Evaluation of hydrothermal carbonization in urban mining for the recovery of phosphorus from the organic fraction of municipal solid waste

[EN] The organic fraction of municipal solid waste was identified as an alternative phosphorus resource: hydrothermal carbonization provided phosphorus-rich hydrochar. Two alternative valorization pathways can be considered for the latter: the use as a fertilizer or as solid fuel after phosphorus extraction. By means of life cycle assessment (LCA) the environmental impact of extracting phosphorus and using the hydrochar as solid fuel was evaluated. Therefore, in a first step, phosphorus extraction with nitric acid, hydrochloric acid and sulfuric acid was experimentally investigated on laboratory scale. Nitric acid proved to be the most suitable because it offered high extraction efficiency and improved solid fuel properties such as lower ash content and lower levels of chlorine and sulfur. In contrast, hydrochloric acid increased the chlorine content and sulfuric acid only replaced phosphate by sulfate, but did not reduce the ash content of hydrochar. Then phosphorus can be precipitated and used as fertilizer. Although technically feasible, LCA points out that the separate use of hydrochar and phosphorus represents an overall environmental burden for wide range of impact categories, including climate change and resource depletion. Therefore, other applications for phosphorus-rich hydrochars, like agriculture and horticulture, should be considered.The authors are grateful for the financial support received from the Spanish Ministry of Economy and Competiveness under the RTC-2015-4017-3 of the state programme "Research, Development and Innovation Oriented to the Challenges of Society"Oliver-Tomás, B.; Hitzl, M.; Owsianiak, M.; Renz, M. (2019). Evaluation of hydrothermal carbonization in urban mining for the recovery of phosphorus from the organic fraction of municipal solid waste. Resources Conservation and Recycling. 147:111-118. https://doi.org/10.1016/j.resconrec.2019.04.023S11111814

Environmental Performance of Hydrothermal Carbonization of Four Wet Biomass Waste Streams at Industry-Relevant Scales

[EN] Hydrothermal carbonization (HTC) of green waste, food waste, organic fraction of municipal solid waste (MSW), and digestate is assessed using life cycle assessment as a potential technology to treat biowaste. Water content of the biowaste and composition of the resulting hydrochar are important parameters influencing environmental performance. Hydrochar produced from green waste performs best and second best in respectively 2 and 10 out of 15 impact categories, including climate change, mainly due to low transportation needs of the biowaste and optimized pumping efficiency for the feedstock. By contrast, hydrochar produced from the organic fraction of MSW performs best in 6 impact categories, but has high potential impacts on human health and ecosystems caused by emissions of toxic elements through ash disposal. The greatest potential for environmental optimization for the HTC technology is in the use of heat and electricity with increasing plant size, but its overall environmental performance is largely influenced in a given geographic location by the incumbent waste management system that it replaces. Impact scores are within the range of existing alternative treatment options, suggesting that despite being relatively immature technology, and depending on the geographic location of the plant, HTC may be an attractive treatment option for biowaste.This research was funded by the European Commission under the seventh framework program; SME-2013-2: NEWAPP, grant agreement 605178.Owsianiak, M.; Ryberg, MW.; Renz, M.; Hitzl, M.; Hauschildt, MZ. (2016). Environmental Performance of Hydrothermal Carbonization of Four Wet Biomass Waste Streams at Industry-Relevant Scales. ACS Sustainable Chemistry and Engineering. 4(12):6783-6791. https://doi.org/10.1021/acssuschemeng.6b01732S6783679141

Fuel and chemicals from wet lignocellulosic biomass waste streams by hydrothermal carbonization

[EN] Most valorization processes for biomass waste require dry raw material or at least a relatively low amount of residual humidity. In contrast, hydrothermal carbonization (HTC) is a valorization process for lignocellulosic biomass which uses water as a reaction medium. The product, hydrochar, can be used as dry solid fuel making the post-process drying procedure much more energy-efficient. Herein, three lignocellulosic biomass waste feedstocks, i.e. the organic fraction of municipal solid waste (OFMSW), orange peel waste (OPW) and the residues of a pepper plantation, were processed by HTC on a ton scale and the product evaluated as solid fuel in form of pellets for domestic use (EN ISO 17225). A critical property of the product is the ash content which has to be adjusted by post-treatment. Ash content below the established limit was achieved by acid treatment with sulfuric acid. An implementation of the treatment into the pilot plant is straightforward. An organic liquid fraction was obtained as an additional effluent in the pilot plant depending on the biomass feedstock. For instance, limonene in a mixture with other monoterpenes was separated when orange peel waste was processed, constituting approximately 3 wt% of the dry matter. It is further shown at laboratory scale that the monoterpene mixture can be directly used or can easily be transformed into para-cymene, a fragrance compound, by catalytic dehydrogenation. Therefore, the HTC process can be considered as a source for valuable apolar platform molecules derived from lignocellulosic biomass waste in addition to the production of hydrochar.Authors are grateful for financial support from the EU (FP7-SME-2013-605178-NEWAPP) and from the Spanish Ministry of Economy and Competitiveness (Innpacto Programme, IPT-2012-0023-120000). We thank our NEWAPP partners (http://newapp-project.eu/en/partners.html), especially M. Ryberg and M. Owsianiak from the Technical University of Denmark (DTU) and L. Doyle from TTZ Bremerhaven, for fruitful discussions and valuable suggestions.Burguete Llorens, PL.; Corma Canós, A.; Hitzl, M.; Modrego Latorre, R.; Ponce Ballester, E.; Renz, M. (2016). Fuel and chemicals from wet lignocellulosic biomass waste streams by hydrothermal carbonization. Green Chemistry. 18(4):1051-1060. https://doi.org/10.1039/C5GC02296GS1051106018

Stereotactic radiotherapy in the treatment of brain metastases

This thematic review is part of a larger, comparative dosimetric analysis of the evaluation of treatment plans created by different modulated intensity irradiation, which is delivered by means a linear accelerator for the treatment of multiple metastases in the brain. There is currently no consensus as to which method is dosimetrically better. A further study will be aimed at determining the dosimetric advantages of each irradiation technique to introduce additional certainty into the planning process

The hydrothermal carbonization (HTC) plant as a decentral biorefinery for wet biomass

[EN] The hydrothermal carbonization (HTC) is a very suitable process to transform wet biomass feedstocks into a peat-like material without drying the biomass input. Therefore, the energetic balance is more favorable than for alternative processes converting biomass as a whole. Further synergies can be achieved when the plant is employed as central hub for a regional biorefinery. Hence, a HTC pilot plant is operated with garden prunings and monitored during two years. It is shown that the elemental composition of HTC carbon is relatively constant. A carbon content of higher than 60% (based on dry, ash-free matter) is achieved. Fixed carbon content and volatile matter show low variation being the volatile content quite high with 61% on average. Dried in a post-process treatment which is less energy-demanding than drying of the raw biomass and pressed into pellets or briquettes the HTC carbon can be used as solid biofuel fulfilling the European standard (EN 14961-6). With a regional thermal valorization of the biofuel the ashes can be returned as phosphorous source to the crop land from which the biomass was harvested. Part of the process water, which involves a high amount of potassium, can be used for crop irrigation. In this way, valuable plant nutrients are recovered for soil remediation. Hence, closing the nutrient cycles a HTC plant can be considered as a sustainable local biorefinery producing a solid biofuel. Thereby, solar energy is exploited which was fixed before by photosynthesis together with the carbon dioxide which is liberated in the combustion of the solid biofuel. Optionally, the process water might serve as an alternative source of energy as it is demonstrated that its carbon content can be exploited for biogas productionAuthors are grateful for financial support obtained from the Spanish Ministry of Economy and Competitiveness (Innpacto Programme, IPT-2012-0023-120000) and the European Union (FP7-SME-2013-605178-NEW APP).Hitzl, M.; Corma Canós, A.; Pomares Garcia, F.; Renz, M. (2015). The hydrothermal carbonization (HTC) plant as a decentral biorefinery for wet biomass. Catalysis Today. 257:154-159. https://doi.org/10.1016/j.cattod.2014.09.024S15415925

Effects of Early Life Stress on Bone Homeostasis in Mice and Humans

Bone pathology is frequent in stressed individuals. A comprehensive examination of mechanisms linking life stress, depression and disturbed bone homeostasis is missing. In this translational study, mice exposed to early life stress (MSUS) were examined for bone microarchitecture (μCT), metabolism (qPCR/ELISA), and neuronal stress mediator expression (qPCR) and compared with a sample of depressive patients with or without early life stress by analyzing bone mineral density (BMD) (DXA) and metabolic changes in serum (osteocalcin, PINP, CTX-I). MSUS mice showed a significant decrease in NGF, NPYR1, VIPR1 and TACR1 expression, higher innervation density in bone, and increased serum levels of CTX-I, suggesting a milieu in favor of catabolic bone turnover. MSUS mice had a significantly lower body weight compared to control mice, and this caused minor effects on bone microarchitecture. Depressive patients with experiences of childhood neglect also showed a catabolic pattern. A significant reduction in BMD was observed in depressive patients with childhood abuse and stressful life events during childhood. Therefore, future studies on prevention and treatment strategies for both mental and bone disease should consider early life stress as a risk factor for bone pathologies

Evaluation of hydrothermal carbonization in urban mining for the recovery of phosphorus from the organic fraction of municipal solid waste

The organic fraction of municipal solid waste was identified as an alternative phosphorus resource: hydrothermal carbonization provided phosphorus-rich hydrochar. Two alternative valorization pathways can be considered for the latter: the use as a fertilizer or as solid fuel after phosphorus extraction. By means of life cycle assessment (LCA) the environmental impact of extracting phosphorus and using the hydrochar as solid fuel was evaluated. Therefore, in a first step, phosphorus extraction with nitric acid, hydrochloric acid and sulfuric acid was experimentally investigated on laboratory scale. Nitric acid proved to be the most suitable because it offered high extraction efficiency and improved solid fuel properties such as lower ash content and lower levels of chlorine and sulfur. In contrast, hydrochloric acid increased the chlorine content and sulfuric acid only replaced phosphate by sulfate, but did not reduce the ash content of hydrochar. Then phosphorus can be precipitated and used as fertilizer. Although technically feasible, LCA points out that the separate use of hydrochar and phosphorus represents an overall environmental burden for wide range of impact categories, including climate change and resource depletion. Therefore, other applications for phosphorus-rich hydrochars, like agriculture and horticulture, should be considered.The authors are grateful for the financial support received from the Spanish Ministry of Economy and Competiveness under the RTC-2015-4017-3 of the state programme >Research, Development and Innovation Oriented to the Challenges of Society