@article{banerjee_sastri_aggarwal_hakovirta_2022, title={Dewatering coal with supercritical Carbon Dioxide}, volume={42}, ISSN={["1939-2702"]}, DOI={10.1080/19392699.2020.1715962}, abstractNote={ABSTRACT Supercritical CO2 (sCO2) dewaters coal through two mechanisms. For bituminous coal of 9.5% average moisture content the water is dissolved out of the coal and the concentration of water in the bulk sCO2 approximates its solubility limit. For lignite (54% average moisture content) the water extracted by the sCO2 exceeds its solubility limit in sCO2, which implies that a part of the water is displaced from, rather than dissolved out of the coal. Thus, there is a clear distinction between wet coals where most of the water is displaced, as compared to drier coals where the water is dissolved out. Hence, sCO2 dewatering will be especially efficient for high-moisture coals where there is significant free water available for displacement. Precedent for this process is available from the dewatering of wood flakes.}, number={5}, journal={INTERNATIONAL JOURNAL OF COAL PREPARATION AND UTILIZATION}, author={Banerjee, Sujit and Sastri, Bhima and Aggarwal, Salonika and Hakovirta, Marko}, year={2022}, month={May}, pages={1393–1399} }
 @article{aggarwal_hakovirta_2021, title={Supercritical carbon dioxide drying of municipal sewage sludge - Novel waste-to-energy valorization pathway}, volume={285}, ISSN={["1095-8630"]}, DOI={10.1016/j.jenvman.2021.112148}, abstractNote={Eighty percent of the world's wastewater is discharged back into nature without reuse and further treatment and solid byproduct of wastewater is either spread on land or landfilled. The valorization of municipal sewage sludge for energy use is a major opportunity for sustainable energy applications. This includes effective dewatering and drying of the sludge in addition to producing biogas during the anaerobic digestion. Supercritical CO 2 extraction process was investigated for the purpose of drying municipal sewage sludge. Remarkably our results showed that after sCO2 processing the higher heating value (HHV) of sludge at wet basis moisture content of 52% was 14 MJ/kg and thus higher than the HHV of brown coal with similar moisture level (12 MJ/kg). Our research also shows that under specific conditions sCO2 extraction reduces the moisture content of the municipal sludge from 89% to 53% in 15 min. Although, more research is needed this dewatering process could be considerably less energy intensive than conventional thermal and other drying processes. Another benefit is extraction of micro pollutants by sCO2 treatment and thus making the dried sludge more useable in energy applications as per regulations. Our results show an alternative and novel pathway for highly effective dewatering and drying of municipal and other types of sludge.}, journal={JOURNAL OF ENVIRONMENTAL MANAGEMENT}, author={Aggarwal, S. and Hakovirta, M.}, year={2021}, month={May} }
 @article{aggarwal_johnson_saloni_hakovirta_2019, title={Novel 3D printing filament composite using diatomaceous earth and polylactic acid for materials properties and cost improvement}, volume={177}, ISSN={["1879-1069"]}, url={http://dx.doi.org/10.1016/j.compositesb.2019.107310}, DOI={10.1016/j.compositesb.2019.107310}, abstractNote={There are a large variety of different materials currently used for producing 3D printing filaments. In this paper we are investigating the utilization of diatomaceous earth as a potential component for polylactic acid based 3D printing composite materials. The results clearly show that with only minor deterioration of the basic mechanical properties of the 3D printed material at least 10 wt% of the polylactic acid usage can be reduced and replaced by diatomaceous earth. Our thermal analysis also shows nucleation and chain mobility phenomena in the presence of diatomaceous earth particles. The results also show that we are able to engineer 3D printing surfaces with diatomaceous earth protruding from the composite structure and thus allowing us to create high surface area on the 3D printed objects surface. With this research we have shown for the first time an opportunity for cost reduction compared to using pure polylactic acid filaments and a pathway to immobilizing chemical sensing, antibacterial and antiviral agents on 3D printed objects for many applications such as biomedical.}, journal={COMPOSITES PART B-ENGINEERING}, author={Aggarwal, Salonika and Johnson, Shelly and Saloni, Daniel and Hakovirta, Marko}, year={2019}, month={Nov} }
 @article{aggarwal_johnson_hakovirta_sastri_banerjee_2019, title={Removal of Water and Extractives from Softwood with Supercritical Carbon Dioxide}, volume={58}, ISSN={["0888-5885"]}, DOI={10.1021/acs.iecr.8b05939}, abstractNote={Supercritical CO2 (sCO2) removes both water and extractives from wood chips and flakes at 60 °C. The water appears to be mostly displaced by sCO2 because its nominal concentration in sCO2 exceeds its solubility limit. SEM imaging and contact angle measurements show no major differences in surface properties between sCO2-treated and thermally dried flakes, which suggests that their interaction with resin should be similar. An economic analysis for the removal of water and extractives from pine flakes for the manufacture of oriented strand board shows that sCO2 treatment is potentially much more cost-effective than thermal drying from both capital and operational perspectives. The main reasons are that the water is removed by displacement rather than through evaporation, environmental control costs are drastically reduced, and the extractives removed represent a value stream instead of pollutants whose emissions need to be controlled. Because the sCO2 is largely recirculated, the process is greener than con...}, number={8}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Aggarwal, Salonika and Johnson, Shelly and Hakovirta, Marko and Sastri, Bhima and Banerjee, Sujit}, year={2019}, month={Feb}, pages={3170–3174} }