New Technology Transforms Natural Gas Into a Multitude of Useful Products
by David Soane
Natural gas, a mixture comprising primarily methane and similar light hydrocarbon components, provides a relatively clean energy source for the United States. Thanks to widespread deployment of horizontal drilling and hydraulic fracturing technologies in recent years, natural gas is recovered abundantly, so much so that the US now exports its excess production. Unfortunately, cryogenic compression and long-distance oceanic transport to customer destinations are energy-intensive and lead to further emission of greenhouse gas. Often, natural gas is simply flared at wellheads, because its collection and distribution is too costly relative to its market price. Even when production wells are capped, natural gas can leak out, sending methane – a potent greenhouse gas – into the atmosphere. Despite these limitations, natural gas offers enormous potential benefits if it can be economically exploited to yield high-value products in an environmentally conscious manner.
Currently, natural gas is usually burned for heating or generating electricity, a process that creates carbon dioxide, a greenhouse gas responsible for climate change. Natural gas consists mainly of stable carbon molecules that resist conversion into other chemicals except by burning (combustion). Transform Materials has found a way to overcome this inherent stability so that natural gas can be converted into useful petrochemicals while simultaneously locking up carbon atoms that would otherwise be released into the atmosphere. Through this process, the Transform technology co-produces hydrogen, a clean fuel source and a vital chemical for more complex reactions.
Transform’s system turns the methane and light hydrocarbons in natural gas into high-purity hydrogen and chemical-grade acetylene. Hydrogen is a key ingredient for many industrial sectors, such as ammonia synthesis, oil refining, fine chemicals, electronics, and metallurgy. Acetylene is an important and highly reactive precursor for producing high-value chemicals such as vitamins, fragrances and flavors, carbon solids (for example, acetylene black for battery and conductive polymer applications), and high-utility polymers that can be used for personal-care products and structural materials. In addition, a simplified version of the Transform system produces a lower-purity acetylene that is easily and efficiently collected for industrial uses, such as driving acetylene torches for welding and cutting metal.
Transform’s approach features a reaction front end and a purification back end, with its components directly coupled and fully integrated as a synchronized system. At the heart of the reaction front end is a proprietary microwave-driven plasma reactor that converts the hydrocarbons in natural gas into the output products of acetylene and hydrogen, operating at low pressures and mild temperatures that provide inherent safety. The purification back end includes a series of modules that remove contaminants and extraneous products from the output streams, so that the resulting acetylene and hydrogen are of extremely high purity. Transform’s highly efficient chemical conversion technology consumes minimal electricity, resulting in an extremely low variable cost. The overall hardware system is compact and modular, with corresponding commercial advantages.
Over the last two years, an initial 30 kW reactor system has undergone rigorous testing and steady operation at the Transform facility, demonstrating the technology’s long-term reliability. Based on the encouraging results from testing this 30 kW reactor and validating the purification steps required to produce fuel-cell-grade hydrogen and high-purity acetylene, Transform has constructed a larger demonstration system at its facility, comprising a 100 kW microwave-powered reactor and associated purification modules. The demonstration system showcases Transform’s technology at commercial scale. Tested and validated, the 100 kW reactor can be multiplexed for customer installations, allowing copies of the full-scale system to be integrated with correspondingly sized separation and purification units.
The compactness and modularity of these reactors allow customized installations to meet varied specifications of commercial partners and customers. As an added benefit, the outflow of Transform’s system is easily managed, even switched on or off on demand, to synchronize with fluctuating customer need, permitting just-in-time production. For small-scale users, a small-footprint plant is available that can be tailored for specific applications. For more extensive commercial requirements, larger-scale plants can be constructed by taking a modular approach. No matter which size system is developed, projected capital expenditures allow rapid payback with attractive operating costs.
Further, this technology holds the promise of distributed manufacturing, obviating gas shipment in heavy cylinders and tube trailers over long distances, and greatly simplifying production and deployment logistics. When powered by renewable energy such as wind or solar, the system can be operated as carbon-negative, since the carbon component of natural gas is permanently trapped in solid or liquid end-products instead of being released into the atmosphere.
Transform’s process converts methane (or similar light hydrocarbon gases) into hydrogen with approximately half the electricity input as compared to other hydrogen production methods such as electrolysis. With only methane and electricity as inputs, there are virtually no effluent impurities that require complex systems to remove, so that a small-footprint system can yield high-purity products. This translates into a highly efficient technology that is cost-effective to operate.
Two operational features distinguish this approach from existing methods:
- Transform’s single-pass conversion rate of over 90% and co-product selectivity of more than 95%, both achieved at high throughput, ensure efficient plant operation and cost-competitiveness.
- Transform’s process can use feedstock from multiple sources in different geographies. The most common is commercially available natural gas, but alternate sources such as biogas, coal-bed methane, landfill waste gas, flare gas, and others work equally well. In fact, while methane is the most common feedstock component, most if not all light hydrocarbon gases can be added or substituted without plant modification, guaranteeing feed supply flexibility and reliability.
While other technologies exist for producing hydrogen and acetylene, there are important associated drawbacks. Current hydrogen generation technologies include electrolysis, methane steam reforming, and electric arc cracking:
- Electrolysis consumes about twice as much electricity as Transform’s process. Electrolysis is presently under consideration for hydrogen refueling stations, but Transform’s scalable modularity and cost-effectiveness offer an attractive alternative.
- Methane steam reforming is a high-temperature, corrosive process that produces complex by-products, emits greenhouse gas, and is only cost-effective in very large installations. By contrast, Transform’s process produces high-purity hydrogen without need for byproduct removal in an efficient, economical manner for all installation sizes, without producing greenhouse gas.
- Electric arc cracking generates a complex effluent profile and several toxic impurities that are difficult to eradicate. Transform’s system yields a simple effluent profile (hydrogen and acetylene), with no toxic byproducts.
In the case of acetylene manufacturing, technologies include the carbide process, partial combustion, and the Huels process:
- The carbide process (with coal and lime as the raw materials) is extremely energy-intensive, containing impurities from coal (such as phosphorous and arsenic) that accumulate in the acetylene and must be removed before downstream chemical synthesis. Transform’s process is energy-efficient, yielding a simple product mix (acetylene and hydrogen) that is devoid of complex impurities.
- In the partial combustion process, acetylene is collected as a byproduct of syngas production and is difficult to separate and purify. This process is only economical at large scale. Transform’s modular system is economical at all sizes, producing two highly purified gas outputs, acetylene and hydrogen.
- The Huels process generates a complex effluent, requiring multiple steps for separation and soot removal. It also is only economical at large scale. Transform’s economical, modular process generates two effluent streams, acetylene and hydrogen, ready for use without further separation or soot removal.
In summary, this exciting new platform technology can create green hydrogen and sustainable acetylene, each a portal to a multitude of high-value petrochemicals. To learn more, visit transformmaterials.com.
This article was originally published in the November/December issue of SHALE Magazine.