New catalyst improves conversion of butane into butadiene

Researchers have developed a new catalyst that improves the efficiency of converting butane into butadiene, a precursor to synthetic rubber and certain plastics.

Butadiene is a precursor to synthetic rubber and a variety of plastics
Butadiene is a precursor to synthetic rubber and a variety of plastics - AdobeStock

The catalyst, developed by a team at North Carolina State University, is detailed in Science Advances.

Existing techniques for converting butane into butadiene create unwanted by-products or convert a small fraction of the butane into butadiene each time the butane passes through the chemical reactor.

“This is an expensive process in terms of both energy and money,” said Fanxing Li, corresponding author of the work and Alcoa Professor of Chemical and Biomolecular Engineering at North Carolina State University. “Because after every pass through the chemical reactor, you have to separate the butadiene and by-products from the butane – which takes a lot of energy – and run the butane through the reactor again.”

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Consequently, there are very few plants devoted to producing butadiene. Instead, much of the butadiene used in manufacturing comes from plants where butadiene is collected as a by-product of other reactions.

“That’s a problem, because the demand for butadiene far outstrips the available supply,” Li said in a statement. “We wanted to come up with a more efficient way of converting butane into butadiene, making butadiene production facilities more commercially viable – and this work is an important step in that direction.”

The researchers have engineered a catalyst that converts more butane into butadiene with each pass through the reactor, compared to previous catalysts. The work was done using an oxidative dehydrogenation reaction.

“We were able to convert up to 42.5 per cent of the butane into butadiene in a single pass,” Li said. “The previous best performance we could find was around 30 per cent. This is a big first step, but we view it as a proof of concept – we think we can still do a lot more to improve the selectivity of this process.”

The catalyst is a lithium bromide shell surrounding a core of lanthanum strontium ferrite. The reaction requires a modular reactor, and conversion takes place at between 450 and 500 degrees Celsius.

“We’re open to partnerships to further explore the potential of this work,” Li said.