New White Paper - Preserving Solid Fuel Firing in a Post-Coal World

This white paper addresses how economic and environmental concerns are shifting global energy markets away from coal towards natural gas and other technologies, making preservation of the skills associated with solid fuel firing increasingly difficult for heritage operators. The Coalition for Sustainable Rail (CSR), in association with the Natural Resources Research Institute at the University of Minnesota - Duluth (NRRI), is working to stay ahead of this eventuality by developing a direct coal replacement employing sustainable biomass.

Preliminary results are detailed in the paper, outlining steps being taken by CSR to perform instrumented testing and refinement of this material to-date. The project is specifically designed to reduce risk associated with development of the fuel by first conducting tests in quarter scale locomotives and then systematically moving toward larger, and larger equipment. 

UPDATE: A newer version of this paper was re-uploaded in November 2017 that includes minor corrections to the text and content. 

CSR and NRRI Forge Ahead with Biofuel Research, Matching Grant Announced

The Coalition for Sustainable Rail and its research collaborators at the Natural Resources Research Institute are forging ahead with their biofuel initiatives, including pursuit of a wood-based substitute for use in coal-fired steam locomotives. Following a retooling of its large torrefaction reactor, NRRI recently hosted an event announcing the commissioning of the reactor.

NRRI initially began commissioning the reactor in Fall 2016, providing CSR some of the very first torrefied biomass made in the machine. Following those initial trials, the torrefaction reactor was taken out of service for modification and additional testing. One year later, the reactor and a new densification machine are again ready to generate fuels for testing.

The densified fuel made for CSR that was used in the second Zoo trials last fall were quite friable. NRRI has since devised a more advanced way to densify the material.

The new densification unit creates very uniform, half-pill-shaped pellets that burn very much like coal. When burning, this fuel reacts much the same way as coal.

A key portion of the retooling has been the installation of a more advanced densification unit that is able to create pellets with a uniform, and highly compressed profile. This will allow the fuel to burn more like coal and minimize spark emissions, especially when used in a railroad environment.

To test this theory, CSR is heading back to the Milwaukee County Zoo late this Fall to undertake another round of fuel experiments. This testing will serve to verify the viability of this new fuel in anticipation of standard gauge tests at the Everett Railroad in the New Year.

In support trials in Milwaukee and at the Everett Railroad, an anonymous rail industry sponsor has offered a matching grant to CSR. They have offered to match every dollar CSR raises (up-to $10,000) between now and December 15, 2017, dollar-for-dollar.

This is a great opportunity to support CSR's research and help develop a technology to keep historic steam locomotives on the rails for years to come. Every bit helps - $50 buys new thermocouples, $200 buys sensor wiring, and $2,000 pays to ship seven tons of fuel from Minnesota to Pennsylvania. 

Research Team Completes First Milestone of $1.9 Million Grant to Develop Locally Sourced Electricity and Solid Biofuel

D U L U T H,  M I N N. | April 19, 2017 –The Natural Resources Research Institute at the University of Minnesota is Principal Investigator and leader on a $1.9 million Renewable Development Fund grant funded through Xcel Energy to develop a Biofuel Conversion Center at the NRRI Coleraine Lab. The Coalition for Sustainable Rail is one of two industry partners aiding NRRI on the grant; its responsibility includes designing and building a 100 kW steam-electric boiler generator. The other industry partner, SynGas Technology, LLC, is championing development of a proprietary moving bed torrefaction reactor to supply fuel to the boiler generator. This month, the NRRI Development Team completed the first milestone of the Grant: Preliminary Engineering.

“I am excited by the engineering progress seen in the grant work to-date,” explained Don Fosnacht, Ph.D., NRRI Associate Director, CSR Board Member, and the project’s Principal Investigator. “The steam-electric generator the CSR engineering team is designing will be a one-of-a-kind addition to our Biofuel Conversion Center, and it will serve as an important research tool in the development of remote, distributed generation systems.”

NEWS IN BRIEF

• CSR has been awarded a $405,000 portion of a $1.9 million grant from Xcel Energy’s Renewable Development Fund

• CSR is designing and building a modern 100 kW steam-electric boiler generator that runs on torrefied biomass

• This release comes as the NRRI Team completed the first grant milestone

• The boiler generator will build upon the principles of advanced locomotive-style boiler and compound engine

• Zoo train trials also served to provide key biofuel combustion metrics for the boiler generator

The steam-electric generator being developed by CSR will employ an advanced locomotive-style boiler and compound expansion piston steam engine to generate sufficient power to make 100 kW of electricity. The boiler is designed to burn torrefied biomass fuel in a Gas Producer Combustion System and will be able to operate automatically, thanks to an additional $25,000 National Instruments Green Engineering Grant awarded to CSR in support of the RDF project.

“The Xcel grant provides a significant opportunity to push the state-of-the-art in firetube boiler, compound reciprocating steam engine, solid fuel combustion, and distributed generation system design,” said Wolfgang Fengler, MSME, CSR Senior Mechanical Engineer. “Developing an efficient boiler-generator package that can fit into a 20 foot shipping container is no small task, but our experienced team brings a diverse skillset that has translated into an innovative concept which we are eager to fashion into a working prototype.”

The NRRI RDF Grant is broken into multiple milestones, including preliminary engineering, detailed engineering, fabrication, testing, and steady state operation phases. CSR is currently focusing on the detailed engineering and fabrication milestones. Fabrication of boiler, engine, and electrical components is set to begin this summer.

“What the RDF grant has enabled CSR to do is really push boiler and steam piston engine design as can only be achieved through new-build construction,” explained CSR Technical Advisor Hugh Odom, P.E. “I am honored to serve as the Professional Engineer on this project, working with the CSR engineering team in a capacity to verify compliance of the design with ASME and other applicable codes.”

When completed, the boiler generator unit will be installed at NRRI’s Biofuel Conversion in Coleraine, Minnesota, where it will undergo commissioning and steady state operations. That facility is a former Oliver Iron Mining Railroad maintenance complex which has been converted into a one-of-a-kind minerals and biofuel research center by NRRI.
 

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The Biofuel Conversion Center of the Natural Resources Research Institute is housed in the former railroad shops of the Oliver Iron Mining Company in Coleraine, Minnesota. Shown here is the main hall, which serves to house the large torrefaction reactor (center) that can create 14 tons of torrefied material per day. The boiler generator and additional torrefaction reactor will also be housed in this one-of-a-kind reserach facility.

Steam Train Lawsuit Receives Clarity, CSR Position Regarding ATSF 3463 Validated

T O P E K A,  K A N S A S | April 11, 2017 –  Shawnee County District Court has ruled in favor of Sustainable Rail International d/b/a Coalition for Sustainable Rail (CSR) in its case concerning quiet title of the former Atchison, Topeka & Santa Fe Railway (ATSF) steam locomotive No. 3463. District Court Judge, the Honorable Larry D. Hendricks, released a detailed decision concerning the case Wednesday, March 29, 2017, in which he finds that defendant Topeka Children and Santa Fe Railroad, Inc. (TCSFR) has no standing to remain in the lawsuit.  This decision paves the way for CSR to enter negotiations with the City of Topeka concerning the locomotive.

“Now that the court has determined that TCSFR does not have sufficient standing to remain in the lawsuit, we look forward to working with the City of Topeka to resolve the matter,” said CSR President Davidson Ward. “Of specific importance to CSR is outlining a realistic path forward that provides for the preservation of No. 3463 and a secure facility in Topeka for it to call home.”

CSR’s ownership of No. 3463 was first challenged by the TCSFR in April 2013 who, at that time, claimed absolute ownership of the locomotive. Following months of unsuccessful attempts to meet with TCSFR about its claims, CSR filed suit in May 2014 requesting a legal determination as to ownership of No. 3463. Shortly after filing suit, TCSFR reversed its position of outright ownership, claiming instead that they were trustees of a trust to protect the locomotive, and that the City of Topeka was the rightful owner, thus drawing the City into the suit as a Party Defendant.

“Through his decision, Judge Hendricks plainly sets forth why each of TCSFR’s arguments fails as a matter of law. While we were confident in our position, the decision clearly supports CSR and the filing of this litigation,” said outside counsel to CSR Matthew Bergmann, of Topeka-based Frieden, Unrein and Forbes, LLP.  “We are extremely pleased with Judge Hendricks ruling.”

“Of specific importance to CSR is outlining a realistic path forward that provides for the preservation of No. 3463 and a secure facility in Topeka for it to call home.”

— Davidson Ward | CSR

Though the project with No. 3463 has been on hold since 2013, CSR has worked diligently to refine its focus in both the preservation field and the steam and biofuel arenas in response to changing market conditions. Not only has the organization been retained to assist railroads in Germany and the U.S. with matters concerning steam locomotive preservation, but it has also been working with research collaborators at the University of Minnesota to further advance fuel and boiler technologies. 

Locomotive Biofuel Testing in 2016 - a detailed review

Milwaukee County Zoo train locomotive No. 1924 hauls its train up the ~3% shop spur track burning 100% torrefied biomass. This image shows the exhaust at its approximate darkest during the testing in October.

Introduction

Entities working to provide biofuel to power plants are faced with the classic “chicken or egg” dilemma. Biofuel manufacturers need to have guaranteed orders for fuel from power plants to finance installation of fuel processing equipment, but power plants wont agree to order fuel until they can run tests, requiring hundreds of thousands of pounds of fuel that can only be made by the very equipment those manufacturers seek to install. 

The Natural Resources Research Institute (NRRI), a collaborator with CSR, decided to go ahead and buy an “egg” to kick-start development - it purchased an industrial-scale biofuel reactor, in part thanks to CSR, and just recently completed commissioning and testing of the fuel. 

We were fortunate at CSR to receive the very first load of torrefied biomass fuel from the NRRI reactor. After years of installation and preparation work, NRRI produced the first two 55 gallon barrels full of fuel for Zoo tests, 500 pounds in total. The path to get to those first 500 pounds was certainly a quest, but the results of the tests made the process entirely worth it!

This panorama shows the torrefaction reactor (center) as sited at NRRI's Coleraine Lab, a former Oliver Iron Mining Company locomotive shop.

Testing Round One

In early 2016, CSR began thinking of locations where it might be able to test torrefied biomass fuel in a steam locomotive boiler. At that time, NRRI was nearing completion of the installation of its reactor, and the belief was that fuel would be ready for testing by June.

Similar to the situation of making enough fuel for power plants, a standard gauge locomotive often requires between five and thirty-five tons of coal to operate. Making a batch of fuel that large for a set of tests would be both time consuming and expensive. Searching for a more manageable size,  we decided that Milwaukee County Zoo, which operates a 15 inch gauge steam railroad with a locomotive of similar draft and boiler proportion to the those used in preservation around the U.S., would be an ideal test environment.

Our team reached out to Ken Ristow, whose job it is to maintain and operate the Zoo train. Ristow is no stranger to mainline steam, having been involved in the preservation of, and serving as the engineer on, such locomotives as Soo Line 1003 (1913 built 2-8-2), C&NW 1385 (1907 built 4-6-0) Soo Line 2719 (1923 built 4-6-2) and the Nickel Plate 765 (1944 built 2-8-4). 

Ken Ristow is at the throttle of Soo Line 1003 as it races towards Hartford, Wisconsin, for its annual Christmas display in November 2015.

Ristow worked with Zoo management to approve CSR’s use of its equipment for testing. In short time, CSR was granted unencumbered access to the Zoo train equipment and its 1.2 mile-long railroad. 

As the test date in June approached, word came down from NRRI that the torrefaction reactor they were installing was behind schedule. Never to disappoint, NRRI scrambled and located another torrefaction company to supply the required fuel for testing.

Given the short notice, the torrefied biomass fuel New Biomass Energy generously donated to CSR was delivered in traditional fuel pellet size as opposed to larger, coal-lump size as planned. CSR was able to work with the Zoo to modify the grates with stainless steel mesh and spacer pieces to permit air flow while preventing the small pellets from falling between the 3/4 inch pinholes of the grates on No. 1924. 

“We instrumented the locomotive with four, Inconel-sheathed thermocouples to gauge firebed, combustion space, and exhaust gas temperatures when burning coal vs biocoal,” explained CSR Senior Mechanical Engineer Wolf Fengler. “Tests were run on Saturday and Sunday, with trains Saturday burning coal and the first runs of Sunday burning biocoal.” 

The modified grates and ends of the thermocouples can be seen in the accompanying photo. When testing, CSR burned both coal and biocoal on the modified grates as an experimental control.

“We used National Instruments hardware in concert with its LabView software to record second-by-second temperature data from the sensors,” said CSR President Davidson Ward. “Perhaps most exciting was the fact that three of the sensors were directly in the firebox, one submerged in the firebed and two at varying heights above, which provided insight into the combustion behaviors of each fuel.”

The initial results of the June tests indicated that the torrefied biomass had sufficient energy density and combustion characteristics to make steam, but we had concerns that the small pellet size was contributing to inefficient combustion. Since the small pieces packed together tightly and required many layers to build a sufficient firebed, we hypothesized that larger fuel pellets would generate equal heat with less smoke. 

Keep in mind that, to build a firebed 3-3/4” deep with 3/8 inch diameter pellets requires at least ten fuel particles, whereas the same firebed depth with 1-1/4” particles requires just three pieces of fuel. With fewer pieces, there is a larger proportional area and simpler path for combustion air to flow between the fuel, thus aiding combustion.

Testing Round Two

Following the first set of tests, we circled back with NRRI to plan a second round.
As summer turned to fall, NRRI was making steady progress commissioning its large torrefaction reactor that, at full capacity, can produce 28,000 pounds of torrefied material per day. In early October, NRRI let us know it had more than 1,000 pounds of raw torrefied biomass on the ground ready to be densified and that they should be able to amalgamate it for a late October test.

Larger, "stoker coal-sized" torrefied biomass pellets. NRRI Photo

We reached back out to Ristow and his colleagues at the Zoo to see whether a test in late October would be possible. With little delay, we received approval for the second round of testing.

Graduate students and NRRI staff researcher Tim Hagen worked diligently to densify the test material, despite lacking ideal densification binder.  Given the timelines, NRRI opted to proceed with the densification using material it had available to enable the next round of testing. The data that could be received from this round of testing would be quite helpful in informing future densification trials.

Loading barrels of fuel for shipment to Milwaukee. NRRI Photo

CSR President Davidson Ward drove to Coleraine, Minn., to pick up two barrels full of torrefied biomass pellets on the morning of Thursday, October 27. By that evening, he and the pellets were pulling into Milwaukee. To prevent large embers from leaving No. 1924, an engine that lacks both a firebox arch and a master mechanics’ front end, CSR’s Rob Mangels fabricated a spark arresting netting arrangement similar to that employed by the Colorado narrow gauge railroads.

We got to work that Friday, re-equipping the locomotive with thermocouple sensors and test-firing the engine on some of the torrefied biomass fuel. The pellets provided by NRRI were cylinders of approximately 1-1/4 x 2 inches, incidentally the same size as the stoker coal used by the Zoo to run its locomotives.

As shown at in the adjacent photo, the cylindrical pellets were relatively easy to crush, a result of the binder used in densification. By comparison, other pellets on hand densified with different binders were nearly impossible to crush, even with a hammer.

Upon the very first fireup, it became apparent that the torrefied biomass fuel burned much cleaner than coal , and that the larger biofuel pellets permitted a thicker firebed with little-to-no visible smoke as compared with the tests in June. Even when stoking the fire with many scoops of torrefied biomass at one time, the smokestack seldom showed more than a translucent gray haze.

On Saturday morning, we arrived early to fire up test locomotive No. 1924 on the torrefied biomass fuel. After about an hour of stoking, the boiler pressure gauge read just shy of 200 psi, and we were ready to begin operating trains.

With Ken Ristow at the throttle, the 4-6-2 gently  pulled its train downgrade out of the shop and through the tunnel beneath Interstate Highway 94. With the entire train in the tunnel and at the base of an approximate 3% upgrade, Ristow hauled back on the throttle, agitating the torrefied fire unlike it had yet to experience. 

The strong draft, combined with a dormant firebed, resulted in ash and cinders being blasted out of the stack. The engine roared upgrade with its 10 car test train in tow and, once the initial firebed cleaned, the stack went from hazy to clear.

Once at the top of the grade and onto the Zoo mainline, the train stopped to allow crew members to throw the switch. We then began three laps of continuous running to see how the fuel reacted in a “mainline” situation. 

With 22” driving wheels and a loop of track approximately one and one-tenth of a mile in length, the tests were undertaken over a “scale” distance of 10 miles of railroad and a top scale speed of approximately 40 miles per hour. With the biofuel tests were completed, we switched the locomotive from torrefied biomass to coal and ran the balance of the normal trains using coal, logging comparative temperature data.

Results

The results of both biocoal/coal comparison tests, one in June with small pellets and one in October with large pellets, are shown below. It is interesting to note the difference in maximum temperatures between the tests, a function most likely of the difference in grates and the impact they had on the coal firebed. Both graphs represent data recorded on two runs and synced them up, shifting the data along the “x-axis” to relate to similar segments of the railroad. Click on the graphs to enlarge.

It is interesting to note that the torrefied biomass fuel is quicker to ignite than coal and, similarly, that it is quicker to fall off in temperature than coal. This is particularly evident when comparing the findings of the October tests, wherein fuel of analogous sizes were burned. 

Given the differences in the energy content and bulk density of the fuels, these are logical results. Since the torrefied biomass pellets were of lower bulk density and of higher porosity, the increased surface area enables them to ignite quicker. The lower bulk density also means that the fuel reacts and burns quicker, resulting in a more rapid drop-off in temperature. That said, torrefied biomass burned with similar heat across the board, but the peak coal temperature was approximately 100 degrees hotter than the torrefied biomass.

Image from June showing combustion with thinner, small-pellet fire.

Image from October showing more even combustion from thicker, large-pellet fire.

The foregoing combined with the lack of ideal densification binder on the October tests resulted in the fuel tending to break apart prematurely when combusted, leading to fuel particles becoming entrained in the exhaust stream. 

We will be working closely with researchers at NRRI over the winter to develop additional blends of densified torrefied biomass for use on the next series of fuel tests at the Zoo first thing in the Spring of 2017. 

Next Steps - Transition to Standard Gauge

This stunning photo by Oren B. Helbok provides a great broad view of Everett Railroad No. 11. The railroad has offered CSR use of No. 11 for standard gauge fuel tests in 2017.

“The ability to test this alternative fuel is exciting for us; we all must find new and modern ways to help keep historic railroading alive for generations to come”

— Z. Hall, Everett Railroad Steam Foreman

If the next round of tests at the Zoo continue to progress as the past ones, we will be ready to take the torrefied fuel research from the “test scale” at the Zoo to the “pilot scale.” This will be made possible in part through the generosity of the Hollidaysburg, Pennsylvania-based Everett Railroad (EVRR).

The EVRR operates a 1923-built 2-6-0 steam locomotive No. 11, hauling excursion trains through scenic rural Pennsylvania. The management and operations department is excited about the possibility of using torrefied fuel, and they approached CSR about the opportunity.

“We are facing a growing issue of finding a reliable source of high-quality coal that meets our specs and also is low smoke; large amounts of visible smoke is something that we must be very mindful of in the areas we operate,” said EVRR Steam Foreman Zach Hall. “The ability to test this alternative fuel is exciting for us; we all must find new and modern ways to help keep historic railroading alive for generations to come.”

According to Trains magazine, there are approximately 150 coal-fired steam locomotives in operation in the U.S. today, but changing economic and environmental conditions are making the procurement of coal ever more difficult. 

EVRR fireman Stephen Lane shovels a scoop of coal into the firebox of No. 11 during a trip in December 2015. Photo by, and used courtesy of, Oren B. Helbok.

The U.S. has seen a huge decline in coal production, and it does not take much imagination to see a situation where the U.S. may also need to look at importing coal to fire steam locomotives, or even be forced to convert steam engines to oil and lose the art of hand firing. 

Even in Great Britain, birthplace of the iron horse and bastion of steam preservation world-wide, news sources including the Telegraph and the BBC have been reporting such headlines as: “Coal crisis hits steam trains” and “Coal shortage hits Vintage Trains and Severn Valley Railway.”

Thanks to the generosity of EVRR President Alan Maples, the railroad has offered to allow CSR to test fuel on No. 11 over three days in the coming operating season, an in-kind contribution of $9,000 towards this fuel research. 

CSR seeks to raise an additional $27,000 to cover the costs of  fuel densification studies this winter, an additional round of tests at the Milwaukee County Zoo in the Spring, as well as fund the manufacture of approximately 10 tons of torrefied fuel for use by the EVRR on tests with No. 11. 

Can we count on your support as we work to keep steam alive?

We strive to keep this history alive, and our Team is confident that, with the support of many, CSR can help ensure a bright future for steam in generations to come. 

Already, this important fuel research has been supported by the outstanding assistance of the Milwaukee County Zoo, the Natural Resources Research Institute, New Biomass Energy, the American Boiler Manufacturers Association, and the support of CSR’s donors, including generous contributions by Bon French and Fred Gullette. Additional research into the conversion of used railroad ties into torrefied biomass was also underwritten through generous contributions of the Indiana Rail Road. Will you help make this research a reality?

More details on densification research, additional small scale tests, and the planned full scale test will be made known in the coming months!

Biofuel Tests at Zoo - Round Two

Test locomotive No. 1924 blasts up the 3% grade hauling a heavy train. The locomotive is being fired with 100% torrefied biomass fuel and is instrumented with test equipment to gauge firebed and smokebox temperatures.

CSR and NRRI again collaborated with the Milwaukee County Zoo to undertake a comparative test of torrefied biomass fuel and coal this past October. The previous round of tests CSR undertook in June employed very small (3/8 inch diameter) cylindrical fuel pellets. While the finding of those tests were promising, CSR sought to undertake tests with fuel analogous in size to that employed on preserved steam locomotives.

The researchers at the Natural Resources Research Institute (NRRI) produced 500 lbs of torrefied biomass with its recently-commissioned torrefaction reactor and densified it using a B-100 cylindrical densifier to an approximate size of 1-1/4 x 2 inches [shown below, second from left]. These larger pieces of fuel were more analogous to the coal typically used by the Milwaukee County Zoo. As expected, the larger torrefied biomass pieces burned more cleanly in the firebox than the smaller pieces used in the previous round of testing.

As with the previous tests, CSR instrumented the locomotive with four thermocouples [shown at right], three in the firebox and one in the smokebox, to document temperatures on comparative tests between torrefied biomass combustion and coal combustion. To minimize the risk of sparks from coal/torrefied biomass fines, CSR also fabricated and installed a custom spark arrestor for use on the stack of the engine.

Tests revealed that the torrefied biomass burned with similar temperatures as the coal and with little smoke [see images at bottom]. It also revealed that the fuel has a very low ash content compared with coal.

That said, densification of the torrefied fuel still needs refinement to permit the fuel to burn more similar to coal, including for the same duration as coal per unit fired. The less dense torrefied fuel resulted in a quicker dropoff of firebox temperatures when the throttle of the locomotive was closed. These tests provided CSR with much needed data on the characteristics of torrefied biomass combustion in locomotive-style boilers, and it has provided focus for research this winter.

The cooperation of the Milwaukee County Zoo has been second-to-none in undertaking these tests, and it has provided CSR with a very good platform to undertake research. Whereas running tests in a full-size locomotive would take thousands of pounds of fuel, the Milwaukee County Zoo locomotive No. 1924 can operate a full day on 500 lbs of fuel or less. This keeps costs low in developing various fuel typologies (wood stock varieties, densification types, etc.), while still having a one third scale engine on which to test the effects of drafting and combustion.

With these tests completed, CSR is working with NRRI to undertake densification research over the winter. CSR will provide more information on those plans, including proposed future tests on standard gauge equipment, in the coming weeks.

In the meantime, please consider making a tax-deductible contribution to CSR to support the upcoming tests and research!

Firing up on coal, the locomotive had little difficulty making smoke.

Once switched to torrefied biomass fuel, the locomotive made almost no smoke.

Members of the CSR / Zoo research team pose in front of the two steam locomotives operated by the Zoo.

• People, from left to right: Davidson Ward [CSR]; Ken Ristow [Zoo]; Rob Mangels [CSR]; and Wolf Fengler [CSR].
• Locomotives, from left to right: 4-4-2 No. 1916, burning coal; and 4-6-2 No. 1924, burning torrefied biomass - both manufactured by Sandley Light Railway Equipment Works, Wisconsin Dells, Wisconsin.