Using quail waste as an adsorbent on biogas quality

The aim of this research is to determine the effect of coconut and mineral waste of quail as adsorbents on the biogas purity. This research was designed to use the Completely Randomized Design (CRD) method with 6 treatments and 4 replications and the significant influence will be tested using Duncan Test. The result form this research showed that the use of coconut waste and mineral waste of quail as adsorbents gives highly significant influence (P<0,01) to increase the CH4 gas concentration, highly significant influence (P<0,01) to decrease CO2 gas concentration, highly significant influence (P<0,01) to decrease gas pressure and highly significant influence (P<0,01) to increase gas flow rate on biogas purity. The conclusion of this research is the use of 100% of activated coal from coconut waste, the use of 50% of activated coal from coconut waste and 50% of mineral waste from quail waste as an adsorbent are able to increase the quality of biogas. However, it is lack of effectiveness due to inappropriate application of biogas purification. It is suggested to do physical activation for both adsorbents in order to avoid saturation of the adsorbent so those absorbents be able to adsorb optimally the impurities gases on biogas.

Experimental studies of in-line gasification of mechanically activated coal fuel

The 1 MW experimental stand was modernized with a scroll swirler and a crushed fuel supply system. Comparative data on combustion and gasification of coal fuel crushed in high-stress mills - disintegrator, vibrocentrifugal and hammer mill - at a stand with a thermal power of 1 MW were obtained. The experiments used coal of the Kuznetsk Basin, grade D, with technical characteristics: Wr, % = 5.4; Ar, %=22.3; Vr, % = 32.3; Qsr, MJ/kg = 20.0. Elemental analysis showed that: Cr, %=54.6; Hr, % = 4.1; Nr, % = 1.3; Sr, % = 0.5; Or = 11.8. In experiments with grinding coal on a disintegrator mill, the value of H2 = 4.5 vol.% and CO = 9.4 vol.%, when grinding in a vibro-centrifugal mill, the values of H2 = 0.6 vol.% and CO = 5.8 vol.%, when grinding in a hammer mill, the values of H2 = 0.3 vol.% and CO = 2.8 vol.%. When studying the combustion of mechanochemically treated coal samples, it was found that, all other things being equal, the gasification parameters, namely, the gas concentration and the distribution of temperature zones, depend strongly on the type of equipment used for processing. In particular, processing to approximately the same degree of fineness in mechanical mills-activators with constrained impact and in free impact mills (disintegrators) resulted in different flame parameters.

Effects of Expansive Additives on the Shrinkage Behavior of Coal Gangue Based Alkali Activated Materials

The suitability of applying shrinkage reducing additives in alkali activated coal gangue-slag composites is discussed in this study. The effect of sulphoaluminate cement (SAC), high performance concrete expansion agent (HCSA) and U-type expansion agent (UEA) on the reaction process, shrinkage behavior, phase composition, microstructure and mechanical properties are evaluated. The results show that the addition of SAC slightly mitigates the early stage reaction process, while HCSA and UEA can either accelerate or inhibit the reaction depending on their dosage. The addition of SAC presents an ideal balance between drying shrinkage reduction and strength increment. As for HCSA and UEA, the shrinkage and mechanical properties are sensitive to their replacement level; excessive dosage would result in remarkable strength reduction and expansion. The specific surface area and average pore size of the hardened matrix are found to be closely related with shrinkage behavior. SAC addition introduces additional hydrotalcite phases within the reaction products, while HCSA and UEA mainly result in the formation of CaCO3 and Ca(OH)2. It is concluded that applying expansive additives can be an effective approach in reducing the drying shrinkage of alkali activated coal gangue-slag mixtures, while their type and dosage must be carefully handled.