91直播 engineers boost sustainable acrylic acid production using next鈥慻eneration membrane reactor
Acrylic acid is essential for everyday products 鈥� from paints and coatings to absorbent polymers 鈥� yet almost all of it is currently made from propylene, a petrochemical. As global biodiesel production rises, so does the supply of low鈥憊alue glycerol by鈥憄roduct, creating an opportunity for cleaner, renewable chemical manufacturing.
In the new study, 91直播 engineers, including Dr , compared a conventional packed鈥慴ed reactor with an intensified membrane鈥慳ssisted system. By feeding oxygen gradually through a porous ceramic membrane, the team achieved better control of the reaction and suppressed unwanted combustion pathways.
Under optimised conditions, the membrane reactor delivered up to 58.7% acrylic鈥慳cid selectivity 鈥� a 10鈥憄ercent improvement over standard reactor technology. It also helped regulate temperature, reducing hot鈥憇pots and improving reaction stability.
Our membrane reactor concept shows clear advantages for selective oxidation systems. By distributing oxygen gradually along the reactor, we avoid the formation of hot spots and suppress over鈥憃xidation pathways, which ultimately boosts acrylic鈥慳cid selectivity. This is a promising step toward a scalable, lower鈥慹missions alternative to the fossil鈥慴ased acrylic鈥慳cid industry.
A more sustainable route for a globally important chemical
Glycerol is produced in large quantities by the biodiesel sector as a major by-product, with global production growing rapidly over the last two decades. Its oversupply has depressed market prices and created a need for new valorisation routes. Converting this low鈥憊alue by鈥憄roduct into acrylic acid offers a way to lower emissions, reduce reliance on fossil resources and increase the circularity of chemical manufacturing.
The researchers used two catalysts, one to add oxygen in the right way, and one to remove water molecules (orthorhombic Mo鈥揤鈥揙 (Ortho鈥慚oVO) oxidation catalysts and HZSM鈥�5(200) dehydration catalysts) respectively, to enable high glycerol conversion (94鈥�99%) across all tested conditions, while the membrane reactor design strategically minimised over鈥憃xidation to CO/CO鈧� (CO鈧�).
The team applied a statistical Design of Experiments (DoE) approach to map the coupled effects of temperature, GHSV, oxygen-to-glycerol ratio and feed鈥憈o鈥憁embrane ratio. This enabled the identification of precise operating windows that maximise acrylic acid yield while maintaining high conversion and limiting CO鈧� formation.
A 44鈥慼our stability study highlighted that catalyst deactivation is primarily driven by coke deposition on HZSM鈥�5(200), suggesting future work should focus on developing more coke鈥憆esistant materials or regeneration strategies. Ortho鈥慚oVO, by contrast, retained its structure and showed minimal deactivation.
Waste glycerol represents an abundant and under鈥憉sed renewable feedstock. Demonstrating that a membrane鈥慳ssisted reactor can outperform conventional designs at scale is an important milestone for making this conversion route commercially attractive.
Pathway to industrial implementation
The results demonstrate strong potential for integrating membrane鈥慳ssisted reactors into future commercial glycerol鈥憈o鈥慳crylic鈥慳cid processes. Beyond enhanced selectivity, the reactor design:
- reduces oxygen consumption,
- improves temperature control,
- may reduce downstream purification costs due to higher product yields, and
- provides a more sustainable alternative to propylene鈥慴ased production.
The researchers note that next鈥慻eneration membranes specifically engineered for selective oxygen transport could unlock even greater performance improvements, along with opportunities to optimise operating pressure and reactor compactness.
This research was published in: Chemical Engineering Journal
Full title of the paper: Direct valorisation of bio-glycerol to acrylic acid: Experimental comparison of membrane and conventional reactors
DOI: 10.1016/j.cej.2026.175331
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