The separation of ultrafine coal from three Chinese coal samples of easy degradation coal fines in water has been investigated by the application of a hydrophobic agglomeration process. In addition to yielding clean c...The separation of ultrafine coal from three Chinese coal samples of easy degradation coal fines in water has been investigated by the application of a hydrophobic agglomeration process. In addition to yielding clean coal with high recovery, this process requires significantly less oil concentration for agglomeration (less than 0.4% in oil-water weight ratio) and produces stabler agglomerates than general oil agglomeration process, the cost of the oil would no longer be an important consideration for its commercial application. Neutral diesel oil was used to make oleophilic coal particles agglomerated with good rejection of clay minerals under little oil consumption and certain agitation speed at 2000 r/min. An important advantage of this process compared with other cleaning fine coal methods is that it can extremely reduce or eliminate the effects of coal degradation and some clay minerals on coal preparation.展开更多
To make microbial community be applied more easily in practical biotreatment engineering,three acclimation processes were carried out in lab scale. Three kinds of mixed microorganism cultures with degradability for a ...To make microbial community be applied more easily in practical biotreatment engineering,three acclimation processes were carried out in lab scale. Three kinds of mixed microorganism cultures with degradability for a gas-making plant wastewater were obtained. The degradation experiments results of coal-gas wastewater indicated that different acclimation processes had obviously impacted on degradability of microbial community,and under high sludge loading rate,mixed microorganism cultureⅠ(obtained by H.S.B as bacteria source and raw wastewater as alone carbon and energy source)presented stronger degradability for coal gasification wastewater than the others. COD removal rate of mixed cultureⅠcan reach 57.6% under very low MLSS when the influent COD is 900 mg/L. Meanwhile,the results of microscopic examination showed that Protozoa,mainly epistylis and Vorticella species,were stronger activity and larger quantities in mixed cultureⅠ.展开更多
A degradative solvent extraction(DSE)method was proposed to upgrade low-rank coals(LRC)for their cascaded utilizations in a highly-dispersed medium.The derived products exhibited well improved properties in comparison...A degradative solvent extraction(DSE)method was proposed to upgrade low-rank coals(LRC)for their cascaded utilizations in a highly-dispersed medium.The derived products exhibited well improved properties in comparison to the raw LRCs.Previously,the LRCs were pre-dried to eliminate the potential impact of the varied water content of raw LRCs,but in light of the abundant water in fresh coals,the hydrolyzing effect of water on coals under heating,and the energy cost to pre-dry the LRCs,it is consequently essential to clarify the effect of water so as to verify the necessity of pre-drying process.In this study,the roles of inherent water and extra-added water were respectively investigated,using dried,raw and wet coals from two typical LRCs.The results show that increasing the moisture content of raw LRCs contributed to the extraction ability of DSE method without noticeably changing the elemental composition,chemical structure and thermal decomposition behavior of extractable products,thus pre-drying of LRCs before DSE treatment was proven unnecessary.Additionally,the roles of the inherent water were concluded as:1)leading to the formation of stable covalent bond during drying process;and 2)acting as H donor to promote extraction ability,while the added water can only function as H donor.Since excessive water will increase the pressure during DSE treatment and lead to the waste water treatment,the LRCs with a water content between 10%and 30%were consequently recommended for the practical application of DSE treatment.展开更多
文摘The separation of ultrafine coal from three Chinese coal samples of easy degradation coal fines in water has been investigated by the application of a hydrophobic agglomeration process. In addition to yielding clean coal with high recovery, this process requires significantly less oil concentration for agglomeration (less than 0.4% in oil-water weight ratio) and produces stabler agglomerates than general oil agglomeration process, the cost of the oil would no longer be an important consideration for its commercial application. Neutral diesel oil was used to make oleophilic coal particles agglomerated with good rejection of clay minerals under little oil consumption and certain agitation speed at 2000 r/min. An important advantage of this process compared with other cleaning fine coal methods is that it can extremely reduce or eliminate the effects of coal degradation and some clay minerals on coal preparation.
基金Sponsored by the National High Technology Research and Development Program of China(863 Program)(Grant No.2007AA06A411)
文摘To make microbial community be applied more easily in practical biotreatment engineering,three acclimation processes were carried out in lab scale. Three kinds of mixed microorganism cultures with degradability for a gas-making plant wastewater were obtained. The degradation experiments results of coal-gas wastewater indicated that different acclimation processes had obviously impacted on degradability of microbial community,and under high sludge loading rate,mixed microorganism cultureⅠ(obtained by H.S.B as bacteria source and raw wastewater as alone carbon and energy source)presented stronger degradability for coal gasification wastewater than the others. COD removal rate of mixed cultureⅠcan reach 57.6% under very low MLSS when the influent COD is 900 mg/L. Meanwhile,the results of microscopic examination showed that Protozoa,mainly epistylis and Vorticella species,were stronger activity and larger quantities in mixed cultureⅠ.
基金the National Natural Science Foundation of China(21776109)the Foundation of State Key Laboratory of Coal Combustion(FSKLCCB1805).
文摘A degradative solvent extraction(DSE)method was proposed to upgrade low-rank coals(LRC)for their cascaded utilizations in a highly-dispersed medium.The derived products exhibited well improved properties in comparison to the raw LRCs.Previously,the LRCs were pre-dried to eliminate the potential impact of the varied water content of raw LRCs,but in light of the abundant water in fresh coals,the hydrolyzing effect of water on coals under heating,and the energy cost to pre-dry the LRCs,it is consequently essential to clarify the effect of water so as to verify the necessity of pre-drying process.In this study,the roles of inherent water and extra-added water were respectively investigated,using dried,raw and wet coals from two typical LRCs.The results show that increasing the moisture content of raw LRCs contributed to the extraction ability of DSE method without noticeably changing the elemental composition,chemical structure and thermal decomposition behavior of extractable products,thus pre-drying of LRCs before DSE treatment was proven unnecessary.Additionally,the roles of the inherent water were concluded as:1)leading to the formation of stable covalent bond during drying process;and 2)acting as H donor to promote extraction ability,while the added water can only function as H donor.Since excessive water will increase the pressure during DSE treatment and lead to the waste water treatment,the LRCs with a water content between 10%and 30%were consequently recommended for the practical application of DSE treatment.
