Open Access

This study compares the technical viability and ecologic benefits of solar thermal energy systems with PV-supported heat-pump systems within the South African beverage sector. Different configurations of solar thermal (ST), photovoltaics (PV) and heat pumps are modelled and evaluated. After a general consideration, simulation results for three selected cases with operating temperatures below and above 100 °C are modelled and examined. The cost of heat and CO2 emissions are evaluated for solar thermal systems and heat-pump systems with and without photovoltaic support. The effect of “Loadshedding” is discussed, especially for the application of high-temperature heat pumps (HTHP). While batteries are quite expensive, thermal storage tanks can be used to cover most of the process heat demand. The study finds that the LCOH and CO2 emissions can be reduced significantly at temperatures below 100°C compared to oil fired boilers. When high-temperature steam is produced, the LCOH is at least twice that of coal-fired steam boilers. Furthermore, the effect of feed-in tariffs is discussed. Therefore, the study suggests the need for additional research to optimize systems that reduce steam requirements, leading to improved economics of heat pumps and solar thermal. It also calls for a collaborative effort to promote the development and funding of high-temperature heat pumps for industrial use.

Despite the increasing importance of recycling, the medical sector is hardy engaged at this time due to regulatory issues. The aim of this study was to evaluate the influence of γ‐radiation sterilization (48–52 kGy) on the repetitive injection molding of a polypropylene copolymer for medical applications. For this purpose, the material was analyzed after injection molding and irradiation. To evaluate the irradiation and reprocessing influence, optical, rheological, and mechanical properties were investigated in addition to chromatography. The latter comprised the quantitative determination of Irgafos 168 and the qualitative comparison of volatile degradation products formed, including the radiolysis product 1,3‐di‐tert‐butylbenzene. The influence of irradiation on the content of Irgafos 168, volatile organic compounds, and 1,3‐di‐tert‐butylbenzene was greatest after the first irradiation, with a decrease of Irgafos 168 content by 40%. The yellowness index and melting enthalpy were influenced by irradiation and processing, but showed no direct relationship to the individual process steps. The zero viscosity correlated directly with gas chromatography–mass spectrometry results and decreased by 80% after the first irradiation. In addition, the elongation at break was reduced by 95% after the second irradiation. The influence of irradiation on the studied characteristics was high, whereas the influence of repetitive processing did not show any measurable differences

Nickel-copper alloys are commonly used in highly corrosive conditions where strength is required. Typical applications are in the marine sector, petrochemical industry, or energy facilities such as chemical tubes, pumps, heat exchangers and superheated steam systems. This paper compares the microstructure and mechanical properties of a cast alloy with a 3D printed alloy processed via a laser powder bed fusion (LPBF) technique. Small cylindrical specimens were used for tensile tests at room temperature (RT) and elevated temperatures up to 750 °C in air. The tensile stress-strain response was determined for both types of materials. At RT, LPBF material has a higher yield strength and ultimate tensile strength than a cast alloy. At elevated temperatures, the strength of both variants is comparable. However, the fracture elongation of the LPBF material is significantly lower over the entire range of investigated temperatures. Fracture surfaces and polished sections parallel to the specimen axis were investigated to compare the microstructure and damage mechanisms of the nickel-coper alloy 400 prepared by conventional casting and via LPBF.