Fuel pellets from fine paper mill sludge supplemented by sawdust and by refined recovered lubricating oil

Abstract

Fine paper mill sludge (FPMS) disposal has emerged as a problem since the dumping of FPMS was banned. This study investigated the effects of adding a refined recovered lubricating oil (ion-refined oil) to FPMS pellets to increase its heating value and combustion time and decrease ash content and ignition time. Fuel pellets were prepared in three conditions, C-1, C-2, and C-3. In C-1, ion-refined oil was added to FPMS to examine its burning capability. In C-2, two types of pellets were produced mixing sawdust and FPMS ratios of 25:75 and 50:50. A ratio of 50:50 was selected for C-3, to which the ion-refined oil was added in different ratios. The quality of the energy fuel pellets was determined using proximate and ultimate analyses, except for chlorine content, which was determined through liquid ion chromatography. The properties of fuel pellets were determined and compared with national standards. It was confirmed that the results for pellets at a ratio of 50:50 with 10% and 15% ion-refined oil were acceptable, because these results were comparatively similar to the standards. Finally, it was concluded that ion-refined oil was an effective additive to FPMS to increase the heating value for energy demand and lower the ash content.

Calorific Characteristics of Larch (Larix decidua) and Oak (Quercus robur) Pellets Realized from Native and Torrefied Sawdust

“…Ash content determination. A well-known and standardized method was used to determine the ash content of the sawdust (ASTM E1755-01) [25]. The wood sawdust was dried in a laboratory oven at 105 • C for 2 h in order to eliminate the influence of moisture content on the ash content.…”

“…This material was then transformed into torrefied pellets so that they had the same dimensional characteristics as the native ones (untreated). The torrefaction process was performed on a small amount of wooden sawdust for each temperature and time [22][23][24][25][26]. During this period, some changes in the sawdust color occurred [27][28][29].…”

“…Generally, it was determined that when the degree of torrefaction is increased (given by the values of time and temperature), the mass loss will also proportionally increase (Figure 6). Temperatures over 260 • C increased the mass loss [23][24][25][26] of oak pellets to a greater degree. A temperature of 300 • C represented the ideal temperature for torrefaction but was the highest one possible before self-burning occurs.…”

“…The obtained product was very similar to coal. The spontaneous ignition of this fuel has been shown to occur at a temperature of 211 • C. Further research has focused on both the use of other residues obtained from other industries, such as from the coffee [24] and paper [25] industries, or the internationally correlation of standardized properties [26].…”

Potential Use of Paper Mill Sludge in Improving Soil Quality for Plant Growth

“…Moreover, PMS can serve as a source of calcium, silica, and other minerals required in the cement and ceramic manufacturing process [14][15][16][17]. Additionally, due to its organic content, PMS has been explored as a potential alternative fuel source [18][19][20][21]. It can be co-fired with other fuels in power plants or used in the production of biofuels.…”