Improving the temperature measurement in hydro-processing reactors

The world is going to replace renewable and green fuels with fossil fuels to reduce the environmental issues and global warming effects. Bio-based feedstock is a biological source to produce fuel and considered as an alternative that can supersede fossil-based resources in the future. Co-processing is a transition towards green fuel which through a mixture of fossil and bio-based feedstocks are processed. In co-processing, the biomass is blended with fossil-based feed and upgraded through hydro-treating in a catalytic reactor. Since biomass contains high amount of oxygen, the process is highly exothermic releasing heat and causing temperature rise inside the reactor. Hence, reactor temperature needs to be monitored properly to prevent serious accident and retain the required quality of the product. In petro-refineries, use of temperature measurement systems is a need and usually problematic in hydro-processing reactors. When introducing alternative or biomass feedstocks to the process, the problem will be more highlighted due to new reactants and different reactions. The following work has expounded the need for measuring temperature in exothermic reactions. Reactions and products, main hardware and equipment has been described to express the need for temperature monitoring systems. This thesis has considered different approaches and methods in measuring the temperature in reactors mentioning their advantages and disadvantages. Challenges stemmed from the new reactants and new reactions by introducing bio-based feedstocks were identified. The material selection is crucial as almost all available temperature measurement systems has direct contact with the reactants and catalyst. Some widely-used materials in oil and gas industry were compared to choose the proper one for the application. The possible solutions reducing the problematic issues were recommended for design, procurement and installation of the temperature measurement system

Prenatal and Postnatal Hair Steroid Levels Predict Post-Partum Depression 12 Weeks after Delivery

Within three to six months after delivery, 13%-19% of women suffer from post-partum depression (PPD), understood as a dysfunctional adaptation to the postpartum condition and motherhood. In the present cross-sectional study, we compared the hair steroid levels of women 12 weeks before and after delivery and with or without PPD.; The present study was a cross-sectional study conducted twelve weeks after delivery. At that time, 48 women (mean age: 25.9 years) with PPD and 50 healthy controls (mean age: 25.2 years) completed questionnaires on depressive symptoms. Further, at the same time point, 6 cm lengths of hair strands were taken, providing samples of hair steroids 12 weeks before and 12 weeks after delivery in order to analyze hair steroids (cortisol, cortisone, progesterone, testosterone, and dehydroepiandrosterone (DHEA)).; Compared to those of women without PPD, hair steroid levels (cortisol, cortisone, progesterone) were significantly lower in women with PPD both before and after delivery. Lower prenatal cortisone and progesterone levels predicted higher depression scores 12 weeks after delivery. Lower prenatal levels of cortisol and progesterone and higher levels of DHEA, and postnatal lower levels of cortisol, cortisone, and progesterone, along with higher levels of DHEA predicted PPD-status with an accuracy of 98%.; PPD is associated with blunted hair cortisol, cortisone, and progesterone secretions both pre- and postpartum. Such blunted steroid levels appear to reflect a stress responsivity that is less adaptive to acute and transient stressors. It follows that prenatally assessed low hair cortisol and progesterone levels, along with high DHEA levels, are reliable biomarkers of post-partum depression 12 weeks after delivery

Improving the temperature measurement in hydro-processing reactors

The world is going to replace renewable and green fuels with fossil fuels to reduce the environmental issues and global warming effects. Bio-based feedstock is a biological source to produce fuel and considered as an alternative that can supersede fossil-based resources in the future. Co-processing is a transition towards green fuel which through a mixture of fossil and bio-based feedstocks are processed. In co-processing, the biomass is blended with fossil-based feed and upgraded through hydro-treating in a catalytic reactor. Since biomass contains high amount of oxygen, the process is highly exothermic releasing heat and causing temperature rise inside the reactor. Hence, reactor temperature needs to be monitored properly to prevent serious accident and retain the required quality of the product. In petro-refineries, use of temperature measurement systems is a need and usually problematic in hydro-processing reactors. When introducing alternative or biomass feedstocks to the process, the problem will be more highlighted due to new reactants and different reactions. The following work has expounded the need for measuring temperature in exothermic reactions. Reactions and products, main hardware and equipment has been described to express the need for temperature monitoring systems. This thesis has considered different approaches and methods in measuring the temperature in reactors mentioning their advantages and disadvantages. Challenges stemmed from the new reactants and new reactions by introducing bio-based feedstocks were identified. The material selection is crucial as almost all available temperature measurement systems has direct contact with the reactants and catalyst. Some widely-used materials in oil and gas industry were compared to choose the proper one for the application. The possible solutions reducing the problematic issues were recommended for design, procurement and installation of the temperature measurement system