Pilot Plant Experts

In response to environmental pressures, most countries in the world continue to decrease the allowed sulfur levels in diesel used for transportation applications.  Currently (2010) all highway diesel fuel refined in or imported into the United States must have a sulfur content of 15 parts per million (ppm) or lower.  Some countries in Europe are actively promoting the use of 10 ppm or even 5 ppm standards.

While earlier sulfur level reductions (5,000 ppm to 500 ppm to 50 ppm) were relatively easy to achieve, the10 ppm and 5 ppm targets are exponentially more challenging, especially when dealing with lower quality feedstocks and refractory sulfur compounds.  Hydrotreating, the most commonly used process, becomes increasingly expensive as ppm levels go down because deep desulfurization requires higher reactor pressures, greater hydrogen demand and reduced space velocities. 

As an alternative to deep hydrodesulfurization, our customer in Taiwan has developed a novel non-aqueous oxidative sulfur removal technology that includes 1) in situ production of peracetic acid, 2) oxidation of sulfur and nitrogen compounds, and 3) removal of sulfones and nitrogen oxides using liquid-liquid extraction. 

Unitel engineered, designed, constructed and supplied a pilot plant to demonstrate the cost-effectiveness of the customer’s technology.  The unit was sized to desulfurize one barrel per day of diesel or vacuum gas oil (VGO) and sulfur levels below 5 ppm were consistently achieved.  The preliminary economic analysis was equally promising – capital costs at $1,000 per barrel of daily installed capacity – less than half the cost of a new high-pressure hydrotreater. 

Engagement:  C, B, D, O.  Status – completed.