DuPont welcomes alkylation technology

Historically, the expense of converting from HF to sulfuric acid alkylation was estimated by the industry at 80% of the cost of a grassroots sulfuric acid alkylation unit of a similar size. This perceived high conversion cost and the lack of other economic benefits deterred refiners from committing to this change. By reusing existing equipment, conversion cost with DuPont ConvEx technology is estimated to be significantly lower. At approximately 40 – 60% of the cost of a grassroots sulfuric acid alkylation unit, this new technology represents a step-change reduction in cost. In situations where plot space is available near the existing facility, downtime can be reduced by installing new equipment during normal operations. With new equipment installation already complete, the remainder of the conversion work can be finalised within a typical 30 – 45 day turnaround window.

The suite of DuPont’s HF conversion technologies was developed to adapt to the strategic objectives of refiners currently operating HF alkylation units. One of the options that was developed utilises conventional STRATCO® ContactorTM reactors in order to achieve optimum product quality. A second option incorporates a novel reactor design, allowing for significant cost savings with only a minor performance debit. By taking the current HF alkylation unit technology and configuration into consideration, DuPont’s solutions can be tailored to meet specific business needs of a refinery.

Fundamental to the expansion of the technology is the difference in how isobutane is recycled between the HF and sulfuric acid alkylation technologies. HF alkylation units provide isobutane to the reaction zone by recycling it from the fractionation section, while sulfuric acid alkylation units provide half of the required isobutane from fractionation and half from the refrigeration section (see illustration). This difference is significant, as conversion from HF to sulfuric acid alkylation means isobutane required from fractionation is cut in half, freeing up fractionation space and, therefore, effectively doubling the capacity of the alkylation unit without requiring any significant changes to the fractionation equipment.

Read the article online at: https://www.hydrocarbonengineering.com/refining/15092017/dupont-welcomes-alkylation-technology/