Investigations on the Influence of Additives for SO₂ Reduction during High Alkaline Biomass Combustion

Abstract

Straw and other biomasses can cause severe problems when used as fuel in combustion systems. Some of the major problems include high emission of alkalis, HCl, and especially SO 2 to the gas phase. The development of low-cost primary measures for achieving a SO 2 emission below the European Union (EU) emission limit of 200 mg/Nm 3 without the need for the installation of a flue gas desulfurization unit requires an increased understanding of the chemistry of biomass combustion. For this reason, laboratory combustion experiments with two different high alkaline (HIAL) biomasses doped with additives have been conducted in the temperature range of 800-1100°C. The use of a high-pressure mass spectrometry (HPMS) sampling technique allows the on-line specification of combustion byproducts such as K, Na, S, and Cl species in the combustion flue gases. The results of the measurements show that the SO 2 emission may be related to the K/S and K/Si ratios in the initial samples. The release of potassium is mostly dependent on the chlorine content of the samples. Calcium-and potassium-based additives are able to reduce the release of SO 2 into the gas phase.

A thermodynamic study of the gaseous potassium chemistry in the convection sections of biomass fired boilers

“…Part of the potassium reacts with the fuel ash in the furnace forming K 2 OSiO 2 or Al 2 O 3 -SiO 2 -K 2 O silicates [3,18,19]. Another route for the gaseous potassium capture is the reaction with the fuel sulfur:…”

“…The high alkali content accompanied with the often low sulfur and silicon contents of the biomass based fuels leads to high amounts of gaseous alkali compounds in the flue gases that condense on the heat transfer surfaces causing fouling and corrosion [2,3]. Potassium is by far the major alkali in most types of biomass, sodium being present in significant proportions in some biomass fuels, for example in black liquor.…”

Sintesis Zeolit-A dari Abu Dasar Batubara dengan Pemisahan Fe dan Ca

“…Penentuan komposisi kimia yang terkandung dalam abu dasar sangat penting karena dapat diketahui prosentase kandungan berat Si dan Al dalam abu dasar yang merupakan komponen utama dalam pembuatan zeolit. Hasil analisa abu dasar dengan X-Ray Flourescence (XRF) dapat ditunjukkan pada Tabel (1) CaO(s)+HCl(aq) → CaCl 2 (aq)+H 2 O(l) [11] (2) Fe 2 O 3 (s)+HCl(aq)→2FeCl 3 (aq)+3H 2 O(l) [12] (3)…”

Investigations at High Temperature with Molecular Beam Mass Spectrometry Under Equilibrium and Kinetic Conditions

“…Biomass as a source for renewable energy reaches a biological equilibrium during growth period and its content in terms of mineral matter is related to manuring. To understand the correlation between mineral matter and release of K, Cl and S, four types of biomass samples were investigated (10,11). These studies on selected straws containing different inorganic constituents represent the biological variation.…”