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Dr. Ulrich Eberl
Herr Dr. Ulrich Eberl
  • Wittelsbacherplatz 2
  • 80333 Munich
  • Germany
Dr. Ulrich Eberl
Herr Florian Martini
  • Wittelsbacherplatz 2
  • 80333 Munich
  • Germany
pictures

Environmentally compatible: AC motor equipped excavators

"Corex-Process": producing pig iron environmentally compatible

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When is Green Really Green?

In the face of climate change and resource scarcity, green solutions are increasingly in demand. But what does "green" actually mean and when do green strategies make economic sense? Siemens has developed a testing procedure to answer these questions: the Eco-Care Analysis.

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Practically every company offers “green solutions.” But when does this label actually mean something? Most companies answer this question by employing analytical methods such as the carbon footprint and environmental performance assessments that take a product’s impact into account in the context of its entire lifecycle — from acquiring raw materials to design, usage, and disposal.

Environmental performance assessments are also a key part of product lifecycle management (PLM) at Siemens Industry Solutions. PLM systems centrally store and manage all the data about a product from its conception to its disposal. But that wasn’t enough for Prof. Dieter Wegener, Chief Technology Officer at Siemens Industry Solutions. “A truly green solution must be both environmentally and economically beneficial,” he says. “These two characteristics are by no means mutually exclusive.”

To support this view, Wegener needed to come up with a standardized and scientific procedure that would combine ecological performance assessments with capital and operating cost analyses. He found a competent partner for such a project at Denmark Technical University (DTU) in Copenhagen. “Their environmental assessment expertise is impressive,” says Wegener. “I even managed to get the project started the day I visited the university.”

In-depth Analysis. The partnership has resulted in a sophisticated method called Eco-Care Analysis. “Our job was to incorporate environmental compatibility into the analysis,” says Dr. Stig Irving Olsen from DTU. “For example, we had to determine how the emissions from an industrial facility would be affected by the use of different materials or the installation of an electronic control system.” Siemens addressed productivity issues — factors such as how process changes might affect material costs, energy use, or expenditures on personnel and disposal.

These complex calculations led to the creation of an Eco-Care Matrix, a decision-support tool that graphically depicts results and brings environmental impact considerations together with economic factors. An analysis based on this tool can be clearly understood at a glance.

The center of the tool’s matrix always contains a comparative reference point that is derived from traditional technologies. The y-axis shows the new solution’s environmental compatibility relative to the reference point. This combined value includes, but is not limited to, CO2, sulfur dioxide, nitrogen oxides, and dust emissions, as well as water, energy, and natural resource use. The x-axis shows customer benefit expressed as a change in system costs. If a new product or solution is to the right of and above the reference point, customer benefit is higher and environmental impact is lower. The subject is therefore objectively “green” as defined by Wegener. “We’ve been using the Eco-Care Analysis at Industry Solutions since 2009, and it’s now mandatory for all green solutions the Division offers,” he reports.

One of the first applications of the Eco-Care Matrix was an analysis of the Simetal Corex Process, an innovative procedure developed by Siemens VAI Metals Technologies for making pig iron. The process produces pig iron directly from coal and iron ore, which obviates coking and sinter plants that convert coal and ore to coke and sinter in conventional blast furnaces. In other words, the process does away with two stages that consume huge amounts of energy and produce emissions. The Eco-Care Matrix showed the technique would improve environmental compatibility by 30 percent and lower costs by at least five percent.

This forecast proved accurate, which is why Shanghai Baosteel Group, China’s second largest multinational iron and steel manufacturer, put its second Corex facility into operation in March 2011. Both of its Corex units are part of a mill in Luojing near Shanghai — and it’s only thanks to the Corex process that the steel giant can comply with the stringent emission limits for Shanghai. The process reduces CO2 emissions by nearly one-third compared with conventional blast furnaces. Nitrogen oxides and dust emissions are 90 percent lower and sulfur dioxide emissions have been cut by 97 percent — while facility operating costs have fallen by nearly ten percent.

The Eco-Care Matrix has also proved successful in the mining sector, where trucks used in open-pit mining consume huge amounts of diesel fuel and large excavators are operated with electricity from nearby power plants. The exhaust gases from the engines and the emissions from the power plants impact the environment, while fuel and electricity are also major cost factors at a mine. In other words, such locations would be ideal for an Eco-Care Analysis, especially since Siemens’ Simine concept covers solutions for trucks and excavators.

Simine TR, for example, is a drive system concept for heavy-duty dump trucks — gigantic vehicles that weigh over 300 tons. A power electronics system (IGBT technology) ensures that a truck’s diesel-electric alternating current (AC) motor operates optimally, which sharply reduces transmission and shifting losses. Analysis has shown that the system’s environmental compatibility is 11.6 percent higher than that of a reference system with a diesel engine. Operating costs were seven percent lower. In fact the new drive system’s hourly fuel use was cut from 400 to 350 liters.

The Eco-Care Matrix assessment for Simine DRAG was even better. Simine DRAG is a concept for gearless AC motors in dragline excavators — vehicles that pull a bucket freely suspended on a boom across earth or rocks in order to extract material. The high efficiency rating of this Siemens solution makes it 22 percent more environmentally compatible than the DC motor that serves as the reference, while reducing electricity costs by 22 percent.

Eco-Care for Everyone. Many other products have been identified as “green” by the Eco-Care Matrix. Examples include efficient diesel-electric drive systems for passenger and cargo ships and energy-optimized controls for electric filters that are used to treat exhaust gases at industrial facilities and power plants. The matrix has proved to be an important tool for Industry Solutions — one that allows customers to see not only how environmentally friendly a solution is but also the economic utility it offers. Wegener now wants to introduce the Eco-Care Matrix throughout Siemens. “Eco-Care’s main strength is clearly its versatility,” he says. “Whether it’s light bulbs, cars, or steel plants — the matrix can be used for anything. It can even analyze a logistics path from A to B; there are simply no limits.” Wegener himself ensured this would be the case. “We could have put a trademark on Eco-Care, but ultimately I decided against that,” he says. “Whoever wants it can have it. In fact, many interested parties from outside the company ask me about Eco-Care, and I explain the underlying concept and help them to implement the system.”

Nils Ehrenberg