As mankind heads towards a decarbonised global economy, cleaner energy sources are increasingly sought after. Hydrogen could reduce both pollution and the production of harmful greenhouse gases. However, most of the hydrogen currently produced comes from natural gas, coal or oil, all of which create carbon dioxide. Biomass, though, is an almost carbon-neutral renewable energy source. The anaerobic digestion process of residual biomass from various sources – animal waste, sewage treatment plants, industrial wastewater and landfills, for example – produces biogas, a mixture of methane and carbon dioxide. The BIONICO project is assembling a pilot plant to convert biogas directly into hydrogen. The project has developed, built and will soon demonstrate a new system at a real biogas plant, with a novel reactor concept at its core. The plant is expected to produce 100 kg of hydrogen per day. The plant will be the first example of a biogas-to-hydrogen plant based on membrane reactor technology installed in a real biogas plant. “Compared with any other membrane reactor project in the past, BIONICO will demonstrate the membrane reactor at a much larger scale, with more than 100 membranes in a single fluidised bed membrane reactor,” says Dr Marco Binotti from the Polytechnic University of Milan and BIONICO project coordinator. The BIONICO consortium is made up of eight partners from seven different countries across the EU. Each partner has been involved in a different aspect of the mission, such as the design and testing of the reactor together with the main system components. The BIONICO project is based on knowledge gained from three previous projects: ReforCELL, FERRET and FluidCELL. A catalytic core Central to the BIONICO plant is an innovative catalytic membrane reactor. This novel reactor integrates hydrogen production and separation in a single step, leading to over 70 % reaction conversion efficiency at 500-550 °C. Biogas is directly fed to the BIONICO reactor along with steam and air. With the presence of an added catalyst, even at these relatively low temperatures, reactions sustained by the combustion of the methane in the biogas can convert the methane into hydrogen and carbon dioxide. “The yield of this conversion process would be quite limited due to the low operating temperatures. But this can be overcome thanks to the presence of the membranes. Palladium-based membranes act like filters through which only hydrogen permeates. This means the hydrogen can then be collected as an almost pure stream,” explains Dr Binotti. Fuelling a future of sustainable energy The project has many goals. Economically, it aims to show the feasibility and cost-effectiveness of the solution and define the market potential for the new plant. Environmentally, BIONICO wants to establish biogas-produced hydrogen as a viable sustainable energy source, and to quantify the potential environmental benefits from using such plants in the long term. Dedicated tests with different biogas compositions will be carried out to show the flexibility of the process with respect to the biogas type. The project is now in its most important phase: the reactor is currently installed in a lab and, by the end of the year, will undergo a 500-hour test with synthetic biogas. Subsequently, another 2 500 hours of testing will start in a Portuguese landfill site. “Considering that nowadays about 95 % of hydrogen is produced from fossil fuels, I think it is important to remember that the hydrogen provided by BIONICO comes from biogas and it is thus green,” says Dr Binotti.
BIONICO, landfill, energy, hydrogen, animal waste, biomass, biogas, sustainable, green, methane, steam