FASTOX™ Technology

The ironmaking blast furnace has been a keystone industrial technology since man first started using iron in the fifth century B.C. Though the blast furnace has improved in both efficiency and scale over the past two-thousand years, the basic design we use today has changed very little since the 1830’s. Until now.

Sierra Energy is commercializing the most scalable and profitable gasification system ever invented. Sierra’s system, called FASTOX™, converts blast furnaces into large thermal gasifiers that convert diverse materials — such as coal, biomass, and municipal solid waste (MSW)—into clean energy without emissions or waste products.

Centuries of blast furnace experience and development, and a well-established construction and support industry, allow FASTOX™ to achieve commercial scales and efficiencies far beyond that offered by any competing technology. Also, FASTOX™’s basis in the blast furnace industry allow existing idled blast furnaces to be retrofitted as FASTOX™ gasifiers.

FASTOX™ represents the next significant improvement in blast furnace design. Sierra’s FASTOX™ gasifier is essentially a modified blast furnace. But whereas blast furnaces create syngas in order to reduce iron ore into pig iron, Sierra’s FASTOX gasifier will create syngas for its own sake. And whereas blast furnaces operate using a blast of atmospheric air (containing 70% nitrogen), FASTOX™ injects a supersonic stream of pure oxygen shrouded in steam. Because FASTOX™ does not include air, a FASTOX™ blast furnace operates with lower volumes of a significantly more powerful reducing gas, creating a concentrated syngas with over 500 BTU per cubic foot — pure enough to be used in a power turbine or to be liquefied into transportation fuel.

This simple change has profound implications for the ironmaking industry and presents new opportunities for blast furnace operators. This change, with its increased concentration of reducing gases, means that blast furnace operators can make more hot metal, in less time, while using less metallurgical coke, resulting in a less expensive and more environmentally-friendly process and the production of a more powerful and valuable topgas. This change also means that a FASTOX™ furnace can be fed with biomass, rather than with iron-ore, specifically to produce this valuable topgas, known as “syngas” by the clean energy sector.

FASTOX™’s global addressable market for the gasification of MSW alone is more than $200 billion. Other addressable markets include the gasification of biomass, coal, and oil shale and oil sands, all at scales well beyond that possible with any other technology.

How a blast furnace works

An iron-making blast furnace converts iron ore into liquid molten iron. It works in a counter-current manner driven by gravity: iron ore, metallurgical coke, and limestone are stacked into the top of the furnace, and hot air is blasted in at the bottom of the furnace. Hot gasses rise through the furnace, gradually melting the materials stacked inside the furnace.

The chemical process involved is called “reduction”. In this process, the oxidized iron ore (essentially rust) is stripped of its oxygen molecules and is converted to elemental iron. This happens slowly as the iron ore descends in the furnace until a point near the bottom where the iron ore completely melts.

Gasses in the blast furnace move in the opposite direction. Hot air is blasted into the bottom of the furnace through ports called tuyeres. The oxygen in the air immediately reacts with the metallurgical coke in the furnace creating a syngas and heat. This syngas rises through the stack, reducing the iron ore as it passes. When the gas exits the top of the furnace, it still has residual energy, so it is normally burned to heat the air to be blasted into the furnace.

The molten iron that collects in the bottom of the furnace is periodically poured out in liquid form and cast into ingots or sent to the steel plant. The limestone used in the furnace also emerges at this point as a product called slag that is used in construction.

Limitations of current practices

Current iron-making operations are constrained in two related ways:

The amount of oxygen in the air blasted into the furnace limits the rate of the reaction and thus the amount of iron that can be produced in a given furnace; and

The fact that gasses need to rise through the stack of material in the furnace means that those materials must be sufficiently permeable to allow the flow of that gas.

Thus, the critical limitation of the blast furnace in its current form is that only a finite amount of air can be blown into the furnace before the volume of gas exceeds the stack’s ability to let them pass. Beyond this volume, solid materials start to be blown out of the top of the stack.

The FASTOX™ solution

FASTOX™ replaces the conventional blast of hot air into a blast furnace with a jet of pure oxygen inside a shroud of steam. This allows more oxygen to enter the furnace while reducing the total gas volume. Although this change is relatively simple, it provides a number of important benefits even when the blast furnace is just used to produce iron:

1.  It increases the throughput of the furnace (its ability to produce iron) by approximately 30%;

2.  It allows iron producers to use approximately 20% less metallurgical coke (an expensive input needed for gas permeability); and

The 70% nitrogen found in air does not dilute the gasses coming out of the furnace. This makes the resulting syngas much cleaner and more valuable in that it can now be converted to electricity.

While the first two changes significantly benefit the iron industry, it is the third change, the increased syngas value that allows the blast furnace to take on a new role as a highly efficient gasifier for the production of energy.

For an iron producer with multiple blast furnaces, this advance allows the production of more iron using fewer furnaces and with lower material costs. An added benefit is that blast furnaces that are then no longer needed for iron production can be retrofitted as dedicated energy producers, creating electricity for the iron mill or for sale.

For iron companies with a number of idled blast furnaces, the opportunity to put those assets back into service — as energy producing gasifiers — is even more attractive.

The role of steam

Steam is injected into Sierra’s FASTOX™ gasifier to ensure that the gasifier does not overheat. At the 1000°C operating temperatures of the furnace, the injected steam immediately disassociates into hydrogen and oxygen, which further feeds the supply of syngas but consumes enough heat in the process to ensure that the high-temperature gas injection equipment does not melt.

These features are what give FASTOX™ its name: Flexible Accelerated STeam/Oxygen.

Sierra Energyʼs FASTOX™ Process is not only Clean, but Scalable and Profitable

Renewable energy is a broad and growing field, and FASTOX™ isn’t the only renewable energy process being pursued today. But Sierra Energy’s FASTOX™ process has many advantages over other renewable energy technologies, including other gasifiers:

1. FASTOX™ is environmentally friendly and allows for 100% recycling without emissions or toxic waste. Most gasifiers need to sort waste and still send various materials, as well as the toxic ashes they produce, to landfills. But FASTOX™ melts inorganic materials such as metal, glass, and minerals, allowing them to be collected and reused. And FASTOX™ vaporizes organic materials into a clean and usable syngas, offsetting our world’s need for natural gas and other fossil fuels. With FASTOX™, there are no process emissions or toxic residues and nothing remains to be sent to any landfill.

2. FASTOX™ operates continuously with only a 2% parasitic electric load. While plasma-arc furnaces can also reach high temperatures, they are limited to using a batch process to load waste, meaning that they have to be stopped and restarted between loads. They also use 25-30% of the electric energy they produce. But FASTOX™ loads waste in a continuous process, operating for years without stopping. And FASTOX™ only uses 2% of the electric energy it produces. These differences allow FASTOX™ to handle dramatically more waste faster, at more efficiently, and at a lower cost.

3. FASTOX™ can operate at large and small scales. Most gasifiers cannot process more than 300 tons of waste per day, meaning that they are only appropriate for small towns with populations of less than 50,000. Multiple units have to be strung together to handle large amounts of waste. While a small FASTOX™ unit could process such small amounts of waste too, a single FASTOX™ unit can handle more than 25,000 tons of waste per day, making FASTOX™ the only gasifier capable of handling the waste even from major metropolitan areas.

4.  FASTOX™ offers retrofit opportunities. FASTOX™ can be applied as a retrofit of existing facilities. Many future FASTOX™ gasification plants essentially already exist and are just waiting to be retrofitted. Sierra can, with an inexpensive retrofit, turn existing idle blast furnaces into profitable gasifiers. From a cost and a time-to-market perspective, this in an incredibly powerful advantage. By the time any competing technology is capable of achieving FASTOX™-type scales, FASTOX™ will be firmly established in the marketplace.

5. FASTOX™ produces energy both economically and profitably. The thermal efficiency of the FASTOX™ process is upwards of 87%. Not only is the syngas produced profitably salable, but so are the recycled metals and slags produced by the process. FASTOX™’s clean and continuous operation, low parasitic load, and flexible scalability allow FASTOX™ to produce energy on a cost-per-kilowatt basis that is competitive with current solutions, and to do it profitably, even as part of a new construction. Those economics and profitability improve when FASTOX™ is used to retrofit an idled blast furnace, leveraging existing infrastructure to dramatically reduce construction costs.

6. FASTOX™ is based on proven technology with an established support industry. Blast furnaces have been around for thousands of years and have changed little over the past 180 years. Blast furnace technology is supported by a large, global knowledge base and industry. The costs of building, testing, operating, and maintaining blast furnaces are well understood and have been refined to amazing levels of accuracy and efficiency. The modifications involved in the FASTOX™ process are minimal and well understood.

7. FASTOX™ has been independently proven. Independent bench-scale testing of Sierra Energy’s FASTOX™ process has confirmed research predictions and proven that FASTOX more than triples the rate at which a blast furnace can convert feedstocks. The same testing has proven that FASTOX™ triples the caloric value of blast furnace topgas, confirming predictions as to the value of the syngas produced.

8.  FASTOX™ has been thoroughly vetted by outside experts. The following blast furnace experts have confirmed the feasibility of the process: Dr. Dave Wakelin, PhD; Dr. Martin Corbett, PhD (now deceased); Dr. Wei-Kao Lu, PhD, Metallurgy Professor at McMaster University; and TSS Consultants. FASTOX™ is currently undergoing pilot stage testing and prototyping at the Renewable Energy Testing Center. Expert confidence in FASTOX™ derives from the fact that every subset of FASTOX™ technology is one that has been independently proven at a commercial scale.

The result is a process that enjoys best-in-class economics to the point that is capable of doing what no other conversion technology can do: under-bid landfills for tipping-fees, or even pay municipalities to take their waste. This economic advantage gives FASTOX™ a long-term competitive advantage in securing the waste stream needed to take full advantage of its massive scalability.