Holey catalyst: Rive Technology is designing a zeolite catalyst with pores larger than those found in conventional zeolites, which are widely used in petroleum and petrochemical production. The larger pores allow the catalysts to handle a wide range of compounds. Credit: Rive Technology
Rive Technology will help refiners increase production of transportation fuels and process less desirable crudes with its innovative catalyst technology. Mesopores (>4 nanometers) in zeolite enable larger molecules to be cracked. Petroleum refiners would obtain a higher yield of desirable products such as gasoline, diesel fuel, and propylene, and less of undesirable products like heavy cycle oil and coke.
“By the end of the year, we hope to have hit upon the optimum mix of these things,” says Dougherty. “We hope to be in commercial refineries in the second half of 2011.” The plan is to license the recipe to commercial manufacturers of petroleum catalysts, such as BASF or W.R. Grace.
Rive’s proprietary catalyst – RiveCat – is focused on the most important conversion process in the refinery – fluid catalytic cracking (FCC). The FCC process converts or “cracks” the long-chain hydrocarbons found in crude oil into smaller, more valuable molecules such as those that comprise transportation fuels.
RiveCat is more accessible to the bulky hydrocarbon molecules found in FCC feedstock, allowing more of the feedstock to get “cracked”, especially when processing low quality crudes. As result, refiners produce a more valuable slate of products from a barrel of crude and increase throughput in the refinery, leading to higher profit margins. Refiners are also able to purchase cheaper, lower quality crudes and process them economically.
Refiners can utilize RiveCat without significant capital investment or changes in operating conditions, allowing them to immediately improve refining yields and profits.
Andrew Dougherty, vice president of operations at Rive, says that the catalyst could increase the proportion of petroleum processed by as much as 7 to 9 percent.
The company’s technology is based on zeolites–tiny pore-studded particles made of a mix of aluminum, oxygen, and silicon that are a mainstay of the petroleum and petrochemical industries. Heated and mixed in with crude petroleum, zeolites act as a catalyst, breaking apart the complex hydrocarbon molecules of crude into simpler hydrocarbons that make gasoline, diesel, kerosene, and other desirable products in the process known as fluid catalytic cracking. By making zeolites with pores larger than those in conventional ones, Rive hopes to create catalysts that handle a higher proportion of hydrocarbons.
Typically, the openings of pores in zeolites are less than a nanometer wide, which limits the range of hydrocarbon that can get into the porous catalysts. But Javier Garcia Martinez, a cofounder of Rive and now a professor at the University of Alicante, in Spain, came up with a way to control the size of the openings while working as a postdoctoral fellow at MIT’s Nanostructured Materials Research Laboratory. He mixes the constituents of the zeolites in an alkaline solution, then adds a surfactant–a soaplike liquid. The surfactant makes bubbles, and the zeolites form around the bubbles. Then he burns away the surfactant, leaving behind zeolites with openings two to five nanometers wide–big enough to let in larger hydrocarbon molecules. By varying the chemistry of the surfactant, Garcia Martinez can control the size of the pore openings.
Dougherty also sees Rive’s zeolites being used in hydrocracking, a refining technique that employs high-pressure hydrogen to create a low-sulfur diesel. Hydrocracking is a small market, but with the U.S. Environmental Protection Agency trying to reduce sulfur emissions, it’s a growing one, he says. With its ability to choose pore size, the company might also make catalysts for processing tar sands, which contain extremely dense petroleum. Further down the road, the material might also be used to process biofuels, according to the company.