The Italian Biogas and Composting Consortium (CIC), an association of over 130 companies and public authorities, presented a project to produce biofuel from waste at the Ecomondo fair.
And Waste Becomes Natural Gas
Ecomondo is dedicated to green technologies and held in Rimini. For this year’s edition, the CIC introduced a new way to produce biomethane from the organic fraction of municipal waste and agricultural cuttings. An upgrade procedure then turns it into biogas. By raising the relative amount of methane and reducing the amount of CO2, it is possible to approach the quality of natural gas.
CIC biogas is refined biomethane, the result of anaerobic digestion of domestic wet organic waste in a controlled environment. The resulting biogas containing 60% methane is then treated to reduce the proportion of CO2 and hydrogen, bringing the CH4 concentration to over 98%.
This cleansing process involves mechanisms that remove water, hydrogen sulfide and unwanted contaminants. Different methods can be used: biological desulfurization, adding ferrous or ferric chloride, activated carbon, scrubbing with sodium hydroxide, using organic-phase amines and formation of hydrates, molecular sieves and polymeric membranes, cooling to 2-5 °C to remove H2O or -23°C for siloxanes.
For the moment, the biofuel obtained is only suitable for automotive applications.
An Ethical Biofuel
According to the European Biogas Association, Italy is the second biggest biogas producer in the EU in terms of number of facilities (1264 in 2012) and cubic meters generated, just behind Germany. But CIC companies are the only ones producing ethical biofuel, using clearly sourced biomass (domestic wet organic waste such as food scraps) in their digesters. Beyond the technologies involved, this is a real innovation.
CIC Director Massimo Centemero stated,
“Our flagship plant is a company in Montello, near Bergamo. Other plants are located in Bassano del Grappa (Vicenza), Este (Padova), Pinerolo (Turin) and a group of five in Emilia-Romagna. However, there are no technical standards enabling them to extend the network to distributors or into homes, even if plant procedures already have been approved and the granting of incentives authorized.”
The potential is considerable. The total Italian wet waste production capacity could rise to 500 million cubic meters of biomethane per year, about 1% of national demand.