Industrial demonstration shows enhanced production of advanced biofuels
Researchers have developed new technologies that can be used to convert industrial plants to produce fossil-free heat, electricity, fuel, chemicals and materials. They say the technical potential is enormous: using only Sweden's currently existing power plants, renewable fuels equivalent to 10% of the world's aviation fuel could be produced.
The study offers a chance to switch to renewable sources for heating, electricity and fuel, while also providing new opportunities for several industries to produce large numbers of renewable products. The researchers have now offered a way to implement radical changes that could be applied to new installations and in thousands of existing plants around the globe.
The solution involves widespread gasification of biomass, which by itself is not new. At high temperatures, biomass is converted into a gas that can then be refined into end-products that are currently manufactured from oil and natural gas. The Chalmers team has shown that one possible end-product is biogas that can replace natural gas in existing gas networks.
Previously, the development of gasification technology has been hampered by problems with tar being released from the biomass, which interferes with the process in several ways. Now, the researchers have shown that they can improve the quality of the biogas through chemical processes, and the tar can also be managed in new ways. This, in combination with a parallel development of heat-exchange materials, provides new possibilities for converting district heating boilers to biomass gasifiers.
"What makes this technology so attractive to several industries is that it will be possible to modify existing boilers, which can then supplement heat and power production with the production of fossil-free fuels and chemicals," says Martin Seemann, associate professor of Energy Technology at Chalmers.
"We rebuilt our own research boiler in this way in 2007, and now we have more than 200 man-years of research to back us up," says Professor Henrik Thunman. "Combined with industrial-scale lessons learned at the GoBiGas (Gothenburg Biomass Gasification) demonstration project, launched in 2014, it is now possible for us to say that the technology is ready for the world."
The facilities that could be converted to gasification are power and district heating plants, paper and pulp mills, sawmills, oil refineries and petrochemical plants. The facilities that could be modified have a type of combustion boiler called a fluidised bed.
In total, over 100 plants in Sweden have fluidised bed boilers.
If all of these plants were modified to biomass gasifiers, they would be able to produce 346TWh of biogas per year or 278TWh of aviation fuel, given sufficient biomass availability. The researchers say that this corresponds to approximately 1% of the world's total natural gas consumption in 2013 and approximately 10% of the world's total aviation fuel consumption in 2014 respectively.
The technology is very flexible when it comes to end-products. Gasification of biomass produces syngas, which can then be converted to a variety of hydrocarbons. In addition to biogas and aviation fuel, it’s also possible to produce methanol, gasoline and diesel.
