The brownish industrial carpet that a congressional critic once indignantly described as "velvet" is showing a few scuffs and wrinkles where the desks have been taken away, and the walls are bare except for a banner that reads, "It's all over, baby."

By the end of the day the banner will be gone as well, and the Synthetic Fuels Corp. will disappear into the chronicles of federal experiments that fizzled.

After not quite six years, the quasi-governmental agency that was to lead the nation to the promised land of energy independence is closing its doors today, a victim of overwhelming indifference in a nation awash in oil and short on federal funds.

Congress, which launched the agency in an era of oil embargoes and gasoline lines, voted last December to rescind the corporation's remaining $7 billion in budget authority and extract the government from the business of subsidizing synthetic fuels.

By that time nearly 40 percent of the staff had already read the handwriting on the wall and headed for other jobs.

"I had predicted a year and a half ago that we'd be out of business by this spring," said Richard Miller, once the agency's budget chief and now head of what he calls "the sweep-out force."

"I don't know if our death is timely or untimely," he said, "but it was predictable in this town. The agency never had a voting constituency . . . .If you were a congressman, you could speak out against the Synthetic Fuels Corp. and know it's not going to cost you a vote."

The remark underscores the precarious nature of an agency that was conceived in response to one crisis and put to death in response to another.

Despite the fanfare that accompanied Synfuels' creation in 1980, the agency quickly became a target for scorn when the price of oil plummeted, gas station lines faded into memory and fiscal austerity became the new political imperative.

The corporation was plagued with management problems, including inability to muster a quorum for a full year while President Reagan refused to appoint a new director until Congress cut the budget. There were accusations of impropriety against top executives, including two successive presidents who resigned under fire in 1983 and 1984; grumblings about its "posh" quarters on K Street and salaries that ranged up to $135,000 for its president, and persistent complaints about the organization's quasi-private nature, which made its employes exempt from civil service salary and benefit rules.

Miller insists that much of the criticism over salaries and employe perks was overwrought or untrue. "It's one of those Washington myths that develops and hangs on," he said.

But the criticism may have served to divert attention from a far bigger problem at the organization, which almost from the beginning suffered from an excess of expectations.

With an initial budget of $20 billion for loan and price guarantees and a promise of $68 billion more, Synfuels was supposed to be the catalyst for a process that would provide the nation with the equivalent of 500,000 barrels of oil a day by 1987.

The agency has granted subsidies to just four projects: the Cool Water coal gasification project in California, a Dow Chemical syngas project in Louisiana, the Forest Hill "heavy oil" project in Texas, and Union Oil Co.'s oil shale project in Parachute Creek, Colo. Only the first of these is in commercial production, contributing the equivalent of 4,300 barrels of oil a day.

Even if the other three become fully operational by next year -- an optimistic goal -- the total contribution from federally supported synthetic fuels projects will be the equivalent of slightly more than 20,000 barrels a day, enough to trim the nation's 4.8 million daily barrels of imported oil by about four-tenths of a percent. Subsidies the agency promised ranged as high as $60 to $90 a barrel; the price of oil is around $13 now.

Miller acknowledged that the agency could have funded more projects, but "the board had a great deal of respect for the taxpayers' money -- more than they were given credit for by the critics of the agency. Some of the proposals we got in here were real blue-sky stuff."

The agency's legacy of projects will be transferred to the Treasury, along with a contingent of eight employes who will join the ranks of civil servants to monitor the projects.

The dying agency had enough money in its budget to finance the team for two years, although "in principle, the projects will need monitoring for the life of the contract," said former Synfuels vice president Ralph Bayrer, who has already moved into new quarters near the Treasury. "The degree of effort remains to be seen."

At the corporations' headquarters at 2121 K St. NW, a typing table plunked in the middle of a barren room serves as Miller's desk as he leads his rapidly dwindling staff through the final details of shutdown, rather like a funeral director fussing with the minutiae of the service.

Two of the corporation's four floors of office space were empty by midweek. The lease has been turned over to the General Services Administration, the furniture sent to Treasury.

Check forms have been shredded, franked envelopes burned. The agency's supply of printed letterhead "has become scratch paper for a lot of little kiddies," Miller said.

There is one task remaining: The agency must respond to a request for documents from House Energy and Commerce Chairman John D. Dingell (D-Mich.), a leading critic of the corporation who was angered by its last-minute approval of aid to the Parachute Creek project.

Miller said the request will be fulfilled, and there is no rancor in his voice. Bitterness, he said, "is not an institutional attitude" at the corporation.

"The sentiment is disappointment that a good idea and a needed function had to fall by the wayside," he said. "It's like the hole in the roof -- the one you never think about fixing until it rains."