Assessment of greenhouse gas emissions and environmental impacts in the manufacturing process of thermoelectric coolers: A life-cycle impact perspective.

A path to carbon neutrality requires the development of refrigeration units that use no refrigerant or emit less greenhouse gas (GHG), such as Thermoelectric coolers (TECs). Using the life cycle inventory assessment (LCIA), the environmental impacts of the manufacturing process of TECs were analyzed, including greenhouse gas emissions, human carcinogenic toxicity (HCT), terrestrial ecotoxicity (TE), freshwater ecotoxicity (FE), mineral resource scarcity (MRS), and fossil resource scarcity (FRS). The alumina plate manufacturing process produces the most GHG emissions because it uses a lot of electricity in the sintering process.

Development and application of three-dimensional potential source contribution function (3D-PSCF).

A potential source contribution function (PSCF) can indicate the source areas of high air pollutant concentrations using backward trajectories. However, the conventional two-dimensional PSCF (2D-PSCF) cannot consider the emission and transport height of air pollutants. That missing information might be critical because injection height varies depending on the source type, such as with biomass burning.

Effects of volatile solid concentration and mixing ratio on hydrogen production by co-digesting molasses wastewater and sewage sludge.

Co-digesting molasses wastewater and sewage sludge was evaluated for hydrogen production by response surface methodology (RSM). Batch experiments in accordance with various dilution ratios (40- to 5-fold) and waste mixing composition ratios (100:0, 80:20, 60:40, 40:60, 20:80, and 0:100, on a volume basis) were conducted. Volatile solid (VS) concentration strongly affected the hydrogen production rate and yield compared with the waste mixing ratio.

Two-stage biogas production by co-digesting molasses wastewater and sewage sludge.

We evaluated the feasibility of co-digesting molasses wastewater and sewage sludge in a two-stage hydrogen- and methane-producing system. The highest energy was recovered at the 21-h hydraulic retention time (HRT) of the first hydrogenic reactor and at 56-h HRT of the secondary methanogenic reactor. Hence, the two-stage system recovered 1,822 kJ from 1 L of the mixed wastes (19.