The Bioconversion of Sewage Sludge to Bio-Fuel: The Environmental and Economic Benefits

Abstract

This paper aims to analyze the economic feasibility of generating a novel, innovative biofuel—bioenergy—obtained from deposit bio-components by means of a pilot installation of sewage sludge bio-conversion. Fuel produced from sewage sludge biomass bears the potential of being considered a renewable energy source. In the present study, 23 bioconversion cycles were conducted taking into consideration the different contents, types of high carbohydrate additives, moisture content of the mixture as well as the shape of the bed elements. The biofuel was produced using post fermentation sewage sludge for industrial energy and heat generation. Based on the presented research it was concluded that the composite biofuel can be co-combusted with hard coal with the optimal percentage share within the range of 20–30% w/w. Sewage sludge stabilized by means of anaerobic digestion carried out in closed fermentation chambers is the final product. The average values of the CO2, CO, NO, NOx and SO2 concentrations in flue gas from co-combustion of a bioconversion product (20% w/w) and coal were 5.43%, 1903 ppm, 300 ppm, 303 ppm and 179 ppm, respectively. In total, within a period of 4.5 years of the plant operation, 1853 Mg of fuel was produced and successfully co-combusted with coal in a power plant. The research demonstrated that in the waste water treatment sector there exists energy potential in terms of calorific value which translates into tangible benefits both in the context of energy generation as well as environmental protection. Over 700,000 Mg of bio-sewage sludge is generated annually in Poland. According to findings of the study presented in the paper, the proposed solution could give 970,000 Mg of dry mass of biomass qualified as energy biomass replacing fossil fuels.

Farm Machinery and Processes Management in Sustainable Agriculture

“…(2019), caused by the rapidly growing population growth and urbanization, this is also confirmed by analyses carried out by e.g. Smoliński et al (2019). Unfortunately, the diversity of wastewater types, their origin and the production / treatment process leads to differences in sludge properties.…”

Influence of Valorization of Sewage Sludge on Energy Consumption in the Drying Process

“…Biomass burning reduces the balance of CO 2 emissions because the amount of CO 2 previously collected from the environment is released into the atmosphere. The low nitrogen content of biomass waste reduces the emissions of NO x compounds into the atmosphere compared to burning coal [55,56].…”

“…Biomass burning reduces the balance of CO2 emissions because the amount of CO2 previously collected from the environment is released into the atmosphere. The low nitrogen content of biomass waste reduces the emissions of NOx compounds into the atmosphere compared to burning coal [55,56]. The diagram (Figure 11) shows a typical solution for a sewage treatment plant (a) and the feasibility of the solution presented in the article (b) that would consist in the use of a "bypass" between the centrifuge and, for example, a sludge belt dryer.…”

Advanced Biofuels Based on Fischer–Tropsch Synthesis for Applications in Diesel Engines

“…Second-generation biofuels have the potential to reduce CO 2 emissions by up to 90% compared to fossil fuels. According to the LCA analysis, second-generation biofuels show a significant positive difference in the balance of CO 2 production during their life cycle [ 10 , 11 ].…”