With the European Union producing an estimated 90 million tons of food waste each year, the U.K.-based Centre for Process Innovation (CPI) set out to take what’s considered trash and transform it into valuable and renewable resources. 
 
To achieve this goal, CPI initiated the European collaborative project “PlasCarb,” which is exploring ways in which food waste can be transformed into economically viable resources, specifically graphene and renewable hydrogen.
 
According to the organization, the PlasCarb project transforms biogas generated by the anaerobic digestion (AD) of food waste by using a low energy microwave plasma process. This procedure splits biogas (which consists of methane and carbon dioxide), resulting in the chemical components necessary to produce graphitic carbon and renewable hydrogen.
 
Neville Slack, program manager of CPI, explained the process of AD, “which uses organic material, for example slurry/manure, domestic/commercial food waste, food processing (industrial) waste, and crops grown specifically for AD, such as silage etc., and via a biological process converts the remaining energy in this ‘waste’ to produce biogas.”
 
The volume of biogas derived from this process is dependent on the type of material used for the AD process. For example, Mr. Slack said water has very little energy, so food waste with a large amount of water would produce less biogas. With this in mind, he added that, “the volume of biogas can be altered and theoretically increase the amount of graphitic carbon (graphene) and hydrogen, however, this increase in biogas may be lost in the post AD processing.” He concluded that this would have to be tested further and proven on a variety of inputs, such as food waste.
 
CPI oversees the technical aspect of this procedure, with the organization’s infrastructure permitting the trial and optimization of the plasma microwave process. CPI said the objective in fine-tuning of this process is establishing a roadmap for future commercial-scale manufacturing.
 
Rich Resources
The yield from the PlasCarb project provides unique and practical resources.
 
Graphene is a lightweight material stronger than steel, which is excellent at conducting heat and electricity. It can be used in a variety of applications, ranging from strengthening tennis rackets to building semiconductors, electric circuits and solar cells.
 
Europe has identified graphitic carbon as one of the region’s most important raw materials, and critical to the development of future emerging technologies.
CPI estimated the global market for graphite (mined or synthetic) is worth more than €10 billion annually.
 
Meanwhile, renewable hydrogen serves as a promising fuel alternative. A clean burning form of energy, hydrogen can also be used in fuel cells to power electric motors.
 
Mr. Slack noted that the development of fuel cell powered cars are gaining momentum with a number of major automobile manufacturers. While technology using this renewable fuel seems to be on the upswing, certain obstacles still need to be addressed. “One major issue is the hydrogen infrastructure, specifically filling stations,” said Mr. Slack. “Also with respect to hydrogen for automobiles this is required at a fairly high purity level (something like 99.9999%) therefore more extensive work would be needed to address this with respect to hydrogen from consumer waste. That said, hydrogen within the world economy has many other uses, including the manufacture of chemicals, and much of this currently comes from fossil fuels.”
 
As the world looks to turn from its reliance on environmentally damaging and scarce fossil fuels, the usage of alternative energy is a growing area of interest. Renewable hydrogen like that produced in the PlasCarb project is also significant in that, traditionally, hydrogen is primarily produced using fossil fuels (95%), while renewable hydrogen produced from food waste provides a less environmentally and economically volatile option.
 
Progress with PlasCarb
The next steps in the PlasCarb project are aimed at analyzing the market uptake and output products of the new technology. CPI said it would do this by designing an economically sustainable business strategy, along with generating a financial risk assessment of the project results and an adaptable financial model to measure the process’s economic viability.
 
PlasCarb is a 3-year collaborative project, co-funded under the European Union’s Seventh Framework Programme (FP7). The consortium is composed of eight partners led by CPI, including GasPlas AS (NO), CNRS (FR), Fraunhofer IBP (DE), Uvasol Ltd (UK), GAP Waste Management (UK), Geonardo Ltd. (HU) and Abalonyx AS (NO).
 
For more information about PlasCarb visit: www.plascarb.eu.