Process FAQs

Who are your competitors? What processes do they use? Why are you better?

There are a number of companies producing synthetic fuels outside the United States. We believe Rentech has the only operating plant that produces synthetic transportation fuels in the United States.

Shell Oil Company has a natural gas-to-synthetic fuels plant operating in Malaysia. The Shell process uses a fixed bed reactor using a cobalt catalyst. The fixed bed reactor technology requires tens of thousands of small reactors each loaded individually with a more expensive cobalt catalyst. Our technology uses a scalable slurry bubble column reactor using a relatively inexpensive iron-based catalyst. We believe these technology choices make our process more economical.

Sasol has coal-to-liquids facilities in South Africa and a gas-to-liquids facility in Qatar. Its Qatar plant uses natural gas as a feedstock with a cobalt catalyst in a slurry bubble column type reactor. Again, the catalyst is much more expensive. In South Africa, Sasol’s CTL facility uses an iron catalyst but much of the production is using a high temperature fluidized bed reactor system.

What happens to the CO₂ produced in your process? What does it mean to be carbon capture ready?

Carbon capture ready means that, by the nature of our process, we capture the CO₂ generated in a concentrated stream and it can be used beneficially by others for enhanced oil recovery or sequestration. We capture the CO₂ in our process because it makes economic sense to capture it and not let it dilute the synthesis gas we inject into the Rentech reactor. Unlike most current power plants where the CO₂ in the flue gas is at most 5% in the gas stream, our captured CO₂ is highly concentrated so the cost of production of CO₂ from our process is the lowest cost in the marketplace today. At our proposed Natchez facility, we have already signed a contract to sell all the CO₂ we capture to Denbury Resources to use for enhanced oil recovery (EOR), increasing production from previously depleted domestic oil fields. It is estimated that the carbon dioxide generated by the production of one barrel of synthetic fuel, when used for EOR, will facilitate the production of two additional barrels of crude oil.

If this is such a great way to make great fuels, why hasn’t this happened before? Why is now the time?

Over the last 30 years the price of crude oil has been much lower than it is today, at times below $20 per barrel. We believe the long-term price of crude will remain at a level that will enable us to make our products economically. In addition, there is increasing demand for domestic fuels in order to reduce fuel price volatility and to enhance energy security. Unfortunately, for too long, we have imported the overwhelming majority of our crude oil and much of it has been coming from nations that are not particularly friendly to the United States. Growing awareness of environmental issues such as global warming has also increased the demand for clean fuels with carbon footprints smaller than those of petroleum fuels.

Why do you use iron catalyst?

An iron catalyst is cheaper to produce than a cobalt catalyst. The iron catalyst does not pose any hazardous waste issues and can be used with syngas produced from a wide range of different feedstocks including biomass and fossil resources. The iron catalyst has built in water gas shift activity. This means that there is one less syngas preparation step necessary than for other FT processes.

Why do you use a slurry reactor?

We believe the slurry bubble column reactor system is scalable to large scale facilities and results in much better yields and selectivities than a fixed bed technology. A large scale fixed bed facility requires tens of thousands of small separate reactors that each have to be packed (and eventually unpacked) with catalyst.

What pressure is the required pressure for syngas?

We can use a wide variety of pressures in our process.

What poisons your catalyst? How does that show up in your process and how does it impact your economics?

Sulfur is the primary poison to our catalyst. Ammonia is also a minor poison. We remove each of these contaminants upstream of our process. If, however, they did end up in the Rentech reactor, the catalyst usage would increase, which can result in a minor increase in ongoing operating costs.

Why do you need an Upgrader? Why do you use UOP to provide that technology?

The primary product from the Rentech reactor is a mixture of long chain hydrocarbons we refer to as wax. This wax is converted to jet fuel or diesel fuel in an upgrader. The upgrader ensures that the products from the reactor meet applicable fuel specifications. UOP is the world’s premier refining technology provider. The upgrader process we use is similar to processes that UOP has licensed for refineries throughout the world.