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Rentech Tracking to Startup Coal-to-Liquids Pilot Plant in Q4 2006

Rentech has ordered the gasifier and product upgrading units needed for the Fischer-Tropsch (FT) Coal-to-Liquids (CTL) Product Development Unit (PDU) it will be building at the Sand Creek facility in Commerce City, Colorado near Denver. (Earlier post.)

The PDU has been engineered to produce 10-15 barrels per day of FT diesel, naphtha and jet fuel through the Rentech CTL process technology.

A gasifier from BioConversion Technology, LLC capable of processing 25-35 tons per day of coal will provide the synthesis gas (a combination of hydrogen and carbon monoxide). Rentech will primarily process eastern and western coal at the facility with the capability to also process petroleum coke as well as biomass.

Klepper gasification system

BioConversion Technology uses a gasification technology it calls the Klepper Pyrolytic Steam Reforming Gasifier (PSRG) with a Staged Temperature Reaction Process (STRP). (The company also offers the Klepper Ethanol Reactor which catalytically converts syngas into ethanol. BioConversion Technology is Robert (Bud) Klepper’s company.)

The Klepper PSRG with STRP system typically generates syngas from coal, coal slurry, coal fines and other biomass feedstocks with energy content in the range of 400–600 BTU/ft3 at an average thermal energy conversion efficiency of 75%.

The Klepper system has the highest energy efficiency of any system and the highest syngas energy content of any thermochemical biomass conversion system that has been developed for biomass inputs of less than 1,000 tons/day, according to a comparative evaluation of such systems performed for the East Bay Municipal Utility District in Oakland, California.

The Klepper PSRG with STRP employs an entrained flow principle (using a gas to propel the pulverized feedstock through the direct fired reaction zone) but features two separate reactors: a devolitization reactor and a reforming reactor.

The devolitization reactor slowly raises the temperature of the feed material through 450°F (the temperature at which combustion will occur) until a substantial portion of the oxygen has reacted with more reactive material in the feed.

Once the available oxygen has been reacted at below combustion temperature, the feed material temperature is raised to a higher temperature, for example 650°F, prior to combination with super heated steam (1,500°F) and a subsequent rise in temperature to react with the carbonaceous feed material and produce the CO- and H2-rich syngas.

The Klepper system uses the produced syngas and process steam to propel the feedstock through the segregated steam reforming reactor. Among other things, this technique raises the calorific value of the syngas by not diluting the product syngas with nitrogen or carbon dioxide as is the case with an air-blown gasifier. Nor does it require a costly separate supply of oxygen or the elevated temperatures and “run-away” pyrolysis issues associated with the use of an oxygen-blown gasifier.

This multi-stage approach results in a very high conversion efficiency, while at the same time, keeping the tar content in the produced gas extremely low. Another unique feature specific to the Klepper system is that the cyclones and water condenser are integrated and contained within the biomass gasification chamber. This design conserves space and reduces the loss of heat energy.

The product upgrading system will be engineered and fabricated by Zeton, Inc.

The Sand Creek site, which originally operated as a methanol facility, will have the existing natural gas reformer and methanol synthesis unit removed. All of the associated product storage tanks and some utilities will be retained.

Rentech plans to begin site construction—assuming it clears the state and local permitting process—in the second calendar quarter of 2006. The company believes that the integrated CTL facility will be ready for commissioning and startup in the fourth calendar quarter of 2006.

The facility will provide test quantities of FT fuels to numerous groups which have expressed a strong interest in acquiring commercial quantities of Rentech’s fuels, including the Department of Defense; major metropolitan areas such as Chicago and Houston; and state and local government entities in California, Illinois, Ohio, Montana and Wyoming.




Nice buzz phrase, "clean coal without compromise", but where do the CO2 and other pollutants go?


Depends on the application and the supporting systems, but the answer, absent specific CO2 capture and sequestration technology, or the addition of other processes (such as using dolomite to react with the sulfur permitting it to be removed with the ash) is straight up into the air.

Whether that's "more" or "less" depends on what you're comparing it to. Coal gasification for power generation is cleaner than striaight coal combustion for power generation. Coal gasification for FT fuels generation puts a much heavier well-to-tank emissions loading on the resulting fuel than does conventional production and refining for gasoline or diesel. (Although the FT fuels burn cleaner.)

How Coal-to-Liquids compares to, say, the production of synthetic fuels from oil sands is going to depend on a number of factors: the gasification system, whether or not there is any kind of carbon capture system, the upgrading systems, so on and so forth.


Why not add algae scrubbers to capture much of the CO2 in the flue gas and return harvested algae into fuel stream?

Guillermo  Fuego

Clean Diesel fuel is it's own reward, regardless of the CO2 "problem", if any.

This is probably the best way to utilize domestic coal resources and not send any $US to the Wahabbis.


For what its worth, this method appears fair. But it can't possibly be a long term solution. We people are lucky in that we've come to a wall with regards to oil reserves, and after some small panicking, have come to realise that we've got some alternate sources like coal to rely on in the mean time while we get out heads around the problem. It's a buffer.
If it had been the case that nothing else was usable for fuel we'd have all turned to war and savagery. I'm not exactly sure how much coal there is for us to exploit, but even if its enough for another 100 yrs, we won't get a nice second chance. Biodiesel, wind and solar would not have been able to provide at our current levels of technology if they were the only alternatives.

tom deplume

Will the bad mouthing of wind and solar ever end. Just covering the 12 billion square meters of roofing in the US will generate 2,000,000,000 kwh each year. The wind energy potential worldwide each year is several times more than all the btus we'll ever get from all the fossil fuels that will ever be burned.

Robert Schwartz

"The PDU has been engineered to produce 10-15 barrels per day of FT diesel, naphtha and jet fuel through the Rentech CTL process technology."

10-15 barrels a day?


It's a pilot plant, designed to test process and provide some output for fuels testing. Syntroleum's demonstration plant for GTL (Catoosa) outputs about 70 barrels per day.


Of all the backward internet site's there are that propagate lies about "Clean Coal", I can't believe the Green Car Congress is hosting the same propaganda from coal enthusiasts. Well-to-wheels analyses show that FT coal to gasoline conversion is more carbon intensive than refining gasoline from oil, even when the gasification plant sequesters its carbon emissions!(Dr. R. Williams, Princeton University)
If you still think that we probably shouldn't continue experimenting with the planet's climate to see what it's like without a north pole for the 1st time in 3 million years, don't buy into this crap.
To know the truth about coal to liquids, download the following:


Surface Coal Gasification may well pollute the environment. But Underground Coal Gasification (UCG) alongwith CTL processes seems to be another alternative that has good potential and keeps the CO2 emissions low as well.


I think the fact that they can use essentially carbon neutral biomass is promising. CTL is good in a lot of ways... US has vast domestic and secure coal resources. This will help our economy and help reduce trade deficits due to oil imports. Its fuels burn cleaner especially when it comes to sulfur. If we are dealing with peak oil very soon CTL will be a must, at least to a degree to help keep the economy from falling apart. Global warming will no doubt be a problem, I think utilization of wind and solar to replace coal for power generation would be the best step. This would offset the use of CTL technology to a degree when it comes to C02 emissions while still providing the hard to replace fuels which we need... especially for commercial and military jets which cant be plugged in or practically due to lower BTU thus range, ethanol.

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