Cleaning up transport fuels

Transportation vehicle efficiency standards using internal combustion engines are set to improve worldwide as auto manufacturers are poised to commercialise smaller and lighter engines exerting higher compression ratios. These innovative advancements will demand modifications to existing fuel specifications, in particular an increase in gasoline octane. Alkylate, also known as ‘liquid gold’, is a refiner’s preferred gasoline blend stock and thus set to represent a larger proportion of the future cleaner gasoline pool. McDermott’s Lummus Technology unit’s AlkyClean® & CDAlky® provide economical, safety and environmental step changes in alkylate production (Figure 1).

The possibilities of catalytic distillation

Lummus Technology offers state-of-the-art process intensification technologies under the CDTech® brand such as CDEthers, CDMTBE®, CDTAME®, CDETBE®, CDTAEE® which are used for the production of ethers and bioethers gasoline blend stock, allowing refiners to further increase the gasoline octane at minimum reid vapor pressure (RVP) costs while incorporating biorenewable fuels such as ethanol. This is made possible through catalytic distillation (CD), which combines chemical reactors and fractionation equipment, reducing investment and operating costs while achieving conversion well beyond the expected equilibrium level.

Particular gasoline blend stocks such as IsoOctene/IsoOctane produced via isobutylene dimerization is an alternative source of high octane and low RVP material. The Dimer8™ process provides a proven flexible and cost-effective solution for this specific blendstock.

Maximising yields

At the heart of gasoline production is the fluid catalytic cracking (FCC) unit. Lummus Technology’s FCC, Resid FCC and Indmax FCC processes employ proven and trusted catalyst and equipment such as. Micro-Jet Plus™ feed injectors, ModGrid® stripper internals, a patented reaction termination device and multi-stage orifice that 

can be tailored to maximise octane, gasoline and/or alkylate feedstock yields at reduced operating costs in a safe, environmental and reliable manner.

The combination of CDHydro® hydrogenation and CDHDS®/CDHDS+® hydrodesulphurisation processes, effectively reduces the sulphur level of full-range FCC naphtha below 10 parts per million by weight, by simultaneous tailored treating of the various FCC gasoline cuts in the CD column equipped with CDModules®. Hence, this approach efficiently retains most of the octane value without yield loss while minimising capital and operating costs.

Meeting IMO 2020 regulations

Currently, refiners are looking for commercially proven residue upgrading technologies to meet looming IMO 2020 marine fuel specification of <0.5wt% sulphur. Chevron Lummus Global’s ARDS, LC-FINING, LC-MAX and LC-SLURRY technologies along with ISOCRACKING offer the most reliable and well-proven technological solutions to produce clean fuels from residuals.

McDermott prides itself in offering single-source integrated solutions to refiners who are looking at upgrading high sulphur residue to clean fuels and petrochemicals while minimising energy and capital cost for the project.

By Maribeth Duggins, Director of Communications at McDermott