Future Feedstock Flexibility with Pretreatment

BDI BioEnergy’s Manfred Baumgartner discusses how companies can better prepare for the evolving feedstock landscape.

BY ANNA SIMET

With current and future demand for renewable diesel and SAF soaring, so is the number of companies, refineries and other parties interested in partaking in the industry. While some have more experience than others, a crucial factor that all should consider is what might lie ahead in terms of feedstock sourcing, according to Manfred Baumgartner, CEO at BDI BioEnergy International GmbH. “Many want to jump on this train and build a renewable diesel or coprocessing factory, but not everybody has done their homework,” he says. “Some have checked out which feedstocks they can get, others just assume they will be able to get what they want—but it’s limited. All projects that are designed on a basis of relatively good feedstock qualities, I think they will have more problems in the future, as goodquality feedstocks will turn higher in price.”

That’s because good-quality feedstocks require less treatment, smaller investments and lower operating costs. These price increases could force some producers to look at lowerquality feedstocks. “And then, the plant may not be built for this,” Baumgartner says. “We have this discussion with our customers, and some will say they want to be flexible in the future—they want to be able to use everything—and others say they want to start with one thing and focus on that, and see how it turns out.”

Having the ability to adapt to utilize lower-quality feedstocks will be a key parameter in the success of many operations, from BDI’s perspective. The company's proven solution to allow operators to do so is the BDI Advanced PreTreatment Process, which is designed to purify vegetable and waste oils and fats for renewable diesel and SAF production, allowing operators to test and utilize a very wide range of varying-quality feedstocks.

Quality Matters

While used cooking oil (UCO) is one of the most sought-after feedstocks, Baumgartner points out that its quality can differ vastly depending on its origin and collection method. In China, for example, UCO quality is typically good to average. “There is a large quantity coming from China—some is on the worse side, but on average, the quality is not too bad. Throughout Asia, UCO is sometimes collected by traps in big buildings and skyscrapers, so it can be quite contaminated from impurities in the waste that also goes down these traps.”

UCO in the U.S. is often collected with a lot of solids, mainly vegetable oils from cooking, as collection systems there are also different, Baumgartner says. When it comes to animal fats, the time between creation of the waste and rendering greatly impacts the quality of the feedstock, and the work flow of collection in Europe is quite different than in the U.S. “In the U.S., the animal fat rendering is done in large slaughterhouses with their own rendering facilities in the same building, so there is no time until the rendering takes place and the fat is processed,” Baumgartner explains. “In Europe, in most cases, the slaughterhouses are small and the rendering companies are located elsewhere. There is transportation and logistics in between and it can take a few days. Due to this time, the fat is degrading and the quality is worse.”

The most obvious indication of this is high free fatty acids. “This isn’t necessarily a bad quality, but it’s an indication that the fat has been stored for a longer time,” Baumgartner says. “As a side effect of this aging process, there are also other chemical reactions going on—mainly with amino acids—and then we see an increase in phosphorous, metals, sulfur and nitrogen components … all these parameters are important for the refineries, and the effect of aging raw material is a worse-quality feedstock. That’s why the origin is always important for the trader or the companies who are trading it.”

BDI stands behind pretreatment before beginning feedstock processing. “We know of examples where the plants cannot run at full capacity because the impurities in the waste oils are so high that they must perform frequent cleaning actions,” Baumgartner says. “Many production hours are lost due to downtime for cleaning actions.”

In addition to the proven PrePurification system, BDI installs all plants with a built-in cleaning in place (CIP) concept. “This means the heat exchanger isn’t dismantled for cleaning—there is a washing circuit, and we see this is an essential unit for having high availability at the end,” Baumgartner says.

He reiterates the importance of producers looking at all types of feedstocks with varying quality. “We ask our customers, what about the future? What will you get, and how will you keep availability high? Again, this is a topic of initial investment versus operability.”

Looking to the Future

As plant sizes increase, refineries require larger amounts of feedstock and a much higher number of suppliers. Baumgartner suggests that in some instances, processing in campaigns—i.e., pure UCO and pure animal fat—may help optimize the plant. “We could reduce operating costs like adsorbent amounts or energy,” he says. “It’s not always the case, but a lot of times it’s possible that the whole plant could be operated in more optimum conditions, with better results at the end.”

The ultimate goal, of course, is to achieve the best results possible. “This is where we have a great deal of experience—how to train our customers how to run the plant with good operating costs,” Baumgartner adds. “We call this analytical management of the production. It includes laboratory tests, analytics of feedstocks and of steering production, planning ratios of the feedstocks and of the products …there are lots of metrics to consider. This is the real knowhow, and we will hand it over to each customer so they don’t need to try to learn it by themselves—they can start optimizing from day one.”