Flexible Polyurethane Foams Modified with Novel Coconut Monoglycerides-Based Polyester Polyols.

Coconut oil, a low-molecular-weight vegetable oil, is virtually unutilized as a polyol material for flexible polyurethane foam (FPUF) production due to the high-molecular-weight polyol requirement of FPUFs. The saturated chemistry of coconut oil also limits its compatibility with widely used polyol-forming processes, which mostly rely on the unsaturation of vegetable oil for functionalization. Existing studies have only exploited this resource in producing low-molecular-weight polyols for rigid foam synthesis. In this present work, high-molecular-weight polyester polyols were synthesized from coconut monoglycerides (CMG), a coproduct of fatty acid production from coconut oil, via polycondensation at different mass ratios of CMG with 1:5 glycerol:phthalic anhydride. Characterization of the CMG-based polyol (CMGPOL) products showed number-average molecular weights between 1997 and 4275 g/mol, OH numbers between 77 and 142 mg KOH/g, average functionality between 4.8 and 5.8, acid numbers between 4.49 and 23.56 mg KOH/g, and viscosities between 1.27 and 89.57 Pa·s. The polyols were used to synthesize the CMGPOL-modified PU foams (CPFs) at 20 wt % loading. The modification of the foam formulation increased the monodentate and bidentate urea groups, shown using Fourier transform infrared (FTIR) spectroscopy, that promoted microphase separation in the foam matrix, confirmed using atomic force microscopy (AFM) and differential scanning calorimetry (DSC). The implications of the structural change to foam morphology and open cell content were investigated using a scanning electron microscope (SEM) and gas pycnometer. The density of the CPFs decreased, while a significant improvement in their tensile and compressive properties was observed. Also, the CPFs exhibited different resiliency with a correlation to microphase separation. These findings offer a new sustainable polyol raw material that can be used to modify petroleum-based foam and produce flexible foams with varying properties that can be tailored to meet specific requirements.

A novel reaction mechanism for the synthesis of coconut oil-derived biopolyol for rigid poly(urethane-urea) hybrid foam application.

Coconut oil (CO) has become one of the most important renewable raw materials for polyol synthesis due to its abundance and low price. However, the saturated chemical structure of CO limits its capability for functionalization. In this study, a novel reaction mechanism via the sequential glycerolysis and amidation of CO triglycerides produced an amine-based polyol (p-CDEA). The synthesized biopolyol has a relatively higher hydroxyl value of 361 mg KOH per g relative to previously reported CO-based polyols with values ranging from 270-333 mg KOH per g. This primary hydroxyl-rich p-CDEA was used directly as a sole B-side polyol component in a polyurethane-forming reaction, without further purification. Results showed that a high-performance poly(urethane-urea) (PUA) hybrid foam was successfully produced. It has a compressive strength of 226 kPa and thermal conductivity of 23.2 mW (m-1 K-1), classified as type 1 for a rigid structural sandwich panel core and type 2 for rigid thermal insulation foam applications according to ASTM standards. Fourier-transform infrared (FTIR) spectroscopy was performed to characterize the chemical features of the polyols and foams. Scanning electron microscopy (SEM) analysis was also performed to evaluate the morphological structures of the synthesized foams. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were conducted to investigate the foam's thermal characteristics. Thus far, this work is the first to report a novel and effective reaction mechanism for the synthesis of a highly functional CO-derived polyol and the first CO-based polyol with no petroleum-based replacement that may serve as raw material for rigid PUA foam production. PUA hybrid foams are potential insulation and structural materials. This study further provided a compelling case for enhanced sustainability of p-CDEA PUA hybrid foam against petroleum-based polyurethane.

The Integration of Metabolomics with Other Omics: Insights into Understanding Prostate Cancer.

Our understanding of prostate cancer (PCa) has shifted from solely caused by a few genetic aberrations to a combination of complex biochemical dysregulations with the prostate metabolome at its core. The role of metabolomics in analyzing the pathophysiology of PCa is indispensable. However, to fully elucidate real-time complex dysregulation in prostate cells, an integrated approach based on metabolomics and other omics is warranted. Individually, genomics, transcriptomics, and proteomics are robust, but they are not enough to achieve a holistic view of PCa tumorigenesis. This review is the first of its kind to focus solely on the integration of metabolomics with multi-omic platforms in PCa research, including a detailed emphasis on the metabolomic profile of PCa. The authors intend to provide researchers in the field with a comprehensive knowledge base in PCa metabolomics and offer perspectives on overcoming limitations of the tool to guide future point-of-care applications.

Surfactant addition to enhance bioavailability of bilge water in single chamber microbial fuel cells (MFCs).

Effective remediation of bilge water, a shipboard oily liquid waste, is important for both commercial and military vessels due to the domestic and international regulations. In this study, bilge water was used as a substrate for exoelectrogenic bacteria and biodegradation of bilge water and concurrent electricity generation were investigated using Pseudomonas putida ATCC 49128 in single chamber microbial fuel cells (MFCs). To enhance bioavailability of the bilge water, two types of surfactants were added (100 ppm) into the oily wastewater containing 0.1% standard bilge mix (SBM) and their impacts on electricity production were evaluated under various conditions. Anionic surfactant (sodium dodecyl sulfate, SDS) addition increased soluble chemical oxygen demand (SCOD) by forming micelle, producing maximum power density of 225.3 ± 3.2 mW m-2. However, the MFC with nonionic surfactant (Triton X-100) produced only 2.3 ± 0.1 mW m-2 due to no enhancement on biodegradable SCOD. A high NaCl concentration (100-500 mM) adversely affected power production due to decrease in available SCOD caused by emulsion coalescence. This is a first study to use surfactants to enhance bioavailability of non-biodegradable oily wastewater in a single chamber MFC.

Assessing the energy and environmental performance of algae-mediated tertiary treatment of estrogenic compounds.

This study uses a systems-level modeling approach to illustrate a novel synergy between municipal wastewater treatment and large-scale algaculture for production of bio-energy, whereby algae-mediated tertiary treatment provides efficient removal of unregulated, strongly estrogenic steroid hormones from the secondary effluent. Laboratory results from previously published studies suggested that algae-mediated treatment could deliver roughly 75-85% removal of a model estrogen (17ß-estradiol) within typical algae pond residence times. As such, experimental results are integrated into a comprehensive life cycle assessment (LCA) framework, to assess the environmental performance of an algae-based tertiary treatment system relative to three conventional tertiary treatments: ozonation, UV irradiation, and adsorption onto granular activated carbon. Results indicate that the algae-mediated tertiary treatment is superior to the selected benchmarks on the basis of raw energy return on investment (EROI) and normalized energy use per mass of estrogenic toxicity removed. It is the only tertiary treatment system that creates more energy than it consumes, and it delivers acceptable effluent quality for nutrient and coliform concentrations while rendering a significant reduction in estrogenic toxicity. These results highlight the dual water and energy sustainability benefits that accrue from the integration of municipal wastewater treatment and large-scale algae farming.

Comparison of algae cultivation methods for bioenergy production using a combined life cycle assessment and life cycle costing approach.

Algae are an attractive energy source, but important questions still exist about the sustainability of this technology on a large scale. Two particularly important questions concern the method of cultivation and the type of algae to be used. This present study combines elements of life cycle analysis (LCA) and life cycle costing (LCC) to evaluate open pond (OP) systems and horizontal tubular photobioreactors (PBRs) for the cultivation of freshwater (FW) or brackish-to-saline water (BSW) algae. Based on the LCA, OPs have lower energy consumption and greenhouse gas emissions than PBRs; e.g., 32% less energy use for construction and operation. According to the LCC, all four systems are currently financially unattractive investments, though OPs are less so than PBRs. BSW species deliver better energy and GHG performance and higher profitability than FW species in both OPs and PBRs. Sensitivity analyses suggest that improvements in critical cultivation parameters (e.g., CO(2) utilization efficiency or algae lipid content), conversion parameters (e.g., anaerobic digestion efficiency), and market factors (e.g., costs of CO(2) and electricity, or sale prices for algae biodiesel) could alter these results.

Environmental impacts of algae-derived biodiesel and bioelectricity for transportation.

Algae are a widely touted source of bioenergy with high yields, appreciable lipid contents, and an ability to be cultivated on marginal land without directly competing with food crops. Nevertheless, recent work has suggested that large-scale deployment of algae bioenergy systems could have unexpectedly high environmental burdens. In this study, a "well-to-wheel" life cycle assessment was undertaken to evaluate algae's potential use as a transportation energy source for passenger vehicles. Four algae conversion pathways resulting in combinations of bioelectricity and biodiesel were assessed for several relevant nutrient procurement scenarios. Results suggest that algae-to-energy systems can be either net energy positive or negative depending on the specific combination of cultivation and conversion processes used. Conversion pathways involving direct combustion for bioelectricity production generally outperformed systems involving anaerobic digestion and biodiesel production, and they were found to generate four and fifteen times as many vehicle kilometers traveled (VKT) per hectare as switchgrass or canola, respectively. Despite this, algae systems exhibited mixed performance for environmental impacts (energy use, water use, and greenhouse gas emissions) on a "per km" basis relative to the benchmark crops. This suggests that both cultivation and conversion processes must be carefully considered to ensure the environmental viability of algae-to-energy processes.

Environmental life cycle comparison of algae to other bioenergy feedstocks.

Algae are an attractive source of biomass energy since they do not compete with food crops and have higher energy yields per area than terrestrial crops. In spite of these advantages, algae cultivation has not yet been compared with conventional crops from a life cycle perspective. In this work, the impacts associated with algae production were determined using a stochastic life cycle model and compared with switchgrass, canola, and corn farming. The results indicate that these conventional crops have lower environmental impacts than algae in energy use, greenhouse gas emissions, and water regardless of cultivation location. Only in total land use and eutrophication potential do algae perform favorably. The large environmental footprint of algae cultivation is driven predominantly by upstream impacts, such as the demand for CO(2) and fertilizer. To reduce these impacts, flue gas and, to a greater extent, wastewater could be used to offset most of the environmental burdens associated with algae. To demonstrate the benefits of algae production coupled with wastewater treatment, the model was expanded to include three different municipal wastewater effluents as sources of nitrogen and phosphorus. Each provided a significant reduction in the burdens of algae cultivation, and the use of source-separated urine was found to make algae more environmentally beneficial than the terrestrial crops.