF RETURN . . . . . . . . . . . 1 5

LIST OF TABLES

TABLE 1

TABLE 2

MODIFIED COMBUSTION SYSTEM DESIGN DATA SUMMARY . . . . . 7

STEAM COST MODEL INPUT DATA . . . . . . . . . . . . . . 9

iii EROF-50Q.PRE

SECTION 1.0

INTRODUCTION

The U.S. Department of Energy's Pittsburgh Energy Technology Center (PETC) is actively pursuing the development and testing of coal -fired combustion systems for residenti a1 , commerci a1 , and industri a1 market sectors. In response, MTCI initiated the development of a new combustor technology based on the principle o f pulse combustion under the sponsorship o f PETC (Contract No. DE-AC22- 83PC60419). The initial pulse combustor development program was conducted in three phases (MTCI, Development of a Pulsed Coal Combustor Fired with CWM, Phase I 1 1 Final Report, DOE Contract No. DE-AC22-83PC60419, November 1986). Phase I included a review of the prior art in the area of pulse combustion and the development of pulse combustor design concepts. It led to the conclusion that pulse combustors offer technical and base-of-operation advantages over con- ventional burners and also indicated favorable economics for replacement of oil - and gas-fired equipment.

1.1 OBJECTIVES The objective of this Phase I11 program for the development of a commercial-

scale, coal-fired combustion system is to develop and integrate all system components from fuel through total system controls building upon the prior Phase I and I 1 development accomplishments of the MTCI pulse combustion tech- nology and to then field test the complete system in order to evaluate its potential marketability.

The component, system and proof -of -concept test program wi 1 1 be conducted at the MTCI development facility in Baltimore, Maryland. Steady-state tests will be performed to determine combustion efficiency, sulfur capture efficiency, gaseous and particulate emissions, thermal efficiency and turndown ratio of the system as a function of several variables. The parameters to be investigated include: firing rate (1 to 5 MMBtu/hr), multiple air staging (different stoichiometries in the primary, secondary and tertiary air addition zones), Ca/S molar ratio (1 to 3), fuel type (natural gas, 3 different coals), and sorbent

1 EROF-50Q.13

type (1 imestone and dolomite). Start-up, shutdown, steady-state and upset operations of the system will be to evaluate the operability, reliability and availability of the unit. The actual expenditures incurred in operating and maintaining the system will be monitored and recorded.

The long-term, steady-state site demonstration tests to characterize performance, operability, re1 iabil ity, availability, emissions compliance, fuel fl exi bi 1 i ty and economics wi 1 1 be conducted at the Stri egel Supply Company's warehouse. After long-term testing (= 1,000 hours), the unit will be dismantled and inspected to verify the integrity of the materials and the method of construction.

The overall objective of this Phase 111 for the Development and Testing of a Commercial-Scale, Coal-Fired Combustion System is to demonstrate and analyze the performance of a fully integrated system at the 5 to 6 MMBtu level to evaluate its potential marketability. The application assumes the availability of both a coal-based fuel and the equipment required to deliver such fuel to a building, store it within the building or in a storage container or tank adjacent to the building, and transport it from storage to the burner. The fuel is delivered and stored either in the form of a coal-water fuel or as a dry powder.

This program consists of six technical tasks and two additional tasks for program management and reporting. The latter are omitted from the following discussion. The details of each technical task required to meet the following performance goals as specified in the Statement of Work were briefly described in the first quarterly report.

The Project will focus on advanced systems capable of firing rates in the range of 2 to 5 MMBtu/hr, with the following performance goals:

Primary Fuel : ( ' ) e ( z ) Coal-water fuel or dry powder

Secondary Fuel :

Ignition :

Natural gas or petroleum fuels

Fully automatic start-up with system purge and ignition verification

2 EROF-50Q.13

Turndown Rat i o :

Re1 i abi 1 i ty/Safety :

Thermal Efficiency:

Combust i on E f f i c i en cy :

3: I

Comparabl e to oi 1 -fired commerci a1 boi 1 ers

> 80%

> 99%

Routine Operating/Maintenance Labor: Less than one dedicated man-hour per day and an additional two man-hours per week

Ash Removal:

Schedul ed Maintenance:

Service Life:

Emi ss i ons : (3)

Dust-free and automatic or semiautomatic

- < twice a year

Overall system 2 20 years

1.2 lb SOJMMBtu 0.3 l b NO,/MMBtu 0.03 l b particulates/MMBtu

(‘’The coal (s) must be economically recoverable and have sufficient reserves to support a coal-water fuel industry that supplies the proposer-defined appl ication(s) and geographic market sector(s).

having a mineral matier content less than 1 lb/10 Btu and a sulfur content of 0.5 lb or less/lO Btu. These restrictions do not apply here; however, it is emphasized that in order to meet the emissions specifications listed and limit the users ash handling requirements, it is assumed that some coal beneficiation will be necessary.

(2’The 1986 PRDA that initiated Phases I and I 1 charpterized the fuel as

‘3’There are wide variations in state and local air pollution control regulations for commercial-scale space-heating systems. In addition, these regulations are all subject to change. Therefore, the aforementioned emissions specification chosen as the goal for this RFP are those that are anticipated to be achieved based on the present state of development of coal cleaning, combustion, and flue gas cleanup technologies. However, for coal-fired systems to become environmentally and hence commercially acceptable, emissions levels will ultimately need to be comparable to those produced by fuel oil -fired commercial -scale units, viz.:

0.4 1 b S02/MMBtu 0.2 lb NOJMMBtu 0.02 1 b part i cul ates/MMBtu

3 EROF-509.13

In summary, the system should be designed to enable further emission re- ductions, e.g., via advanced flue gas treatment, to be readily applied when necessary.

1.2 SUMMARY STATUS During this 1 3 t h quarter, a steam generation cost model was developed to

compare the economics of steam production in the commercial-scale, coal-fired pulse combustion system with that in a natural gas- or oil-fired system. The purpose of this model is to define the competitive capital cost range for the MTCI system under a specified set of technical and economic conditions.

A current preliminary estimate of the MTCI pulse coal combustion system capital cost turns out to be about $120,000 and this is within the target range o f the U.S. commercial boiler market sector. European differential fuel costs are expected to be more favorable.

Several conceptual arrangements for coal reburn and char burnout were evaluated. The arrangement was selected based on the following considerations viz. utilization of the existing pulse combustor as is, minimization of footprint and vertical space requirement, good mixing of coal, steam and combustion products in the reburn section, and adequate char residence time in the char burnout section.

4 EROF-50Q.13

SECTION 2.0

TECHNICAL DISCUSSION OF WORK ACCOMPLISHED DURING THE REPORTING PERIOD

TASK 3: PROOF-OF-CONCEPT SYSTEM TESTS Several conceptual arrangements for coal reburn and char burnout were

evaluated. The arrangement shown in Fiqure 1 has been selected based on the following considerations viz. uti1 ization of the existing pulse combustor as is, minimization of footprint and vertical space requirement, good mixing o f coal, steam and combustion products in the reburn section, and adequate char residence time in the char burnout section. The bent tailpipe configuration of the pulse combustor has been retained and the tailpipe i s integrated with the reburn chamber comprising concave sections such that the tailpipe exit jet impinges on the concave sections and spins around. This is anticipated to aid mixing and enhance coal particle residence time. A bottom exit is provided to minimize particle settling and accumulation. The products from the reburn chamber enter a vertical char burnout chamber tangentially at the bottom. This will aid in minimizing particle settling at the bottom and the cyclonic upflow against gravity will enhance char particle residence time in the chamber and, in turn, the burnout. Both the chambers are refractory-lined (two layers of refractory - high density and low density) and water-cooled. Reburn coal along with steam are proposed for injection into the tailpipe. Steam i s being considered as a means o f enhancing CH, radical concentration and promoting CH,/NO reactions such that the coal-steam combination would approximate natural gas reburn chemistry. An initial trial of 1 lb steam/lb reburn coal will be made to establish feasi- bility. The addition o f steam will reduce thermal efficiency by about 1 percent. In the design as suggested here, special care has been taken to avoid the use and direct exposure of high-temperature metal surfaces (pipes, cylinders, etc.) to the hot flue gas so as to minimize erosion and corrosion problems. All the components and connecting sections are lined with refractory. The char burnout cyclone incorporates multiple stage ports for air injection. The integration of the char burnout cyclone eliminates the need for the boiler modifications

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rn

Ul 0 .o

w c-l

I

AIR PLENUhi

COMBUSTOR

COAL INIeCTOR \ h

m U R N COAL + STEAU

CHAR BURNOUT CYCLO

AL REBURN CHAMBER

SPACED AIR PORIS

F IGURE 1: COAL REBURNING CHAMBER AND CHAR BURNOUT CYCLONE CONFIGURATION

carried out earlier (radiative shield inside the Morrison tube, swirler, par- tition disk and the boiler extension). The present arrangement would facilitate ease of boiler retrofit.

Detailed material and energy balance calculations were made in designing the reburn and burnout chambers. Table 1 provides a data summary.

TABLE 1: M O D I F I E D COMBUSTION SYSTEM DESIGN DATA SUMMARY

PULSE COMBUSTOR FIRING RATE 6.25 MMBtu/hr

PRIMARY A I R

COMBUSTION CHAMBER TEMPERATURE

COAL

SORBENT

Ca/S MOLAR FEED RATIO

REBURN COAL

REBURN COAL F IR ING RATE

REBURN COAL FEED RATE

STEAM INJECTION RATE

REBURN CHAMBER MEAN TEMPERATURE

SECONDARY A I R INJECTION RATE

OVERALL EXCESS A I R

CHAR BURNOUT CHAMBER MEAN TEMPERATURE

4,380 lb/hr

2300°F

Seacoal

P f i zer Dol omi te

2.5

Seacoal

1.25 MMBtu/hr

89 lb/hr

1 lb/lb reburn coal

2250°F

2210 lb/hr

15%

2265 OF

A materi a1 s 1 i st has been prepared and procurement i ni t i ated. Detai 1 ed fabrication drawings o f the coal reburn and char burnout chambers have been prepared. Support structure modification drawings have also been generated.

7 EROF-50Q.13

Component fabrication has started and it is expected to take about a month to complete. Pursuant to this fabrication, the pulse combustor section will be decoupled from the boiler, reconfigured and integrated with the coal reburn and char burnout chambers and the boiler.

TASK 4: EVALUATE ECONOMICS/PREPARE COMMERCIALIZATION PLAN

SUBTASK 4.1: ECONOMIC EVALUATION

A steam generation cost model was developed to compare the economics of steam production in the commercial-scale, coal-fired pulse combustion system with that in a natural gas- or oil-fired system. The purpose of this model is to define the competitive capital cost range for the MTCI system under a specified set of technical and economic conditions.

The model has a number of flexible input variables covering technical, environmental and financial assumptions. In order to simplify this multi- dimensional model, a baseline parameter set was defined. For these baseline parameters, specific fixed values were employed. Selection of these values were based on technological assessment, vendor cost data and current prices."'2'

Parameters such as capacity factor and differential fuel cost (i .e., natural gas or oil price-coal price per MMBtu) were allowed to vary in order to estimate steam production cost and target capital cost for a coal-fired pulse combustion system. Table 2 summarizes the input parameters for the steam cost model. With coal reburn, the commercial-scale pulse combustion system is expected to fire 7.5 MMBtu/hr at full load. Therefore, gas/oil burner vendors were approached to obtain quotes for a 7.5 MMBtu/hr burner with single-fuel (natural gas) or dual- fuel (natural gas or oil) capability. Current prices for a natural gas burner with blower and controls turned out to be about $14,000 and for a dual-fuel burner system, 632,000.

The results generated from the steam cost model are shown in Ficlures 2, 3, and 4. Figures 2 and 3 indicate the variation in allowable capital cost for the pulse coal combustion system with differential fuel cost for a unit operating at

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TABLE 2: STEAM COST MODEL INPUT DATA

COAL-FIRED SINGLE-FUEL DUAL - FUEL PULSE COMBUST. (NAT. GAS) (N.GAS/OIL) SYSTEM BURNER SYSTEM BURNER SYSTEM

FUEL

SORBENT

F IR ING RATE, MMBtu/hr BOILER CAPACITY, PPH @

COMBUSTION EFFICIENCY, % THERMAL EFFICIENCY, % CAPACITY FACTOR ELECTRICITY CONSUMPTION,

FUEL HHV, B t u / l b FUEL SULFUR, W t . % FUEL ASH, W t . % SORBENT Ca/S FEED RATIO SORBENT PURITY, W t . % SULFUR RETENTION, % FUEL COST, $/#MBtu SORBENT COST, $ / t o n WASTE DISPOSAL COST, $/ton ELECTRICITY COST, $/kWh NO. OF OPERATORS PER SHIFT NO. OF SHIFTS PER DAY OPERATOR COST, $/hr LABOR OVERHEAD, X D i r e c t MAINTENANCE, % I n s t a l l e d TAX & INSURANCE, % I n s t a l l e d CAPITAL COST, $ ENGINEERING, INSTALLATION AND START-UP COST, % C a p i t a l CONTINGENCY, % PAYBACK PERIOD, yr ANNUAL INTEREST RATE, %

15 psig, sa t .

kWh/1000 l b s t e a m

COAL NATURAL GAS N. GAS/OIL

LIMESTONE o r - DOLOMITE

7.5

5,545 99 84

V a r i ab1 e

11.6 12,500

3 8

2.5 90 55 2.0 15 15

0.075 0.125

1 16 80 5

2.5 V a r i ab1 e

37.5 10 5 9

7.5

5,545 99.999

83 V a r i ab1 e

3 23,400

-

- V a r i ab1 e

- 0.075

- 2.5 2.5

14,000

6.25

5 9

-

7.5

5,545 99.999

83 V a r i ab1 e

4.5 23,400

- -

- -

V a r i ab1 e - -

0.075 - - - -

2.5 2.5

32,000

6.25

5 9

-

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2 3 4 5 6 7 8 9 DIFFERENTIAL FUEL COST,$jMMBTU

-t- 55% CAP FACTOR + 65% CAP FACTOR +K- 75% CAP FACTOR 1

FIGURE 2: PULSE COAL COMBUSTION SYSTEM FOR BOILER RETROFIT - NATURAL GAS BURNER REPLACEMENT

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+ 55% CAP FACTOR + 65% CAP FACTOR -+e-- 75% CAP FACTOR

FIGURE 3: PULSE COAL COMBUSTION SYSTEM FOR BOILER RETROFIT - NATURAL GAS/OIL COMBINATION BURNER REPLACEMENT

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2 3 4 5 6 7 8 9 10 DIFFERENTIAL FUEL COST,$/MM BTU

I --)- 5 yr PAYBACK PERIOD + 6 yr PAYBACK PERIOD 1

FIGURE 4: PULSE COAL COMBUSTION SYSTEM FOR BOILER RETROFIT - NATURAL GAS/OIL COMBINATION BURNER REPLACEMENT

(75% CAPACITY FACTOR)

12 EROF-509.13

different capacity factors. (Allowable cost is that capital cost that is competitive with gas/oil burner systems.) Figure 2 presents the data for the replacement of a natural gas burner and Figure 3 presents the results for the replacement of a dual-fuel (natural gas and oil combination burner) system. These capital costs were generated by matching the steam costs ($/lo00 lb) for the single fuel or dual-fuel burner system with the pulse coal combustion system. Note that the design, engineering, installation and start-up cost was factored into the model as a percent of the allowable capital cost. This percent value was made many times higher for the coal system in comparison to that for the gas/oil system (see Table 2) consistent with the complexity o f the coal com- bustion system in relation to the gas/oil system. The allowable capital cost of the pulse coal combustion system varies with the differential fuel cost and capacity factor as shown in Figures 2 and 3. Commercial boilers are typically said to operate at the 75% capacity factor level. At this load and at the current U.S. commercial sector natural gas price of $5 per MMBtu,'2' the differential fuel cost is $3/MMBtu, making the allowable capital cost of the pulse coal combustion system to fall in the range between $100,000 (Figure 1) and $105,000 (Figure 3).

A current preliminary estimate of the MTCI pulse coal combustion system capital cost turns out to be about $120,000 and this is within the target range of the U.S. commercial boiler market sector. European differential fuel costs are expected to be more favorable (efforts are in progress to obtain current international energy prices for coal, oil and gas) and therefore the allowable capital cost for the pulse coal combustion system is expected to exceed the estimated capital cost indicated above. Note that the MTCI system is multi-fuel (gas, coal and oil) capable and is designed to meet stringent emissions stand- ards. The capital cost projections are based on an after-tax payback period of 5 years which typically could correspond to a pre-tax payback period o f 3 t o 3.5 years.

Figure 4 shows the allowable capital cost for the pulse coal combustion system as a function of differential fuel cost for two payback periods (5 and 6 years) at a 75% capacity factor. For a differential fuel cost of $3, the allowable capital cost increases to about $120,000 for a 6-year payback period.

13 EROF-50Q.13

t

Therefore, at current estimates, the MTCI system is marketable with a 6-year payback period and a 75% capacity factor. This corresponds to a 15 percent discounted-cash-flow rate of return (DCFRR) in about 16 years as opposed to a 15 percent DCFRR in 10 years for a 5-year payback period (see Ficiure 5).

Data on the energy prices for the domestic market ( U . S . ) have been obtained from the Energy Information Administration (EIA) publication, "Annual Energy Outlook 1983 with Projections to 2010," DOE/EIA-0383(93). Efforts are in progress to obtain data on international energy prices for local, oil and natural gas. The International Energy Annual (1991) only lists petroleum prices and therefore other sources are being consulted for coal and gas prices. Prices of gas- and oil-fired burners with controls for boiler retrofit are also being acquired to perform the comparative economic analysis. The steam cost model spreadsheet has been put together and the economic analysis will be performed as soon as the data on prices become available.

References

1. International Energy Annual 1991, DOE/EIA-0219 (91), Energy Information Administration, Washington, DC, December 1992.

2.

3 .

Annual Energy Outlook 1993 with Projections to 2010, DOE/EIA-0383 (93), Energy Information Administration, Washington, DC, January 1993.

Perry, R.H. and D.W. Green, Chemical Enqineerinq Handbook, McGraw-Hill Book Company, New York, 1984.

14 EROF-50Q.13

.

(POP), years -

FIGURE 5: RELATIONSHIP BETWEEN PAYBACK PERIOD AND DISCOUNTED-CASH-FLOW RATE OF RETURNc3’

15 EROF-50Q.13

4

SECTION 3 . 0

PLANS FOR NEXT PERIOD

Complete component fabrication.

Reconfigure and integrate combustor section with coal reburn and char burnout chambers.

16 EROF-50Q.13