New breakthrough: RUDN University ecologists patented a method for producing biofuel

The 21st century is facing serious environmental problems: natural resources are being depleted, greenhouse gas emissions are increasing, and large amounts of wastewater are being generated that are poorly treated. These problems are exacerbated by dwindling fossil fuel supplies, clean water, and inadequate sanitation. Therefore, waste management facilities use wastewater as a potential source for energy generation, nutrient recovery and then reuse the treated wastewater for agricultural/domestic purposes. Among these enterprises, biological mitigation of the negative impacts of wastewater using microalgae is considered as an energy-efficient and cost-effective alternative. It provides the means to subsequently convert valuable biomass into biofuels.

The method for producing biofuel involves preliminary mixing of microalgae biomass with water. Hydrothermal liquefaction produces a microbiological suspension in one reactor block heated to 600°C at a pressure of 10-30 MPa for 1-9 minutes to form a liquefaction product. The heating of the reactor is different in that the prepared microbiological suspension is first directed into one buffer container, which, after filling, is sealed and neutral gas is supplied to it at pressure. Then the prepared biomass is fed into the working path of the hydrothermal liquefaction reactor. It includes the first cavity of the recuperative heat exchanger, the working volume of the reactor, the second cavity and a cooled container for receiving liquefaction products. The resulting gaseous products are sent to the first input of the multifuel heater of the hydrothermal liquefaction reactor. Products in the liquid phase are sent to a suction filter, from which products in the solid phase are sent to the second inlet of the multifuel heater. The remaining products in the liquid phase are sent to the decanter. From it, part of the liquid fuel is sent to the third input of the multi-fuel heater, the fourth input of which is connected to the output of the network gas supply line.

“The resulting algae biomass can be converted into biodiesel, biogas and bioethanol. Such an integrated approach could potentially provide solutions not only for effectively reducing wastewater emissions and CO2 emissions, but also for generating additional income through the use of microalgae biomass for biofuel production,” Anna Kurbatova, Associate Professor at the Institute of Ecology, Candidate of Environmental Sciences.

For reference:

Patent for invention No. 2794959 “Method for producing biofuels”.