Air transport describes an inevitable part in the day to day life of the modern world. It is highly responsible for the worldwide social contacts and business developments. The use of petroleum fuels ...as energy source for air transport is not sustainable. Aviation is one of the leading contributors to the total greenhouse gas emissions. Also, the fossil fuel prices are becoming more volatile day by day. So it is very essential to introduce and industrialize alternative aviation fuels generated from renewable resources, especially biomass. A number of industrial commitments and collaborations have emerged to find alternative ways to reach bio aviation fuels. Research on the conversion of biomass based sources to bio jet fuels is of current interest. The main concern is the production of biojet fuel, from renewable resources, with relatively low greenhouse gas life cycle and sustainability with affordable price. The present paper overviews the opportunities and challenges in the development of alternative fuels for aviation. The production process, feedstock used and the most promising global projects are also reviewed.
Proliferation of renewable energy resources in distribution networks has captured distribution companies' attention towards more active management tools. Thanks to the smart grid paradigm, hourly ...network reconfiguration, which is still among immature ideas, can bring the activeness required to handle fluctuating output of renewable resources. The aim of this study is to analyze the worthiness of the hourly reconfiguration in the presence of renewable energy resources. For doing so, a mathematical model is devised to minimize daily network losses via applying hourly reconfigurations. The model is a mixed integer second-order cone programming problem and is solved via MOSEK solver. The electrical demand variations as well as renewable power generation fluctuations during a day are taken into account. The proposed method is applied to the Baran 33-bus system and the results including a great deal of sensitivity analyses on key parameters are presented and discussed.
This paper evaluates the bioeconomic performance of individual fishing quota (IFQ) regulations in multiple-species fisheries. In our model, a manager chooses the aggregate quotas under uncertainty ...over the true stock abundances of two jointly-harvested fish species. Fishers conduct harvest operations under full knowledge of the species-specific productivities of fishing gear. We derive the profit maximizing fishing mortality and economic rent outcomes implemented by fishers under various regulatory designs. We compare bioeconomic performance of an IFQ regulation with discretion over the mix of harvested species against an IFQ regulation that bans at-sea discarding. Both regulations eliminate discards. Discretion allows closer alignment between fisher implemented outcomes and those that maximize long term expected fishery value. Incorporating discretion into regulatory designs provides new prospects for improving fisheries management.
We analyze welfare effects of trade in renewable resources, which is induced by consumer love of variety in resource consumption. We model two countries, one being relatively wealthy in labor and ...capital, the other one being relatively resource abundant. For open-access resources, we show that trade freeness benefits the country that is wealthy in labor and capital, as it improves access to a larger variety of resources, especially to those of the resource-abundant country. The resource-abundant country also benefits from improved access to variety, but due to the increased resource demand and resulting overuse, this country’s welfare may depend on trade freeness in a non-monotonic fashion. We derive conditions such that welfare first decreases and then increases when trade freeness varies from autarky to costless trade. In direct comparison, autarky may generate higher welfare than costless trade only under restrictive conditions, in particular if endowments are very asymmetric and if the love of variety effect is weak. We also consider resource harvesting under private property rights and show that only for a sufficiently low discount rate the welfare increase from trade freeness in the resource-abundant country is sustainable.
•Terra Legal had no overall impact on deforestation as of 2012.•Deforestation levels increased following Terra Legal in highly registered counties.•Spatial spillovers from Terra Legal were minimal in ...the short term.•Temporary crop cultivation decreased with greater registered area.•Investment loans increased in counties with more area registered by small and medium farms.
This paper estimates the early impacts of Terra Legal, a large property rights reform, on deforestation and farming in the Brazilian Amazon. Twelve and a half million hectares, more than 2.5% of the Brazilian Amazon, have been registered under this program. The establishment of property rights may increase a farmer’s incentive to invest in his land and expand his farm due to a lower risk of expropriation. On the other hand, the enforcement of conservation requirements may be easier when farmers have legal titles to their land. We use county level data from 2007 to 2012 on farm registrations, deforestation, crop choice and bovine management to test the impact of the Terra Legal land reform. While we find no overall impact of the program on deforestation during the period in our sample, we do show that there is substantial heterogeneity in impacts across counties. Counties with the largest area registered do have an increase in the level of area deforested, but they also have a decrease in the rate of deforestation. We investigate the extent to which changes in deforestation are related to the amount of registration that occurs among small, medium and large farms, and find limited support for less deforestation among counties with more area registered by small farms; more area registered by large farms is associated with a higher level of deforestation, but a decreased deforestation rate. Our results suggest that land tenure reform can create incentives to decelerate deforestation. Farm size has a strong impact on the farm management changes generated by improved property rights; coupling land tenure reforms with incentives to intensify production rather than expand could lead to reduced deforestation, particularly among small farms.
The permanence of land management practices adopted under agri-environmental schemes (AESs) is often questioned. This paper investigates the drivers of farmers' decisions as to whether to maintain ..."proenvironment" practices beyond the duration of a contract, and in particular the effect of social norms. Our results, based on the stated intentions of 395 French farmers, show that both pecuniary and nonpecuniary motivations drive farmers' decisions, which are also significantly influenced by information about a social norm. Therefore "nudging" farmers, by conveying information to them on other farmers' proenvironmental practices, appears to be a means of maintaining the long-run benefits of AESs.
In a tele-coupled and globalized World, understanding the links between demand for wood products and land use is becoming challenging. World's economies are increasingly open and interconnected, and ...international trade flows of wood products are continuously growing. The increasing resource consumption of humanity is increasingly dependent on international trade. In this context, the study of forest products demand from a global-multi-regional perspective emerges as a critical issue to achieve the goal of sustainable consumption and production. In this paper, we introduce a novel accounting framework for assessing the forest footprint of nations. The method combines Multi-regional Input-Output techniques and detailed data from the Food and Agriculture Organization of the United Nations on production, consumption and bilateral trade of primary, intermediate and final wood products, advancing with respect to existing approaches with these practical distinctions for more accurate computations. The approach tracks resource flows along the global supply chain and provides detailed information on the production, transformation, international trade, and final use of 20 forest products in 223 countries, having also much wider coverage than most previous studies. We test this framework to analyse forest footprint of nations in the year 2014, showing that 22 Million hectares (Mha) of forest were harvested for the extraction of roundwood for global demand, being 9.1 Mha to satisfy the foreign demand of wood products (42% of the total forestland harvested area). Harvested forestland is concentrated in America (32%), Asia (29%) and Europe (28%), representing Africa (7%) and Oceania (4%). More than 50% of the reported forest area harvested worldwide is located in USA (15%), China (14%); Russia (11%) and Canada (8%). In terms of forest footprint, Asia shows the highest share of the total forest footprint (44%), followed by America (25%), Europe (21%), Africa (7%) and Oceania (2%). Country-wise, half is concentrated in China (24%), USA (16%), India (5%), and Russia (5%).
Oils and fats of vegetable and animal origin have been the most important renewable feedstock of the chemical industry in the past and in the present. A tremendous geographical and feedstock shift of ...oleochemical production has taken place from North America and Europe to southeast Asia and from tallow to palm oil. It will be important to introduce and to cultivate more and new oil plants containing fatty acids with interesting and desired properties for chemical utilization while simultaneously increasing the agricultural biodiversity. The problem of the industrial utilization of food plant oils has become more urgent with the development of the global biodiesel production. The remarkable advances made during the last decade in organic synthesis, catalysis, and biotechnology using plant oils and the basic oleochemicals derived from them will be reported, including, for example, ω‐functionalization of fatty acids containing internal double bonds, application of the olefin metathesis reaction, and de novo synthesis of fatty acids from abundantly available renewable carbon sources.
More than just a greasy spoon: Oils and fats are the most important renewable feedstock of the chemical industry. Recent and exciting advances in chemistry and biotechnology were made within the last 10 years concerning their utilization as a chemical feedstock. This progress in organic synthesis, catalysis, and biotechnology using plant oils and their derivatives is highlighted.
Funneling and functionalization of a mixture of lignin‐derived monomers into a single high‐value chemical is fascinating. Reported herein is a three‐step strategy for the production of terephthalic ...acid (TPA) from lignin‐derived monomer mixtures, in which redundant, non‐uniform substitutes such as methoxy groups are removed and the desired carboxy groups are introduced. This strategy begins with the hydro‐treatment of corn‐stover‐derived lignin oil over a supported molybdenum catalyst to selectively remove methoxy groups. The generated 4‐alkylphenols are converted into 4‐alkylbenzoic acids by carbonylation with carbon monoxide. The Co‐Mn‐Br catalyst then oxidizes various alkyl chains into carboxy groups, transforming the 4‐alkylbenzoic acid mixture into a single product: TPA. For this route, the overall yields of TPA based on lignin content of corn stover could reach 15.5 wt %, and importantly, TPA with greater than 99 % purity was obtained simply by first decanting the reaction mixture and then washing the solid product with water.
PET project: Terephthalic acid (TPA) is obtained in high yield and purity from corn stover lignin by a three‐step conversion strategy. Thus, TPA is available for making polyethylene terephthalate and other plastics.
The blue paradox McDermott, Grant R.; Meng, Kyle C.; McDonald, Gavin G. ...
Proceedings of the National Academy of Sciences - PNAS,
03/2019, Volume:
116, Issue:
12
Journal Article
Peer reviewed
Open access
Most large-scale conservation policies are anticipated or announced in advance. This risks the possibility of preemptive resource extraction before the conservation intervention goes into force. We ...use a high-resolution dataset of satellite-based fishing activity to show that anticipation of an impending no-take marine reserve undermines the policy by triggering an unintended race-to-fish. We study one of the world’s largest marine reserves, the Phoenix Islands Protected Area (PIPA), and find that fishers more than doubled their fishing effort once this area was earmarked for eventual protected status. The additional fishing effort resulted in an impoverished starting point for PIPA equivalent to 1.5 y of banned fishing. Extrapolating this behavior globally, we estimate that if other marine reserve announcements were to trigger similar preemptive fishing, this could temporarily increase the share of overextracted fisheries from 65% to 72%. Our findings have implications for general conservation efforts as well as the methods that scientists use to monitor and evaluate policy efficacy.
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