Background

In order to tackle the global energy challenges resulting from greenhouse gases, new and emerging technologies are being developed at an accelerating pace. Plasma, the fourth state of matter, an electrically charged gas mixture, offers a promising and attractive alternative for the synthesis of fuels and chemicals, providing a unique way to enable thermodynamically unfavourable reactions to take place at ambient conditions. In non-thermal plasmas, the gas temperature remains low (as low as room temperature), while the electrons are highly energetic with a typical electron temperature of 1-10 eV, which is sufficient to activate inert molecules (e.g. CO₂ and CH₄) present and produce a variety of chemically reactive species including radicals, excited atoms, molecules and ions. These energetic species, which are produced at a relatively low temperature, are capable of initiating a variety of different reactions. Plasma systems have the flexibility to be scaled up and down. In addition, high reaction rate and fast attainment of steady state in a plasma process allows rapid start-up and shutdown of the plasma process compared to other thermal processes, which significantly reduces the overall energy cost and offers a promising route for the plasma process powered by renewable energy (e.g. wind and solar power) to act as an efficient chemical energy storage localised or distributed system.

Technology Overview

Researchers at the University of Liverpool have developed a novel method for converting the greenhouse gasses methane and carbon dioxide into other useful chemicals at room temperature and ambient pressure. The process eliminates the need for high pressure and temperature while improving yield. This novel technology has been demonstrated for a number of commercially relevant reactions, and research continues to increase the range of possible reactions and improve the efficiency of the method (, ).

This technology offers the potential for improving the economics and environmental impact of large-scale chemical processes, and is relevant to a number of fields – in particular the energy sector. This is a major breakthrough technology that has great potential to deliver a step-change in future methane activation, CO₂ conversion and utilisation and chemical energy storage.

The process could also provide a promising solution to end gas flaring from oil and gas wells through the conversion of flared methane into valuable liquid fuels and chemicals which can be easily stored and transported.

Stage of Development

In a paper published in chemistry journal Angewandte Chemie the researchers report a unique plasma synthesis process for the direct, one-step activation of carbon dioxide and methane into higher value liquid fuels and chemicals (e.g. acetic acid, methanol, ethanol and formaldehyde) with high selectivity at ambient conditions (room temperature and atmospheric pressure).

This is the first time this process has been shown, as it is a significant challenge to directly convert these two stable and inert molecules into liquid fuels or chemicals using any single-step conventional (e.g. catalysis) processes bypassing high temperature, the energy intensive syngas production process, and high-pressure syngas processing for chemical synthesis.

The one-step room-temperature synthesis of liquid fuels and chemicals from the direct reforming of CO₂ with CH₄ was achieved by using a novel atmospheric-pressure non-thermal plasma reactor with a water electrode and a low energy input.

Opportunity

The University of Liverpool is seeking a development and commercialisation partner to help take this patented technology to market. This will require further refinement, scale-up and demonstration at scale.