Biomass ashes as potential raw materials for mineral wool manufacture: initial studies of glass structure and chemistry

Abstract

The energy intensive and CO2-generating nature of commercial mineral wool and glass production necessitates advances and changes in materials and processes. The derivation of raw materials from waste products arising from biomass energy generation offers the possibility of a two-fold environmental benefit: partial replacement of carbonate raw minerals in production, leading to lower CO2 release during melting; and the utilisation and valorisation of byproducts which may otherwise be sent to landfill. Glass samples with a basaltic mineral wool composition were produced with additions to the raw materials of 0, 1, 5 and 10 wt% of a fly ash and a bottom ash arising from biomass combustion. The resulting glasses were analysed by x-ray fluorescence, x-ray diffraction, dilatometry, 57Fe Mössbauer and Raman spectroscopies, and their densities, molar volumes and viscosity–temperature profiles were calculated and compared against benchmark glass samples. All biomass ash-containing glasses were closely similar in both composition and properties to the benchmark glass, with up to 10 wt% ash additions to the raw materials. In addition, the use of the biomass fly ash led to a reduction in batch CO2 content estimated to be 1·5 kg CO2 per tonne of batch for each 1 wt% addition. These initial results provide evidence supporting the further development of these ash materials as potential value-added raw materials for mineral wool manufacture.

Alternative raw material research for decarbonization of UK glass manufacture

“…[20][21][22][23][24] However, the benefits of introducing biomass ash as an alternative glass raw material are potentially numerous. [50][51][52] It is therefore very important to note and understand the historical context of plant-based ashes in glassmaking. Biomass ashes are known to contain elements including Si, Al, Na, Mg, P, and especially K and Ca in the form of oxides, which have potential value in glass manufacture as alternative raw materials.…”

“…Most ashes generated from biomass power plants are currently sent to landfill or used in lower‐value applications such as road building, water, and soil treatment, or concrete and cement production after further processing 20–24 . However, the benefits of introducing biomass ash as an alternative glass raw material are potentially numerous 50–52 . It is therefore very important to note and understand the historical context of plant‐based ashes in glassmaking.…”

“…After extensive investigations on different types of biomass ashes from multiple biomass power plants across the UK, 50,53 a typical bottom biomass ash, generated in a UK biomass power plant by burning herbaceous biomass fuel, was selected as a potential alternative raw material for glass manufacturing. Biomass ash samples were collected in different time periods during stable production phases for further processing and characterization.…”