Reforma a seco de metano com catalisadores Ni/MCM-41 sintetizados a partir de fontes alternativas de sílica

The production of synthesis gas has received renewed attention due to demand for renewable energies to reduce the emissions of gases responsible for enhanced greenhouse effect. This work was carried out in order to synthesize, characterize and evaluate the implementation of nickel catalysts on MCM-41 in dry reforming reactions of methane. The mesoporous molecular sieves were synthesized using as silica sources the tetraethyl orthosilicate (TEOS) and residual glass powder (PV). The sieves were impregnated with 10% nickel to obtain the metallic catalysts (Ni/MCM-41). These materials were calcined and characterized by Thermogravimetric Analysis (TG), Infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Temperature-Programmed Reduction (TPR) and N2 Adsorption/Desorption isotherms (BET/BJH). The catalytic properties of the samples were evaluated in methane dry reforming with CO2 in order to produce synthesis gas to be used in the petrochemical industry. The materials characterized showed hexagonal structure characteristic of mesoporous material MCM-41 type, being maintained after impregnation with nickel. The samples presented variations in the specific surface area, average volume and diameter of pores based on the type of interaction between the nickel and the mesoporous support. The result of the the catalytic tests showed conversions about 91% CO2, 86% CH4, yelds about 85% CO and 81% H2 to Ni/MCM-41_TEOS_C, and conversions about 87% CO2, 82% CH4, yelds about 70% CO and 59% H2 to Ni/MCM-41_PV_C. The similar performance confirms that the TEOS can be replaced by a less noble materials

Desenvolvimento e políticas públicas: uma avaliação do PRONAF nos assentamentos de reforma agrária do Rio Grande do Norte

The research DEVELOPMENT AND PUBLIC POLICY: AN EVALUATION OF PRONAF IN THE SETTLEMENTS AGRARIAN REFORM OF RIO GRANDE DO NORTE aimed to evaluate the effectiveness of the National Program for Strengthening Family enhancerelement od development in rural settlements od Rio Grande do Norte. The methodological approach consisted of the completion of desk research and literature on development issues, policies, and rural credit and field research through semi- structured interviews with managers and technicians who work with the program and conducting focus with farmers settles who accessed the PRONAF the period from 2000 to 2006. The survey results confirm the central hypothesis of this work, that acces to PRONAF A is not causing efetivations relevant in the lives of farm workers settlers in Rio Grande do Norte. In the setllements where efetivations these occur, they are short of what the program intends to carry out and rely on a set of conditionalities that are beyond the operational frameworks of the same. Such questions point to the need to revise the program in order to estabilish adjustments that in practice the approach of the proposed objectives. For this purpose it is necessary to invest in factor that contribute to the program has a positive effect not only to increase income, but to contribute to the autonomy of the resettled farmers, expanding its capabilities and increased the power of choise with respect to life who wish to take

Direito à moradia em cidades sustentáveis: parâmetros de políticas públicas habitacionais Natal 2013

The right to housing is included in several international human rights instruments and in Brazilian legal system integrates the constitutional catalog of fundamental social rights (art. 6) and urban development policy (art. 182 and 183). Besides, it is for all federative governments its effectiveness by building programs and improvement of housing conditions and sanitation (art. 23, IX), which justifies the investment in urban planning and public policy of housing affordability because they are tools for achieving this right. Newer strategies in this area have been based on tax incentives, combined with the mortgage as a way to induce the construction of new housing units or reform those in a precarious situation. However, there is still a deficit households and environmental soundness, compounded with the formation of informal settlements. Consequently, we need constant reflections on the issue, in order to identify parameters that actually guide their housing policies in order to meet the constitutional social functions of the city and ensure well-begins of its citizens (art. 182). On the other hand, the intervention of the government in this segment can not only see the availability of the home itself, but also the quality of your extension or surroundings, observing aspects related to environmental sanitation, urban mobility, leisure and services essential health, education and social assistance. It appears that the smoothness and efficiency of a housing policy condition to the concept of adequate housing, in other words, structurally safe, comfortable and environmentally legally legitimate, viable from the extensive coordination with other public policies. Only to compliance with this guideline, it is possible to realize the right to housing in sustainable cities

Reforma a vapor catalítica do metano: Otimização da produção e seletividade em hidrogênio por absorção in situ do CO2 produzido

Topics of research related to energy and environment have significantly grown in recent years, with the need of its own energy as hydrogen. More particularly, numerous researches have been focused on hydrogen as energy vector. The main portion of hydrogen is presently obtained by reforming of methane or light hydrocarbons (steam, oxy, dry or auto reforming). During the methane steam reforming process the formation of CO2 undesirable (the main contributor to the greenhouse effect) is observed. Thus, an oxide material (sorbent) can be used to capture the CO2 generated during the process and simultaneously shifting the equilibrium of water gas shift towards thermodynamically more favorable production of pure hydrogen. The aim of this study is to develop a material with dual function (catalyst/sorbent) in the reaction of steam reforming of methane. CaO is well known as CO2 sorbent due to its high efficiency in reactions of carbonation and easy regeneration through calcination. However the kinetic of carbonation decreases quickly with time and carbonation/calcination cycles. A calcium aluminate (Ca12Al14O33) should be used to avoid sintering and increase the stability of CaO sorbents for several cycles. Nickel, the industrial catalyst choice for steam reforming has been added to the support from different manners. These bi-functional materials (sorbent/catalyst) in different molar ratios CaO.Ca12Al14O33 (48:52, 65:35, 75:25, 90:10) were prepared by different synthesis methodologies, among them, especially the method of microwave assisted self-combustion. Synthesis, structure and catalytic performances of Ni- CaO.Ca12Al14O33 synthesized by the novel method (microwave assisted selfcombustion) proposed in this work has not being reported yet in literature. The results indicate that CO2 capture time depends both on the CaO excess and on operating conditions (eg., temperature and H2O/CH4 ratio). To be efficient for CO2 sorption, temperature of steam reforming needs to be lower than 700 °C. An optimized percentage corresponding to 75% of CaO and a ratio H2O/CH4 = 1 provides the most promising results since a smaller amount of water avoids competition between water and CO2 to form carbonate and hydroxide. If this competition is most effective (H2O/CH4 = 3) and would have a smaller amount of CaO available for absorption possibly due to the formation of Ca(OH)2. Therefore, the capture time was higher (16h) for the ratio H2O/CH4 = 1 than H2O/CH4 = 3 (7h) using as catalyst one prepared by impregnating the support obtained by microwave assisted self-combustion. Therefore, it was demonstrated that, with these catalysts, the CO2 sorption on CaO modifies the balance of the water gas-shift reaction. Consequently, steam reforming of CH4 is optimized, producing pure H2, complete conversion of methane and negligible concentration of CO2 and CO during the time of capture even at low temperature (650 °C). This validates the concept of the sorption of CO2 together with methane steam reforming

Ecossocialismo: a gênese de uma ecologia social em assentamentos de reforma agrária a partir dos movimentos sociais do campo

The world`s ecology crisis has in the capitalism way of production one of the possible causes. The unstopped search for the profits, into unlimited exploration of limited resources, made a huge transformation in human relationships with the nature, causing environment devastation, shortage of resources and species disappearance. Arises the necessity of question the society model that we are and which brings this crisis state, while we are impelled to search an alternative way. The ecosociallist praxis blows marxist principles with ecological matters, bringing important contributions regarding alternatives to capital/exploratory modus, advocating for a social fair society and environmentally sustainable. This way, by bibliographic review, we will research about this theory which have been growing in academic middles. In the same way, we will analyze the rural social movements paper in the construct of this reality. Throut the half estruture interviwes, bibliografic research and visities in the space of settlement called Moacir Lucena, that is today a exemple of rural resignification