Low severity Fischer-Tropsch synthesis for the production of synthetic hydrocarbon fuels

Currently, the main source for the production of liquid transportation fuels is petroleum, the continued use of which faces many challenges including depleting oil reserves, significant oil price rises, and environmental concerns over global warming which is widely believed to be due to fossil fuel derived CO2 emissions and other greenhouse gases. In this respect, lignocellulosic or plant biomass is a particularly interesting resource as it is the only renewable source of organic carbon that can be converted into liquid transportation fuels. The gasification of biomass produces syngas which can then be converted into synthetic liquid hydrocarbon fuels by means of the Fischer-Tropsch (FT) synthesis. This process has been widely considered as an attractive option for producing clean liquid hydrocarbon fuels from biomass that have been identified as promising alternatives to conventional fossil fuels like diesel and kerosene. The resulting product composition in FT synthesis is influenced by the type of catalyst and the reaction conditions that are used in the process. One of the issues facing this conversion process is the development of a technology that can be scaled down to match the scattered nature of biomass resources, including lower operating pressures, without compromising liquid composition. The primary aims of this work were to experimentally explore FT synthesis at low pressures for the purpose of process down-scaling and cost reduction, and to investigate the potential for obtaining an intermediate FT synthetic crude liquid product that can be integrated into existing refineries under the range of process conditions employed. Two different fixed-bed micro-reactors were used for FT synthesis; a 2cm3 reactor at the University of Rio de Janeiro (UFRJ) and a 20cm3 reactor at Aston University. The experimental work firstly involved the selection of a suitable catalyst from three that were available. Secondly, a parameter study was carried out on the 20cm3 reactor using the selected catalyst to investigate the influence of reactor temperature, reactor pressure, space velocity, the H2/CO molar ratio in the feed syngas and catalyst loading on the reaction performance measured as CO conversion, catalyst stability, product distribution, product yields and liquid hydrocarbon product composition. From this parameter study a set of preferred operating conditions was identified for low pressure FT synthesis. The three catalysts were characterized using BET, XRD, TPR and SEM. The catalyst selected was an unpromoted Co/Al2O3 catalyst. FT synthesis runs on the 20cm3 reactor at Aston were conducted for 48 hours. Permanent gases and light hydrocarbons (C1-C5) were analysed in an online GC-TCD/FID at hourly intervals. The liquid hydrocarbons collected were analyzed offline using GC-MS for determination of fuel composition. The parameter study showed that CO conversion and liquid hydrocarbon yields increase with increasing reactor pressure up to around 8 bar, above which the effect of pressure is small. The parameters that had the most significant influence on CO conversion, product selectivity and liquid hydrocarbon yields were reactor temperature and catalyst loading. The preferred reaction conditions identified for this research were: T = 230ºC, P = 10 bar, H2/CO = 2.0, WHSV = 2.2 h-1, and catalyst loading = 2.0g. Operation in the low range of pressures studied resulted in low CO conversions and liquid hydrocarbon yields, indicating that low pressure BTL-FT operation may not be industrially viable as the trade off in lower CO conversions and once-through liquid hydrocarbon product yields has to be carefully weighed against the potential cost savings resulting from process operation at lower pressures.

Adaptation to flood risk:the case of businesses in the UK

Despite Government investment in flood defence schemes, many properties remain at high risk of flooding. A substantial portion of these properties are business establishments. Flooding can create serious consequences for businesses, including damage to property and stocks, being out of business for a considerable period and ultimately business failure. Recent flood events such as those in 2007 and 2009 that affected many parts of the UK have helped to establish the true costs of flooding to businesses. This greater understanding of the risks to businesses has heightened the need for business owners to adapt their businesses to the threat of future flooding. Government policy has now shifted away from investment in engineered flood defences, towards encouraging the uptake of property level flood resistance and resilience measures by businesses. However, implementing such adaptation strategies remains a challenge due a range of reasons. A review of the current state of property level flood risk adaptation of UK businesses is presented, drawing from extant literature. Barriers that may hinder the uptake of property level adaptation by businesses are revealed and drivers that may enhance uptake and effectively overcome these barriers are also discussed. It is concluded that the professions from the construction sector have the potential to contribute towards the adaptation of business properties and thereby the flood resilience of businesses at risk of flooding.

Geographical variation in carbon dioxide fluxes from soils in agro-ecosystems and its implications for life-cycle assessment

1. Exchange of carbon dioxide (CO2) from soils can contribute significantly to the global warming potential (GWP) of agro-ecosystems. Due to variations in soil type, climatic onditions and land management practices, exchange of CO2 can differ markedly in different geographical locations. The food industry is developing carbon footprints for their products necessitating integration of CO2 exchange from soils with other CO2 emissions along the food chain. It may be advantageous to grow certain crops in different geographical locations to minimize CO2 emissions from the soil, and this may provide potential to offset other emissions in the food chain, such as transport. 2. Values are derived for the C balance of soils growing horticultural crops in the UK, Spain and Uganda. Net ecosystem production (NEP) is firstly calculated from the difference in net primary production (NPP) and heterotrophic soil respiration (Rh). Both NPP and Rh were estimated from intensive direct field measurements. Secondly, net biome production (NBP) is calculated by subtracting the crop biomass from NEP to give an indication of C balance. The importance of soil exchange is discussed in the light of recent discussions on carbon footprints and within the context of food life-cycle assessment (LCA). 3. The amount of crop relative to the biomass and the Rh prevailing in the different countries were the dominant factors influencing the magnitude of NEP and NBP. The majority of the biomass for lettuce Lactuca sativa and vining peas Pisum sativum, was removed from the field as crop; therefore, NEP and NBP were mainly negative. This was amplified for lettuces grown in Uganda (-16·5 and -17 t C ha-1 year-1 compared to UK and Spain -4·8 to 7·4 and -5·1 to 6·3 t C ha-1 year-1 for NEP and NBP, respectively) where the climate elevated Rh. 4. Synthesis and applications. This study demonstrates the importance of soil emissions in the overall life cycle of vegetables. Variability in such emissions suggests that assigning a single value to food carbon footprints may not be adequate, even within a country. Locations with high heterotrophic soil respiration, such as Spain and Uganda (21·9 and 21·6 t C ha-1 year-1, respectively), could mitigate the negative effects of climate on the C costs of crop production by growth of crops with greater returns of residue to the soil. This would minimize net CO2 emissions from these agricultural ecosystems.

Lichen growth and lichenometry

Lichenometry is one of the most widely used methods available for dating the surface age of various substrata including rock surfaces, boulders, walls, and archaeological remains. It depends on the assumption that if the lag time before colonisation of a substratum by a lichen is known and lichen age can be estimated, then a minimum date can be obtained by measuring the diameter (or another property related to size) of the largest lichen at the site. Lichen age can be determined by variety of methods including calibrating lichen size against surfaces of known age (‘indirect lichenometry’), by constructing a growth rate-size curve from direct measurement of lichen growth (‘direct lichenometry’), using radio-carbon (RC) dating, and from lichen ‘growth rings’. This chapter describes: (1) lichen growth rates and longevity, (2) methods of estimating lichen age, (3) the methodology of lichenometry and (4) applications of lichenometry. Despite its limitations, lichenometry is likely to continue to play an important role in dating a variety of surfaces and also in providing data that contribute to the debate regarding global warming and climate change.

A környezethez való jog és a Kiotói Jegyzőkönyv (Right to environment and Kyoto Protocol)

A Kiotói Jegyzőkönyv az 1992-ben Rio de Janeiro-ban megrendezésre került Környezet és Fejlődés Világkonferenciáján elfogadott nyilatkozatának 1997-ben aláírt kiegészítő jegyzőkönyve. A Kiotói Jegyzőkönyvben minden aláíró ország vállalta, hogy egy bizonyos százalékos arányban csökkenti országában a kibocsátott üvegházhatást okozó gázok mennyiségét, ezáltal mérsékelve a globális felmelegedés előrehaladtát. A Jegyzőkönyvhöz az Egyesült Államok és több fejlő ország, mint Kína vagy India gazdasági megfontolásból másrészt politikai szűklátókörűségből nem csatlakozott. Ez azonban a komoly aggályokat vet fel azzal kapcsolatban, hogy a környezetvédelmi szabályokat betartó államok erőfeszítései önmagában elegendőek lesznek-e a globális felmelegedés megállítására, de legalábbis csökkentésére. _____________ The Kyoto Protocol signed in the Japanese city in Kyoto in 1997 is a supplemental document to the United Nations Conference on Environment and Development organized in Rio de Janeiro. In the Kyoto Protocol individual countries have mandatory emissions targets for the greenhouse gases they must meet to slow down global warming. The United States of America, and several developing countries, as China and India did not yet joined the Protocol partly because of economic reasons and other ways because of narrow-minded political interests. This brings up serious doubt weather the efforts of the parties of the Protocol can make any change in the recent global processes.

Scenarios and roots of climate change

There have been more and more words about climate change and global warming in the last few decades. But what do we really understand them? Is it logic that the climate change derived by human behaviour or is it an independent process of nature that occurs no matter how we try to stop it? Is the climate change a global warming or global cooling method? We know for sure that something is changing around us and we heard a million times that if we exhaust the resources of the Earth than we will cause permanent and irreversible damage. In the first part of this chapter we will see the facts. There will be a few different perspectives from a few different institutions publication about the methodology of measurement on climate change. In the second part of the chapter we shall distinguish how big part of the changes may be the results of the human activities, or is it even possible to distinguish what causes the climate change. In the last part of this chapter the IPCC’s scenario will be explained on the case if the process of the climate change can not be stopped, or if human kind does not do anything for mitigation.

Climate change impacts on migration and labour market

Floods, droughts and monsoons have always disturbed human settlements, but there are more settlements now and more people in the world. Therefore, if a natural disaster happens, more will suffer than ever before. Moreover, climate in the past several decades has been greatly degraded by anthropogenic activity. In some cases, the chain of causality of human influence on the climate is direct and unambiguous (e.g. the effects of irrigation on local humidity), though there are instances where it is less clear. Presently, the scientific consensus (IPCC, 2007) on climate change is that human activity is very likely the cause for the rapid increase of global average temperatures, more generally known as global warming.

Soot measurements in steady and pulsed ethylene/air diffusion flames using Laser-Induced Incandescence

Combustion-generated carbon black nano particles, or soot, have both positive and negative effects depending on the application. From a positive point of view, it is used as a reinforcing agent in tires, black pigment in inks, and surface coatings. From a negative point of view, it affects performance and durability of many combustion systems, it is a major contributor of global warming, and it is linked to respiratory illness and cancer. Laser-Induced Incandescence (LII) was used in this study to measure soot volume fractions in four steady and twenty-eight pulsed ethylene diffusion flames burning at atmospheric pressure. A laminar coflow diffusion burner combined with a very-high-speed solenoid valve and control circuit provided unsteady flows by forcing the fuel flow with frequencies between 10 Hz and 200 Hz. Periodic flame oscillations were captured by two-dimensional phase-locked LII images and broadband luminosity images for eight phases (0° – 360°) covering each period. A comparison between the steady and pulsed flames and the effect of the pulsation frequency on soot volume fraction in the flame region and the post flame region are presented. The most significant effect of pulsing frequency was observed at 10 Hz. At this frequency, the flame with the lowest mean flow rate had 1.77 times enhancement in peak soot volume fraction and 1.2 times enhancement in total soot volume fraction; whereas the flame with the highest mean flow rate had no significant change in the peak soot volume fraction and 1.4 times reduction in the total soot volume fraction. A correlation (fvRe-1 = a + b·Str) for the total soot volume fraction in the flame region for the unsteady laminar ethylene flames was obtained for the pulsation frequency between 10 Hz and 200 Hz, and the Reynolds number between 37 and 55. The soot primary particle size in steady and unsteady flames was measured using the Time-Resolved Laser-Induced Incandescence (TIRE-LII) and the double-exponential fit method. At maximum frequency (200 Hz), the soot particles were smaller in size by 15% compared to the steady case in the flame with the highest mean flow rate.

Tocqueville in Miami: Political culture and political organizing in Miami's Cuban community

This study examines the effectiveness of civic organizations focusing on leadership and the role of culture in politics. The study is based on a quasi-experimental research design and relies primarily on qualitative data. The study focuses on Miami's Cuban community in order to examine the role of public initiative in grassroots civic and community organizations. ^ The Miami Cuban community is a large, institutionally complex and cohesive ethnic community with dense networks of community organizations. The political and economic success of the community makes it an opportune setting for a study of civic organizing. The sheer number of civic organizations to be found in Miami's Cuban community suggests that the community's civic organizations have something to do with the considerable vibrancy and civic capacity of the community. How have the organizations managed to be so successful over so many years and what can be learned about successful civic organizing from their experience?^ Civic organizations in Miami's Cuban community are overwhelmingly ethnic-based organizations. The organizations recreate collective symbols that come from community members' memories of and attachments to the place of origin they hold dear as ethnic Cubans. They recreate a collective Cuban past that community members remember and that is the very basis of the community to which they belong.^ Cuban Miami's ethnically based civic organizations have generally performed better than the literature on civic organizations says they should. They gained greater access to community ties and social capital, and they exhibited greater organizational longevity. The fit between the political culture of civic organizations and that of the broader political community helps to explain this success. Yet they do not perform in the same way or in support of the same social purposes. Some stress individual agency rather than community agency, and some pursue an externally-oriented social purpose, whereas others focus on building an internal community.^

Factors Affecting Current and Future Treeline Locations and Dynamics in the Peruvian Andes

The elevational distributions of tropical treelines are thought to be determined by temperature, and are predicted to shift upslope in response to global warming. In contrast to this hypothesis, global-scale studies have shown that only half of all studied treelines are shifting upslope. Understanding how treelines will respond to climate change has important implications for global biodiversity, especially in the tropics, because tropical treelines generally represent the upper-elevation distribution limit of the hyper-diverse cloudforest ecosystem. In Chapter 1, I introduce the idea that grasslands found above tropical treelines may represent a potential grass ceiling which forest species cannot cross or invade. I use an extensive literature review to outline potential mechanisms which may be acting to stabilize treeline and prevent forest expansion into high-elevation grasslands. In Chapters 2-4, I begin to explore these potential mechanisms through the use of observational and experimental methods. In Chapter 2, I show that there are significant numbers of seedlings occurring just outside of the treeline in the open grasslands and that seed rain is unlikely to limit seedling recruitment above treeline. I also show that microclimates outside of the closed-canopy cloudforest are highly variable and that mean temperatures are likely a poor explanation of tropical treeline elevations. In Chapter 3, I show that juvenile trees maintain freezing resistances similar to adults, but nighttime radiative cooling near the ground in the open grassland results in lower cold temperatures relative to the free atmosphere, exposing seedlings of some species growing above treeline to lethal frost events. In Chapter 4, I use a large-scale seedling transplant experiment to test the effects of mean temperature, absolute low temperature and shade on transplanted seedling survival. I find that increasing mean temperature negatively affects seedling survival of two treeline species while benefiting another. In addition, low temperature extremes and the presence of shade also appear to be important factors affecting seedling survival above tropical treelines. This work demonstrates that mean temperature is a poor predictor of tropical treelines and that temperature extremes, especially low temperatures, and non-climatic variables should be included in predictions of current and future tropical treeline dynamics.

Soot Measurements in Steady and Pulsed Ethylene/Air Diffusion Flames Using Laser-Induced Incandescence

Combustion-generated carbon black nano particles, or soot, have both positive and negative effects depending on the application. From a positive point of view, it is used as a reinforcing agent in tires, black pigment in inks, and surface coatings. From a negative point of view, it affects performance and durability of many combustion systems, it is a major contributor of global warming, and it is linked to respiratory illness and cancer. Laser-Induced Incandescence (LII) was used in this study to measure soot volume fractions in four steady and twenty-eight pulsed ethylene diffusion flames burning at atmospheric pressure. A laminar coflow diffusion burner combined with a very-high-speed solenoid valve and control circuit provided unsteady flows by forcing the fuel flow with frequencies between 10 Hz and 200 Hz. Periodic flame oscillations were captured by two-dimensional phase-locked LII images and broadband luminosity images for eight phases (0°- 360°) covering each period. A comparison between the steady and pulsed flames and the effect of the pulsation frequency on soot volume fraction in the flame region and the post flame region are presented. The most significant effect of pulsing frequency was observed at 10 Hz. At this frequency, the flame with the lowest mean flow rate had 1.77 times enhancement in peak soot volume fraction and 1.2 times enhancement in total soot volume fraction; whereas the flame with the highest mean flow rate had no significant change in the peak soot volume fraction and 1.4 times reduction in the total soot volume fraction. A correlation (ƒv Reˉ1 = a+b· Str) for the total soot volume fraction in the flame region for the unsteady laminar ethylene flames was obtained for the pulsation frequency between 10 Hz and 200 Hz, and the Reynolds number between 37 and 55. The soot primary particle size in steady and unsteady flames was measured using the Time-Resolved Laser-Induced Incandescence (TIRE-LII) and the double-exponential fit method. At maximum frequency (200 Hz), the soot particles were smaller in size by 15% compared to the steady case in the flame with the highest mean flow rate.

Extrafiscalidade: análise da norma potiguar regulamentadora do imposto sobre propriedade veicular automotora à luz da tutela ambiental

From the second half of the twentieth century the state bega n to use exaction beyond your fiscalist character, also as a means of alignment deformities economic and social balance, influencing in different directions, according to economic, social and political policy. It is what is usually called the extrafiscalit y. It is in light of this phenomenon and the constitutional perspective, the present work aims to analyze item IV of article. 8 of Law n. 6.967/96, regulatory Property Tax Vehicle Automotive (property taxes) in the State of Rio Grande do Norte, in view of its possible incompatibility with the principles of the Basic Statute and with international guidelines for protection of the environment The problem of this research is Seated in art. 225 of the Constitution, which provides that everyone has the right to an ecologically balanced environment. From the reading of this standard, extracted it is the responsibility of the state protecting the environment, which requires the adoption of suitable actions to that end. However, we look to state law cited follows th e constitutional path, since it exempts the collection of property taxes automotive vehicles with over 10 years of manufacturing, which could encourage the conservation of a fleet of old vehicles, mostly more polluting and harmful to the environment and hu man health. Would the state legislature oblivious to the constitutional principles and the global trend of environmental preservation? Thus questions whether such an incentive for more polluting vehicles, emitting more gases in the atmosphere. Moreover, th e international community is already moving through important conventions in an attempt to minimize and control global warming and climate change. Predicting the theme in CF/88 demonstrates that the country is no stranger to the issue. Thus, the work is a retelling of Law No. 6.967/96 order to check whether it is compatible with the existing system. The methodology consists of a documentary, deductive, dialectical literature. At the end of the survey, it was found that provide a tax benefit to these vehicle s is encouraged to maintain them in circulation and contribute to the increase in air and noise pollution, in addition to the traffic problems generated. Thus, this potiguar anything standard can be expressed extrafiscality because the medium and long term there is encouragement and worsening environmental problem. Despite the ability to pay clause, but this remission is an affront to legally protected interests. Thus, this device goes in reverse order compared to the values of the legal system and in relat ion to sustainable development. Modern Tax Law should be used as a tool to achieve the purposes collimated by the State, and not otherwise. It was noticed that the vast majority of Brazilian states does not follow this rule, including Mato Grosso and Minas Gerais have no such exemption. Therefore, the RN State does not constitute a model for sustainable public policies, nor example of environmental protection by state law.

Estimativas, variabilidade e análise de tendência da evapotranspiração de referência em perímetros irrigados, no semiárido do nordeste brasileiro

The variability / climate change has generated great concern worldwide, is one of the major issues as global warming, which can is affecting the availability of water resources in irrigated perimeters. In the semiarid region of Northeastern Brazil it is known that there is a predominance of drought, but it is not enough known about trends in climate series of joint water loss by evaporation and transpiration (evapotranspiration). Therefore, this study aimed to analyze whether there is increase and / or decrease evidence in the regime of reference evapotranspiration (ETo), for the monthly, annual and interdecadal scales in irrigated polo towns of Juazeiro, BA (9 ° 24'S, 40 ° 26'W and 375,5m) and Petrolina, PE (09 ° 09'S, 40 ° 22'W and 376m), which is the main analysis objective. The daily meteorological data were provided by EMBRAPA Semiárido for the period from 01.01.1976 to 31.12.2014, estimated the daily ETo using the standard method of Penman-Monteith (EToPM) parameterized by Smith (1991). Other methods of more simplified estimatives were calculated and compared to EToPM, as the ones following: Solar Radiation (EToRS), Linacre (EToL), Hargreaves and Samani (EToHS) and the method of Class A pan (EToTCA). The main statistical analysis were non-parametric tests of homogeneity (Run), trend (Mann-kendall), magnitude of the trend (Sen) and early trend detection (Mann-Whitney). The statistical significance adopted was 5 and / or 1%. The Analysis of Variance - ANOVA was used to detect if there is a significant difference in mean interdecadal mean. For comparison between the methods of ETo, it were used the correlation test (r), the Student t test and Tukey levels of 5% significance. Finally, statistics Willmott et al. (1985) statistics was used to evaluate the concordance index and performance of simplified methods compared to the standard method. It obtained as main results that there was a decrease in the time series of EToPM in irrigated areas of Juazeiro, BA and Petrolina, PE, significant respectively at 1 and 5%, with an annual magnitude of -14.5 mm (Juazeiro) and -7.7 mm (Petrolina) and early trend in 1996. The methods which had better for better agreement with EToPM were EToRS with very good performance, in both locations, followed by the method of EToL with good performance (Juazeiro) and median (Petrolina). EToHS had the worst performance (bad) for both locations. It is suggested that this decrease of EToPM can be associated with the increase in irrigated agricultural areas and the construction of Sobradinho lake upstream of the perimeters.

(Table 1) Sympagic meiofauna and amphipods inhabiting the meltponds in the Central Arctic sampled during POLARSTERN cruise ARK-XXII/2

Meltponds on Arctic sea ice have previously been reported to be devoid of marine metazoans due to fresh-water conditions. The predominantly dark frequently also green and brownish meltponds observed in the Central Arctic in summer 2007 hinted to brackish conditions and considerable amounts of algae, possibly making the habitat suitable for marine metazoans. Environmental conditions in meltponds as well as sympagic meiofauna in new ice covering pond surfaces and in rotten ice on the bottom of ponds were studied, applying modified techniques from sea-ice and under-ice research. Due to the very porous structure of the rotten ice, the meltponds were usually brackish to saline, providing living conditions very similar to sub-ice water. The new ice cover on the surface had similar characteristics as the bottom layer of level ice. The ponds were thus accessible to and inhabitable by metazoans. The new ice cover and the rotten ice were inhabited by various sympagic meiofauna taxa, predominantly ciliates, rotifers, acoels, nematodes and foraminiferans. Also, sympagic amphipods were found on the bottom of meltponds. We suggest that, in consequence of global warming, brackish and saline meltponds are becoming more frequent in the Arctic, providing a new habitat to marine metazoans.

Selected soil properties and bacterial abundance in the glacier forefields 'Black Valley Transect' and 'Glacier Transect' on Larsemann Hills, East Antarctica

Antarctic glacier forefields are extreme environments and pioneer sites for ecological succession. Increasing temperatures due to global warming lead to enhanced deglaciation processes in cold-affected habitats, and new terrain is becoming exposed to soil formation and microbial colonization. However, only little is known about the impact of environmental changes on microbial communities and how they develop in connection to shifting habitat characteristics. In this study, using a combination of molecular and geochemical analysis, we determine the structure and development of bacterial communities depending on soil parameters in two different glacier forefields on Larsemann Hills, East Antarctica. Our results demonstrate that deglaciation-dependent habitat formation, resulting in a gradient in soil moisture, pH and conductivity, leads to an orderly bacterial succession for some groups, for example Cyanobacteria, Bacteroidetes and Deltaproteobacteria in a transect representing 'classical' glacier forefields. A variable bacterial distribution and different composed communities were revealed according to soil heterogeneity in a slightly 'matured' glacier forefield transect, where Gemmatimonadetes, Flavobacteria, Gamma- and Deltaproteobacteria occur depending on water availability and soil depth. Actinobacteria are dominant in both sites with dominance connected to certain trace elements in the glacier forefields.