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Abstract Lignin is considered as a renewable and sustainable resource for producing value-added aromatic chemicals and functional carbon materials. Herein, we develop a one-step catalyst-free depolymerization strategy to convert lignin into aryl monomers and carbon nanospheres simultaneously. Importantly, microwave-assisted depolymerization (MAD) in conjunction with dichloromethane (CH2Cl2) vapors is developed. The total mass yield of guaiacols reached the highest amount of 225.1 mg/g at 600 °C, and the highest yields of phenols (49.0 mg/g) and aromatic hydrocarbons (155.1 mg/g) were obtained at 700 °C. Hydrogen radicals and hydrogen chloride (HCl) are in-situ formed from CH2Cl2, significantly decreasing the activation barrier and reforming pyrolysis vapors to promote the formation of aryl monomers. Interestingly, uniform carbon nanospheres with an average size of 140 nm were produced as co-products at 700 °C. The microwave “hot-spots”, allied with the continuous surface erosion and the decrease in surface energy of lignin-derived carbon precursors by CH2Cl2 vapor, can be considered the driving force for the ultimate formation of carbon nanospheres. The CH2Cl2/MAD system produces aryl monomers (26.8 wt% yield) and carbon nanospheres (36.6 wt% yield) at 700 °C. We provide a facile, intriguing and scalable approach to convert lignin to valuable aryl monomers and sustainable carbon materials that can be applied in the chemistry, energy and environmental fields.

AbstractThe U.S. Department of Energy has launched the commercial building initiative (CBI) in pursuit of its research goal of achieving zero‐net‐energy commercial buildings (ZNEB), i.e., ones that produce as much energy as they use. Its objective is to make these buildings marketable by 2025 such that they minimize their energy use through cutting‐edge, energy‐efficiency technologies and meet their remaining energy needs through on‐site renewable energy generation. This paper examines how such buildings may be implemented within the context of a cost‐ or CO2‐minimizing microgrid that is able to adopt and operate various technologies: photovoltaic (PV) modules and other on‐site generation, heat exchangers, solar thermal collectors, absorption chillers, and passive/demand‐response technologies. A mixed‐integer linear program (MILP) that has a multi‐criteria objective function is used. The objective is minimization of a weighted average of the building's annual energy costs and CO2 emissions. The MILP's constraints ensure energy balance and capacity limits. In addition, constraining the building's energy consumed to equal its energy exports enables us to explore how energy sales and demand‐response measures may enable compliance with the ZNEB objective. Using a commercial test site in northern California with existing tariff rates and technology data, we find that a ZNEB requires ample PV capacity installed to ensure electricity sales during the day. This is complemented by investment in energy‐efficient combined heat and power (CHP) equipment, while occasional demand response saves energy consumption. A large amount of storage is also adopted, which may be impractical. Nevertheless, it shows the nature of the solutions and costs necessary to achieve a ZNEB. Additionally, the ZNEB approach does not necessary lead to zero‐carbon (ZC) buildings as is frequently argued. We also show a multi‐objective frontier for the CA example, which allows us to estimate the needed technologies and costs for achieving a ZC building or microgrid. Copyright © 2010 John Wiley & Sons, Ltd.

Developing Asia is the driver of today’s emissions intensive global economy. As the principle source of future emissions, the region is critical to the task of global climate change mitigation. Reflecting this global reality and a range of related domestic issues, the governments of the People’s Republic of China, India, Indonesia, Thailand, and Viet Nam have embarked upon an ambitious policy agenda. This report reviews the present and future policy settings for climate change mitigation and green growth in Asia’s major emerging economies.

The overall objective of the project was to define a two-stage reactive fractionation process for converting corn stover into a solid cellulose stream and two liquid streams containing mostly hemicellulosic sugars and lignin, respectively. Toward this goal, biomass fractionation was conducted using a small continuous pilot unit with a nominal capacity of 100 pounds per day of dry biomass to generate performance data using primarily corn stover as feedstock. In the course of the program, the PureVision process was optimized for efficient hemicellulose hydrolysis in the first stage employing autohydrolysis and delignification in the second stage using sodium hydroxide as a catalyst. The remaining cellulose was deemed to be an excellent substrate for producing fermentation sugars, requiring 40% less enzymes for hydrolysis than conventional pretreatment systems using dilute acid. The fractionated cellulose was also determined to have potential higher-value applications as a pulp product. The lignin coproduct was determined to be substantially lower in molecular weight (MW) compared to lignins produced in the kraft or sulfite pulping processes. This low-MW lignin can be used as a feed and concrete binder and as an intermediate for producing a range of high-value products including phenolic resins. This research adds to the understandingmore » of the biomass conversion area in that a new process was developed in the true spirit of biorefineries. The work completed successfully demonstrated the technical effectiveness of the process at the pilot level indicating the technology is ready to advance to a 2–3 ton per day scale. No technical showstoppers are anticipated in scaling up the PureVision fractionation process to commercial scale. Also, economic feasibility of using the PureVision process in a commercial-scale biorefinery was investigated and the minimum ethanol selling price for the PureVision process was calculated to be $0.94/gal ethanol vs. $1.07/gal ethanol for the NREL process. Thus, the PureVision process is economically attractive. Given its technical and economic feasibility, the project is of benefit to the public in the following ways: 1) it demonstrated a novel biomass fractionation process that can provide domestic supply of renewable transportation fuel from all three biomass components (cellulose, hemicellulose and lignin), 2) the lignin stream from the process has many higher-value applications beyond simply burning the lignin for energy as proposed by competing technologies, 3) it can be deployed in rural areas and create jobs in these areas, and 3) it can add to the nation’s economy and security.« less

While substance use disorders (SUD) continue to be a global concern, harm reduction approaches can provide sustainable harm minimization to people who inject drugs (PWID) without requiring abstinence. Yet, the evidence for the sustainable implementation of harm reduction approaches is newly emerging. This scoping review sought to map the evidence on implementation qualities of sustainable harm reduction needle and syringe programs (NSPs). We searched the Cochrane Database of Systematic Reviews, PubMed, ProQuest Central, and Directory of Open Access Journals for empirical studies (a) with an explicit focus on harm minimization NSPs, (b) with a clearly identified study population, (c) that described the specific NSP implementation protocol, (d) that provided information on accessibility, affordability, and feasibility, and (e) were published in English between 2000–2020. Following narrative qualitative synthesis, the evidence suggests individual implementer characteristics directly influenced sustainable availability and scope of NSP provision while implementation processes explained the predictability and continuity of service provision across services. External factors including community perceptions of NSPs and policing activity influenced the sustainability of NSP implementation. The emerging evidence suggests that sustainable NSP programs for PWID require provider, consumer, and community engagement, supported by enabling health policies.

AbstractTwenty-five years since foundational publications on valuing ecosystem services for human well-being1,2, addressing the global biodiversity crisis3 still implies confronting barriers to incorporating nature’s diverse values into decision-making. These barriers include powerful interests supported by current norms and legal rules such as property rights, which determine whose values and which values of nature are acted on. A better understanding of how and why nature is (under)valued is more urgent than ever4. Notwithstanding agreements to incorporate nature’s values into actions, including the Kunming-Montreal Global Biodiversity Framework (GBF)5 and the UN Sustainable Development Goals6, predominant environmental and development policies still prioritize a subset of values, particularly those linked to markets, and ignore other ways people relate to and benefit from nature7. Arguably, a ‘values crisis’ underpins the intertwined crises of biodiversity loss and climate change8, pandemic emergence9 and socio-environmental injustices10. On the basis of more than 50,000 scientific publications, policy documents and Indigenous and local knowledge sources, the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) assessed knowledge on nature’s diverse values and valuation methods to gain insights into their role in policymaking and fuller integration into decisions7,11. Applying this evidence, combinations of values-centred approaches are proposed to improve valuation and address barriers to uptake, ultimately leveraging transformative changes towards more just (that is, fair treatment of people and nature, including inter- and intragenerational equity) and sustainable futures.