Mango Materials moves on methane gas for bioplastics

Methane gas could be used as a feedstock to produce affordable PHA bioplastic, according to the CEO of a US-based start-up.

Mango Materials produces biodegradable plastics from waste biogas (methane).

It uses methane-fed bacteria to produce a biodegradable polymer called PHB (Polyhydroxybutyrate) which is a polyhydroxyalkanoate (PHA). PHB has a variety of end uses, including packaging.

Methane as a feedstock

Mango Materials said methane is everywhere and on a price point it is advantageous and more affordable than sugar.

Having the methane as a feedstock changes the process as it uses a different type of bacteria, so has different sterilisation and other processes that should significantly drop the price, said the firm.                

Molly Morse, CEO of Mango Materials, said the methane gas can be any form of methane from wastewater treatment plants, agricultural facilities or landfills or natural gas methane.

“We use that methane to feed to our bacteria to produce a biopolymer called PHA,” she told FoodProductionDaily at the European Bioplastics Conference.  

“We use methane because it is very widely available, generally wherever there are people there is methane. So this is a feedstock that people don’t often think about and don’t realise how readily available it is,” she said.  

“So we can have these decentralised production facilities at the site of methane production.

“We are continuously scaling and making sure everything works the way we think it should work and building larger fermentation systems.”

Past, present and future

Morse said it is based on intellectual property from Stanford University that was exclusively licensed and the firm was incorporated in 2010.

It received the first round of funding in 2011 and has been validating and scaling up since.

Morse said the barrier properties are pretty good and biodegradability properties allow different end of life options for PHAs with the rate of degradation depending on the environment and thickness of the material. 

She said the melt and degradation temperature are a little close, so something could be done to change that to make the processability easier.

“One of the key limitations to date has been the price point, PHA has historically been very expensive and that’s what we are trying to do, significantly drop that price so we can make affordable bioplastic that can help grow the industry.”

Morse said it was still pre-commercial and was working on validating the technology.

“I wouldn’t consider ourselves commercial until we have our first standard plant up and running which is still at least one to two years away,” she said.

“So we are validating the technology as we go, building larger systems, doing a lot of optimisation of the downstream processing.

“We’ve got a lot of the fermentation steps sorted but making sure this process is dewatered and purified in an effective manner is really key to what we are working on right now.”

Mango Materials said it would prefer its first standard plant to be located where it could easily get to it.

“It will be a commercial plant so we can sell the product, but it will still be a lot of validation and confirmation so it would be great to be close, however if we had the right partner it wouldn’t mean we wouldn’t go somewhere else,” said Morse.

“Especially if there is someone used to building similar plants before or someone experienced in the aerobic digestion space, we would be open to other locations.

“The key is we would need to be located at the site of methane as you don’t want to be shipping the methane.”