Hydrotreated vegetable oil, or HVO, is a paraffinic fuel derived from organic lipids. It is a hydrogenation, with the use of catalysts, where the fatty acid chains are completely saturated, obtaining paraffinic fuel and bio-propane.
There are two production ways for it:
- Co-process. Taking advantage of the desulfurization units of the oil refineries, at the same time that the diesel is being treated to eliminate the sulphur, a quantity of refined oil is added, which is transformed into paraffinic fuel HVO, and bio-propane. The HVO is mixed with the diesel and the propane is separated.
- Direct process. Pure HVO and bio-propane are produced just like the previous case. Pure HVO can then go through the isomerization and cracking process where its conditions improve, this technology is the basis for the future development of sustainable aviation fuels (SAF)
Traditionally, both processes have worked with vegetable refined. With a RBD refined is enough to obtain a quality product preserving installations and heterogeneous catalysts.
Biofuels based on vegetable oils are in extinction, with the incorporation of advanced raw materials being the reality and the growing trend today.
Advanced raw materials are generally waste materials. The residual materials have much higher refining needs than a first-use vegetable oil. The most abundant materials of this type today are recovered frying oils (UCO), cat1 & cat2 animal fats, tall oil, high acidity products, etc.
These raw materials cannot in any way be used directly in the manufacture of HVO. Since they would be a serious risk to the installation, in addition to poisoning the heterogeneous catalyst used, shortening the life of this expensive supply.
The elements and their repercussions are detailed below:
- Phosphorus: Oil must enter in the process at a value less than 5 ppm. Higher values affect the duration of the catalyst, and the quality of the final fuel. In more, the presence of phospholipids can generate emulsions that hinder the separation processes.
- Metals: The total value of metals must be very low, less than 20 ppm. Metals cause scale in equipment, as well as being the main catalyst poison.
- Oleic acidity: Oleic acidity is not a problem itself in the production process, but values above 20% oleic FFA can cause corrosion problems in the medium term.
CMBItaly, with a presence in the oil refining market since 1950 and hundreds of facilities worldwide, has the technology capable of refining residual oils to HVO quality. In the refining process it can help them incorporate glycerine as an advanced raw material.
But it is also the only process capable of removing chlorine from the raw material.
Chlorine is negatively charged, and activated bleaching earths treatments are not efficient, since they work well only in reactions that require cation exchange.
The presence of chlorine in the raw material has three undesirable effects:
- Corrosion: The hydrotreating reaction can generate hydrochloric acid, which attacks facilities.
- Catalyst poisoning: Free chlorine attacks the catalyst, poisoning it and reducing its useful life.
- Formation of organochlorine compounds: The hydrogenation process in the presence of chlorine can generate organochlorine compounds that can end up in the final product, compromising its specification.
Chlorine can be removed easily using the proprietary CMBItaly process. Do not hesitate to contact us for more information.
Raül Sanchis i Gonzàlez
Tata Genaro S.L.