5
Winner of the Shell Eco-marathon 2006. A
biofuel-powered prototype which won with an
energy consumption equivalent to 2,885 km/l
of petrol
The world is demanding much more energy for development (which currently means more fossil fuels) and a solution to climate change. It cannot have both unless safe and cost-effective ways are found to capture and store CO2 from coal, oil and natural gas.
There are many technical options for capturing CO2. Once it is captured, CO2 can then be stored underground (in aquifers or in some oil and gas fields). It can also be used in industrial processes. However, capturing and storing CO2 is energy intensive and expensive. At a mediumsized coal-fired power plant, for example, capture and storage would lower the plant’s overall energy efficiency by about 10% and add several hundred million dollars to investment costs. Storage will also require acceptance by planning authorities and by local communities.
We are involved in large-scale demonstration projects in this area. One of these is ZeroGen, a low CO2 coal-fired power project being considered in Australia (see below). Another, in Norway, is the largest offshore project to date to store CO2 and use it to enhance oil recovery. If it were to go ahead, the Halten project, which we are working on together with the Norwegian Government and Statoil, would solve a power shortage in central Norway and reduce CO2 emissions by up to 2.5 million tonnes a year. Both projects are at the feasibility stage.
We are also supplying waste CO2 from our Pernis refinery to greenhouses in the Netherlands and exploring CO2 management opportunities in the Middle East with Mitsubishi Heavy Industries.
Government policy will play a decisive role in determining the future of CO2 capture and storage. The significant additional investment involved means it will not be rolled out on a large scale without government action. At the moment, emission reductions achieved through capture and storage do not qualify for emission credits. Our appeal is for more effective project permitting and measures to reduce costs, for example through the European Technology Platform for Zero Emission Fossil Fuel Power Plants. These include granting carbon credits for captured CO2, and setting emission targets beyond 2012 to create a stable long-term investment framework.
Zerogen: Climate friendly coal-fired power
The Queensland State Government in Australia is working on a project to demonstrate that coal-fired power and low CO2 emissions can go hand in hand. If it goes ahead, the ZeroGen project would be the world’s first demonstration plant to produce low-emission electricity by combining coal gasification with CO2 capture and storage.
The plan is to turn the coal into a hydrogen-rich gas and high-pressure CO2. The gas would then be burned to drive a high-efficiency turbine to produce power. The CO2 would be piped approximately 220 km and stored away in underground aquifers. Shell is the preferred provider of the gasification technology and is currently providing drilling and CO2 storage expertise.
Up to 70% of the plant’s CO2 emissions (up to approximately 420,000 tonnes annually) could be captured and stored. Commercial versions would have CO2 emissions nearly 40% lower than those from a comparable sized gas-fired power plant.
At present, the owners of coal-fired power plants have no economic reason to make the extra investment in CO2 capture and storage. If this promising technology is to be rolled out more widely, government support in establishing a price signal for emitting CO2 will be needed.