Mobil Oil Corp. scientists unveiled a new chemical process Thursday that they said could make the conversion of coal to gasoline commerically feasible by the mid-1980s.

Described as a "scientific break-through" by Mobil, the new process utilizes a Mobil-developed catalyst that readily converts methanol - which can be produced by gasifying coal - into high octane gasoline. Under current conditions, however, gasoline produced by this process would cost more than $1 per gallon, Mobil says.

"We'll be able to provide people with gasoline made from coal in the years ahead, long after crude oil becomes too scarce or too expensive," said Dr. John Wise, a Mobil vice president who directs research and development.

Government and industry scientists have been working for decades to develop technology that would convert coal to oil on a commercial scale.

President Carter and Energy Secretary James R. Schlesinger have assigned coal gasification a high priority in the Department of Energy's more than $3 billion a year energy research and development program.

The United States now imports nearly half the oil it consumes, but has enormous domestic coal reserves. Perfecting coal gasification technology, similar to processes used by the Germans during World War II, would provide this county with an alternative to costly oil imports.

Energy Department officials said that the Mobil process could be used to convert methanol, or wood alcohol, which can be produced from natural gas or coal gasification processes, into gasoline.

"It's breakthrough, but not from an economic standpoint," said the department's Harvey Weisenfield, who heads the Division of Coal Conversion. He said that while the economic feasibility of Mobil's process still has to be demonstrated, "We do think it was a worthwhile effort."

The project, which Mobil spokesman Ken Peterson said the company spent "many millions on," was funded in part with a $675,000 research grant from the Energy Research and Development Administration. ERDA was folded into the Energy Deparment when it was created last year.

Peterson said that Mobil has patented the process and that the company will make it available commercially to its competitors. The company, in the meantime, has plans under way to construct a larger demonstration plant utilizing the new catalyst.

Often, private companies doing government-funded energy research and developments are barred from securing patents on their discoveries, but ERDA's grant was given under conditions allowing Mobil to secure a patent on the process.

Wise said, "This is the only process that can convert methanol to gasoline, and we think it will be better and cheaper than any other coal liquefaction process we've hard of."

Methanol can be used as a fuel without further refining, but it corrodes engines and, depending on its use, can be highly toxic.

Peterson said that Mobil's researchers made the unexpected discovery while trying to develop new catalysts to convert crude oil into gasoline.