Recovery of energy and carbon fibre from wind turbine blades waste (carbon fibre/unsaturated polyester resin) using pyrolysis process and its life-cycle assessment.

Recovery of carbon fibres and resin from wind turbine blade waste (WTB) composed of carbon fibres (CF)-reinforced unsaturated polyester resin (UPR) has been environmentally challenging due to its complex structure that is not biodegradable and that is rich in highly toxic styrene (main component of UPR). Within this framework, this paper aims to liberate CF and UPR from WTB using a pyrolysis process. The treatment was performed on commercial WTB (CF/UPR) up to 600 °C using a 250 g reactor. The UPR fraction was decomposed into liquid and gaseous phases, while CF remained as a residue. The composition of gaseous phase was monitored during the entire treatment using a digital gas analyser, while gas chromatography-mass spectrometry (GC-MS) was used to characterize the collected liquid phase. CF fraction was collected and exposed to additional oxidation process after treatment at 450 °C for purification propose, then it was analysed using FTIR and SEM-EDX. Finally, the life cycle assessment (LCA) of the CF/UPR pyrolysis was studied using SimaPro software and the results were compared with landfill disposal practices. The pyrolysis results manifested that 500 °C was sufficient for UPR decomposition into styrene-rich oil and gaseous products with yields of 15.23 wt% and 6.83 wt%, respectively, accompanied by 77.93 wt% solid residue including CF. The LCA results showed that pyrolysis with oxidation process has high environmental potential in WTB recycling with significant reduction in several impact categories compared to landfill. However, the pyrolysis scenario revealed several additional environmental burdens related to ecosystems, acidification, Ozone formation, and fine particulate matter formation that must be overcome before upscaling.

Biomass gasification to syngas in thermal water vapor arc discharge plasma.

This study investigated biomass (wood pellets) gasification to syngas using direct current (DC) thermal arc plasma at atmospheric pressure. Water vapor was used as a main gasifying agent and a plasma-forming gas. The biomass gasification system was quantified in terms of the producer gas composition, the tar content, the H2/CO ratio, the carbon conversion efficiency, the energy conversion efficiency and the specific energy requirements. It was found that the gasification performance efficiency was highest at the water vapor-to-biomass ratio of 0.97. The producer gas was mostly composed of H2 (43.86 vol.%) and CO (30.93 vol.%), giving the H2/CO ratio of 1.42 and the LHV of 10.23 MJ/Nm3. However, high content of tars of 13.81 g/Nm3 was obtained in the syngas. The yield of H2 and CO was 48.31% and 58.13%, respectively, with the highest producer gas yield of 2.42 Nm3/kg biomass. The carbon conversion efficiency and the energy conversion efficiency were 100% and 48.83%, respectively, and the production of 1 kg of syngas required 1.78 kWh of electric energy input. Finally, the obtained results were compared with different plasma methods, including plasma-assisted application coupled with conventional gasification.

Synergetic approach for energy recovery from coastal wastes based on combination of biological and thermal treatment.

Marine biomass is a promising renewable energy source, especially as this waste contains a large amount of cellulose and hemicellulose, which can contribute to convert it into energy products using anaerobic digestion (AD) and pyrolysis processes. This work was focused on a synergetic view of marine coastal waste treatment (seaweed) using two different technologies, anaerobic microbiological co-digestion, and pyrolysis. The experiments were performed with two merged technologies to assess the captured energy from the digestate in case it is contaminated. Anaerobic co-digestion was conducted using a periodic load laboratory bench with a vertical biogas digester. An evaluation of possible product yields and composition during pyrolysis at a laboratory-scale bench has been performed. The products obtained after the thermal treatment analyzed using an online gas measurement system and gas chromatographs Agilent 7890A with TCD detector (for gases) and Agilent 7890A with MS detector (for liquids).The results demonstrated that biogas yield was 174.1 l/kg (DM). Seaweed washed by seawater yields a higher amount of biogas (202.5 l/kg). Meanwhile, seaweed, sewage sludge, and digestate samples subjected to thermal treatment produced 17%, 30%, and 15% of liquids products, respectively. The economic performance assessment showed that the application of the developed merged approach on an industrial scale could provide an economic return of up to 8.3 $/100 kg of waste. Based on that, merged AD and pyrolysis technologies could be adapted as a promising technology to valorize seaweed wastes and utilize them as a new sustainable source for renewable energy.

A new strategy for using lint-microfibers generated from clothes dryer as a sustainable source of renewable energy.

Lint-microfibers (LMs) generated during clothes drying are classified as primary microplastics and consist mainly of cotton, polyester and lignin. This research aims to convert LMFs into energy products using a pyrolysis treatment. The pyrolysis experiments were performed using a pilot pyrolysis plant. SEM-EDS was used to observe the morphology and elemental composition of the feedstock and the obtained biochar, while a digital unit of Instantaneous Gas analyzer and Gas chromatography (GC) were used to observe the concentration of O2, N2, CO2, CO, H2, CH4 gases during the whole conversion process. Finally, a simple mathematical model was developed to evaluate the economic and environmental performance of the suggested strategy based on the LMFs generated by one million persons. Based on the results of the developed model and yield of pyrolysis process, around 45 tons of LMFs are generated by one million persons annually and this amount is enough to produce 13.8 tons of oil (~31%), 21.5 tons of gas (47.7%), and 9.7 ton of char (21.6%) with estimated profitability of 120,400$ and reduction in carbon footprint estimated at -42,039,000kg CO2-eq/t of LMFs.

Investigation of sewage sludge treatment using air plasma assisted gasification.

This study presents an experimental investigation of downdraft gasification process coupled with a secondary thermal plasma reactor in order to perform experimental investigations of sewage sludge gasification, and compare process parameters running the system with and without the secondary thermal plasma reactor. The experimental investigation were performed with non-pelletized mixture of dried sewage sludge and wood pellets. To estimate the process performance, the composition of the producer gas, tars, particle matter, producer gas and char yield were measured at the exit of the gasification and plasma reactor. The research revealed the distribution of selected metals and chlorine in the process products and examined a possible formation of hexachlorobenzene. It determined that the plasma assisted processing of gaseous products changes the composition of the tars and the producer gas, mostly by destruction of hydrocarbon species, such as methane, acetylene, ethane or propane. Plasma processing of the producer gas reduces their calorific value but increases the gas yield and the total produced energy amount. The presented technology demonstrated capability both for applying to reduce the accumulation of the sewage sludge and production of substitute gas for drying of sewage sludge and electrical power.