Papers by Author: Yong Chi

Abstract: Oily sludge is inevitably produced in numerous petroleum processing operations. Five oily sludge samples were collected to identify the compositions and to characterize the extracted solids. The results indicated that three fifths of the samples contained significant amounts of oil and could be potentially recovered as energy resources. All of the samples had high concentration of water. The compositions of C, H, and N, as well as H/C in the separated oils were close to those in oil sands bitumen. The high concentration of asphaltenes agreed with the low H/C. The XRD spectra showed that the major minerals contained in the extracted solids were quartz and calcite.

Abstract: The experimental material is source-separated municipal solid waste. Remaining waste from primary assortment is compressed into RDF with mechanical molding equipment. We used high-temperature tube furnace for pyrolysis experiment of RDF. The effects of pyrolysis temperature, material composition, choice of additives and the content of the additive on the productivity of pyrolysis for these samples were investigated; the variation trend of content for K and Na elements in semi-coke was analyzed under various factors. The results show that adding plastics, CaO or DHC-32 is conductive to improve the effect of RDF pyrolysis. Increasing pyrolysis temperature is in favor of the process of pyrolysis reaction, meanwhile, the apparent variation trends are presented for the content of K and Na in semi-coke under the various experimental conditions.

Abstract: In this paper, the classical sewage sludge and coal co-combustion power generating system was optimized. The regenerative steam in the extraction turbine was partly used for the sludge drying. And then, the mathematics model was established based on the exergy theory. Several extraction points were compared to find out the most optimization parameters (drying efficiency of the dryer, pressure and tempreture). The result showed that, with different steam temperature and pressure at different extraction points, the influence to the system exergy efficiency caused by the percentage of moisture and drying efficiency was different. When the sludge moisture content went to about 35%, the generating capacity increment was moderating. After the calculation and comparison, the error between the calculation results of the mathematical optimization model and the classical thermodynamic method was very small. The calculation in mathematical optimization model based on exergy analysis was relatively simple, and analysis of the relationship between variables was easier.