Techno-Economic Evaluation of Co-Removal of NOx and SOx Species from Flue Gases via Enhanced Oxidation of NO by ClO2—Case Studies of Implementation at a Pulp and Paper Mill, Waste-to-Heat Plant and a Cruise Ship

Abstract

Co-absorption of NO2 and SO2 from flue gases, in combination with the enhanced oxidation of NO by ClO2(g), is studied for three different flue gas sources: a medium sized waste-to-heat plant; the kraft recovery boiler of a pulp and paper mill; and a cruise ship. Process modeling results are used to present the technical potential for each site together with cost estimation and optimization using a bottom-up approach. A process set-up is proposed for each site together with equipment sizing and resulting flows of process fluids. The simulation results, supported by experimental results, show that removal rates equal to or greater than current best available technologies are achievable with more than 90% of NOx and 99% of SO2 removed from the flue gas. The resulting cost of removing both NOx and SO2 from the flue gases is 2100 €/ton for the waste-to-heat plant, 800 €/ton for the cruise ship and 3900 €/ton for the recovery boiler. The cost estimation show that the consumption and cost of chemical additives will play a decisive role in the economic feasibility of the investigated concept, between 50% and 90% of the total cost per ton acid gas removed.

Role of Sulfite Oxidation in NO2 Absorption in a pH-Neutral Scrubber Solution

“…Several previous studies have investigated the chemistry of simultaneous absorption of SO 2 and NO 2 . ,− Li et al investigated the NO 2 absorption in a Na 2 CO 3 solution with SO 2 gas concentrations between 500 and 2000 ppm. With 500 ppm SO 2 , the NO 2 concentration decreased from 300 to 150 ppm, while with 2000 ppm SO 2 , the NO 2 concentration decreased from 300 to 100 ppm.…”

“…Additionally, higher sulfite additions might be required due to the lack of SO 2 . Johansson et al performed technoeconomic evaluations for the simultaneous absorption of SO x and NO x from various industrial processes . The presented case of a recovery boiler required the highest sulfite addition as was the case with the lowest SO 2 concentration.…”

“…The presented case of a recovery boiler required the highest sulfite addition as was the case with the lowest SO 2 concentration. In such cases, it is crucial to understand the consumption of sulfite by NO 2 and SO 2 to reduce the overall consumption of chemicals . Johansson et al investigated the simultaneous absorption of NO x and SO x from flue gases from a 100 kW gas-fired furnace.…”

Role of Thiosulfate in NO2 Absorption in Aqueous Sulfite Solutions

“…NO 2 absorption in aqueous sulfite solutions has recently gained more attention in order to reduce NO x emissions from thermal conversion of non-recyclable waste and fuels with high nitrogen contents. − The NO x in flue gases consists mostly of NO. Due to the low solubility of NO in water, NO is oxidized to NO 2 which has a higher solubility in water. , NO 2 reacts with water forming nitrite and nitrate (see R ).…”

Estimation Complete Combustion Coefficient in Rotary Kilns

“…A literature review indicates that presently a great number of studies are being conducted worldwide with the aim of improving the environmental safety as well as technical and economic efficiency of waste incineration processes. For example, issues related to reduction of emission of harmful substances to the natural environment are discussed in papers [5][6][7][8][9][10]. The conditions of energy and material recovery in these processes have been tackled in articles [11][12][13].…”