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Rentech Planning to Build Biomass to Synthetic Fuels and Electric Power Plant in California

The Rentech Process is based on Fischer-Tropsch chemistry. Click to enlarge.

Rentech, Inc., a Fischer-Tropsch process company, plans to build a plant in Rialto, California for the production of synthetic fuels and electric power from renewable waste biomass feedstocks.

The Rialto Renewable Energy Center (Rialto Project) is designed to produce approximately 600 barrels per day of renewable synthetic fuels and export approximately 35 MW of renewable electric power. The carbon footprint of the plant is designed to be near zero as the fuels and power would be produced only from renewable feedstocks.

RenDiesel, the renewable synthetic diesel to be produced at the facility, meets all applicable fuels standards, is compatible with existing engines and pipelines and burns cleanly, with emissions of particulates and other regulated pollutants significantly lower than the emissions from the combustion of CARB ultra-low sulfur diesel. The low carbon footprint of RenDiesel would help the transportation sector meet targets established by the Low Carbon Fuel Standard.

The power generated by the Rialto Project is expected to qualify under California’s Renewable Portfolio Standard (RPS) program, which requires utilities to increase the amount of electric power they sell from qualified renewable-energy resources. The plant will be capable of providing enough electricity for approximately 30,000 homes.

The SilvaGas process. Click to enlarge.
  1. Biomass input.
  2. Biomass is mixed with hot sand (1,800 ºF), turning it into product gas and residual char. A small amount of steam and the rapid release product gas provides the conveying force for the reaction.
  3. Residual char and cooled sand (1,500 ºF) are separated from the product gas by a cyclone separator and discharged to the combustor.
  4. Sand is reheated in the combustor by adding air and burning the residual char. The reheated sand is removed from the combustion gas by a cyclone separator and returned to the gasifier.
  5. Product gas is cleaned in a scrubber.
  6. Flue gas is recovered for uses such as biomass drying, steam production or direct heating.

Rentech has entered into a licensing agreement with SilvaGas Corporation for biomass gasification technology for the Rialto facility. Between 1998 and 2001, a 400 ton-per-day plant using the SilvaGas biomass gasification technology successfully operated in Burlington, VT, producing synthesis gas (syngas) from wood-based biomass in a series of operating campaigns.

That plant was built in partnership with the US Department of Energy, Battelle Columbus Laboratory and the National Renewable Energy Laboratory (NREL).

The Battelle Memorial Institute originally developed the “Low Gas Inlet Velocity High Throughput Gasification Process” in the 1980s. This process is now known as the SilvaGas process.

The conditioned syngas will be converted by the Rentech Process in a commercial scale reactor to finished, ultra-clean products such as synthetic diesel and naphtha using upgrading technologies under an alliance between Rentech and UOP, a Honeywell Company. (Earlier post.)

The Rentech reactor. Click to enlarge.

The Rentech Process uses a slurry bubble column reactor. Synthesis gas is fed into the bottom of the reactor where it is mixed with liquid wax and Rentech’s proprietary iron-based catalyst. The catalyst and wax are collectively referred to as slurry.

The reaction is exothermic and steam is generated in the internals of the reactor to produce steam and to remove heat and control the reaction temperature.

While some other Fischer-Tropsch technologies use a fixed bed reactor, Rentech says the slurry bubble reactor as it is simpler in design, less expensive to build and operate, and also provides for an easier scale up than the fixed-bed reactor. Additionally, Rentech believes that a slurry-bed reactor provides better product yield than the alternative.

Renewable electric power will be produced at the facility by using conventional high-efficiency gas turbine technology. The power is anticipated to be sold to local utilities under the California RPS program.

Having completed preliminary scoping studies, Rentech has engaged Jacobs Engineering Group Inc. to conduct the feasibility engineering phase of the project, which is expected to be completed over the next several months. This work will advance project development activities including preliminary design and plot plans and provide construction cost estimates that would then continue to be refined throughout the subsequent detailed engineering phases of the project. Based on the range of current preliminary scoping cost and yield estimates, the Rialto Project is expected to provide rates of return that would make the project commercially viable.

Rentech has an exclusive option on a site for the Rialto Project within the proposed Rialto Eco-Industrial Park, which is located adjacent to an existing City of Rialto Wastewater Treatment Plant and EnerTech Environmental Regional Bio-Solids Processing Facility. The location allows the proposed Rialto Facility to take advantage of established infrastructure including access to water, wastewater disposal and zoning.

The primary feedstock for the Rialto Project will be urban woody green waste such as yard clippings, for which Rentech is currently negotiating supply agreements. The location of the project will provide local green waste haulers with a cost-effective alternative to increasingly scarce landfills for the disposal of woody green waste. The plant is designed to also use biosolids for a portion of the feedstock which is expected to be provided under a supply agreement with EnerTech Environmental.

We expect the Rialto Project to be the prototype for many waste-to-fuels projects for Rentech. These projects are being designed at smaller scale than fossil-based projects, and feedstock costs are low or negative, resulting in significant potential returns on investment.

—Doug Miller, Executive Vice President of Renewable Energy Businesses for Rentech

In 2005, Rentech acquired a Royster-Clark nitrogen fertilizer plant in East Dubuque, Illinois, in a $50-million deal for a platform for Rentech’s polygeneration strategy: the co-production of fertilizer, Fischer-Tropsch synthetic fuels and electric power via coal gasification. (Earlier post.)



If diesel goes over $5 per gallon again, this process could gain favor. You make the money on the electricity mostly, but can make some on the fuels as well. I wish them the best in scaling this up over time.

I would like to see power plants become energy plants. Power plants have waste heat and fuel plants require heat. You get a good combination with the right design balance.


The diagram shows coke and coal inputs. But I think it is from another Rentech process. Their web site indicates they are willing to operate from coal in the Illinois plant but use biomass in other places.

Apparently they adapt to whatever inputs will be available locally and can be licensed. That won't be coal in CA.

Unless I missed a decimal point the revenue potential for this plant is $20-$30M annually depending on how much CA subsidizes renewable electric rates under the RPS program.

IMO the key question is not should this be done. But whether Rentech and Rialto will do a good job. These biomass munchers will spring up where the funding can be obtained. With the current policies against nuclear and coal what is the alternative?

And Rialto city is also putting in money; this will be built in the Rialto Eco-Industrial Park. That park effort almost certainly gets federal and perhaps state subsidies.


Let's hope this approach works out and can be made even smaller scale. It's like having a portable oilfield. Ideally the trucks bringing in the biomass would use the fuel and take back some mineral rich leftovers to spread on the soil. That way it's really the sun powering the whole operation. The net energy might be improved if just a cleaned up gas was used as a vehicle fuel, not a liquid.

black ice


Yeah, that's a good idea to use some of the product as transport fuel. In this case that might be the C3-C4 LPG fraction of the F-T product. Compressed syngas will probably not do the job as the energy density will be to small


In addition to returning some mineral leftovers, they could also return (part of) the char to the fields. With the right carbon-price and the advantage of soil-enrichment this may make it a carbon-negative fuel.


A positive project. Yes, we hope they do a good job and demonstrate efficacy and eventual costs cutting through energy sales. Good to see people not just thinking this way but building this way.


Nice idea. It's great when the ideas for change comes from the top. It would be cool if they would do like Denmark politicians are doing now. They all are using Green cars. That's a huge impact in the population!
I really liked that. The article can be found here:

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