Improving Renewable Diesel Production: The Role of Sorbsil® Silicas in Feedstock Pretreatment

Vinit Sodhi and Arnold Wong
1 day ago
3 min read

The integration of Sorbsil® silicas into the feedstock-pretreatment process for renewable diesel production offers several key benefits.

Feedstock pretreatment is a critical step in renewable diesel production, designed to remove impurities from crude feedstocks such as fats, oils and greases prior to refining. This process typically involves two main stages: degumming, which eliminates bulk impurities, followed by bleaching, which reduces contaminants to trace levels that meet hydrotreater-catalyst specifications through adsorption and filtration.

In the bleaching step, adsorbents play an essential role by capturing and removing impurities such as metals, phosphorus and organic compounds. This significantly improves the quality of the feedstock, ensuring it meets the stringent requirements for downstream processing.

Without this crucial step, impurities could harm the hydrotreating catalysts or compromise the quality of the final renewable diesel product. The combined use of adsorbents and filter aids ensures thorough purification and effective filtration.

Silica-gel adsorbents stand out for their high surface area, excellent adsorption capacity, purity and consistency. Their superior performance boosts the efficiency and lifespan of the hydrotreating process, making them a preferred solution in renewable diesel production.

PQ Sorbsil® Silica: Consistency, High Purity, Reliable Quality

PQ offers Sorbsil® R40F and R92F for the renewable fuels markets. While both products have similar physical properties, R92F contains citric acid that increases the efficiency of metals removal. As Sorbsil® silicas are engineered materials, PQ carefully controls the physical properties to ensure consistent high-quality adsorbents for our customers.

For example, PQ precisely controls product particle-size distribution (PSD) during the milling process, ensuring excellent consistency that reduces batch-to-batch variation. In the depicted laser diffraction particle-size data, a narrower particle size distribution was observed in PQ’s Sorbosil® silica hydrogel than competitors’ activated bleaching earth (ABE). The reduced population of fine particles less than 1 micron (µm) allows for an increased filtration rate versus competitor products.

Filtration Performance

Permeability and filtration performance are improved by controlling the PSD in the milling process. In PQ’s laboratory filtration testing procedure, we directly compare the filtration rate of PQ Sorbsil® silica hydrogel versus ABE and demonstrated over 10 percent faster filtration rate at equivalent adsorbent dosages. With Sorbsil® silicas’ increased efficiency in contaminant removal, reducing the silica-gel dosage would further improve filtration rate. In addition to a faster filtration rate and lower adsorbent dosage, the plant benefits from longer filtration runs, reduced oil losses, decreased waste disposal and increased product throughput.

Removal of Impurities

PQ’s Sorbsil® silica hydrogel offers high surface area and pore volume, enhancing its efficiency in removing impurities. Silica has a distinct advantage over ABE by removing an averaged 85 percent of phosphorous at a 0.5 percent dosage compared to ABE’s 3 percent dosage level. PQ’s Sorbsil® R92F with citric acid outperforms ABE by removing 96 percent of trace metals at a 0.5 percent dosage and 99 percent at a 1 percent dosage by weight.

Cost Efficiency

Sorbsil® silica hydrogel delivers a cost-effective solution by improving plant efficiency through superior impurity removal and faster filtration rates. Their use helps reduce oil losses, minimize waste-disposal costs and boost the throughput of high-quality oil to your hydrotreater.

Safety

As an amorphous silica, our synthetic silica hydrogel offers a safer alternative to competitors’ bleaching earths. Amorphous silica is not known to have any adverse health effects and is not prone to autoignition, or smouldering, once spent.

Improved Feedstock Pretreatment Performance

The integration of Sorbsil® silicas into the feedstock-pretreatment process for renewable diesel production offers several key benefits:

Cost-effectiveness: Sorbsil® silica decreases operating expenses by increased operational throughput, lower oil losses, and higher efficiency in impurities removal, which protects and extends the life of the catalyst for superior renewable diesel production.

Impurities removal: Sorbsil® silica effectively removes impurities, such as phosphorus and metals, at lower dosages than bleaching earth, enhancing feedstock quality and downstream processing.

Filtration: Increased filtration and operational throughput are possible thanks to Sorbsil® silicas’ tightly controlled PSD.

Overall, the use of Sorbsil® silicas in renewable diesel production maximizes efficiency and reduces costs, highlighting their strategic value in the process.

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