Turning waste sawdust into activated carbon

Taupo-based Activated Carbon NZ is the ultimate example of an environmental and business win:win – using waste sawdust from sawmills and turning it into activated carbon. 

Activated carbon is a product that is used in a wide range of applications, including removing toxic gases in industrial waste and effluent, to purify water, and in the supplement, cosmetic, and food and beverage sectors. Activated carbon is even used in candle manufacturing.

In addition, activated carbon conducts electricity and insulates heat. There are even experiments underway to look into its use as a binder with hemp.

Activated Carbon NZ Ltd is the only New Zealand manufacturer of activated carbon. Being able to supply the product domestically is proving to be extremely important as supply chains for activated carbon from overseas continue to be severely disrupted due to COVID-19.

In the past, New Zealand businesses have typically sourced their activated carbon from China or Australia, but often from much less environmentally friendly source material such as coal or coconut shells.

“We know that businesses are looking for high-quality activated carbon that is more sustainable and we’re able to provide that for them with no supply issues,” says Activated Carbon NZ Director Grant Hughes. “We’re able to provide activated carbon as a fine powder, granulated, or in capsule form wholesale for industrial customers or for everyday consumers via our online shop.”

Having worked in the farming sector for most of his life, Grant then moved into providing short-term financing solutions, which is how he came across the Activated Carbon business. He immediately saw its potential and worked to put the factory together that would form the heart of their business.  

“We imported a piece of kit from China that theoretically worked but didn’t in reality. I spent the next couple of years with a grinder and welder and with the help of some really talented locals we developed the plant we needed to create the high quality activated carbon.”

Activated carbon cleanses through adsorption or ionic exchange. It is made by eliminating the organic volatiles from carbon-rich organic materials, leaving just the carbon pore structure and increasing the surface area. This means that one teaspoon of activated carbon has more surface area than a football field. The pores and microstructure are able to attract toxins and chemicals, which is why activated carbon works so well as a purifier. In general, the greater the surface area of the activated carbon the higher the quality. Commercially produced activated carbon typically falls within a range of 300m² to 900m² per gram.

“A lot of the activated carbon coming from China is at the low end of this range however we are able to average 900-1200m² per gram of activated carbon, sometimes as high as 1500m².

“We are passionate about combating environmental pollution,” says Grant. “Creating a business that we believe is carbon positive is very important to us. We even supply the wood vinegar that is the byproduct of our manufacturing process for use in organic farming.

“COVID has given us the opportunity to highlight our sustainable New Zealand-made activated carbon to businesses that might not otherwise have considered whether or not there are better options for them right on their doorstep.

“We have a huge carbon resource here in New Zealand. We don’t need to dig up our national parks or mine our seabed to get to this resource, it’s all around us. We still have poor utilisation in our plantation forests and there is still a lot of waste. Pine trees continue to be planted but by-products of timber production, such as sawdust, are currently being thrown away or getting chucked into a hole to rot. Meanwhile, there is a domestic and global market for activated carbon that is undergoing significant growth, and we have the ability to make and supply a really good product for that market.

“Rather than choosing activated carbon that’s produced from unsustainable sources that’s been dumped in the New Zealand market for less than it costs to ship it here, we need businesses in New Zealand to make a choice that’s better for our environment and is a higher quality product that will achieve better results for them.”

For a summary of the product go to: https://bit.ly/3iRcWYI