FAQ on Clean Technology

Questions & Answers on Clean Technology.

Energy generation and climate protection
Isn't CCS just a way of keeping old, harmful power plants artificially alive?
Absolutely not. Despite all the effort and subsidies being invested into renewable energies, non-renewable sources will continue to dominate the world's energy mix for many decades to come. Which is why it is essential that we continue to evolve current technologies – such as those used in coal-fired power plants – and tap existing fossil resources in as environmentally sound a manner as possible. Carbon Capture and Storage (CCS) is an important technology in the move to improve the carbon balance of fossil fuel combustion in the near future. We desperately need technologies such as CCS as we transition to a low-carbon economy. Just as we need sponsored research projects that test and demonstrate CCS capabilities to speed industrial-scale deployment.
Given the current economic situation, how are we to fund the costs for CCS and climate protection in general?
We must not let the current focus on the need to rebound from the effects of the economic and financial crises and bring prosperity back to our economies detract from the importance of sustainable energy sourcing and lowering emissions of harmful gases such as carbon dioxide (CO2). That is the only way we can leave an intact environment so that future generations can enjoy a high standard of living.
Can we even put a price tag on the financial consequences of climate change?
No. Nobody can predict the consequences of climate change with complete certainty at this point. But we do know enough to understand the risks. The German Institute for Economic Research (DIW), for example, puts a EUR 137 billion price tag on damage resulting from climate change by 2050 in Germany alone if corrective measures are not implemented in time. Viewed long-term, the mitigation of climate change is a growth strategy. The objective is to position climate-friendly technologies and eco-innovations as mega-trends and drive their market success, thus turning the costs involved in climate protection into wise investments securing our future.
The economic viability of CCS technologies hinges largely on political support through schemes such as emissions trading. What would be the ideal political framework?
A global position on CCS is an absolute must. If the EU continues to operate solo in the fight against emissions, European competitiveness will ultimately suffer. Pending an international climate protection agreement, we must therefore ensure that emissions trading does not compromise the competitiveness of European industry. To achieve this, the EU Commission has defined exposed sectors that would be disadvantaged through the mandatory purchase of emissions certificates or higher electricity rates. Many energy-intensive chemical plants have been understandably classified as exposed. Initially, they are to be allocated most of the certificates they require free of charge. This exemption will be waived once a global agreement on carbon reduction has been reached. However, eliminating exemption raises the risk of carbon leakage and a job drain in favour of Eastern European countries with more relaxed legislation. Many of the details have yet to be worked out. The method applied by the EU Commission to define exposed sectors is disputed, for example, and concrete benchmarks for the free allocation of certifications will not be defined until the end of 2010. At the same time, industry needs clear signals so it can plan accordingly.
Climate protection is seen as a costly business. How can we achieve a breakthrough?
The success of climate protection depends on our ability to factor the economic and social ramifications into new innovations from the ground up – in other words, from the development phase onwards. All decisions must balance acceptance by the general public with the need for financial success. We should meet the climate change cost challenge head on with innovative technologies – with products and processes that make renewable energies cost-effective, conserve natural resources and help reduce or even eliminate harmful emissions and waste.
That is the only way to harmonise ecological success with business success. Roland Berger Strategy Consultants estimate that the global market for environmental technology is already worth more than EUR 1 trillion. This could be as much as EUR 2.5 trillion by 2020. Particularly dynamic growth is projected for climate protection technologies, estimated to grow to EUR 1.7 trillion worldwide by 2020.
Hydrogen
What energy sources can be used to produce hydrogen?
Hydrogen can be obtained from any form of primary energy whether renewable or conventional. Natural gas is the primary feedstock. It is used in a process called steam reforming to generate the vast majority (75 percent) of the world's industrial hydrogen gas. This is because steam reforming is a very efficient, proven process and natural gas is readily available.
Isn't the technology behind hydrogen production too exotic to seriously become established?
The technology for producing hydrogen has been around for a long time. We have been generating hydrogen on an industrial scale for over one hundred years now and large volumes of this gas are used in many industrial processes today. Over 50 million tonnes of hydrogen are currently produced each year. A freight train carrying this much hydrogen would stretch almost four times around the earth's equator. Linde is a global leader in the production and distribution of hydrogen and has in-depth experience in safe handling practices. Today, the vast majority of hydrogen is used in refineries to desulphurise petrol and diesel. So it is already making a key – and growing – contribution to the production of cleaner fuels. Large volumes of hydrogen are also required in the chemical and metal processing industries.
Doesn't producing hydrogen require more energy than the energy subsequently released by the hydrogen?
When judging the efficiency of hydrogen sourced from natural gas, the entire production and consumption chain has to be factored into the equation. A hydrogen fuel cell is highly efficient. This means that hydrogen matches or exceeds the energy efficiency of conventional transport fuels. Hydrogen offers us a route to oil-free mobility, for generations to come. It will improve the quality of air in cities and play an important role in reducing and – ultimately – eliminating CO2 emissions.
When can we expect true 'green' hydrogen?
Linde already provides its customers with climate-neutral and green hydrogen on request. Through the purchase of carbon credits, Linde is able to supply hydrogen for mobile applications that classifies as climate neutral. And green hydrogen is already a reality in Magog (Quebec, Canada), where The Linde Group uses hydroelectric sources to produce enough hydrogen to power over 35,000 fuel-cell vehicles every day. Linde aims to significantly increase the proportion of hydrogen it produces from sustainable energy sources in the long term. Which is why the company is breaking new ground in regenerative production processes as it explores possibilities such as algae and biomass as the feedstock. Conventional hydrogen production is already a more climate-friendly option, bringing greater diversity to our primary energy mix in road transport. A car powered by conventional hydrogen derived from natural gas reduces the well-to-wheel carbon footprint of a modern diesel car by up to 30 percent. To realise zero-emissions mobility with economically viable, regenerative hydrogen, however, we must also be able to generate hydrogen from electricity or biomass, for example, and explore the possibilities of carbon capture.
Using electrolysis to produce hydrogen requires water. Will this conflict with drinking water supplies?
Securing water supplies is one of the greatest challenges facing mankind.
The electrolytic breakdown of water into hydrogen and oxygen during H2 generation and the later recombination of these two gases to pure water during 'combustion' in a hydrogen-powered car is a closed cycle. In other words, no water is actually consumed.
There is a lot of pressure and support for vehicle electrification at the moment. Do we even need hydrogen fuel?

The electrification of cars will play a crucial role in the transition to low-emission road transport. Vehicles with fuel cells and batteries are just two examples of electrification and both models complement each other very well. Both systems have proven to be technically viable, so it is now a matter of commercialising competitive, appealing products. Approximately one third of the components used in battery-operated and fuel-cell cars are the same, so progress and development in one area is beneficial to the other. However, there are big differences in range and refuelling times.

Cars powered exclusively by electric batteries currently have very limited ranges. Even looking to the future, lithium-ion batteries are not expected to take cars further than 200 kilometres on a single charge until 2020 at the earliest. Recharging times are also less than ideal for consumers. Today's drivers face an average wait of up to seven hours. In contrast, hydrogen-powered vehicles can already be fully refuelled in around three minutes. In addition, pre-series H2 cars already run for almost 700 kilometres on a single tank.

How much does hydrogen cost?
A kilogram of hydrogen currently costs around six to fifteen euros. When used in conjunction with a fuel cell, this corresponds to a range of around 100 kilometres and is thus comparable to the cost of conventional fuels running in regular engines. However, the price may fluctuate greatly depending on a number of factors. Hydrogen is produced, transported and sold regionally and – unlike oil – does not have a regulated global market price. The cost of hydrogen is currently heavily dependent on variables such as factor costs, production path, demand, geographical location and the degree of purity required. Since the technology used to produce hydrogen as a fuel is still very new, there is vast scope for cost efficiencies in the long term. Hydrogen that is produced and consumed on an industrial scale is considerably cheaper than hydrogen produced and offered on a limited scale at fuelling stations set up for demo projects. In the long term, the price point of hydrogen at fuelling stations (including tax) must be attractive to drivers of hydrogen-powered cars.
When will hydrogen be able to compete with other fuels?
Hydrogen fuel is revolutionising a century-old tradition in automotive technology. It therefore makes sound environmental and economic sense to expand the hydrogen footprint gradually. The technology enabling the hydrogen fuel chain is still young and therefore offers huge scope for cost efficiencies, so we will see price drops in the medium term. Today, the price of untaxed hydrogen can already compete with conventional fuels. Taking all factors into consideration, the long-term cost of fuel-cell cars will be lower than conventional technologies.
How mature is hydrogen technology? And if it is sufficiently mature, why hasn't it already been widely commercialised?

Unlike the industrial sector, the mobility market for hydrogen is still in its infancy. Advances are taking place in the wider fields of production, storage and distribution for this market.

At the same time, commercialisation of hydrogen calls for the development and standardisation of efficient fuelling processes and the evolution of automotive technologies. In recent years, significant progress has been made in the move towards market-ready systems and products, both in terms of vehicle design and the supporting infrastructure. Public hydrogen fuelling stations, however, will only be economically viable once there are a sufficient number of hydrogen-fuelled cars on the road. To drive progress in this area, Daimler, EnBW, Linde, OMV, Shell Deutschland, Total Deutschland, Vattenfall Europe and the National Organisation for Hydrogen and Fuel Cell Technology (NOW) signed a Memorandum of Understanding to form the 'H2 Mobility' initiative. The aim of these founding members is to dovetail the market availability of hydrogen vehicles with the emergence of a supporting infrastructure. Similar developments are also taking place in Japan and the USA.

How many hydrogen fuelling stations are there already?
Around two hundred hydrogen fuelling stations are currently in operation worldwide. Germany alone already has almost thirty stations, some of which are open to the public, making Germany the hydrogen pioneer in Europe.
How much would it cost to build an infrastructure with full coverage?
The Linde Group estimates that initial nationwide coverage in Germany would involve infrastructure costs of around EUR 1.7 billion. That would create approximately 1,000 fuelling stations. Around EUR 3 billion in investments would be required for a Europe-wide infrastructure of fuelling stations by 2020. That was one of the findings of Europe's most extensive study to date on the prospects of various drivetrain concepts for personal mobility presented on 8 November 2010 in Brussels.
Is hydrogen a more dangerous fuel than petrol?
Many pilot and demo fuelling stations around the world have shown that hydrogen can be handled safely as a fuel. It is the lightest element in the world and volatilises very rapidly in air, giving it a major advantage over petrol, which dissipates more slowly and is heavier than air. Petrol therefore stays on the ground longer, where the threat of ignition is highest. Petrol and hydrogen also burn differently. If liquid petrol leaks, spreads onto a surface and burns, it produces a very broad flame that emits a large amount of heat. In contrast, hydrogen burns with a narrow almost perpendicular flame that does not emit much heat. Unlike a bright petrol flame, however, a pure hydrogen flame is difficult to see in daylight. Hydrogen's overall ignition properties are generally more favourable than today's common energy carriers. Petrol's flammability limit (0.6 volume percent) and explosion limit (1.1 volume percent) are very close together, which means that when petrol ignites, there is almost always the danger of explosion. Hydrogen's flammability limit of 4 volume percent and its explosion limit of 18 percent are much further apart. At 0.24 millijoules, however, petrol's minimum ignition energy threshold is significantly higher than hydrogen's – although the energy in a spark is still sufficient to ignite petrol. And petrol's relatively low auto-ignition temperature (220 to 280 degrees Celsius) also means that it can ignite on contact with hot metal parts such as a catalytic converter or exhaust manifold. This is not the case with hydrogen, which has an auto-ignition temperature of 585 degrees Celsius. Extensive tests carried out for example by the German testing, inspection and certification authority, TÜV Süd, have shown that hydrogen-powered cars are not any more dangerous than conventional vehicles.
What steps are being taken to make hydrogen available for safe, daily use?
Safety is a global issue in the gases industry. Leading manufacturers across the world come together to continually improve standards and make systems even safer. The task forces formed under the umbrella of the European Industrial Gases Association (EIGA) are a prime example of how companies come together to discuss safety issues and develop joint solutions. Plants and components are also subject to a large number of studies and tests to keep inherent risks posed by all energy carriers to an absolute minimum.
Is it true that hydrogen makes metals brittle?
It is true that hydrogen can cause material fatigue. This phenomenon, known as hydrogen embrittlement, was already discovered at the end of the 19th century and has been the subject of research ever since. Today’s engineers have this problem under control. Numerous institutes, for example, the German Federal Institute for Materials Research and Testing (BAM), are always willing to advise and help. If this were not the case, it would be impossible to safely transport hydrogen using steel cylinders, tanks or pipelines.
Natural gas
What is LNG?
LNG stands for liquefied natural gas. The gas is cooled to temperatures as low as minus 164 degrees Celsius, compressing it to 1/600th of its original volume. This enables it to be efficiently transported by ship or truck.
Why is natural gas liquefied?
As with oil, most natural gas deposits are located far away from the actual point of use. Traditionally, the vast majority – around 90 percent – of natural gas is pipelined over long distances to power plants, industrial facilities and homes. However, pipelines become uneconomical if the reserve is small or very distant from customers. The costs for pipelaying, materials and compressor stations are just too high, calling for new strategies to overcome the distance challenge. One solution is liquefaction. It enables this raw material to be cost-effectively transported over thousands of kilometres in liquid state. Up until now, massive tankers have mainly been used for large-scale LNG transport. Today, LNG is proving an increasingly popular and cost-effective way of getting natural gas from source to market. It allows smaller reserves to be cost-effectively developed and brings gas to more remote regions not connected to a pipeline grid.
What role does natural gas play in securing global energy supplies?
In 2010, natural gas covered around 24 percent of global demand for primary energy (excluding biomass), making it the world's third most important energy carrier. Although natural gas extraction fell in 2009, in response to a drop in demand, it increased by around 200 billion cubic metres in 2010 to a record high of 3.2 trillion cubic metres. As with crude oil, naturally occurring gas deposits are unevenly distributed. In 2010, around 975 billion cubic metres of natural gas (around 30 percent of the total market volume) was traded across borders. 69.5 percent of gas exports were pipelined, clearly outweighing the LNG share at 30.5 percent. Almost a third of global gas exports went to the US (10.8 percent), Japan (9.6 percent) and Germany (9.5 percent).
At the end of 2010, global natural gas resources amounted to around 531 billion cubic metres. The largest share of these is located in the Russian Federation, followed by the United States, China, Canada, Argentina and Mexico. Substantial shale gas potential has catapulted Argentina and Mexico into the ranks of the world's ten most resource-rich countries for the first time. In 2010, extraction rates soared, particularly in the Russian Federation and Qatar, which produced around 30 percent more natural gas than in 2009. The United States also raised production levels, primarily through non-conventional gas extraction, making it the world's biggest natural gas producer alongside the Russian Federation. The two countries accounted for almost 38 percent of natural gas extracted worldwide in 2010. The US and Russia are also the largest natural gas consumers, followed by Iran and China, with China consolidating its position as Asia's main natural gas consumer.
Sources: Reserves, Resources and Availability of Energy Resources 2010, German Federal Institute for Geosciences and Natural Resources; Statistical Review of World Energy 2011, British Petroleum (BP)
How can natural gas contribute to an eco-friendly energy chain?
The release of greenhouse gases such as carbon dioxide (CO2) cannot be stopped overnight. However, by turning to natural gas, we can already achieve significant reductions in emissions from private households, industrial companies and the transport sector. This is the most climate-friendly of the fossil fuels, releasing less CO2 on combustion than either coal or hydrocarbons such as heating oil, diesel or LPG. And it is estimated that our gas reserves will last several hundreds of years, in contrast with just 40 years for oil. Natural gas can also play an important role in generating electricity. Gas-fired power stations allow rapid start-up and shut-down, so are flexible enough to help counterbalance fluctuations in wind power, for example. In a nutshell, natural gas is a key stepping stone on the pathway towards more climate-friendly energy choices. It is similar to oil in terms of its versatility but generates significantly lower levels of CO2, at least 20 to 30 percent less than other comparable fuels. Innovative natural gas technologies can thus play a key role in the transition to a zero-carbon economy.
What technologies does Linde offer for natural gas liquefaction?
Across the globe, The Linde Group is playing a major role in unlocking the benefits of this primary energy carrier at all key steps in the value chain, from the source to the point of use. Converting natural gas to LNG requires the latest cryotechnology, and the company is a specialist in this field. Linde engineers have been able to adapt liquefaction systems to even the most challenging environmental settings, as seen at the most northerly LNG plant in the world – Hammerfest in Norway. Before LNG can be transported, many elements – such as heavy hydrocarbons, CO2, nitrogen, sulphur compounds and water – have to be separated from the methane. Cryogenic heat exchangers lie at the heart of Linde's liquefaction plants. Most world-scale LNG plants use coil-wound heat exchangers that are up to 70 metres high. Linde is one of just two companies in the world to master this technology. Its heat exchangers are not only used in the Group's own LNG facilities, but also by companies such as Shell, Woodside and ConocoPhillips. Linde also provides innovative LNG transport solutions and is actively contributing to the ever-expanding LNG infrastructure. Linde engineers have developed storage tanks for ports and ships, for instance. The Linde Group also designs, builds and operates LNG microplants to supply truck fuelling stations or other local needs.
Why are natural gas prices rising?
The main cause of rising gas prices is increased global demand across the entire energy sector. Ongoing political instability in various producing countries and immense economic growth in nations such as India and China have sent demand for all the key energy carriers skyrocketing on the global market – and this has already lead to several massive surges in price. However, the price rises for natural gas remain significantly more moderate than for other energy carriers.
What is unconventional natural gas?
Unconventional natural gas does not differ in composition from its 'conventional' counterpart – it is actually the technology used to extract it that is unconventional, rather than the gas itself. Conventionally, vertical drilling is all that is needed for gas to flow to the surface due to natural pressure within the reservoir. Unconventional gas, on the other hand, is trapped between layers of stone, such as sandstone, siltstone or coalbeds. So additional technology is required to release this gas from the bedrock. First, the gas-containing layers are vertically drilled, and then the drilling continues horizontally, into the stone. Finally, to extract the gas, a mixture of water, sand and various chemicals is pumped into the boreholes at high pressure, breaking up the stone and freeing the gas. This high-pressure process is known as fracking. Some of the mixture is subsequently removed through the boreholes. Breaking up the stone by horizontal drilling unlocks huge reservoirs of natural gas. The International Energy Agency estimates that unconventional extraction processes will open up reservoirs amounting to 921 billion cubic metres of gas throughout the world – five times as much as we can access with traditional methods. In the US, unconventional extraction has gained so much ground within just a few years that the country is now the world's largest producer of natural gas alongside the Russian Federation. In addition, natural gas costs a third less than petroleum-based fuels on an energy equivalent basis.
Can natural gas and biogas streams be mixed?
Biogas is often referred to as the raw gas resulting from the anaerobic digestion of biomass. This gas consists mainly of methane and CO2 and has a high humidity level. Water, CO2 and other unwanted substances are removed so that the biomethane stream is pure enough for the target application. Once purified, the gas can be liquefied or pumped directly into the grid network. It can also be used as a fuel for vehicles such as waste collection trucks, buses and cars. As long as the biogas is sufficiently pure, it can be easily mixed with natural gas. This is already common practice in regions with natural gas pipeline systems.