EFT has embraced a philosophy of “employ the best, develop the rest” in order to provide a solution based on “commercially proven” components that are sound, verifiable and project financeable as described herein. Key technology components are outlined below:
Production of Synthesis Gas (Syngas)
For natural gas and biogas based projects, EFT has developed relationships with multiple engineering/fabrication firms that can provide syngas systems to EFT.
For all other carbonaceous feedstocks (MSW, biomass, CO2, etc or “XTL”) projects, we can work with the client’s specified gasifier or recommend one for the application. EFT can then provide the FT Synthesis and product upgrading and, in some cases, the syngas clean-up design, to be incorporated into the overall plant process design.
For natural gas and biogas applications EFT incorporates a combination of commercial proven and well established proprietary, patented clean-up steps in its design to bring key contaminants down to ppb (parts per billion) levels. This step is critical for protecting the FT catalysts and can extend its useful life significantly.
Methods to produce oxygen (required for syngas production) have changed significantly in the last 10 years, bringing the cost, and size, down to a range that fits a small scale GTL project well. Cryogenic oxygen and Vacuum Pressure Swing Adsorption (VPSA) are both viable options for small scale GTL. Multiple vendors (Praxair, Air Products, Air Liquide, Matheson) can supply the oxygen unit for purchase or provide oxygen “over the fence” for a processing fee. EFT maintains working relationships with key suppliers in this field to support our design activities. EFT has several patents related to efficiently utilizing VPSA oxygen sources.
Advanced Fixed Bed FT Catalyst/Reactor System
The EFT Advanced Fixed Bed FT Catalyst/Reactor System is the result of over 10 years of R&D targeting the optimum integration of catalyst and reactor geometry while maintaining the simplicity and scalability of a conventional fixed bed tubular reactor. The result is a highly cost-effective design with improvements in performance that exceed all historically demonstrated performance for conventional tubular reactors:
|Methane Selectivity||less than 8%|
|Alpha||Schultz Flory Alpha greater than 0.92|
|Productivity||2 to 3 times more than a conventional fixed bed reactor system|
Methane Selectivity – Methane selectivity refers to that portion of the FT product stream that is converted back into methane. The less methane that is made, the more useful products are made per unit of feedstock. Conventional fixed bed tubular reactors tend to produce high methane selectivity (12 to 16%). EFT has demonstrated consistent performance well below 8% selectivity over thousands of hours of runtime.
Alpha – A parameter used in FT technology to indicate the chain growth probability where a higher number approaching 1 means a higher percentage of heavy waxy product that is easily hydrocracked into the middle distillates range. The higher the alpha, the higher the potential yield of middle distillates.
Productivity – This refers to the amount of products made per unit of time per unit of reactor volume. The higher the productivity, the smaller the reactor volume and FT catalyst volume, for a given throughput.
Conventional tubular fixed bed reactors are heat transfer limited. With a target productivity significantly higher than that of a conventional tubular fixed bed reactor, the new reactor design required a different approach. To accomplish this, EFT’s catalyst and reactor development occurred in parallel and was demonstrated as an integrated unit. Over 250 catalyst variations and several reactor configurations were tested to optimize the FT catalyst/reactor system. This system is based on fundamental principles used in multiple commercial applications and has proven to be highly cost effective. EFT has both issued and filed patents on the unique designs employed in both the reactor and catalyst in this system.
EFT has accumulated over 500,000 hours of catalyst performance data. Our database of proprietary FT catalysts, some with multiple runs of 5,000 to 25,000+ hours, has demonstrated performance that meets or exceeds our targeted objectives. This database also demonstrates not only initial or “start of run” performance but also transient responses to upset conditions as well as rejuvenations and regenerations over the catalyst life cycle and end of run performance. This database is critical for the validation of operating procedures which is an essential part of commercializing the technology.
A key operating issue (and cost) with all FT catalysts is how often the catalyst must be regenerated and what conditions are required to accomplish the regeneration. EFT has committed thousands of hours of development and testing to improve catalyst regeneration procedures. EFT’s FT catalysts have demonstrated continuous runs of 1 year without regeneration making it possible to schedule regeneration with annual plant downtime for routine maintenance. More important, the catalyst can be regenerated “in situ” at low temperatures. EFT Has a patented process to optimize activation and regeneration of an FT catalyst.