One of Neste Oil’s short-term goals is to add lower-quality inputs to the existing types of feedstock used for producing NEXBTL renewable diesel. Looking slightly further ahead, microbial oil, wood, and algae oil are on the agenda.
Neste Oil’s Biotechnology Department includes a number of staff not normally found on the payroll of an oil company, such as microbiologists, biologists, and experts on wood chemistry.
Neste Oil needs the expertise these people represent to help it search out new raw materials to add to the feedstock base that it uses for producing NEXBTL renewable diesel.
“Our development work over the short term is concentrating on how we can make even greater use of waste and residues,” explains Petri Lehmus, Neste Oil’s Vice President, Research and Technology. “Over the longer term, we’re interested in completely new types of raw materials.”
The NEXBTL process is capable of handling a very wide range of raw materials without compromising on the quality of the end-product.
“That’s because although our raw materials vary, they share much of the same chemistry,” says Petri.
Despite its flexibility, the process cannot handle everything though. If inputs contain excessively high levels of impurities or contaminants, the catalysts used in the process lose their effectiveness.
“Our job is to find out where the acceptable limits are. When we know this, we can use lower-quality materials and extend our feedstock base to include more waste fat, which is widely available and attractively priced.”
The better Neste Oil can deal with impurities in its feedstock, the easier it is to use inputs such as used cooking oil, for example.
A number of completely new potential feedstocks are also being studied, including microbial oil, wood, and algae oil. Neste Oil opened Europe’s first microbial oil pilot plant at its Porvoo refinery in 2012.
Microbial oil is produced when straw and grasses are processed to produce lignocellulose-based sugars, which are then fed to microbes, which convert them into fat or microbial oil. Neste Oil is developing this technology in collaboration with DONG Energy.
Wood also represents an interest raw material, according to Petri Lehmus.
“We’re involved in a project that’s investigating how catalytic pyrolysis can be used to produce traffic fuel from wood. The challenge here is to achieve sufficiently high-quality product properties. We did a lot of work on wood gasification technology earlier, but the total costs involved proved too high.”
Algae oil is also another avenue that is being actively investigated. This can be produced by growing algae in seawater in photobioreactors or in open basins.
“We’re focusing on how algae oil can best be refined. We’ve signed agreements with algae oil producers and when they’re able to produce this oil in commercial quantities we’ll be ready to use it.”
So when does Petri Lehmus think renewable diesel produced from algae oil will be on the market?
“My most optimistic estimate at the moment is 2016.”