Wei Su

Research on the Recycling of Distillation Waste in Ethanol Fermentation from Food Waste and Its Influence

Ethanol fermentation from food waste could reduce the solid waste pollution and realize energy utilization. In order to decrease distillation waste, the recycle of such waste was adopted in ethanol fermentation. It demonstrated that such treatment could only last for four times due to the existence of side products. The distillation waste would gradually reduce ethanol concentration and sugar utilization ratio, lactic acid would be accumulated to 8 g/L, and salinity would be accumulated to 10 g/L, pH decreased to less than 3.5. Three-dimensional fluorescence analysis showed protein-type substances, microbial metabolism type substances, and humic substances were accumulated during the recycling. In order to resolve such problems, addition of protease was chosen in this research. The recycling time could enhance to seven times and the highest ethanol concentration was 35 g/L, the lowest ethanol concentration was 20 g/L. The recycling of distillation waste could save water resource, reduce wastewater discharges with high COD lees and reduce the cost. Which provided a new way for the clean production of bioethanol production from food waste.

Discharge and Disposal of Coking Residue and Distribution Characteristics of PAHs in it

The research studied the treatment ways of discharging coking residues and the distribution characteristics of PAHs in two kinds of typical coking residues. The outputs of coal tar (100,000t/a for Plant A, 84,000t/a for Plant B) were great and it had become an important by-product. Coal tar residue, with the yields of 4,500 t/a and 6,400 t/a for Plant A and B, respectively, were always reused for coal blending. The concentration of PAHs with 5-6 aromatic rings was 1.08×104 mg/kg in coal tar residue, the concentration of PAHs in coke discharging smoke & dust (28.81 mg/kg) was relatively low compared with coal tar residue. The ∑BaPeq were 4.2×103 mg/kg and 0.71 mg/kg for coal tar residue and coke discharging smoke & dust, respectively.

TG Analysis on Burning Characteristic of Food Waste Ethanol Fermentation Residue Mixed with Coal

In order to reduce and re-utilize the ethanol fermentation residue from food waste, this study utilized residues to produce solid biomass fuel and carried out burning test by thermal gravity (TG) analysis. The results demonstrated that the residue from food waste shared the characteristic of high volatile content, high heat potential, low fixed carbon and low ash content. The burnable content was about 86.99% based on dry mass, while the heat potential was 23.06 MJ•kg-1. Lignitous coal or blind coal was adopted as the additive to improve the burning characteristic of the fermentation residue. The result for a mixture of lignitous coal and residue was better than those of blind coal with the increase of complex burning index S from 2.38E-07°C-3•min-2 to 7.99E-08°C-3•min-2, decrease of ignition point, enhancement of average burning ratio and amelioration of burning characteristic. All these provided theoretical guidance for fermentation residue utilization as the solid fuel.

Research on Biodiesel and Ethanol Production from Food Waste

In order to solve the pollution caused by food waste, research was carried out to test the feasibility of biodiesel and ethanol production from food waste. With separation process, waste oil and rudimental solid component of food waste were obtained. Chemical synthesis was utilized for biodiesel production with oil and fermentation was chosen for ethanol production from solid parts. The result demonstrated that biodiesel produced from waste oil were mixed fatty acid methyl esters with the main components of Octadecenoic acid methyl ester, Octadecadienoic acid methyl ester and Hexadecanoic acid methyl ester. Since they were similar to the composition to those produced with other traditional raw biodiesel materials, it demonstrated that this was a possible way to utilize waste oil. Furthermore, the solid part of food waste could produce 44 g/L ethanol under 35°C for 3 days with yeast cultured. Ethanol and biodiesel production from food waste could to a large extent save the production cost as well as solve the pollution problem.

Environmental Evaluation for Three Typical MSW Incineration Based on Life Cycle Assessment

Garbage incineration is an effective minimization and resource processing methods, but there are no comparative analysises about the environmental impact of incineration processes. To investigate the environmental impacts of three typical MSW incineration processes, we modeled scenarios, calculated energy consumed and six aspects which classified as GWP, ODP, AP, EP, POCP and DUST. The classification results showed the value of the environment impact potential respectively. The impact potential of heat recover-dry absorption processes according to normalized results in descending order is GWP>EP>DUST>AP>POCP>ODP, in contrast the rank of heat recover-wet absorption and semidry processes is GWP>EP>AP>DUST>POCP>ODP, global warming impacts is the most significant penitential factor. The rank of impact potential according to weight factor in descending order is GWP>EP>DUST>AP>ODP>POCP. Dust potential became more significant. The weight factor of Dust is almost twice as much as that of AP. This is because there is a large gap between baseline level and the target level, the solid-waste are the focus of control in these years. In environmental terms, the environmental depletion index of heat recover-dry absorption process is lowest with minimal environmental impact and the heat recover-wet absorption process is the highest with largest environmental impact. The incineration with dry absorption program is the best environment-friendly process in term of environmental impact. Utilization of waste water and reducing total amount of water entering the system can effectively reduce the environmental implication for both HW and HS processes.

Discharge and Disposal of Coal Gasification Methanol Production Residue and Distribution Characteristics of PAHs in it

To determine the quantities and the treatment ways of coal gasification methanol production residues, questionnaire survey and field investigation were carried out in this research. Moreover, the distribution characteristics of PAHs in two typical residues were determined by GC-MS technique, according to USEPA8100 method. The outputs of gasifier slag and boiler ash for were 127,494 t/a and 164,850t/a, respectively, all the boiler ash and 80% of the gasifier slag would be reused for brick-making. Coal tar residue, with the yield of 480 t/a, was always delivered to coke plant for coking, which was a effective measure to save energy and solve the environmental issues caused by the storage of this residue. The results indicated that the concentration of PAHs with 5-6 aromatic rings was 905 mg/kg in coal tar residue, accounting for 9.23% of the total PAHs concentration, its Benzo (a) pyrene concentration was 160 mg/kg, making it a major health hazard. The concentration of PAHs in gasifier slag was 189mg/kg and the PAHs with 2-3 aromatic rings accounted as high as 81.41% of the total PAHs concentration, the PAHs with 5-6 aromatic rings made up only 1.1%. TheBaPeq were 322.9 mg/kg and 0.23 mg/kg for coal tar residue and gasifier slag, respectively.

Environmental Evaluation for Three Typical Steel Pipe Production Processes Based on Energy Materials and Life Cycle Assessment

Steel pipe applications are more widely used, but there are no comparative analysises about the environmental impact and energy consum of steel pipe and its production processes. This article investigated the environmental implications of three typical steel pipe production processes based on energy materials and life cycle assessment perspective. We modeled scenarios, calculated energy consumed and six aspects which classified as GWP, ODP, AP, EP, POCP and DUST. The rank of energy consumed in descending order is C-Pipe> H-Pipe> W-Pipe. Welded steel pipe is the best energy-friendly material in term of energy consumption. The rank of impact potential according to normalized results in descending order is GWP>AP>DUST>EP>POCP>ODP. The rank of impact potential according to weight factor in descending order is AP>DUST>GWP>ODP>EP>POCP. Acid Potential is the most significant factor. The weight factor of AP is almost twice as much as that of GWP. In environmental terms, the environmental depletion index of welded pipe production process is lowest with minimal environmental impact and the cold drawn pipe production process the highest with largest environmental impact. Welded steel pipe is the best environment-friendly material in term of environmental impact. Utilization of green energy and waste heat can effectively reduce the environmental implications for both hot rolling pipe and cold drawn pipe production processes.