Costain has helped to introduce carbon capture technology to the Emirates Steel Industries’ plant, UAE.
The project started in November 2013, and links the steel works to the UAE’s oil industry. A £93.54M ($123M) compression facility captures the carbon, which is then taken via a 50km pipeline for storage in the Abu Dhabi National Oil Company’s oil fields.
The CO2 flushes oil from the reservoirs, a cheaper alternative to using methane. It also results in 10% more oil being recovered, according to Costain.
“It’s re-using a waste product to help drive out what they want from the oilfields,” said Costain power sector director Nigel Curry. “It is also more economical than buying a specialised gas to inject”
“From an environmental perspective it is massively beneficial that you’re not letting carbon escape into the atmosphere and economically it’s a sensible route as well. Capturing, compressing and transporting carbon are all proven techniques, but it’s the capability that pulls them all together that’s the relatively new part.”
Costain energy business unit director Philip Evans said: “When the CO2 is captured it’s at atmospheric pressure, but it’s wet. We have to initially dehydrate it, otherwise it creates carbonic acid within the process pipework. It’s then compressed in two stages: firstly by rotating machinery to about 60 bar, when it turns into liquid (dense phase), then we use reciprocal compression to take it up to 245 bar.”
“The terrain over which the pipeline to the oilfield was laid on sabkha which has a saline water table just one metre beneath the surface and it has no mechanical strength – it’s like quicksand. So, they put down a layer of gatch (hardcore), lay the pipe on it and bury it above ground in a berm.”
“Because there are a lot of pipelines in the area, they have quite well-protected pipeline corridors with lots of pipelines and berms, so the terrain within a pipeline corridor looks corrugated.”