Vlatko Materic holding sample of Hot Lime Pellets

Brand new business based on borrowing rather than creating new carbon dioxide

The most successful businesses spring into life when a problem meets someone who can solve it.

Technology Valley Seaview-based Hot Lime Labs (HLL) invented itself when founder Dr Vlatko Materic serendipitously discovered that high tech greenhouses require boosted carbon dioxide (CO2) levels to elevate crop production.

Vlatko’s research at Callaghan Innovation in Gracefield, and before that Industrial Research Ltd, had perfected a limestone-based means for coal and other fossil-fueled power stations to remove the component of their waste stream by having modified calcium carbonate absorb it.

In 2017 Vlatko found a use for technology he had been working on for ten years at Industrial Research. Carbon capture technology, initially developed for large scale power plants, found a home on a chance visit to a greenhouse where he discovered a large unmet need for carbon dioxide.

This sees carbon dioxide (CO2) from wood waste (such as forestry slash) burnt in a low oxygen environment in a gasifier, captured and stored in modified limestone pellets, which can then be released into a high-tech greenhouse to help boost production by up to 20%.

Because such a use of CO2 completes a natural carbon cycle, this carbon dioxide is considered ‘green’ - since it is not newly created from the burning of fossil fuels.

Fast forward three years and HLL is gearing up its first, green, fully modular and self-contained CO2 production and storage system just north of Taupo. Ironically this proof of final production installation takes place at the same Mokai greenhouse where Vlatko originally discovered the great need for increased CO2 levels in controlled environments.

The company’s intent is to be a global supplier in high-tech greenhouse production systems. Further evidence of an organisation building locally but thinking globally is HLL’s vision to convert half the world’s greenhouses to renewable heat and CO2.

“The world has increasing concerns around creating both the heat and carbon dioxide from fossil fuels,” says Hot Lime Labs Chief Operating Officer Tijs Robinson.

“We see that what we have is a catalyst in changing that,” he says.

HLL expects to be able to provide CO2 for around half the cost of traditionally used fossil fuel based sources.

HLL Pilot system CEO founder Vlatko Materic 
Three year journey

The three year journey to take Vlatko’s initial process engineer thinking into an onsite deliverable product and service has been a labour of love, development, investment and applied engineering.

Since 2017, Vlakto and an increasingly large team of engineers and scientists have developed a process which essentially converted the making of grams of limestone nodules (almost literally by hand) into a manufacturing means to make tonnes of the fingernail sized balls at a time.

Smart chemistry enables the limestone pellets to absorb CO2 (like a sponge) from combustion gases which are not suitable for contact with plants and then with hardly any additional energy to release clean CO2 that can be safely used for greenhouse plants. There’s a nice, simple chemically balanced and repeatable reaction that takes place to achieve this.

The HLL engineering team also had to learn how to make a gasifier that best makes use of woody wastes. Traditionally a gasifier burns its substrate in the absence of air, and produces byproducts such methane and CO2.

Early on the privately-owned company decided it would create modular production units, fitted inside a standard shipping container.

“It took us three years to develop these units,” says Tijs. “We deliberately went down that path as we want to initially make a complete unit locally, and ship them around New Zealand.”

“The first commercial unit will produce enough CO2 for two hectares of a high-tech, hydroponic greenhouse.”

HLL has a strong affinity for the Hutt Valley, and is working with several local companies to create the units. These companies include Acme for much of the steel fabrication, and Dydo for the refractory insulation. At the same time the company continues to work alongside Callaghan Innovation as well as WREDA to access their expertise and investment capabilities.

Technology is market ready

Until recently the company’s breakthrough technology answer has developed on the quiet, but this is also about to change. The technology has been proven at Pilot scale, and with the first commercial size units due in market in 2021 HLL has started taking pre orders for systems. Both local and international growers have shown interest in the technology and preparations are underway to start serial production of the machines.

HLL will also continue to develop its base technology to enable use of a variety of feedstocks such as green and agricultural wastes as well as waste lubrication oil. There are many more uses for its CO2 capture capabilities and “lots of waste wood and lots of people willing to pay for it,” Tijs says.

“Watch this space.”


Caption: Hot Lime Labs CEO Dr Vlatko Materic with a sample of the CO2 absorbing lime pellets