Technical, Environmental, and Economic Analysis Comparing Low-Carbon Industrial Process Heat Options in U.S. Poly(vinyl chloride) and Ethylene Manufacturing Facilities.

Electrification and clean hydrogen are promising low-carbon options for decarbonizing industrial process heat, which is an essential target for reducing sector-wide emissions. However, industrial processes with heat demand vary significantly across industries in terms of temperature requirements, capacities, and equipment, making it challenging to determine applications for low-carbon technologies that are technically and economically feasible. In this analysis, we develop a framework for evaluating life cycle emissions, water use, and cost impacts of electric and clean hydrogen process heat technologies and apply it in several case studies for plastics and petrochemical manufacturing industries in the United States. Our results show that industrial heat pumps could reduce emissions by 12-17% in a typical poly(vinyl chloride) (PVC) facility in certain locations currently, compared to conventional natural gas combustion, and that other electric technologies in PVC and ethylene production could reduce emissions by nearly 90% with a sufficiently decarbonized electric grid. Life cycle water use increases significantly in all low-carbon technology cases. The levelized cost of heat of viable low-carbon technologies ranges from 15 to 100% higher than conventional heating systems, primarily due to energy costs. We discuss results in the context of relevant policies that could be useful to manufacturing facilities and policymakers for aiding the transition to low-carbon process heat technologies.

Environmental Impact and Cost Savings of Operating Room Quality Improvement Initiatives: A Scoping Review.

BACKGROUND: Operating rooms are major contributors to a hospital's carbon footprint due to the large volumes of resources consumed and waste produced. The objective of this study was to identify quality improvement initiatives that aimed to reduce the environmental impact of the operating room while decreasing costs. STUDY DESIGN: A literature search was performed using PubMed, Scopus, CINAHL, and Google Scholar and included broad terms for "operating room," "costs," and "environment" or "sustainability." The "triple bottom line" framework, which considers the environmental, financial, and social impacts of interventions to guide decision making, was used to inform data extraction. The studies were then categorized using the 5 "Rs" of sustainability-refuse, reduce, reuse, repurpose, and recycle-and the impacts were discussed using the triple bottom line framework. RESULTS: A total of 23 unique quality improvement initiatives describing 28 interventions were included. Interventions were categorized as "refuse" (n = 11; 39.3%), "reduce" (n = 8; 28.6%), "reuse" (n = 3; 10.7%), and "recycle" (n = 6; 21.4%). While methods of measuring environmental impact and cost savings varied greatly among studies, potential annual cost savings ranged from $873 (intervention: education on diverting recyclable materials from sharps containers; environmental impact: 11.4 kg sharps waste diverted per month) to $694,141 (intervention: education to reduce regulated medical waste; environmental impact: 30% reduction in regulated medical waste). CONCLUSIONS: Quality improvement initiatives that reduce both cost and environmental impact have been successfully implemented across a variety of centers both nationally and globally. Surgeons, healthcare practitioners, and administrators interested in environmental stewardship and working toward a culture of sustainability may consider similar interventions in their institutions.

Plastics to fuel or plastics: Life cycle assessment-based evaluation of different options for pyrolysis at end-of-life.

Pyrolysis is a leading technology to convert non-recyclable plastic waste to fuels or chemicals. As interest in the circular economy grows, the latter option has seemingly become more attractive. Once waste plastic is pyrolyzed to, for example, naphtha, however, additional steps are required to produce a polymer product. These steps consume additional energy and water and emit greenhouse gases (GHG). It is unclear whether this more circular option of non-recyclable plastics to virgin plastics offers environmental benefits, compared to their conversion to fuels. We therefore examine whether it is possible to determine the best use of pyrolyzing non-recyclable plastic - fuels or chemicals (low-density polyethylene (LDPE) as product)- from a life cycle perspective. We use recently published life cycle assessments of non-recycled plastics pyrolysis and consider two functional units: per unit mass of non-recyclable plastics and per unit product - MJ of naphtha or kg of LDPE. In the U.S., on a cradle-to-gate, per unit mass waste basis, producing fuel is lower-emitting than producing LDPE from pyrolysis. The opposite is true in the EU. But expanding the system boundary to the grave results in LDPE as the lower-emitting product in both regions. Naphtha and LDPE produced from non-recyclable plastics are less GHG-intensive than conventional routes to these products. Fossil fuel and water consumption and waste generation are all lower in the P2F case. Our results highlight that prioritization of P2P and P2F may depend on regional characteristics such as conventional waste management techniques and water scarcity.

Co-optimization of Heavy-Duty Fuels and Engines: Cost Benefit Analysis and Implications.

Heavy-duty vehicles require expensive aftertreatment systems for control of emissions such as particulate matter (PM) and nitrogen oxides (NOx) to comply with stringent emission standards. Reduced engine-out emissions could potentially alleviate the emission control burden, and thus bring about reductions in the cost associated with aftertreatment systems, which translates into savings in vehicle ownership. This study evaluates potential reductions in manufacturing and operating costs of redesigned emission aftertreatment systems of line-haul heavy-duty diesel vehicles (HDDVs) with reduced engine-out emissions brought about by co-optimized fuel and engine technologies. Three emissions reduction cases representing conservative, medium, and optimistic engine-out emission reduction benefits are analyzed, compared to a reference case: the total costs of aftertreatment systems (TCA) of the three cases are reduced to $11,400(1.63 ¢/km), $9,100 (1.30 ¢/km), and $8,800 (1.26 ¢/km), respectively, compared to $12,000 (1.71 ¢/km) for the reference case. The largest potential reductions result from reduced diesel exhaust fluid (DEF) usage due to lower NOx emissions. Downsizing aftertreatment devices is not likely, because the sizes of devices are dependent on not only engine-out emissions, but also other factors such as engine displacement. Sensitivity analysis indicates that the price and usage of DEF have the largest impacts on TCA reduction.

Biofuel and bioproduct environmental sustainability analysis.

Life cycle analysis (LCA) is a key tool in the evaluation of biofuel and bioproduct sustainability. Recent advances in these analyses include increased incorporation of spatially explicit elements of feedstock growth including changes in soil carbon and fertilization rates. Furthermore, new evaluations of processes to convert biomass to fuels (ethanol, algal-derived fuels, jet fuels, and others) and products have been conducted that examine emerging conversion technologies. Co-product allocation among co-produced biofuels and bioproducts continues to raise LCA methodological challenges; approaches to allocation can drive LCA results. Given the variations in feedstocks, spatially explicit factors, conversion process design, and LCA methodological choices (e.g. co-product allocation), transparency in reporting biofuel LCA methodology and results is critical to enable cross-comparison of studies.