Making ethanol more efficiently

Continuously improving efficiency and reducing carbon emissions is standard practice across INEOS. We know that a lot of small improvements will amount to a big difference.

On paper, converting ethylene to ethanol is relatively simple - just add water. In practice, the industrial chemistry that underlies the process is somewhat more complex, requiring large amounts of water, steam and energy. But here’s how our team in Grangemouth recently both improved plant efficiency and made a major cut to emissions.

The INEOS Grangemouth ethanol plant was commissioned in 1983 and has been significantly upgraded over the last 5 years to improve performance and reliability. The production process requires an excess amount of water for the reaction to take place, but needs the right balance be struck. Using more water in the reaction will decrease impurities, while further down the line more steam is needed to purify and ‘dry’ the product by boiling off the water – a costly process. Conversely, too little water increases production of unwanted by-products and not enough ethylene is converted into ethanol.

The technical team decided to review the entire manufacturing process. Was there a way to be more efficient, reducing water and steam usage, with a reduction in carbon emissions per tonne of product too?

Determined to come up with a solution, they carefully examined every aspect of the manufacturing process alongside the operations team, from the temperature the reactants enter the reactors to the management of energy and steam across the asset.

The results have been impressive.

The asset has installed new operating procedures that deliver a more efficient process for making ethanol. The team determined optimal production rates to allow for less water use in the reaction section, which means lower volumes need to be boiled off in the purification process. The management and use of steam for heating the reactors and in the distillation columns has been improved too.

More importantly, emissions have been reduced by between 6,000 and 7,000 tonnes per year, the equivalent of removing 3,700 cars from the UK road network.

And there are other benefits: with reduced process temperatures and pressures, combined with longer runs between catalyst regeneration shutdowns and start-ups, there is less stress on the plants’ infrastructure, on pipework, pumps and valves. The plant can now operate over longer periods of time.

Fiona Buchanan, Ethanol and Hydrocarbons Plant Manager, said, “The work we have undertaken on ethanol demonstrates our collective focus on the relentless pursuit of reducing emissions across the site and across our business. Initially driven by the desire to improve the efficiency of the ethanol plant, we’re delighted with a solution that not only improves efficiency but makes another major contribution to the site’s net zero roadmap.”

Go to the sustainability section of the INEOS O&P Europe website for more on our agenda.

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