PHILLIPS READY TO LICENSE PROCESS FOR PRODUCTION OF FUEL ETHERS

Phillips Petroleum Co. is poised to license its high conversion process to produce fuel ethers for blending in reformulated gasolines. The technology has been proven in a Phillips semiworks at Bartlesville, Okla. "The low investment, low utility process gives refiners an economical way to produce whatever ether product best utilizes their C4 and C5 feedstocks to meet market demands and comply with environmental regulations," said Gary Patton of Phillips' licensing division.

April 19, 1993

3 min read

Phillips Petroleum Co. is poised to license its high conversion process to produce fuel ethers for blending in reformulated gasolines.

The technology has been proven in a Phillips semiworks at Bartlesville, Okla.

"The low investment, low utility process gives refiners an economical way to produce whatever ether product best utilizes their C4 and C5 feedstocks to meet market demands and comply with environmental regulations," said Gary Patton of Phillips' licensing division.

The process can produce methyl tertiary butyl ether, ethyl tertiary butyl ether, tertiary amyl methyl ether, or tertiary amyl ethyl ether with typical refinery process equipment and techniques. Phillips said it can achieve conversion levels of 92-99%, depending on the ether.

The ether produced is determined by which hydrocarbon fraction is used for feedstock and which alcohol is chosen for reaction.

In refineries producing MTBE, for example, the process makes possible an easy switch to TAME with its lower Reid vapor pressure, thus helping refiners meet tightening government Rvp limits.

"If the U.S. continues tax subsidies for ethanol in gasoline blends, refineries equipped with the Phillips process could easily produce ETBE or TAEE, which use ethanol and quality for the subsidy," Patton said.

"The Phillips TAME process improves reactive isoamylene conversion rates by as much as 22% over conventional fixed bed units, reduces the need for alcohol recovery operations by promoting more complete reaction of olefins and alcohol, and reduces catalyst damaging by-products by more efficient conversion and cooler reaction temperatures than with competitive processes."

In addition, the process uses standard refinery unit operations.

The process, based on commercial scale operations in Phillips plants, has been producing MTBE since the 1970s. It can convert more than 92% of reactive isoamylenes into TAME and more than 99% of isobutene to MTBE, for example. Conventional processes convert only 70% of reactive isoamylenes to TAME and only about 96% of isobutene to MTBE, Phillips said.

The process also can be combined with the Phillips STAR (STeam Active Reforming) process for light paraffin dehydrogenation to produce MTBE from isobutane.

The process uses conventional distillation and liquid phase, down flow, fixed bed reactors, thus avoiding specialized equipment required by catalytic distillation and other technologies.

By controlling alcohol/olefin ratios and operating conditions, the Phillips etherification process minimizes formation of by-products such as tertiary amyl alcohol, tertiary butyl alcohol, dimethyl ether, and diethyl ether, thus reducing or eliminating the need for oxygenate removal systems and increasing catalyst life compared with other etherification processes.

RAFFINATE STREAM

While other processes can leave as much as 0.5% of MTBE in the raffinate, the Phillips process more completely separates ether products, the company said. This can result in a nearly oxygenate free raffinate stream suitable as alkylation unit feedstock without further processing.

For example, the HF alkylation unit at Phillips' 175,000 b/cd Sweeny, Tex., refinery takes feed directly from a Phillips MTBE unit without additional oxygenate removal equipment. The operating experience on this unit has been satisfactory as far as ASO production and acid consumption are concerned.

Phillips said its unit design allows easy catalyst changeout without shutdown. Refiners can continue to produce ether while changing out a portion of the ion exchange catalyst during a 1-3 day procedure.

Phillips is working with Xytrel-Bechtel Inc. (XBi) to provide the etherification technology to the refining industry using modular construction techniques.