Compressors CO2 Capture with Integrally–Geared Centrifugal Compressor
Oil sands have become a major source of unconventional oil: Canada produces around 1.25 million barrels per day from oil sands. Extracting the oil, nevertheless, causes CO2 emissions. Carbon capture and storage (CCS) is a new approach to hamper emissions from bitumen extraction. Compressor specialist MAN took the challenge of providing technology for the Quest CCS Project.
MAN Diesel & Turbo (MDT) is providing the compressor technology for Shell Canada’s Quest CCS Project, in Alberta, Canada. This project will be the world’s first commercial-scale approach to use CCS in an oil sand operation. From 2015 on, Quest shall capture more than one million tonnes of CO2 per year for permanent underground storage.
Under Ground, Under Pressure
To inject the climate gas into the rock, Shell ordered an RG-type integrally-geared centrifugal compressor from MDT. “Having won the order for engineering in 2011, the supply contract has now been signed”, says bid manager Christof Hüls. MDT Berlin will construct and hand over this type RG90-8 frame size for the first time.
Four pinions are engaged with a different gear ratio, thus leading to diverse rotating speeds. Each pinion mounts two impellers in a back-to-back arrangement. They are compressing the CO2 in eight stages to a discharge pressure of 130 bar.
This compressor, constructed of familiar components which have proved reliable in different frame sizes, handles 80,000 cubic meters of CO2 per hour. The discharge pressure of 130 bar is enough to send the compressed CO2 via a 60 kilometres underground pipeline to a wellhead at the injection site. From there, the dense phase gas is pumped into a saline rock formation 2.3 kilometres below the surface.
An Early Adopter
CCS is regarded as a potential technology to fight climate change by many industrial countries, as it can be applied for different applications including gas and coal-fired power plants. “We are gaining further experience and competence in this area through Shell’s order”, says Ulrich Mudrack, head of the Refineries and Hydrocarbon Processing department of MDT in Berlin. Now, the company’s early investments in CO2 applications with integrally geared centrifugal compressors are paying off, Mudrack states: Already in 1999, MDT delivered two RG compressors to the Dakota Gasification Corporation. These compressors have been in service to deliver CO2 for the production of synthetic gas from coal since the turn of the century.
“Our experience and the reliability of our centrifugal compressors have become an important reference”, reports Christof Hüls. Ulrich Mudrack adds: “Including Shell’s Quest project all our global orders for CO2 compression for Enhanced Oil Recovery (EOR) and CCS have been won in the last 18 months. This means we are steadily consolidating our technology leadership position.” DST