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This research addresses the critical necessity for energy-efficient solutions in port operations. The primary objective of this paper is to introduce and assess the viability of an innovative infrastructure termed Underground Reefer Container Storage (URCS) devised to mitigate the significant and increasing energy demand posed by reefer containers in ports. This study employs a discrete-event simulation (DES) model to evaluate the feasibility, environmental implications, and cost-effectiveness of three distinctive URCS infrastructure designs. These designs are compared against conventional storage methods to ascertain their capacity for minimizing energy usage and greenhouse gas emissions. The analysis reveals that the best scenario for a specific case study involves a multi-block layout comprising two underground yards, capable of accommodating 39% of the overall refrigerated container capacity at a port. This layout cuts CO 2 emissions by 61% from the 2.704 GWh/year energy used by refrigerated containers, yielding around 1.4 million USD/year cost savings. Further analyses using weighted searches to prioritize URCS container slotting led to shorter container dwell times at ports, rendering energy savings 23% higher than in similar unplanned settings. Moreover, this study presents URCS as an eco-friendly alternative for port-based reefer container storage, offering practical alignment with sustainability goals and regulations. The innovative design and its successful application provide holistic insights, paving the way for enhanced port energy management and environmental care. In addition, the implementation of URCS has the potential to reshape port procedures, yielding economic and ecological benefits. This initiative contributes to diminishing the carbon footprint of ports, aligning with global endeavors towards greener and more responsible practices. [Display omitted] • Conventional stacking at ports consumes high energy for reefer containers, risking the cold chain. • Underground reefer container storage (URCS) reduces heat exchange by storing reefers in a colder underground deposit. • Multi-level block storage is preferred in URCS, according to a multi-criteria assessment. • Simulation recommends energy savings with proper stacking in multi-level block storage. • URCS enables environmentally responsible port operations, improving standards feasibly. [ABSTRACT FROM AUTHOR]

Some agricultural industries such as livestock and poultry farming produce "growing items" whose weight and value constantly increase over time. Growing items and their related industries are vital in supplying the needed food and fiber for the world population. More importantly, concerns for the preservation of natural resources have led to sustainable goals of reducing greenhouse gas emissions (GHGEs) released by growing items. Recently, an inventory system called "economic growing quantity (EGQ)" was designed for growing items. This paper designs, develops, and optimizes a sustainable model for EGQ system, entitled "sustainable EGQ (SEGQ)", where the hidden costs and revenues associated with the sustainability of growing items are considered under a carbon tax policy. The cost function incorporates purchasing, transportation, feeding, shortage, setup, holding, and carcass disposal costs as well as the tax costs of greenhouse gas (GHG) emitted from manure, feed fermentation, carcasses, holding and transportation processes. The revenue function takes the earned income from the sale of grown items as well as their byproducts into account. Accordingly, a nonlinear program (NLP) is developed to maximize the total profit. The novelty of this paper resides in its consideration of the reproductive patterns and byproducts of growing items, gradual sales, shortage costs, major sources of GHGEs and their hidden costs, and finally a design of the main variables to mitigate the GHGs emitted by the growing items. Findings demonstrate that the SEGQ model with reproducible items and profitable byproducts increases the growth cycle and decreases the quantity of growing items needed at the start of the inventory cycle. [Display omitted] • Sustainable design of the related variables to inventory management of growing items. • The reproductive patterns of growing items under carbon emission considerations. • The profitable byproducts of growing items. • Identification and mitigation of other main sources of GHGEs in growing items. • An NLP model of hidden related costs and revenues to growing items under gradual sell. [ABSTRACT FROM AUTHOR]

An emerging strategy to remove CO 2 from the atmosphere and compensate for the greenhouse-gas emissions of cement and concrete is based on incorporating biochar into concrete. With this approach, concrete can be turned into a functional carbon sink (C-sink). Until now, biochar has been mainly used without modification to replace part of the cement or of the aggregates in concrete. However, this technology comes with a number of practical problems, which include the high water absorption of the biochar (due to its high specific surface) and hazards (dust, risk of combustion). In this paper we present an alternative approach, in which biochar is first processed into lightweight aggregates in a cold-bonding process. To this end, biochar is pelletized together with water and a small amount of hydraulic binder forming round pellets that further harden with hydration. In this way, carbon-rich lightweight aggregates (C-LWA) are obtained that are easier to handle than the original biochar. The C-LWA pellets have similar porosity and strength as conventional LWA and can be used for similar applications. Yet, the CO 2 emissions from sintering traditional LWA are avoided and the C-LWA are instead an effective C-sink. We demonstrate that it is possible to incorporate in the pellets and eventually in the concrete a sufficient amount of carbon to compensate for the original emissions of concrete. The net-zero emissions concrete obtained with this approach possesses mechanical performance sufficient for typical structural applications in buildings. • Biochar is processed into lightweight aggregates in cold-bonding process. • The biochar-rich lightweight aggregates added to concrete act as a safe carbon sink. • Structural concrete with net-zero greenhouse gas emissions becomes possible. [ABSTRACT FROM AUTHOR]

Replacing the current mainly fossil-based, disposable, and non-biodegradable sanitary products with sustainable, functional alternatives is an industry priority. Suggested biobased alternatives require evaluation of their actual impact on greenhouse gas (GHG) emissions. We evaluated GHG emissions of biobased baby diapers as the most consumed sanitary product, using a biodegradable functionalized protein superabsorbent polymer (bioSAP) and compared them with currently used fossil-based counterparts. Assessment of the diapers also included estimated GHG emissions from the production of the biobased components, transport, and end-of-life combustion of these items. It was shown that only a few of the biobased diaper alternatives resulted in lower GHG emissions than commercial diapers containing fossil-based materials. At the same time, it was demonstrated that the production of the bioSAP via chemical modification of a protein raw material is the primary GHG contributor, with 78% of the total emissions. Reduction of the GHG contribution of the bioSAP production was achieved via a proposed recycling route of the functionalization agent, reducing the GHG emissions by 13% than if no recycling was carried out. Overall, we demonstrated that reduced and competitive GHG emissions could be achieved in sanitary articles using biobased materials, thereby contributing to a sanitary industry producing disposable products with less environmental pollution while allowing customers to keep their current consumption patterns. [Display omitted] • Superabsorbents contribute the highest CO 2 emission share in a biobased diaper. • Recycling of reagents for production of biobased superabsorbents reduces CO 2 emission by 50%. • Only a few biobased diapers resulted in lower CO 2 emissions than fossil-based ones. • Biodegradable diapers are superior from a circular perspective. • Biobased superabsorbents are currently on a low TRL and need to be developed. [ABSTRACT FROM AUTHOR]