Collaborative logistics and eco-efficiency indicators: an analysis of soy and fertilizer transportation in the ports of Santos and Paranaguá

The present study aims to investigate the use of collaborative logistics between soybean export and fertilizer import operations in the main logistical corridors in the state of Mato Grosso to the ports of Santos and Paranaguá, aiming to identify, analyze and propose an indicator of eco-efficiency that seeks to reduce the financial and environmental impacts of this practice. For that, two scenarios were analyzed, namely: base and ideal. In the ideal scenario, the entire imported fertilizer load participates in collaborative logistics. The base scenario was defined by applying a questionnaire to 96 drivers working in the ports of Santos and Paranaguá, thus identifying the incidence of trucks that return loaded from the port areas with fertilizers. Comparing the base scenario with the ideal scenario, the potential impact regarding the costs of road transport of fertilizers is around R$14,696,509.89 in the port of Santos and R$ 11,806,055.10 in Paranaguá, totaling R$ 26,502,564.99. In the ideal scenario, there was a reduction in CO2 emission during 2018 in the order of 29.48 kg CO2 per ton transported in the port of Santos, with the reduction obtained in Paranaguá was 14.38 kg CO2 per ton

Environmental and economic issues concerning the use of wet scrubbers coupled to bagasse‑fired boilers: a case study in the Brazilian sugarcane industry

For decades, wet scrubbers have been used to control particulate matter (PM) emitted by bagasse-fired boilers in the sugarcane industry. This choice was justified by their acceptable performance in meeting environmental standards, the abundance of water resources, and the fact that their operation was simpler and less expensive than other dry cleaning operations. However, the progressive tightening of PM emission limits, as well as the need for more rational water and wastewater management in these applications, has changed this aspect of the industry. Despite the extensive technical literature on wet scrubbers, the lack of up-to-date indicators of their performance in sugarcane industries has prevented the optimization of wet scrubbing processes. This paper clearly shows that the use of wet scrubbers can result in significant water and heat losses, as well as high operating costs for wastewater treatment stations (WTSs). Mass and energy balances were determined for a typical ethanol-sugar plant operating in Brazil, which is the world’s largest sugarcane producer. The key boiler and scrubber performance indicators were evaluated experimentally over the course of a crop season and were compared to the legal particulate emission and water quality requirements in Brazil. The boiler processed an average of 114.8 t/h of bagasse containing 46.8% moisture and generated 4.75 t of gas and 28.2 kg of PM for each ton of dry burned bagasse. Of the total PM (ash and soot), 68% was collected as dry material in the grate, heat exchangers, and multicyclone; 25% was collected in the wet scrubber; and 7% was emitted to the atmosphere, in compliance with the Brazilian standards. The operation of the WTS linked to the gas cleaning system was inefficient, using 70% of the water to convey the dry PM retained in the boiler, heat exchangers, and multicyclone and only 30% to operate the wet scrubber. Evaporation caused the loss of 10.5% of the scrubbing water to the atmosphere. The transportation of moist cake (7.9 t/h, 78% wb) for disposal in fields resulted in significant fuel costs and water losses. The operation of the WTS accounted for 62% of the total capital expenditure of the cleaning system, while the wet scrubber accounted for only 38%. This work provides updated performance indicators and alternatives for optimizing a gas cleaning system to promote more rational water and wastewater management and savings for the sugarcane sector

Permeability Behavior and Wastewater Filtration Performance of Mullite Bonded Porous SiC Ceramic Membrane Prepared Using Coal Fly Ash as Sintering Additive

With SiC as starting powder, waste fly ash as sintering additive and metal oxide as catalyst, mullite bonded SiC ceramic membrane was prepared at 1000 degrees C using the conventional solid-state reaction method. Permeability parameters in both air and water flow tests were obtained using laboratory made set-up and the pure water permeability was measured at variable transmembrane pressures. The membrane exhibited excellent pure water flux of 5261 L.m(-2).h(-1).bar(-1) with open porosity of 44.7% and mean pore size of 3.7 mu m. With this membrane a high oil removal efficiency of 91% was achieved from the kitchen wastewater having initial oil concentration of 1657 mg.L-1. The method developed here is technologically benign and addressed prevention of environmental pollution by utilizing hazardous waste material for fabrication of porous SiC ceramic membrane at a reduced cost with good mechanical, permeability characteristics and wastewater filtration efficiency. Hence, the proposed method for SiC membranes has good sustainability and is scalable for oily wastewater treatment

High-efficiency aerosol filters based on silicon carbide foams coated with ceramic nanowires

none4sinoneInnocentini, Murilo Daniel De Mello; Coury, José Renato; Fukushima, Manabu; Colombo, PaoloInnocentini, Murilo Daniel De Mello; Coury, José Renato; Fukushima, Manabu; Colombo, Paol