VTara’s focus is to develop technology that synergistically uses two waste biomass streams to generate two bioproducts and enhance the process of anaerobic digestion.
The digestion of wastewater can be improved sludge by incorporating biomass-derived, carbon-sequestering char within the digester, thus creating pipeline-quality renewable natural gas while using the remaining biosolids for a high-quality fertiliser.
Biochar, charcoal derived from plant material, is created in processes such as gasification and pyrolysis, which also produce energy in the form of syngas or liquid fuels. Demonstrated success using biochar from gasification of agricultural waste such as both corn stover and waste wood sources.
Anaerobic digestion usually creates biogas that is mainly a combination of carbon dioxide (CO2) and methane, and extra steps are required to upgrade the biogas to renewable natural gas by removing the CO2 and other contaminants. However, by adding biochar directly to the anaerobic digester sequesters the CO2 and creates a biogas stream that is more than 90% methane and less than 5 parts per billion hydrogen sulfide.
The biochar was also said to improve many of the operating conditions for anaerobic digestion, and furthermore, it is nutrient-rich, so the digestate left after the process is completed can serve as a high-quality fertilizer.
- To drive the commercialisation of the technology could dramatically improve the economics of anaerobic digestion projects.
- To further reduce capital and operating expenses by improving digester conditions and producing fertilizer, which would provide even greater economic benefit.
- To demonstrate of waste to energy technologies for sustainable, cost-competitive biofuels and bioproducts from cellulosic biomass.