Preliminary investigation to characterize deposits forming during combustion of biogas from anaerobic digesters and landfills

Abstract

Available onlineKeywords: Silicate-deposits Landfill gas Biogas Municipal solid waste Digester Combustion engine a b s t r a c tThe objectives of this study were to compare composition and morphological characteristics of the deposits forming in engines operated with biogas from anaerobic digesters and from landfills. Engine deposit samples were collected from biogas to energy facilities in Florida, USA. The deposit samples were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Similarities and differences between the deposit samples collected from the engines operated with biogas from anaerobic digesters and biogas from landfills were analyzed in terms of chemical composition and morphology. The sample obtained from the anaerobic digester gas did not contain potassium while calcium and zinc were present at a higher ratio. Relatively high levels of carbon were present in the crystalline deposits forming during the combustion of biogas. C:O:Si ratios were about 5:7:1 in the deposits obtained from the engines operated with biogas from the anaerobic digesters and 2:3.5:1 in the deposits from the engines operated with landfill gas. In general, the silicon content from deposits found in facilities utilizing biogas from anaerobic digesters was lower than those operated with landfills gas. The difference was made up with higher phosphorus, sulfur and calcium content in the deposits from the engines operated with digester gas.

Mineral Deposit Formation in Gas Engines During Combustion of Biogas from Landfills and Municipal WWTP

“…In general, the silicon species content in biogas derived from biogas plant integrated with municipal wastewater treatment plant was lower compared to their content in a biogas from landfill wastes. A higher content of phosphorus, sulphur and calcium was additionally identified in the sludge from agricultural biogas-powered engines [28].…”

Regulated Emissions of Biogas Engines—On Site Experimental Measurements and Damage Assessment on Human Health

“…Problems in engine running with biogas. Surita and Tansel [66] compared the deposits formation during combustion of biogas derived from anaerobic digesters and landfills. Engine deposits are analysed to determine their chemical composition and morphology.…”

Fluctuations of the elemental composition in the layers of mineral deposits formed on the elements of biogas engines

“…In addition to hydrogen sulphide in biogas, there are several hundred other compounds in trace amounts, among them organohalogen and organosilicon. They can cause the destruction of installations and devices for the energy use of biogas, raising the operating and investment costs for treatment by various methods [3][4][5][6][7][8][9][10][11][12][13][14][15][16] . Commonly occurring in sewage sludge organosilicon compounds -siloxanes play a special role.…”