Neste Oil produces NExBTL diesel (and its other renewable fuel cousins such as jet fuel) by using a proprietary process to hydrogenate vegetable oil or animal fat feedstocks. The result is a tailored drop-in fuel; with several major NExBTL refineries worldwide, Neste is currently the leading producer of renewable diesel.

However, unlike a biomass-to-liquids technology pathway (e.g., gasification of the biomass and conversion of the resulting syngas to fuel), the NExBTL process out-of-the-box had no option to utilize cellulosic biomass as a feedstock. Since the sustainability of the oils it sources for NExBTL is a concern, Neste began pursuing the production of microbial oils—essentially, extracting sugars from biomass to feed microbes to produce oil, and thereby gain the sustainability advantage of the waste feedstock.

Our microbial oil pilot plant at Porvoo has demonstrated that we have the technical capability for producing microbial oil. Seen in terms of sustainability, using waste and sidestreams generated by agriculture and forestry as well as industry has a very important role to play in the future, and we have successfully used straw, for example, to produce microbial oil. Two years of in-depth microbial oil research at the pilot plant has generated a lot of valuable know-how and extended our patent portfolio, and we will be able to use the results of this work in other research projects.

The time is not yet ripe for a commercial-scale microbial oil plant, however. Lignocellulose material is not a financially competitive industrial feedstock for producing renewable diesel using the microbial oil process at the moment. We will continue researching agricultural and forestry waste and residues, and believe that lignocellulose inputs will play an important role in future renewable applications

—Lars Peter Lindfors, Neste Oil’s Senior Vice President, Technology

Background. Neste Oil’s microbial oil technology is designed to produce feedstock for Neste’s renewable fuel process by using yeast and fungi efficiently to convert sugars from waste and residues into oil. The microbes, which can produce up to 80% of their cell weight as oil, are grown at high densities in bioreactors similar to those used in the biotech and brewing industries. The cells are then harvested and the oil recovered for use in the NExBTL process. However, in 2012, Neste Oil said that commercial-scale production was expected by 2015 at the earliest.

In its 2013 financial report for 2013, issued 4 February 2014, Neste noted that its main achievement in its Renewable Feedstock program during 2013 had been the the expansion of its renewable feedstock portfolio with the addition of technical corn oil (TCO); spent bleaching earth oil (SBEO); and tall oil pitch (TOP).

The company noted that it was continuing extensive R&D work to develop new, long-term renewable inputs for NExBTL production. The short-term focus for 2013—which is also one of the main focus areas for this year— was on gaining customer and market acceptance for different types of feedstock.

Neste Oil focused on expanding the use of waste- and residue-based feedstock, particularly waste animal fat; palm fatty acid distillate (PFAD); and technical corn oil (TCO), in 2013. (Technical corn oil is the oil derived from the corn residue in a corn ethanol process; 1 ton of corn contains approx. 14 kg technical corn oil. Neste sources TCO from the US.) The usage of waste and residue-based inputs increased by 476,000 tons to 1,219,000 tons and accounted for approximately 52% (35%) of total renewable feedstock usage in 2013.

Technical corn oil was used in production for the first time during 2013. Non-residue vegetable oils, principally palm oil, accounted for approximately 48% of the inputs used in renewable diesel production in 2013.

Later in February 2014, Neste Oil announced a partnership with DONG Energy, one of the leading energy groups in Northern Europe, to develop an integrated process to produce renewable diesel and aviation fuel derived from agricultural residues. DONG Energy’s Inbicon technology was to be used in the first part of the process to pre-treat biomass and produce cellulosic sugars that could then be converted into microbial oil with Neste Oil’s technology.

Neste Oil and Dong Energy had already passed the laboratory and pilot phase at the time of the announcement; the technologies were to be optimized and verified on a larger scale. (Earlier post.)

Neste Oil Corporation is a refining and marketing company concentrating on low-emission, high-quality traffic fuels and is the world’s leading supplier of renewable diesel (NExBTL). Forest Footprint Disclosure (FFD) has ranked Neste Oil as one of the best performers in the oil & gas sector.