### Bachman, Tom A.
From: Sent: To: Subject:



### Tom, John Graves [jgraves@minnkota.com] Wednesday, March 24,20108:34 AM Bachman, Tom A. Use of Confidential Information



### HaldourTopsoehas agreedto the use oftheirinformation as youpreviously described.

John T. Graves, P.E. Environmental Manager MinnkotaPowerCooperative, Inc. P.O. Box 13200 Grand Forks, N.D. 58208-3200 Tel: (701) 795-4221 Fax: (701) 795-4214

1HALDOR TOPSOE, INC. Catalyst Division Houston, TX This page Is claimed aa 

### CONFIDENTIAL
In accordance with Air Pollution Control Rules

forthe State ofNorth Dakota at 33·15·01·16 October 12, 2009 Page 5 of 30 HTI Quotation No. 09-6362

3.3 Catalyst Specification, Exceptions &Offer

Based on the current data available, including the Microbeam Technologies report dated August 20, 2009, HTI believes that the low dust (after ESP) option is the mostviable. HTI feels that deactivation of the catalyst due to alkali poisoning (sodium) will be the biggest challenge. However, with that said, HTI also recognizes that chemical deactivation can generally be managed with the adjustment of catalyst volume and/or·guarantee life while the potential exists that physical deactivation due to catalyst blinding and pll:lgging could be severe enough to make SCR a non-viable option for controlling NOx emissions.

The absence of S02 downstream ofthe FGO has been discussed and the effect it might have on physical deactivation ofthe catalyst due to blinding. Considering that most of the calcium will be removed in the ESP, calcium sulfate formation should be minimal. Also, considering the low operating temperature of the SCR (-600F) chemical poisoning ofthe catalyst affects the observed activity much more than does physical poisoning (blinding) of the catalyst. The tail-end option should be considered further with actual slip stream or mini reactortesting on an operating unit but at this time HTI feels that with the datacurrently available that the low dustoption is the best option available. HTI's main concern in relation to the lignite fuel is the content of alkali metals (sodium in the case of NO lignite) which leads to chemical poisoning of the catalyst by reacting with the vanadium active sites. The deactivating effect of sodium (and potassium) will be the same, whether in the form of oxide, Sulfate oranother salt. The deposition rate of the aerosols could be different, though, depending on whetherthey are in the form of oxides or sulfates due to differences in mobility.

Information contained herein is confidential and may not be used by orconveyed to anythird partywithoutourwritten authorisation· HaldorTopslle AlS

### · Bachman, Tom A.
From: Sent: To: Subject:



### Tom" John Graves Ugraves@minnkota.com] Wednesday, March 17, 20109:22 AM Bachman, Tom A. Minnkota BACT

- Use of Confidential information



### CERAM will allow the use ofseveralparagraphs from their October 13, 2009 proposal inyour analysis ofour recentBACT submittals. Specificallytheywill allow theuseofthematerial onPage 3, paragraphs 2, 3 and 5(which continues onpage4) beginningwith "Thehigh levels

....." and ending with"

...calciumoxidepresent inthe flue gas."

John T. Graves, P.E. Environmental Manager Minnkota PowerCooperative, Inc. P.O. Box 13200 Grand Forks, N.D. 58208-3200 Tel: (701) 795-4221 ·Fax: (701}795-4214

1

# CERAM 

# -------_.... CATALYSTS + HONEYCOMSS



### MinnkotaPowerCooperative Attn. Mr. LutherKyemen Milton R. Young StationUnits 1 & 2 1822 Mill Road GrandForks, ND 58208-3200 CERAM Environmental, Inc. Porzellanfabrik Frauenthal GmbH

This page Is claimed as 

## CONFIDENTIAL
In accordancewith Alr'Poliutlon Control Rules

forthe State of North Dakota at 33·15-01·16

October 13,2009

7304 W. 130th Street Suite 140. Overland Park, Kansas 66213 Tel: (913) 239-9896. Fax: (913) 239-9821MinnkotaPowerCooperative M.R. Young Station

BoilerType and FuelAnalysis This page Is claImed as 

## CONFIDENTIAL
In accordance with Air Pollution Control Rules

forthe State of North Dakota at 33·15'{)1·16 October 

### 13,2009 Page 3

The levels ofK 2 0 in the ND lignite ash are in the high end range found in many biomass fuels, such as wood and switch grass. However; the levels ofNa2 0 are much greaterthan that found in biomass or coal fired SCR applications. Different boiler types will affect deactivation. CERAM's experience with biomass applications that utilize a bubbling fluidized bed (BFB) boiler with the SCR in a high dust arrangement have been successful because we were able to size the catalyst appropriately and take advantage of the lower flame temperature (e.g., less oxidized poisons), available sorbent (e.g., limestone) that can absorb a portion ofthe catalyst poisons and the fact that a large portion ofthe ash is entrained. Pulverizedcoal (PC), stokerand cyclone boilers in the high dust arrangement can lead to an increase in deactivation due to the higher local flame temperatures and areas ofincomplete combustion that both can lead to a severe increase in oxidized poisons. Solutions to reduce catalyst deactivation have been to use low dust (e.g., catalyst downstream of a baghouse with sorbent injection) and tail end (e;g., downstream baghouse and scrubber) configurations. However, our experience on low dust and tail end biomass and incinerator applications with similar fuel characteristics have shown that increaseddeactivation will still occurcomparedto similarapplications firing sub-bituminous and bituminous coals.
The high levels ofNa20 in the ash for the ND lignite are notcommonly found in sub-bituminous and bituminous coals which are fired with SCR**systems~** CERAM is unaware of any SCR application experience in the industry with this level and form ofsodium in the ash. Sodiumis a well known catalyst poison. In particulate form the effects of sodium can be controlled by maintaining warm and dry conditions on the catalyst at all times during layup. Allowing moist conditions on the catalyst will result in the particulate bound sodium leaching into the pore structure of the catalyst where catalyst poisoning will occur. Small aerosol particles can penetrate and neutralize active catalyst sites evenin dryconditions. CatalystDeactivation

For this application we canassuinethat most ofthe ash will be removed; however catalyst deactivationwillstill occurdue to gaseous constituentsin the flue gas and from the small amount ofash that will reach the reactor. Even though this application maybe ether a low dust or tail end application it is not a "no dust" application. Deactivation can be caused by exposure to various catalystpoisons and fouling agents, such as alkaline metals, arsenic, sulfate compounds,

CONFIDENTIALMinnkotaPowerCooperative M.R. Young Station This page Is claimed as 

## CONFIDENTIAL
In accordance with Air Pollution Control Rules

forthe State of North Dakota at 33·15·01·16 October 13,2009 Page4

silica and phosphorous compounds, hydrochloric and hydrofluoric acids, sodium and potassium in the ash, etc., thatare formed during the combustion process. Catalyst installed in even low dust and tail end locations are poisoned from the exposure to the flue gas. Some ofthe potential catalystpoisons that could leadto deactivation ofour catalyst are found in the mineral and trace analysis or can be controlled by temperature. The amount ofsulfur dioxide, sulfur trioxide and sulfuric acidare a function oftemperature, thereby ifthe temperatureis controlled above the acid dew point then no problems should exist. In addition, the amount oflead, mercury, chromium and other metals listed in the trace analysis are typically extremely low and should not bea major influencing factor for a coal fired application. Moreover, the high levels ofphosphorous, sodium and potassium found in the mineral analysis will increase deactivation rates. Arsenic poisoning will occur, however the levels for which this can he attributed to are a function ofthe amount ofcalcium oxidepresentinthe flue gas. \,

CONFIDENTIAL