Comparative systems analysis of thermochemical and biochemical recycling of organic waste towards industrial feedstocks

Shifting the resource base for chemical and energy production from fossil feedstocks to renewable raw materials is seen by many as one of the key strategies towards sustainable development. The utilization of biomass for the production of fuels and materials has been proposed as an alternative to the petroleum-based industry. Current research and policy initiatives focus mainly on the utilization of lignocellulose biomass, originating from agriculture and forestry, as second generation feedstocks for the production of biofuels and electricity. These activities act on the assumption that significant amounts of biomass for non-food purposes are available. However, given a certain productivity per area, the current massive growth in global biofuels demand may in the long term only be met through an expansion of global arable land at the expense of natural ecosystems and in direct competition with the food-sector. Although many studies have shown the potential of biofuels production to reduce both, greenhouse gas emissions and non-renewable energy consumption, these production routes are still linear processes which depend on significant amounts of agricultural or forestry production area. Cascading use, i.e. when biomass is used for material products first and the energy content is recovered at end-of-life, may provide a greater environmental benefit than primary use as fuel. Considering waste and production residues as alternative feedstocks could help to further reduce pressures on global arable land. This research focused on thermochemical and biochemical technologies capable of utilizing organic waste or forestry residuals for energy, chemical feedstock, and synthetic materials (polymers) generation. Routes towards synthetic materials allow a closer cycle of materials and can help to reduce dependence on either fossil or biobased raw materials. The system-wide environmental burdens of three different technologies, including (1) municipal solid waste (MSW) gasification followed by Fischer-Tropsch synthesis (FTS), (2) plasma gasification of construction and demolition (C&D) wood for syngas production with energy recovery, and (3) forest residuals use in a biorefinery for polyitaconic acid (PIA) production, were assessed using life-cycle assessment. The first two studies indicated that MSW gasification and subsequent ethylene and polyethylene production via FTS has lower environmental impacts than conventional landfilling. In the future, as societies may shift towards the use of renewable energy, power offset by conventional waste-to-energy systems would not be as significant and chemicals production routes may then become increasingly competitive (in terms of environmental burdens) also to waste incineration. While production cost of Fischer-Tropsch derived chemicals seems not yet competitive to fossil-based chemicals provision, future price increases in global oil prices as well as changes in waste tipping fees, and efficiency gains on site of the waste conversion systems, may alter the economics and allow carbon recycling routes to reach a price competitive to fossil-based production routes. The third study found that plasma gasification of C&D wood for energy recovery has roughly similar environmental impacts than conventional fossil-based power systems. However, process optimization with respect to coal co-gasified, coke used as gasifier bed material, and fuel oil co-combusted in the steam boiler, would allow to significantly lower the system-wide environmental burdens. The fourth study looked at PIA production from softwood hemicellulose in a stream integrated approach (with the partially macerated wood and lignin being used in other existing processes such as pulp & paper plants for conventional pulp and bioenergy production). The assessment indicated lower global warming potential, energy demand, and acidification, for the wood-based PIA polymer, when compared to corn-based PIA and fossil-based polyacrylic acid (PAA). However, water use associated with wood-derived PIA was found to be higher than for fossil-based PAA production and land occupation is highest for the wood-derived polymer. It is hoped that results of this dissertation will add to the current debate on sustainable waste and biomass utilization and to establish future supply chains for green and sustainable chemical products

Towards better monitoring of technology critical elements in Europe: Coupling of natural and anthropogenic cycles

The characterization of elemental cycles has a rich history in biogeochemistry. Well known examples include the global carbon cycle, or the cycles of the ‘grand nutrients’ nitrogen, phosphorus, and sulfur. More recently, efforts have increased to better understand the natural cycling of technology critical elements (TCEs), i.e. elements with a high supply risk and economic importance in the EU. On the other hand, tools such as material-flow analysis (MFA) can help to understand how substances and goods are transported and accumulated in man-made tech- nological systems (‘anthroposphere’). However, to date both biogeochemical cycles and MFA studies suffer from narrow system boundaries, failing to fully illustrate relative anthropogenic and natural flow magnitude and the degree to which human activity has perturbed the natural cycling of elements. We discuss important interconnections between natural and anthropogenic cycles and relevant EU raw material dossiers. Increased integration of both cycles could help to better capture the transport and fate of elements in nature including their environ- mental/human health impacts, highlight potential future material stocks in the anthroposphere (in-use stocks) and in nature (e.g., in soils, tailings, or mining wastes), and estimate anticipated emissions of TCEs to nature in the future (based on dynamic stock modeling). A preliminary assessment of natural versus anthropogenic ele- ment fluxes indicates that anthropogenic fluxes induced by the EU-28 of palladium, platinum, and antimony (as a result of materials uses) might be greater than the respective global natural fluxes. Increased combination of MFA and natural cycle data at EU level could help to derive more complete material cycles and initiate a dis- cussion between the research communities of biogeochemists and material flow analysts to more holistically ad-dress the issues of sustainable resource management

Mapping supply chain risk by network analysis of product platforms

AbstractModern technology makes use of a variety of materials to allow for its proper functioning. To explore in detail the relationships connecting materials to the products that require them, we map supply chains for five product platforms (a cadmium telluride solar cell, a germanium solar cell, a turbine blade, a lead acid battery, and a hard drive (HD) magnet) using a data ontology that specifies the supply chain actors (nodes) and linkages (e.g., material exchange and contractual relationships) among them. We then propose a set of network indicators (product complexity, producer diversity, supply chain length, and potential bottlenecks) to assess the situation for each platform in the overall supply chain networks. Among the results of interest are the following: (1) the turbine blade displays a high product complexity, defined by the material linkages to the platform; (2) the germanium solar cell is produced by only a few manufacturers globally and requires more physical transformation steps than do the other project platforms; (3) including production quantity and sourcing countries in the assessment shows that a large portion of nodes of the supply chain of the hard-drive magnet are located in potentially unreliable countries. We conclude by discussing how the network analysis of supply chains could be combined with criticality and scenario analyses of abiotic raw materials to comprise a comprehensive picture of product platform risk

Criticality on the international scene : quo vadis?

This paper brings a discussion on the current state-of-the-art in criticality assessment in an international context. It analyzes the status of resource criticality concepts and their calculation methods. The current practice often exhibits a common two-axis assessment framework but the way the two axes are further operationalized shows heterogeneous approaches. Apart from the two-axis as key element of criticality assessment, the scope of the materials, the role of substitution, the delineation of the supply chain and data, and indicator selection are addressed as key elements, The abovementioned criticality assessment practice is approached in function of the upcoming international debate on criticality. The paper tackles the role of criticality assessment in the context of the sustainability assessment toolbox and it proposes a clear distinction between criticality assessment and resilience to criticality. The insights offered in the paper may feed the international discussion in the identification of elements that may be harmonized and elements that may be better left open in function of the particular application

EU methodology for critical raw materials assessment : policy needs and proposed solutions for incremental improvements

Raw materials form the basis of Europe's economy to ensure jobs and competitiveness, and they are essential for maintaining and improving quality of life. Although all raw materials are important, some of them are of more concern than others, thus the list of critical raw materials (CRMs) for the EU, and the underlying European Commission (EC) criticality assessment methodology, are key instruments in the context of the EU raw materials policy. For the next update of the CRMs list in 2017, the EC is considering to apply the overall methodology already used in 2011 and 2014, but with some modifications. Keeping the same methodological approach is a deliberate choice in order to prioritise the comparability with the previous two exercises, effectively monitor trends, and maintain the highest possible policy relevance. As the EC's in-house science service, the Directorate General Joint Research Centre (DG JRC) identified aspects of the EU criticality methodology that could be adapted to better address the needs and expectations of the resulting CRMs list to identify and monitor critical raw materials in the EU. The goal of this paper is to discuss the specific elements of the EC criticality methodology that were adapted by DG JRC, highlight their novelty and/or potential outcomes, and discuss them in the context of criticality assessment methodologies available internationally

Clinical challenges in isolation care

OVERVIEW: In 2014, the authors published the results of a study investigating nurses\u27 use of personal protective equipment (PPE) in the care of a live simulated patient requiring contact and airborne precautions. The 24 participants were video-recorded as they donned and doffed PPE. Variations in practices that had the potential to cause contamination were noted. In this article, the authors comment on those variations, analyzing each element of proper PPE protocols and examining why the behaviors are a safety concern for the nurse and a potential risk for disease transmission in the hospital or other clinical area. The authors note that making use of reflective practice for complicated care situations such as infection control may help nurses improve decision making in isolation care