STRATCO® Alkylation Technology Innovation for Different Feed Types
The STRATCO® alkylation technology has commercial experience processing a wide range of alkylation feedstocks including FCC olefins, MTBE olefins, and large quantities of propylene, isobutylene, and amylene. This commercial experience makes the STRATCO® alkylation technology the most flexible alkylation technology on the market. The STRATCO® alkylation technology allows refiners the flexibility to process different feedstocks as market conditions dictate throughout the life of the unit with little to no capital or process changes. Details on Elessent’s vast commercial alkylation experience are provided below.
Elessent has dozens of operating units worldwide processing an olefin feedstock from an FCC unit. A FCC mixed butylene feedstock is the most common feedstock to an alkylation unit. These feeds produce an alkylate product with a 96-97 RON depending on the amount of isobutylene present.
The STRATCO® alkylation technology is flexible and able to handle changes in feedstock composition or rate resulting from a change in operation of the upstream FCC unit. The STRATCO® alkylation technology is still able to produce the highest quality alkylate in the event of a new catalyst or increased throughput in the FCC unit. Refiners in the U.S. and throughout the world operate Elessent Clean Technologies’ STRATCO® alkylation units processing FCC types feeds with varying levels of C3 and C5 olefins. This flexibility allows Elessent customers the ability to adapt with the marketplace efficiently and cost effectively.
The Elessent STRATCO® alkylation technology has successfully started up 11 grassroots alkylation units processing FCC olefin feeds since 2009. Details of these units can be seen below. An additional eight licenses for future alkylation units processing FCC olefins have been awarded during the same time frame.
The STRATCO® alkylation technology is the preferred sulfuric acid alkylation technology of refiners worldwide for MTBE raffinate olefin feedstocks. Customers prefer the established flexibility and reliability of the STRATCO® alkylation technology as evidenced by the recent five grassroots alkylation licenses with Sinopec awarded to Elessent Clean Technologies.
The MTBE raffinate stream is an ideal sulfuric acid alkylation feedstock as it contains a low percentage of isobutylene and produces a high quality alkylate product. Active STRATCO® alkylation units processing an MTBE raffinate feedstock typically see product octane in excess of 98 RON. With few contaminant concerns, MTBE raffinate streams are a logical alkylation target using the STRATCO® alkylation technology.
Recent market trends have dramatically improved the economic outlook of alkylating propylene whether from an FCC unit, petrochemical feedstock or from dehydrogenating low value propane. The Elessent STRATCO® alkylation technology has a long history or processing propylene in conjunction with butylenes and has now developed a unique solution for a stand-alone propylene alkylation unit. This is an especially attractive option as the spread between gasoline and propylene prices increases and petrochemical markets fluctuate.
Elessent has also developed a solution to reduce acid consumption from a propylene unit by 15-20% or increase product quality by utilizing a novel reaction zone configuration.
With increased hydraulic fracturing in the United States, there is an oversupply of butanes and propane. These butanes in particular can be converted in a dehydrogenation unit to isobutylene and alkylated in a STRATCO® alkylation unit.
Elessent Clean Technologies has been awarded the two first ever licenses for the alkylation of a 100% isobutylene feedstock from a dehydrogenation unit. Elessent completed a commercial test run at an existing alkylation unit where the designed unit feedstock was substituted with a 100% isobutylene feedstock. During the test run, the predicted product quality of RON 95+ was achieved.
Recently, many refiners have considered the alkylation of amylenes as an option for reducing gasoline pool RVP and olefin content. The positive impact to the gasoline pool RVP by alkylating amylenes becomes especially valuable as the cost of the feedstocks (amylenes and isobutane) continues to decline.
Elessent Clean Technologies has been awarded the first ever license for a 100% amylene alkylation unit. Many operating STRATCO® alkylation units process a percentage of amylene olefins from the FCC, but this unit will be the first alkylation unit to process only amylenes. The design for this unit was optimized to utilize spent sulfuric acid from an adjacent alkylation unit that processes butylene olefins.
As global demand for alkylate increases, Elessent Clean Technologies has continued to invest in research and development allowing refiners to process unique opportunity olefins using the STRATCO® alkylation technology. Recent work by the Elessent team has yielded successes in the alkylation of C6 olefins and ethylene dimerization feedstocks. Ethylene dimerization units yield an ideal alkylation feedstock of primarily n-butene. In recent work with this feedstock Elessent has been able to produce alkylate with an octane exceeding 99 RON.