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

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