Decarbonisation Technology - August 2023 Issue

Compression & drying

Light ends

Quench column

Ethylene purication section

Innovative heat recovery system

Reaction section

Ethylene product

C+

Recycle water treatment

Recycle

Produced water

Ethanol feed

The endothermic dehydration reaction is carried out in the vapour phase at moderate pressure. The use of water as a heat diluent makes it possible to smoothly control the endotherm of the reaction, and this translates into a simple, fixed-bed adiabatic reaction section with much less equipment compared to other dehydration processes. In addition, the reaction section benefits from an innovative, patented thermal integration system, allowing for maximum heat recovery, resulting in minimum consumption of utilities.

Figure 2 Simplified Atol process flow diagram

to impurities typically associated with bio- ethanol. It is fully regenerable and can be regenerated online. On top of that, the catalyst can accept very high water contents in the feedstock, including ethanol coming straight from primary distillation. This translates into an enhanced flexibility that makes it possible to convert a wide range of ethanol feedstocks that are not compatible with traditional dehydration processes. The catalyst delivers high ethylene yields with excellent selectivity and minimal side reactions. This translates into fewer low-value by-products, positively impacting the operating expenditure related to ethylene purification. The catalyst is used in a process set-up that enables an innovative energy recovery system to minimise production costs and further improve the economic performance of the plant. The technology, therefore, provides a promising opportunity for investors looking for an attractive business case. In a nutshell, the combination between the catalyst and process allows Atol to provide three key benefits: improved versatility in terms of compatible ethanol feedstocks, increased yields through enhanced selectivity, and energy efficiency by heat recovery. Versatile solution for bio-ethanol feedstocks As mentioned above, the key benefit of Atol technology is its enhanced versatility in terms

of the types of bio-ethanol feedstocks that are compatible with the catalyst at the core of the dehydration process. Thanks to this robust catalyst, the technology can convert any kind of bio-ethanol feedstock into high-quality ethylene, from crop-based sources to advanced bio- ethanol feedstocks originating from agricultural, industrial, or municipal wastes and residues. The pathway toward high-quality ethylene is now affordable. Indeed, the future of ethylene production may well depend on our ability to leverage advanced renewable feedstocks. When combined with cellulosic ethanol produced using Futurol technology, Atol could open up a vital pathway for the production of bio-ethylene our society needs, reducing both the use of fossil-based ethanol and offering a sustainable alternative to sugarcane and beetroot crops grown exclusively for bio-ethanol production. Efficient ethylene production The second benefit delivered by the Atol catalyst is its ability to efficiently convert even highly diluted, contaminated, or anhydrous ethanol and bio-ethanol feedstocks into high- quality bio-ethylene. The improved efficiency, in terms of activity and selectivity, of this catalyst helps to reduce costs and improve flexibility for industrial ethylene producers. Traditional bio-ethanol dehydration processes can only process purified bio-ethanol feedstocks