Question
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What are some of the optimal strategies for processing (or co-processing) second- and third-generation renewable feedstocks?
Mar-2023
Answers
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Peter Andreas Nymann, Topsoe, PAN@topsoe.com
Like first-generation renewable feedstocks, second- and third-generation feedstocks also contain oxygen, leading to high H2 consumption and temperature rises. Many of the same strategies therefore apply to these as well. Second and third may have different contaminant profiles that need to be dealt with by specialised grading material. Content of particulates from upstream processing and high acidity (like for the first generation) also needs to be managed in storage and equipment. Second- and third-generation renewable feedstocks that are triglyceride based may be treated in HydroFlex units by applying the same strategies as for first-generation feedstocks.
However, in contrast to the first-generation renewable feedstocks, the second- and third-generation often come from solid-to-liquid conversion processes and, therefore, contain different hydrocarbons, not mainly triglycerides. These molecules include ring structures that need saturation and often ring opening. The requirement for hydrocracking catalysts will, therefore, be more pronounced when processing second- and third-generation feedstocks, and co-processing in hydrocrackers of these feeds will be more feasible than processing in medium-pressure hydrotreaters. Several projects and plants processing crude tall oil, pyrolysis oils from plastics or tyres or other second- and third-generation renewables are currently in operation or the late stages of implementation using Topsoe technologies.
Mar-2023
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