CO2: Why just a by-product?
By Joanna Sampson “It’s a question of balancing the production of carbon dioxide (CO2),” said ASCO Carbon Dioxide’s Head of Marketing and Communication when he spoke with gasworld nearly two months on from what was described as the “worst supply situation to hit the European CO2 business in decades.”
“To us, Europe’s CO2 shortage was actually something predictable because it happens every year,” David Oehler explained. “It’s a problem in the supply chain because it’s the industrial gas companies that cannot deliver to their customers. Whether that’s bottlers, breweries, dry ice users, it’s a supply chain that gets to its limits in the summer time.” “So, instead of focusing so much on only by-product recovery, it’s a question of balancing the production of CO2 and taking alternative production methods into consideration. It’s in the industrial gas companies interests to balance the production and have a continuous supply level throughout the year.” Multiple industries were affected by the shortage of CO2 back in June, amid longer than expected shutdowns at ammonia and bio-ethanol plants across Europe, made worse by an increase in demand for soft drinks and beer and the hot weather. Factories can’t turn a profit on making pure CO2 alone so instead, the gas is made as a by-product of other chemicals, often ammonia fertiliser. But why is such an essential component of the food and beverage, dry ice and farming industries produced as a by-product from chemical processes? “This is the cheapest way of getting CO2 because in these plants CO2 exists in very high concentrations,” Oehler replied. “We’re talking about above 95% CO2 in their waste that would be ventured into the atmosphere.” “From a production point of view, this means one only has a purification step and a liquefaction step in order to get CO2 that is ready for transport or storage.” “When we talk about stack gas recovery, we have a concentration that’s lower than 10%. So, all the exhaust that goes into the atmosphere only contains 10% maximum of CO2. That of course makes it much more expensive to recover the same amount of CO2 then with the by-product.” “Thinking of production steps besides purification and liquefaction, one needs a pre-treatment step and a concentration step upfront – and it’s these additional steps that make the difference in cost.” CO2 recovery “The shortage proves there is a need for CO2 recovery and we think it proves more investment is needed in this industry,” Oehler added. “The most interesting stack gas sources for CO2 recovery are the ones running in non-stop operation like for example the waste incineration plants. Whenever a waste incineration plant is planned to be built in a region, it should be in the interest of the operator to run such a recovery plant. Or even an industrial gas company could think of operating such a recovery operation if they have no other CO2 source around.”This article appeared on the gasworld website at https://www.gasworld.com/co2-why-just-a-by-product/2015247.article