Gasification characteristics of glass fiber-reinforced plastic (GFRP) wastes in a microwave plasma reactor

An overview of commercialization and marketization of thermoelectric generators for low-temperature waste heat recovery

According to statistics, low-temperature waste heat below 300°C accounts for more than 89% of industrial waste heat. If the waste heat is not recycled, a large amount of low-temperature waste heat will be released into the atmosphere, thereby exacerbating global warming and posing a significant threat to human survival. Although the power generation efficiency of solid-state thermoelectric generation technology is lower than the organic Rankine cycle, it only requires a smaller construction area, which increases its market acceptance, applicability, and penetration. Especially in the pursuit of net-zero emissions by global companies, the importance of low-temperature waste heat recovery and power generation is even more prominent. The current thermoelectric conversion efficiency of commercial thermoelectric chips is about 5%. Power generation cost, thermoelectric conversion efficiency, and energy use efficiency are highly correlated with the commercialization of solid-state thermoelectric technology. This research shares five practical waste heat power generation cases commercialized by recycling three heat sources. It also points out the three significant challenges facing the commercialization of power generation from low-temperature waste heat recovery. This study analyzes 2,365 TEG patents submitted by 28 companies worldwide to determine the basic technology for realizing waste heat recovery through TEG and explore the potential commercialization of related waste heat recovery products. The future challenge for the large-scale commercialization of solid-state thermoelectric technology is not technological development but financial incentives related to changes in international energy prices and subsidies that promote zero carbon emissions.

Valorization of synthetic textile waste using CO2 as a raw material in the catalytic pyrolysis process

Since an invention of synthetic fibers (textiles), our life quality has been improved. However, the cumulative production and disposal of them have perceived as significant since they are not biodegradable and hard to be upcycled/recycled. From washing textiles, microplastics are released into the environment, which are regarded as emerging contaminants. As a means for source reduction of microplastics, this study proposed a rapid disposal platform for waste textiles (WTs), converting them into value-added products. To this end, catalytic pyrolysis of WT was studied. To offer more environmentally sound process, CO₂ was used as a raw material for WT pyrolysis. Thermal cracking of WT led to the production of syngas and CH₄ under the CO₂ environment. CO₂ resulted in additional CO production via gas phase reaction with volatile compounds evolved from pyrolysis of WT. To expedite the reaction kinetics for syngas formation, catalytic pyrolysis was done over Co-based catalyst. Comparing to non-catalytic pyrolysis, CO₂-assisted catalytic pyrolysis had 3- and 8-times higher production of H₂ and CO, respectively. This process also suppressed catalyst deactivation, converting more than 80 wt% of WT into syngas and CH₄. The more generation of CO from the use of CO₂ as a raw material offers an effective means to minimize the formations of harmful chemical species, such as benzene derivatives and polycyclic aromatic hydrocarbons.