Issuu

More energy with fewer emissions in Mannheim Hot rocks: making geothermal work with nickel THE MAGAZINE DEVOTED TO NICKEL AND ITS APPLICATIONS

CLEANER ENERGY Nickel makes it possible

April 2015, Vol. 30, No. 1

Carbon capture and sequestration at Boundary Dam

MECH-TOOL ENGINEERING

CASE STUDY 04

r Armada Platform w Installation of accommodation modules w Stair module

ARMADA PLATFORM ACCOMMODATION MODULES T

he Armada Platform is operated by BG Group and exploits three gas condensate fields in the Central North Sea, 250km east of Aberdeen, Scotland. In 2009, the living facilities on the platform were extended to accommodate an additional 59 personnel. Corrugated nickelcontaining stainless steel was used for the structural cladding of these accommodation modules. Austenitic stainless steel grade 1.4401 (UNS S31600) with a 2B standard mill finish in accordance with EN 10088-2 technical standards was chosen. While carbon steels need regular repainting and maintenance in harsh offshore environments, stainless steels typically require little upkeep. It’s not easy to carry out maintenance in the severe conditions of the North Sea and the cantilevered design of the modules means that it is even more challenging. In order to avoid costly maintenance over the 30 year design life, it was stipulated that all steel exposed to external conditions should be stainless. The stainless steel panels were prefabricated with the insulation and welded onto the carbon steel structural frame. After fabrication, the sheets were acid cleaned to remove any embedded iron particles which might rust when exposed to marine conditions. The completed modules were transported by road to the coast, then shipped to the Armada Platform. Lifting pad-eyes were attached to the carbon steel frame at the four corners of each module through the cladding. The pad-eyes also doubled as guides for positioning the modules on the second level. The lower modules were attached to the module support frame (MSF) using steel grade A4-80 bolts (S31600 with 800MPa tensile strength). The modules were connected together in a 2-on-2 formation with a provision for a third storey in the future. The stair modules were attached at either end and sit on their own support frame.

2 NICKEL CASE STUDY

The accommodation modules each measure 11.93m long by 4.50m wide by 3.20m high and weigh around 23 tonnes. The frame and stiffened ﬂat plate ﬂoor and roof are carbon steel, overclad with corrugated stainless steel wall panels 250mm wide, 80mm deep and 2.0mm thick. The modules have a fire resistance rating of H60. This means they must maintain their load-bearing function for a period of 60 minutes if exposed to a hydrocarbon fire reaching a temperature of 1100 °C. The selected Grade 1.4401 (S31600) also exhibits adequate retention of strength and stiffness after 60 minutes exposure, as well as excellent ductility and toughness that will minimise deformation in the event of an explosion with a peak blast pressure of 110 millibars with equal rise and decay times of 10 millisecs. Stainless steel is an ideal material for explosion-resistant structures because it has high strength, good energy absorption characteristics and high ductility. Stainless steels can therefore absorb considerable impact without fracturing. The structural performance of the modules under all the critical load combinations was analysed. Wind, snow and ice loadings were considered. This article has been adapted from a series of Structural Stainless Steel case studies produced on behalf of Team Stainless by SCI and available for download from: www.nickelinstitute.org

nickel, vol. 30, no. 1, april 2015

PLATFORM PHOTO: TERRY CAVNER

ISTOCKPHOTO.COM © EGAL

DESIGNED FOR SAFETY

NICKEL, VOL. 30, NO. 1, APRIL 2015

ISTOCKPHOTO.COM © ROBAS

The Magazine Devoted to Nickel and its Applications Nickel magazine is published by Nickel Institute www.nickelinstitute.org Tim Aiken, President Clare Richardson, Editor crichardson@nickelinstitute.org Contributors: Richard Avery, Nicole de Boer, Les Boulton, Gary Coates, Jutta Klöwer, Bruce McKean, Klaus Metzger, Frank Smith

Nickel Institute can be contacted at: Eighth Floor Avenue des Arts 13-14 Brussels 1210, Belgium Tel. +32 2 290 3200 communications@nickelinstitute.org Material has been prepared for the general information of the reader and should not be used or relied upon for specific applications without first securing competent advice. While the material is believed to be technically correct, Nickel Institute, its members, staﬀ and consultants do not represent or warrant its suitability for any general or specific use and assume no liability or responsibility of any kind in connection with the information herein. ISSN 0829-8351

TALKING ABOUT ENERGY Everyone (and every government) talks about energy except, perhaps, when they are in Iceland enjoying the benefits of heat from a geothermal source. Sometimes it can go beyond talk to serious economic, political and environmental confrontations. Some view the world too dependent on one kind of energy source, others worry about shortages or surpluses and the economic gyrations those cause. Energy can be seen to be too expensive, too cheap, too dangerous. Oil and gas, nuclear, wind, solar, hydro: they all have their critics.

World electricity production from all energy sources in 2012 5% 4% | |

Printed on recycled paper in Canada. Cover: Constructive Communications Cover Photo: Boundary Dam CCS facility © Kristopher Grunert

11% |

40%— —17%

TABLE OF CONTENTS In Focus Editorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Case Study Accommodation modules . . . . . . . . . . . . 2 Special Feature Nuclear power plants . . . . . . . . . . . . . . . 4-5 Geothermal energy . . . . . . . . . . . . . . . . . 6-7 Carbon capture and sequestration . . 8-9 High temperature coal-fired power plants . . . . . . . . . . . . . . . . . . . . . 10-11 In Use Wirelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Ozone water treatment . . . . . . . . . . . . . . 13 Maria Pergay . . . . . . . . . . . . . . . . . . . . . . . . . 16 In Brief UNS details. . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Nickel nanostructures . . . . . . . . . . . . . . . . 15 Nickel gallium catalyst. . . . . . . . . . . . . . . . 15 Web links . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

nickel, vol. 30, no. 1, april 2015

| 23%

Others Oil Nuclear Hydroelectric Gas Coal

SOURCE: WWW.TSP-DATA-PORTAL.ORG

Design: Constructive Communications

1042 879 2344 3619 4744 8390

Total = 21,016 TWh

What most will agree on, however, is that modern societies are viable only because of the availability of affordable and reliable energy, regardless of how it is produced, transported and stored. This issue of Nickel focuses on some of the applications where nickel is making a difference in how energy is being produced or how the consequences of energy production are being reduced. Of particular importance is coal, which as the chart shows, looks set to remain dominant in the medium term at least. We look at two innovative approaches to tackling greenhouse gas emissions from coal: the Mannheim power station in Germany and the Boundary Dam Carbon Capture and Sequestration complex in Saskatchewan, Canada. Both are showing how the most abundant carbon fuel we have can be exploited in less harmful ways. And neither could be done without the special qualities of nickel-containing alloys. Coal is not the only controversial fuel. The article on pages 4-5 reveals some surprising numbers on the future of nuclear power. That 11% of total electricity from nuclear you see on the chart is not likely to diminish any time soon. The conversations on energy are not going to stop, nor should they. The evolution of how the world secures its energy future will continue but whatever the choices and wherever there is innovation in energy production you will find nickel helping to make it happen.

Clare Richardson Editor, Nickel magazine

NICKEL IN FOCUS 3

Enduring nuclear zero carbon emissions enabled by nickel

r Yangjiang power plant poster: there will be six reactors when construction is completed in 2018. Jingyu

s Nuclear power plants in China (2008 data)

Liaoning Donggang Xudabao

Rongcheng

Hongyanhe Ganshu Baiyin

evidence suggests that the amount of electricity from nuclear looks set to remain steady

Rushan Haiyang

Luoyang

Tianwan II, Jiangshu II

Xianning Dafan

Tianwan Jiyang Anhui Wuhu Qinshan II Qinshan I Qinshan I,II,III Sanmen, Sanmen II Pengze Ningde Nanping

Beyond the news headlines, however, the evidence suggests that the amount of electricity from nuclear looks set to remain steady in percentage terms and may well increase. China and Saudi Arabia provide two examples.

Planned In Operation

Fuqing I Fuling

Chongqing Shizhu Changde

Source: Research Institute of Tepia (as of Nov 2008)

China There are two challenges for China. How to provide the energy it needs for its burgeoning economy, and how to manage its serious contributions to greenhouse gases. This is a particularly difficult situation given China’s very large and easily exploited reserves of coal. While China has become closely identified with renewable energy, especially solar, there has clearly been a decision to use nuclear energy for a sizeable part of the base load (non-interruptible) supply of electricity. As of 2013, China’s 21 nuclear power plants provided only 2.1% of China’s electrical needs. However there are 26 new nuclear plants under construction, 64 in the planning stage and 123 proposed. It is highly unlikely all of these will be realised but the scale of 4 NICKEL SPECIAL FEATURE

Sanming

Peng’an

Under Construction

Taohuajiang Xiaomoshan Guangxi Fangchenggang

Putian Zhangzhou Lufeng Ling’ao II Taishan Yangjiang Daya Bay, Ling’ao Hainag Changjiang

ISTOCKPHOTO.COM © FOREST_STRIDER

Capital costs are enormous but operating costs and consequences in human and environmental terms compare favourably with carbon-based alternatives. It is also true that attitudes towards nuclear energy vary greatly from country to country.

WIKIMEDIA COMMONS

lectrical power from nuclear energy has always been understood as different and that will not change. While the focus of the world has been on renewable energy and the extraordinary progress it has made, nuclear energy remains a significant component of base-load electrical generation. While controversy remains it seems clear that choices and decisions are being made for a variety of reasons that favour fission as a source of electricity.

the commitment to nuclear energy is clear as are the reasons for doing so: breathable air for Chinese citizens and meaningful reductions in greenhouse gases. Saudi Arabia The reasoning behind Saudi Arabia’s commitment to build 16 new reactors by 2030 (from zero at the moment) differs from that of China. In addition to the industrial aspirations of the government there is the understanding that burning hydrocarbons to make electricity—while cheap and logical in a country so well endowed—is an inefficient use of a finite resource that can be upgraded into so many value-added products. The conclusion is clear. The “nuclear age” has not ended and that for the nuclear industry as for every other source of electrical energy, nickel-containing materials will remain essential. nickel, vol. 30, no. 1, april 2015

w The Sanmen nuclear facility will have six reactors when completed. One under construction in February 2014 is shown here. Twenty six nuclear plants are currently being built in China.

Nickel in nuclear power A nuclear power station is like any other power station: a heat source converts water (pressurised light or heavy in the case of nuclear) into steam in boilers that feed turbines which run generators. The nature of the fuel dictates, however, a very different treatment of the heat source. Still, all the nickel you would expect to find in any power station will be there: nickel alloys in the boilers, boiler tubes, pumps, piping, turbines and generators. For power stations that use salt water for cooling, additional nickel will be found in materials for pipework, filters and heat exchangers. With a nuclear station there are special sensitivities and attention to service life including the storage and transport of spent fuel. Some of the additional nickel-containing elements prominent in the nuclear industry include: • Mechanical modules: machinery, pumps, valves, all contained in module units made of a sandwich of carbon steel, concrete and a lean duplex stainless steel 2101 (UNS S32101). The mechanical module for the Westinghouse-designed AP1000 nuclear facility uses approximately 500 tonnes of duplex.

s Everything associated with steam power plants is on a large scale and nickel-containing materials are found throughout.

• Steam separator units: These allow dry (dewatered) steam to be fed to turbines. These specialised pressure vessels are typically made of 316L (S31603) stainless steel—35 to 50mm thickness—controlled for very low cobalt content (<0.06% Co). Note that such units are not unique to the nuclear industry as dry steam is important to reduce and control erosion of turbine blades. • Accumulator tanks: Safety is paramount for nuclear and the protocols surrounding emergency shutdowns are especially demanding. Accumulator tanks, with their reservoirs of coolants in close proximity to the reactor chamber, are typically made of 304L (S30403) with similarly low cobalt content. • Short/medium term storage of spent nuclear fuel: Radioactivity declines over time but the most demanding situations arise in the early years. The containers (CASTORs: Containers for the Storage and Transport of Radioactive materials) vary in size and construction but a special variant of 304L with boron is often used, e.g., S30467 with 2% boron, an element known for its ability to moderate/absorb radiation. • Long term storage of spent nuclear material: various versions exist but most include the use of nickel-containing stainless steels.

NICKEL, VOL. 30, NO. 1, APRIL 2015

NICKEL SPECIAL FEATURE 5

HOT ROCKS

eothermal energy for electric power production has a low profile yet is significant in the current and potential energy mix for a number of countries. It has also been described as the most reliable of the renewable energy sources, above weatherdependent wind, solar and hydropower. The production environments are often demanding, and nickel alloys and nickel stainless steels are needed to make geothermal energy viable from an engineering point of view. Building a geothermal power station is an expensive undertaking but once up and running, the operating costs are relatively low.

WIKIMEDIA COMMONS

Paths to geothermal energy Geothermal energy is obtained by capturing the heat from the earth’s thermal core.

r Iceland’s Nesjavellir Geothermal Power Plant

ISTOCKPHOTO.COM © ALEXEYS

Geothermal energy and the role of nickel

WIKIMEDIA COMMONS

s The separator at the Mighty River 100MW power station at Kawerau, New Zealand separates hot water from the geothermal field into steam and water.

Geothermal fluid is a naturally occurring mineralised mixture of pressurised water and steam heated underground to between 200–325 ºC. The steam and hot water are drawn up from a geothermal field by production wells from depths of up to three kilometres. High-pressure hot water from the geothermal field is separated at a geothermal plant into steam and water, and the dry steam is used to spin the turbines of generators to produce electric power. There is also a potential to generate geothermal energy from underground hot dry rocks, where there is heat but no liquids to be tapped. Enhanced Geothermal Systems (EGS) are maturing technologies where bore holes over three kilometres deep are drilled down to extremely hot underground granite rock. Water is forced into the holes, heated by the rocks and then pumped back through return wells to the surface for use. One important benefit of geothermal power is that waste fluids from geothermal energy production are injected back into the geothermal field. This process helps to replenish the geothermal fluids which are then reheated underground. Return injection also avoids contaminating surface waters with the geothermal brine. Geothermal brines are corrosive. They are acidic and often contain metal ions, corrosive chlorides and siliceous compounds as well as corrosive gases, such as carbon dioxide, sulphur oxides and hydrogen sulphide. Corrosive compounds and gases at high temperatures will come into contact with much of a geothermal plant’s processing equipment and piping which means that nickel-containing materials have an important role.

6 NICKEL IN USE

nickel, vol. 30, no. 1, april 2015

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

Reservoir Pump house Heat exchanger Turbine hall Production well Injection well Hot water to district heating Porous sediments Observation well Crystalline bedrock

Making it work with nickel Corrosion damage was a major issue for older geothermal power plants employing carbon steel for pipework and process equipment. As operating experience grew, nickel-stainless steels such as Types 304L (UNS S30403), 316L (S31603), 310S (S31008) and 321 (S32100) were increasingly used and are now the workhorse alloys used in much of the geothermal industry.

…corrosion resistant alloys with higher nickel content have been increasingly employed

ISTOCK.COM © 1TOMM

WIKIMEDIA COMMONS

Enhanced geothermal system

However, some stainless steels are vulnerable to pitting corrosion and chloride or sulphide-induced stress corrosion cracking in geothermal brines. Because of this, corrosion-resistant alloys with higher nickel content have been increasingly employed.

Geothermal hot spots

Where corrosive environments cannot be controlled by using corrosion inhibitors, duplex stainless steel Types 2205 (S32205), 2507 (S32750) and 2707 (S32707) and high nickel stainless steels such as 904L (N08904) and 6% Mo alloys (e.g. S31254 or N08367), have often performed well.

• USA, Philippines, Italy, Mexico, Indonesia, Japan, Iceland and New Zealand are the major world producers and users of geothermal power

The wide variation in geothermal brines has meant, however, that there is not one universal solution. Research has been needed to match the best performing material to the process ﬂuids. Depending on the operational demands, nickel alloys such as Alloy 625 (N06625), C-276 (N10276) and even higher alloys are needed. Other nickel alloys such as Alloy 600 (N06600), 601 (N06601) and 825 (N08825) have found selective use to cope with specific high corrosivity geothermal operations.

• 220 trillion BTUs of geothermal energy was produced in 2013

Geothermal is a useful and growing source of environmentally attractive energy made accessible thanks to the use of nickel alloys.

nickel, vol. 30, no. 1, april 2015

• Strong correlation between geothermal potential and geologically active parts of the world

• Most are experiencing steady growth in geothermal electric power production

• Initial capital costs are high, thermal efficiency is low, but the heat, once accessed, is free, clean, constant (ideal for base electrical loads) and effectively inexhaustible in human terms • Compact geothermal power plants can raise the standard of living of isolated communities where the cost of importing fossil fuels or connection to an electricity grid is prohibitive

NICKEL IN USE 7

Full circle carbon

Nickel allows coal-fired power generator to reduce carbon emissions by 90%

he numbers and the necessity are controversial but societies are steadily moving to control the amount of carbon they emit. Every tool in the box is being tried and tested, from economic disincentives (“carbon tax”) to substitutions to lower carbon emissions (fuel oil to natural gas) or to have zero operational carbon (hydro and other weather-influenced renewables and geothermal). Another path is to gain the energy from global superabundant coal resources while preventing the carbon dioxide produced from entering the atmosphere where it would impact the climate. This approach requires carbon capture and sequestration—CCS—and its promise is being tested for the first time on an industrial scale at the Boundary Dam coal-fired power station in Saskatchewan, Canada. And nickel-containing materials are used very extensively. The process Pulverized lignite coal is burned to produce heat which is used to make steam, with the flue gases flowing to the CCS facility. Firstly, 100% of the sulphur dioxide (SO2) is captured by a dedicated amine chemical absorber column and stripper circuit. The gases then pass to a 52 metre high absorber column with amine chemicals that capture 90% of the carbon

the facility avoids the emission of one million tonnes of carbon dioxide every year dioxide (CO2) after which the treated flue gas leaves the system. The carbon-rich amine solution goes to a CO2 stripper for separation, condensation and compression. The now lean (low carbon) amine solution is cleaned and recycled back into the absorber column. Both the CO2 and SO2 amine circuits are closed. This is a simplified description (see chart) of a very complex interplay of chemical reactions, temperatures and demanding material specifications for piping systems, linings, pumps, heat exchangers, compressors and supporting machinery, almost all

of which depend on some nickel content for their reliable and long service life. The products The objective of the CCS facility is to reduce emissions—the facility avoids the emission of one million tonnes of carbon dioxide every year. The need of the facility is to generate revenue. In addition to the electricity that is sold at market rates and the sales of CO2 for enhanced oil production, the fly ash from combustion has a low but real value as an addition to concrete. And the SO2 is turned into sulphuric acid, an input for many industrial processes. The CO2 from Boundary Dam has two destinations. The majority is piped to an oil field 65km away where it is injected into the field to increase pressure and thus the amount of recoverable oil. The remainder is injected into a stable saline aquifer 3.4km underground.

CARBON CAPTURE PROCESS to Heat Recovery Boiler

Existing Stack

CO2 Absorber

CO2 Stripper

CO2 Gas Enhanced Oil Recovery Facility

Pulverized Lignite Coal

Fly Ash for Sale

SO2 Absorber SO2 Stripper

CO2 Injection Well Sulphuric Acid for Sale Oil Bearing Formation 1.5 km Underground

Steam from Turbine Condensate Return

Cooling Tower

Steam from Turbine Condensate Return

Dust Collection

8 NICKEL SPECIAL FEATURE

Oil Recovery

Aquistore Carbon Storage

INFOGRAPHIC: CONSTRUCTIVE COMMUNICATIONS, SOURCE INFORMATION:SASKPOWER

sSO2 capture and conversion into sulphuric acid, and CO2 capture, use and storage: a complex process dependent on nickel-containing materials

Saline Sandstone Formation 3.4 km Underground

nickel, vol. 30, no. 1, april 2015

KRISTOPHER GRUNERT

v Boundary Dam CCS facility

The size of the challenge The Boundary Dam CCS facility cost approximately $US1.1 billion to remove 1,000,000 tonnes of carbon dioxide from one lignite coal powered 139MW generator (one of four generators that make up the facility). According to the Intergovernmental Panel on Climate Change, the Boundary Dam or similar technology will need to be installed on all 7000 existing or yet-to-be-built coalfired power plants by 2050 if the global warming trend is to be held to only 2 Â°C.

PHOTOS: SASKPOWER

The operator, SaskPower, believes that lessons learned will significantly reduce the cost of building and operating future similar plants. That said, the cost of capital compared to revenues expected and the uncertainty over the future cost of carbon (and thus the benefit of not emitting carbon) mean that CCS today is a maturing technology but not yet economic.

rr (top and right) The extensive use of nickel-containing stainless steel is evident throughout the plant. r (left) The CO2 stripper prior to installation. The nickelcontaining heart of the operation captures 3000 tonnes of carbon dioxide every day.

nickel, vol. 30, no. 1, april 2015

NICKEL SPECIAL FEATURE 9

r Grosskraftwerk Mannheim GKM Power Plant

HOTTER, HIGHER, CLEANER More eﬃciency from coal-ﬁred power plants with nickel alloys

n fossil-fuelled power plants, efficiency can be increased by raising the steam temperature to 700 °C and steam pressure to 350 bar. At the same time, CO2 and other emissions are reduced. Nickel-containing materials are playing a crucial role in such high temperature, high pressure environments. Higher and variable temperatures The World Energy Outlook 2014, published by the International Energy Agency, forecasts a rise in primary energy demand of 37% by 2040. Although energy from renewable sources is increasing rapidly, conventional technologies, including highly efficient coal-fired power plants, will continue to make important contributions. Currently, the average efficiency of a coal-fired power plant is about 33% worldwide and 38% in the European Union. Since the efficiency of any power plant is a function of steam temperature, efforts are underway to increase the operating temperature from today’s maximum of 620 °C to 700 °C and above and, at the same time, increase steam pressure from 250 to 350 bar. This would bring operating efficiency up to 50%—a 30% improvement over the current best performance. Sustained high temperatures are not the only challenge. The growing use of renewable energy means that coal-fired power plants will need to work flexibly to be able to balance the fluctuating feed of wind and solar energy. Boiler cycling (start-up and cool down) introduces additional material and operational challenges. Up to 200 cycles per year with about 4,500 operation hours require thin walled parts that can be heated and cooled quickly. Baseload range operation with less or no flexibility (approximately 7,500 operating hours) can be achieved with thick walled parts in the boiler and run with maximum pressure.

10 NICKEL SPECIAL FEATURE

r Thick walled components of HWT II Mannheim Higher nickel alloys needed Until now and depending on the operating temperature, the boilers of coal-fired power plants are made of structural ferritic, bainitic or martensitic steels such as P91 (UNS K90901) and P92 (K92460), stainless steels such as Type 314 (S31400) or nickel alloys. About ten years ago the ~50% Ni Alloy 617 (N06617) was selected for manufacturing the first boilers in the European ultra-supercritical 700 °C boiler projects. This nickel alloy is widely used for industrial

nickel, vol. 30, no. 1, april 2015

gas turbines and industrial furnaces due to its high creep resistance in combination with good workability and weldability. With operational experience, a modified version with tighter alloying element tolerances and lower limits for boron was created. This modified alloy, known as VDM® Alloy 617 B, shows an increase in creep rupture strength of about 25% at 700 °C.

PHOTOS: GKM — GROSSKRAFTWERK MANNHEIM

part of the HWT II test track is run with temperature cycles between 725 °C and 400 °C Field testing at Mannheim power station Field trials are important to investigate how materials and finished components behave under real conditions in the power plant. In 2011, a project called HWT II was launched (HochtemperaturWerkstoff-Teststrecke/High temperature material test track) to examine the operating and failure performance of thick-walled components for highly efficient power plants. For this purpose, a 725 °C test track with thick-walled pipelines and pipe fittings was set up in the Grosskraftwerk Mannheim GKM Power Plant in Germany, and came on stream successfully in 2012. In addition to the on-going high temperature base load trial, a part of the HWT II test track is run with temperature cycles between 725 °C and 400 °C. This simulates the start of the boiler when, for example, there is no wind or solar energy available and a shutdown of the boiler when sufficient wind or solar energy is available.

The steam flow leading to the test track is taken from the main boiler and led into separate superheater tubes, in this case thin-walled tubes made of Alloy 617 B and VDM® Alloy C-263 (UNS N07263), to the boiler’s hottest parts. In the boiler, steam is heated in the tubes from 530 °C to the desired 725 °C. It is then fed into the HWT II test track. It is also possible to cool the steam down to 400 °C by introducing cold steam and water into the test track so the effects of repeated thermal cycling on materials can be observed.

Material preparation and performance VDM delivered a total of almost 20 tonnes of Alloy 617 B and the precipitation-hardening Alloy C-263 for the HWT II test tracks. Both materials were selected because of their good resistance (100,000 hours creep rupture strength) under the specified operating conditions. Due to the high requirements for purity, the alloys were melted and cast under vacuum via Vacuum Induction Melting (VIM), and then remelted via Electroslag Remelting (ESR) and Vacuum Arc Remelting (VAR) respectively, to avoid inclusions as far as possible. Different dimensions were produced, for example 60mm diameter valve parts in Alloy 617 B and thick-walled pipes in Alloy C-263 up to 220mm diameter. More than 9,900 operating hours at 725 °C and more than 2,600 temperature cycles of 725 °C–520 °C–400 °C–725 °C have been achieved. An inspection has shown no material problems or indications of cracking in the components.

Project partners The HWT II project is funded by the German Federal Ministry of Economics and Technology (BMWi) and was run in cooperation with 29 partners, including the Grosskraftwerk Mannheim GKM: Salzgitter Mannesmann Stainless Tubes SMST (thin-walled boiler tubes), Vallourec (thick-walled tubes), Bilfinger-Piping-Technology, KAM, Bopp & Reuther, Welland & Tuxhorn, KSB (test track manufacture), TÜV SÜD and SLV (material-technological associations), Alstom and BBS (boiler manufacturers) and E.ON and VGB (power generators). Instrumentation of the test track (temperature measurements and high-temperature strain gauges on the tubes) and the scientific work will be conducted by the Materialprüfungsanstalt Universität Stuttgart MPA (Material Testing Institute of Stuttgart University), the Institut für Werkstoffmechanik Freiburg IWM (Institute for Material Mechanics) and the Institut für Werkstoffkunde Darmstadt IfW (Institute of Materials Science). Nickel magazine is grateful to: J. Klöwer and N. de Boer, VDM Metals; K. Metzger, Grosskraftwerk Mannheim GKM

Advanced ultra supercritical steam in China

PHOTO © SIEMENS AG

hina has for many years been working to increase the efficiency of coal-fired power plants. For example, the four 1000MW ultrasupercritical (USC) boilers at Yuhuan, in Zhejiang province, operate at an efficiency of around 45% by using 605 °C steam. The first of these units came on-line in 2006, the final one in 2007. But the goal is for even higher steam temperatures, 700 °C or higher, which can lead to efficiencies of over 50%. This is called Advanced USC technology. Nickel-containing austenitic stainless steels are needed at these temperatures for reasons of creep strength, but modifications to existing alloys are needed for cost-effectiveness. Three different alloys are currently being tested, but the most promising is called Super304H. By introducing 3% copper, precipitates will form that allow for high strength at 700 °C while maintaining adequate ductility for use as superheater and reheater tubes. The alloy has also small amounts of niobium, nitrogen and boron as well as a high carbon content. The alloy can be classified as a precipitation hardenable alloy. It is believed that this alloy is one of the keys to achieving 50% efficiency on a commercial scale. r Steam turbine of type SST5-6000 at Yuhuan power plant

nickel, vol. 30, no. 1, april 2015

NICKEL SPECIAL FEATURE 11

Fishing for carbon T

he continued search for new oil and gas fields has resulted in deeper wells, often with more aggressive downhole environments. Nickel-containing alloys play small but vital roles in the exploration and production of new fields. One such role is the use of nickel-rich alloys in wireline. In recent years, considerable effort and investment have been directed towards developing alternative sources of energy in order to reduce the world’s dependence on fossil fuels (oil, natural gas and coal). Renewable and pollution-free energy sources, particularly solar and wind, have experienced increased research, investment and application. Other energy sources, such as tidal, run-of-river and bio-mass, are being developed and may play a larger role in the future.

harsh operating conditions require wirelines made from nickel-containing alloys highly resistant to corrosion However, until these alternative sources are fully developed and brought on-line on a significant scale, the world will remain dependent on fossil fuels. Diving deeper When oil and gas wells are drilled, the geologists and drill rig personnel need to know the nature and characteristics of the formations that they are encountering downhole. To help them obtain this vital information, drilling is periodically halted and logging tools packed with sophisticated, and very expensive analytical equipment are lowered into the well. These tools carry out chemical and physical measurements on the various downhole strata and capture the data for evaluation. The tools are lowered into a well attached to a wireline. Wireline comes in two basic forms: “slick” and “electric” line. Slick lines are solid, load-bearing metallic wires which are commonly available in diameters of 1.83–4.06mm. Electric wirelines consist of insulated electrical signal wires surrounded by braided metallic wires for protection that make up the essential load-bearing cable which supports the weight of the measuring tool.

Strength, corrosion resistance, flexibility Both forms of wireline must, of course, be very strong in order to support both the weight of the tool and the weight of the long length of wire that is necessary to lower the tool to the required depth. Wells are now routinely drilled kilometres deep, and higher strength alloys such as 2205 (UNS S32205) can replace lower strength Type 316 (S31600). Wirelines must, of course, possess very high tensile strengths (breaking loads), but must not suffer excessive elongation (stretching) when loaded. As wells are drilled to greater depths, higher downhole temperatures and pressures are encountered. In addition, downhole chemical environments are often very hostile to the wireline materials. Aqueous chloride conditions are frequently encountered, often accompanied by high levels of carbon dioxide and hydrogen sulphide gases, which make the aqueous phase acidic. These harsh operating conditions require wirelines made from nickel-containing alloys highly resistant to general corrosion, pitting corrosion and stress-corrosion cracking, such as Alloy 926 (N08926), Alloy 28 (N08028), Alloy 31 (N08031), Alloy 936 (N08936), Alloy 27-7Mo (S31277) and Alloy MP35N (R30035). High nickel-containing alloys meet these challenges and will be the alloys of choice for wirelines for as long as drilling for hydrocarbons continues. And that looks set to continue for many years to come. Wireline nickel alloys Additions of nickel enable stainless steels and higher alloys to attain the necessary superior mechanical properties and corrosion resistance levels. Type 316 stainless steel (10-14% nickel) is usually offered as the basic grade of wireline, for wells with moderate conditions. For more demanding r Several reels of wireline conditions, alloys with progressively higher nickel content are required.

CENTRAL WIRE

ISTOCKPHOTO.COM © AHOPUEO

In addition to suspending measuring tools, slick lines are used to place essential production equipment downhole, such as packers and valves. When production is started from a

productive formation zone, slick line is used to suspend “bomb hangers” which, when detonated, drive projectiles through the well casing pipe. The holes thus produced allow hydrocarbons to flow into, and up, the well. Slick line is also used during “fishing” operations in order to retrieve equipment that is no longer needed downhole or to remove broken components that may be blocking the well bore.

12 NICKEL IN USE

nickel, vol. 30, no. 1, april 2015

PORTLAND WATER DISTRICT

Aerial view of the lower bay section of Sebago Lake and the water treatment plant, the first free-standing ozonation plant in the USA to meet the disinfection requirement with ozone alone.

Water: an urban and recreational balance Nickel-containing stainless steels make it possible

afe drinking water, and the care and treatments needed to make it so, are serious responsibilities for cities. It is also where, unseen by citizens, many nickel-containing stainless steel applications are at work. Drinking water and recreation Portland Maine, a city of 66,000 people on the North American eastern coast, provides an example of how stainless steels are ensuring one essential of life—drinking water—even as another important part of quality of life—recreational use of water—continues. Inland some 30 kilometres from Portland are a number of fresh water lakes, the largest being Sebago Lake. It is a deep lake, with a surface area of some 115 square kilometres (45 square miles) and containing almost 3.78 billion cubic metres of water (approximately one trillion US gallons). In 1869 a connection to the lake was established and the fi rst water service came to Portland. Today the lake water remains vital for the city of Portland but some 90% of the lake remains open to public boating and swimming, secure in the knowledge that the city’s drinking water will arrive in homes clean and healthy.

ISTOCKPHOTO.COM © DA-KUK

Increasing demands on materials The federal Safe Drinking Water Act was amended in 1986 to require that surface water be fi ltered and established new standards for disinfection. The exceptional quality of water from Sebago Lake meant fi ltration was not required but the Portland Water District (PWD) decided to switch from chloramines (a less problematic alternative to the use of chlorine) to ozone for primary disinfection. The Portland facility was the fi rst free-standing ozonation plant in the USA to meet the disinfection requirement with ozone alone. A project to update the ozone disinfection process and install a new UV water treatment system was completed in 2014. Gaseous oxygen for ozone generation is now obtained from liquid oxygen stored outside the plant and delivered through

nickel, vol. 30, no. 1, april 2015

r The large diameter stainless steel outer shell encompasses water being treated and the UV lamps.

a stainless steel system. Joel Anderson, Chief Operator of the water treatment plant, notes that two Ozonia ozone generators, one acting as a spare, now generates the ozone used to make the 8 to 10% ozone gas that is dissolved into process water and then added to the reaction tank. The generator shells and associated piping are all stainless, mostly Type 316 (UNS S31600). Once treatment is complete, any remaining ozone is converted back to oxygen in ozone destruction units. The oxygen is then discharged into the atmosphere. A more recent Federal Environmental Protection Agency regulation focused on concern for the pathogen Cryptosporidium (a diarrhea-causing protozoan). While PWD has never detected Cryptosporidium in a two year monitoring program, UV treatment was incorporated as an additional level of protection against potential contamination. Two Wedeco UV units were installed, and again back-up is provided as only one unit is used at a time. Until the water leaves the plant, essentially all piping is stainless steel. For corrosion control and to prevent possible contamination in the non-stainless steel potable water distribution system, chemical inhibitors and chloramines are added. But the water that enters the system is as safe and of as high a quality as Sebago Lake can offer, thanks to appropriate treatments enabled by nickel-containing stainless steel.

NICKEL IN USE 13

UNS details UNS No.

Chemical compositions (in percent by weight) of the alloys and stainless steels mentioned in this issue of Nickel.

0.002

0.1

18.0

3.0

bal.

0.8

0.2

0.4

9.0

0.2

617 B p. 11

0.80-1.3

0.0010.005

0.050.08

11.013.0

21.023.0

1.5 max.

1.00 max

8.0010.00

0.6 max.

bal.

0.012 max.

0.008 max.

0.03

0.250.50

0.6 max.

K90901 p. 10

0.04 max.

0.080.12

8.09.5

bal.

0.300.60

0.851.05

0.0300.070

0.61.0

0.40 max.

0.020 max.

0.010 max.

0.200.50

0.180.25

K92460 p. 10

0.04 max.

0.006 max.

0.060.13

8.09.5

bal.

0.300.60

0.0300.070

0.030.10

0.40 max.

0.020 max.

0.010 max.

0.50 max.

0.150.25

1.502.20

N06600 p. 7

0.15 max.

14.0017.00

0.50 max.

6.0010.00

1.00 max.

72.0 min.

0.015 max.

0.50 max.

N06601 p. 7

1.01.7

0.1 max.

21.025.0

1.0 max.

bal.

1.0 max.

58.063.0

0.015 max.

0.50 max.

N06617 p. 10

0.801.50

0.006 max.

0.050.15

10.015.0

20.024.0

0.50 max.

3.00 max.

1.00 max.

8.0010.00

44.5 min.

0.015 max.

1.00 max.

0.60 max.

N06625 p. 7

0.40 max.

0.10 max.

20.023.0

5.0 max.

0.50 max.

8.010.0

3.154.15

bal.

0.015 max.

0.50 max.

0.40 max.

N07263 p. 11

0.30.6

0.040.08

19.021.0

0.20 max.

0.7 max.

0.60 max.

5.66.1

bal.

0.015 max.

0.007 max.

0.40 max.

1.92.4

N08028 p. 12

0.03 max.

26.028.0

0.61.4

bal.

2.50 max.

3.04.0

30.034.0

0.030 max.

1.00 max.

N08031 p. 12

0.015 max.

26.028.0

1.01.4

bal.

2.0 max.

6.07.0

0.150.25

30.032.0

0.020 max.

0.010 max.

0.3 max.

N08367 p. 7

0.030 max.

20.022.0

bal.

2.00 max.

6.007.00

0.180.25

23.525.5

0.040 max.

0.030 max.

1.00 max.

N08825 p. 7

0.2 max.

0.05 max.

19.523.5

1.53.0

bal.

1.0 max.

2.53.5

38.046.0

0.03 max.

0.5 max.

0.61.2

N08904 p. 7

0.020 max.

19.023.0

1.002.00

bal.

2.00 max.

4.005.00

23.028.0

0.045 max.

0.035 max.

1.00 max.

N08926 p. 12

0.020 max.

19.021.0

0.51.5

bal.

2.00 max.

6.007.00

0.150.25

24.026.0

0.030 max.

0.010 max.

0.50 max.

N08936 p. 12

0.020 max.

26.0028.00

0.50 max.

bal.

4.006.00

5.006.00

0.300.50

33.0035.00

0.025 max.

0.010 max.

0.50 max.

N10276 p. 7

0.02 max.

2.5 max.

14.516.5

4.07.0

1.0 max.

15.017.0

bal.

0.030 max.

0.08 max.

0.35 max.

3.04.5

R30035 p. 12

0.025 max.

bal.

19.0021.00

1.00 max.

0.15 max.

9.0010.50

33.0037.00

0.015 max.

0.010 max.

0.15 max.

1.00 max.

S30403 p. 5, 7, 16

0.03 max.

18.0020.00

bal.

2.00 max.

8.0012.00

0.045 max.

0.030 max.

1.00 max.

S30467 p. 5

1.752.25

0.08 max.

18.020.0

bal.

2.00 max.

0.10 max.

12.015.0

0.045 max.

0.030 max.

0.75 max.

S31008 p. 7

0.08 max.

24.0026.00

bal.

2.00 max.

19.022.0

0.045 max.

0.030 max.

1.50 max.

S31254 p. 7

0.020 max.

19.5020.50

0.501.00

bal.

1.00 max.

6.006.50

0.1800.220

17.5018.50

0.030 max.

0.010 max.

0.80 max.

S31277 p. 12

0.020 max.

20.523.0

0.501.50

bal.

3.00 max.

6.58.0

0.300.40

26.028.0

0.030 max.

0.010 max.

0.50 max.

S31400 p. 10

0.25 max.

18.019.0

bal.

2.00 max.

19.0022.00

0.045 max.

0.030 max.

1.503.00

S31600 p. 2, 12, 13

0.08 max.

16.0018.00

bal.

2.00 max.

2.003.00

10.0014.00

0.045 max.

0.030 max.

1.00 max.

S31603 p. 5, 7

0.030 max.

16.0018.00

bal.

2.00 max.

2.003.00

10.0014.00

0.045 max.

0.030 max.

1.00 max.

S32100 p. 7

0.08 max.

17.0019.00

bal.

2.00 max.

9.0012.00

0.045 max.

0.030 max.

1.00 max.

5xC min.

S32101 p. 5

0.040 max.

21.022.0

0.100.80

bal.

4.0-6.0

0.100.80

0.200.25

1.351.75

0.40 max.

0.030 max.

1.00 max.

S32205 p. 7,12

0.030 max.

22.023.0

bal.

2.00 max.

3.003.50

0.140.20

4.506.50

0.030 max.

0.020 max.

1.00 max.

S32707 p. 7

0.030 max.

0.52.0

26.029.0

1.0 max.

bal.

1.50 max.

4.05.0

0.300.50

5.59.5

0.035 max.

0.010 max.

0.50 max.

S32750 p. 7

0.030 max.

24.026.0

bal.

1.20 max.

3.05.0

0.240.32

6.08.0

0.035 max.

0.020 max.

0.80 max.

Super304H typical p. 11

14 NICKEL IN BRIEF

nickel, vol. 30, no. 1, april 2015

Nanocrystalline nickel nanostructures aid in understanding how infections can be prevented

T MOFRAD LAB AND THE NANOMECHANICS RESEARCH INSTITUTE

he bacterium Staphylococcus Aureus (S.aureus), also known as Staph, is a common source of post-surgery infections involving prosthetic joints and artificial heart valves. The bacteria adhere to medical equipment and if they get inside the body a serious and even life-threatening infection may result. The emergence of drug-resistant strains of S.aureus makes matters worse.

JENS HUMMELSHOJ/SLAC

r Scanning electron microscopy image of bacterial cells (blue) suspended from the mushroom-shaped nanostructure’s overhangs

Staphylococcus cells first need to adhere to a surface that is going into a surgical site. This is why a team of researchers led by Berkeley Lab (Lawrence Berkeley National Laboratory) scientists are exploring how surface features facilitate bacterial adhesion. The scientists used electron beam lithographic and electroplating techniques to fabricate nanocrystalline nickel nanostructures of various shapes and sizes, not much bigger than the staph cells themselves. They investigated for the first time how individual S.aureus bacteria cells adhere and found that adhesion and survival rates vary depending on the nanostructure’s shape. The bacteria seem to sense the nanotopography of the surface and form stronger adhesions on specific nanostructures. “By understanding the preferences of bacteria during adhesion, medical implant devices can be fabricated to contain surface features immune to bacteria adhesion, without the requirement of any chemical modifications,” says Mohammad Mofrad, a faculty scientist in Berkeley Lab’s Physical Biosciences Division and a professor of Bioengineering and Mechanical Engineering at UC Berkeley. This research was recently published online in the journal Biomaterials.

Clean Innovation more and better methanol using nickel

cientists from Stanford University and the Technical University of Denmark have discovered a nickel-gallium (Ni5Ga3) catalyst that synthesises methanol using hydrogen produced by wind or solar power and CO2 emissions from power plants.1 “Methanol is processed in huge factories at very high pressures using hydrogen, carbon dioxide and carbon monoxide from natural gas,” said study lead author Felix Studt of SLAC. “We are looking for materials than can make methanol from clean sources under low-pressure conditions, while generating low amounts of carbon monoxide.” “We spent a lot of time studying methanol synthesis and the industrial process,” says Studt. “It took us about three years to figure out how the process works and to identify the active sites on the copper-zinc-aluminium catalyst that synthesise methanol.” Once he and his colleagues understood methanol synthesis at the molecular level, they began the hunt for a new catalyst

NICKEL, VOL. 30, NO. 1, APRIL 2015

capable of synthesising methanol at low pressures. Rather than testing for compounds in the laboratory, they searched in a massive computer database2 (a technique known as computational materials design). The most promising candidate turned out to be a littleknown compound called nickel-gallium. The Danish team carried out the task of synthesising nickel and gallium into a solid catalyst. This confirmed that the database had pointed them in the right direction. At high temperatures, nickel-gallium produced more methanol than the conventional copperzinc-aluminium catalyst and considerably less of the carbon monoxide by-product. More work is needed to achieve the goal of a truly carbon neutral process without unwanted by-products but again it is nickel that is supporting both innovation and a better environment. 1.

The results are published in the online edition of the journal Nature Chemistry Database developed at the SLAC National Accelerator Laboratory by Studt and co-author Frank Abild-Pedersen

v Artist’s rendering of the nickel-gallium active site, which synthesises hydrogen and carbon dioxide into methanol. Nickel atoms are light grey, gallium atoms dark grey, and oxygen atoms red.

NICKEL

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NICKEL IN BRIEF 15

MARIA PERGAY

r Drape Cabinet, 2005 stainless steel, ebony macassar, palm wood

MAKING DREAMS MATERIALISE F

Lit Tapis Volant / Flying Carpet Daybed, 1968 r

During the 1970s and 1980s Maria Pergay enjoyed much success with commissions from the likes of the Saudi Royal family, fashion designer Pierre Cardin and Salvador Dali. In 2004, she was persuaded to start exhibiting again by New York gallerist Suzanne Demisch. And for her first New York show in 30 years, at the Demisch Danant gallery in 2006, she revealed 15 new stainless steel pieces. Since then she has been producing seven to ten new designs annually and exhibits regularly. Maria Pergay’s pieces are one-offs or limited to just a very few editions—they come up for auction rarely and have become collectors’ items. When asked to describe her work, she simply says “My pieces, like the Flying Carpet and Invisible Table are about making dreams materialise.”

PHOTOS: COURTESY OF DEMISCH DANANT

Born to Russian parents in Moldavia, Maria Pergay emigrated to Paris as a child in 1937. She started out by creating window displays in the 1950s and went on to design small scale objects in silver for French luxury accessories manufacturer, Hermès. Impressed by this work, stainless steel producer Ugine Gueugnon approached her to broaden the appeal of ‘inox’ and show consumers that it wasn’t just a material for ‘everyday pots and pans’. Despite initial scepticism, Pergay convinced them that she could make stainless steel furniture and the following year, her first full exhibition received instant acclaim. Pieces including the Flying Carpet daybed—immortalised in a 1970 photograph of a reclining Brigitte Bardot—and the Ring Chair have since become recognised as design icons.

or almost fifty years, Parisian designer Maria Pergay has blazed a trail for stainless steel, creating magnificently quirky yet functional furniture. Now, in her eighties, this designer of timeless pieces with a fantasy-like quality, is still at the height of her creativity. Since the 1960s, Pergay has favoured nickel-containing 304L (UNS S30403) stainless steel, admiring its qualities of strength, durability and formability. “There is a reciprocal charm between us. I am charmed by what it can give me. In return, stainless steel allows itself to be transformed into something extraordinary.”

rr Maria Pergay r Chaise Anneaux / Ring Chair, 1968 stainless steel