"Lower dry ice costs and reduced CO2 emissions thanks to ASCO CO2 recovery systems"

ASCO: Mr. Schwinn, can you explain how the ASCO CO₂ recovery system RRSi works?

Schwinn: In any dry ice production without recovery, the conversion rate of LCO₂ (= "liquid CO₂") into dry ice is only about 40 - 45 % due to physical reasons. During the production process. I.e. 55 - 60 % of the CO₂ is lost to the atmosphere. With an ASCO CO₂ recovery system (RRSi), most of the lost CO₂ is captured and returned to the CO₂ tank to make it usable again. This ultimately leads to a conversion rate of 90 - 95 % for the customer.

1. The CO₂ buffer balloon: stores the recovered CO₂ (gaseous) from dry ice production at a slightly increased ambient pressure.
2. The CO₂ compressor: The recovered CO₂ (gaseous) is compressed to approx. 18-20 bar.
3. The CO₂ liquefier: Liquefies the compressed CO₂ gas by means of a refrigeration cycle. The reliquefied CO₂ is then returned to the storage tank for liquid CO₂ to be used again in dry ice production.
4. The control system: The central control system automatically controls the entire process.

Even though the process of our new ASCO RRSi systems remains the same. we were able to achieve an increase in value through more efficient motors and future oriented R449A refrigerant for the refrigeration compressor. This means approx. 10 % energy savings for the refrigeration processor compared to the past.

Fig.1: CO2 recovery process in dry ice production.

ASCO: What are the differences between the ASCO RRSi and comparable systems?

Schwinn: First I would like to mention the advantages of CO₂ recovery in general. For me personally, these are the minimized CO₂ footprint, since the RRSi converts the LCO₂ used almost completely into dry ice and roughly speaking the required LCO₂ input can be more than halved. Of course, this also has a major effect on profitability, as it increases the return on investment. The production costs are reduced substantially as a result. Further advantages are that we can maintain the CO₂ quality and return it directly into the storage tank. Due to our "system openness" - the RRSi is also suitable for dry ice pelletizers from other manufacturers.

Our plants are particularly characterized by the high conversion rate from LCO₂ to dry ice. With a factor of 1:1.1 (for 100 kg of dry ice, approx..110 kg of LCO₂ are needed), it is one of the best on the market. Furthermore, I have already mentioned that we recycle the recovered CO₂ directly into the tank, thus maintaining food grade (provided the original quality of the CO2 was food grade). The standard equipment includes remote monitoring and diagnosis, which should certainly be mentioned. And finally, of course, the "experience" factor; the ASCO recovery system has been on the market since 1997 and has already been installed at 46 different locations.

Download: Overview advantages of ASCO CO2-Recovery RRSi.
 

ASCO: How do you view the latest developments in the CO₂ market? What do you advise your customers?

Sammali: In recent months, energy and raw material costs have risen sharply and CO₂ prices have not been spared. One of the long-term causes of rising CO₂ prices is the expected changes in ammonia production. The production of ammonia produces CO₂ as a waste product. Today, this represents the largest part of the CO₂ needed worldwide for various industries. But thanks to the Harber-Bosch process, ammonia will in the future be produced in a largely climate-neutral way. This supports the worldwide effort to reduce CO₂ emissions. But this means that there will be less CO₂ worldwide in the future. Or else, other (more expensive) sources will be needed. The recovery plant helps to reduce supply bottlenecks and the dependence on suppliers. With rising CO₂ prices, a recovery plant makes sense. Of course, we are happy to offer interested parties an individual ROI (return-on-investment) calculation.

ASCO: How do you think the relevance of CO₂ recovery will develop in the future?

Sammali: Although the amount of available CO₂ will steadily decrease in the future, the demand for dry ice and CO₂ will remain high or even increase. This is partly due to the increased popularity as a cooling medium during the Covid19 pandemic, when it was needed to ship vaccines around the world. The recovery plant cuts the price of dry ice production in half. This means that customers can produce dry ice more economically, which will become more important in the future! In addition, from an ecological point of view, LCO₂ consumption is reduced, and CO₂ transport costs are lowered, as truck journeys can be minimized.

                
Mr. Christian Schwinn                                                      Mr. Roberto Sammali
Chief Technology Officer                                                 Head of Sales Dry Ice Systems