Energy-intensive industries such as downstream hydrocarbons are pushing forward with decarbonization projects as part of their sustainability goals. Hydrocarbon Processing spoke with Emerson’s Julie Valentine to discuss this topic in a “The Main Column” podcast, Digital technologies: A path to increased production and decarbonization.
After some introductions, Julie was asked about biofuels and what constitutes a biofuel. She explained that the source of their production was living matter—plant, algae, animal waste, forest residues, etc. The first generation of biofuels included ethanol and biodiesel. An issue with these biofuels was that they needed to be blended with petroleum-based fuels to be used as energy sources.
Julie noted that the next generation of biofuels included renewable or green diesel, and sustainable aviation fuel. These fuels don’t require blending with hydrocarbons in internal combustion processes.
Next, she was asked about some of the process challenges with renewal biofuel production processes. Renewable diesel plants have three primary sections—feed pretreatment, reactor, and logistics to store and transfer the feedstocks and products. Across all these sections, the feedstock’s variability and physical properties can pose a challenge. Feedstocks such as distillers’ corn oil and chicken or beef fat have very different properties and are challenging to measure flow rates and levels in the tanks and vessels.
The technologies in the measurement devices need to be considered to ensure that they can withstand these physical property changes and the variability and still give reliable measurements.
Julie highlighted another challenge for effective process control is the reactions for biodiesel that are very highly exothermic. More exothermic than most reactions in a typical refinery. The control systems need to be designed to ensure that temperatures stay within operational limits. By closely monitoring feed recycle and purge rates that need to adapt to the varying feedstocks, software that incorporates AI-based solutions offers a significant advantage in process control optimization.
Record keeping is another challenge for renewable diesel plants versus traditional refining operations. In addition to feedstocks and products accounting, plant personnel have to quantify the amount of hydrogen consumption, the fuel gas consumption used in fired heaters, and other energy-consuming processes. Usage for correct allocations is also required and particularly challenging for the renewable diesel units located within a traditional refinery. Accurate measurement systems and a data repository to track, analyze and report that data in a verifiable manner are critical.
Listen to the podcast as Julie describes other challenges such as corrosion and catalyst deactivation, recycle gas byproduct buildup, and the digital technologies, such as Plantweb Optics, that can help address these challenges. Visit the Downstream Hydrocarbons section on Emerson.com for more on the technologies and solutions to drive performance improvements for traditional and renewable refining operations.