다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Foreword 1. Prosperity Lost 2. The Age of Irresponsibility 3. Redefining Prosperity 4. The Dilemma of Growth 5. The Myth of Decoupling 6. The 'Iron Cage' of Consumerism 7. Keynesianism and the 'Green New Deal' 8. Ecological Macro-Economics 9. Flourishing - within Limits 10. Governance for Prosperity 11. The Transition to a Sustainable Economy 12. A Lasting Prosperity Appendices References Endnotes

Prosperity without growth : economics for a finite planet

Biodiesel is produced by the transesterification of oil triglycerides with methanol or ethanol, in the presence of a homogeneous or heterogeneous catalyst. This study aims to report the results of the transesterification of sunflower oil with methanol to produce biodiesel using CaO nanoparticles supported on NaX zeolite as catalyst. The effect of the CaO nanoparticles concentration on the NaX zeolite surface was studied in the range of 5−25 wt %. The transesterification reaction was carried out at reflux temperature of methanol, atmospheric pressure, a reaction time of 6 h, and with a 6:1 molar ratio of methanol to sunflower oil. Catalyst characterization was carried out by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. It was concluded that methyl esters content is highly influenced by basicity and that the best catalyst was the one holding 16 wt % CaO nanoparticles. The produced biodiesel was 93.5% methyl esters and was found to fulfill the specifications of Europ...

Preparation and Characterization of CaO Nanoparticles/NaX Zeolite Catalysts for the Transesterification of Sunflower Oil

The world is confronted with the twin crises of fossil fuel depletion and environmental degradation. The indiscriminate extraction and consumption of fossil fuels have led to a reduction in petroleum reserves. Petroleum based fuels are obtained from limited reserves. These finite reserves are highly concentrated in certain region of the world. Therefore, those countries not having these resources are facing a foreign exchange crisis, mainly due to the import of crude petroleum oil. Hence it is necessary to look for alternative fuels, which can be produced from materials available within the country. Although vegetative oils can be fuel for diesel engines, but their high viscosities, low volatilities and poor cold flow properties have led to the investigation of its various derivatives. Among the different possible sources, fatty acid methyl esters, known as Biodiesel fuel derived from triglycerides (vegetable oil and animal fates) by transesterification with methanol, present the promising alternative substitute to diesel fuels and have received the most attention now a day. The main advantages of using Biodiesel are its renewability, better quality exhaust gas emission, its biodegradability and the organic carbon present in it is photosynthetic in origin. It does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the green house effect. This paper reviews the source of production and characterization of vegetable oils and their methyl ester as the substitute of the petroleum fuel and future possibilities of Biodiesel production.

Biodiesel production through the use of different sources and characterization of oils and their esters as the substitute of diesel: A review

Methane is the main component of biogas, which could be used as a renewable energy source for electricity, source of heat, and biofuel production after upgrading from biogas. It also contains toxic compounds which cause environmental and human health problems. Therefore, in this work, the removal of a toxic compound (toluene) from methane gas was studied using a dielectric barrier discharge (DBD) reactor. It was observed that the removal of the toxic compound could be achieved from methane carrier gas using a dielectric barrier discharge reactor, and it depends on plasma input power. The maximum removal of the toxic compound was 85.9% at 40 W and 2.86 s. The major gaseous products were H2 and lower hydrocarbons (LHC) and the yield of these products also increases with input power. In the current study, the yield of gaseous products depends on the decomposition of toxic compounds and methane, because the decomposition of methane also produces H2 and lower hydrocarbons. The percentage yield of H2 increases from 0.43–4.74%. Similarly, the yield of LHC increases from 0.56–7.54% under the same reaction conditions. Hence, input power promoted the decomposition of the toxic compound and enhanced the yield of gaseous products.

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Removal of toluene as a toxic VOC from methane gas using a non-thermal plasma dielectric barrier discharge reactor

Abstract A “reactive coupling” process for one-pot transesterification of rapeseed oil into fatty acid methyl esters (FAME) for biodiesel, and in situ acetalisation of the glycerol by-product to solketal was investigated by both an experimental and a kinetic modelling approach. The aim was to develop a process with a more valuable co-products than glycerol, and to minimise glycerol production. The results showed that a one-stage reactive coupling achieved a solketal yield of 39.5 ± 5.1% and FAME yield of 99% after 8 h at 10:7:1 of methanol: acetone: oil molar ratio. However, based on these results and the predictions of the kinetic model developed, a “two-stage” reactive coupling process was investigated, in which some of the acetone was added later in the process. The two-stage process was demonstrated to achieve up to 98 ± 0.5% FAME and 82 ± 4% solketal yields under the same operating conditions.

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A reactive coupling process for co-production of solketal and biodiesel

This paper presents a comparison of a high-temperature heat pump and an organic Rankine cycle (ORC) plant for the recovery of low-grade waste heat for a UK inorganic chemicals case study. Superficially, the two technologies appear equally suitable for use here; therefore, both technologies are modelled in order to provide data for a comparison in terms of expected technical and economic performance. Both technologies are proven to be feasible in this case study, with the heat pump helping to significantly reduce the natural gas requirement of the plant and the ORC producing a significant net output of electricity. This leads to each technology being attractive from the economic and environmental viewpoints. However, the proposed ORC achieves greater potential greenhouse gas reductions (499 tCO2 eq/year as opposed to 401 tCO2 eq/year) and greater potential cost savings (£69 000/year as opposed to £37 800/year). Therefore, the ORC machine is shown to be the preferred technology in this case. A sensitivity analysis based on continuation of the utility cost trends is performed and shows that the ORC plant would gain in profitability in future years whereas the potential profit of the heat pump system would diminish to almost zero by 2020. Such results suggest that ORCs may be further utilised in future years whilst the use of heat pumps may decline.

Techno-economic comparison of a high- temperature heat pump and an organic Rankine cycle machine for low-grade waste heat recovery in UK industry

This study reports substantial improvement in the process for oxidising α-pinene, using environmentally friendly H2O2 at high atom economy (∼93%) and selectivity to α-pinene oxide (100%). The epoxidation of α-pinene with H2O2 was catalysed by tungsten-based polyoxometalates without any solvent. The variables in the screening parameters were temperatures (30–70 °C), oxidant amount (100–200 mol%), acid concentrations (0.02–0.09 M) and solvent types (i.e., 1,2-dichloroethane, toluene, p-cymene and acetonitrile). Screening the process parameters revealed that almost 100% selective epoxidation of α-pinene to α-pinene oxide was possible with negligible side product formation within a short reaction time (∼20 min), using process conditions of a 50 °C temperature in the absence of solvent and α-pinene/H2O2/catalyst molar ratio of 5 : 1 : 0.01. A kinetic investigation showed that the reaction was first-order for α-pinene and catalyst concentration, and a fractional order (∼0.5) for H2O2 concentration. The activation energy (Ea) for the epoxidation of α-pinene was ∼35 kJ mol−1. The advantages of the epoxidation reported here are that the reaction could be performed isothermally in an organic solvent-free environment to enhance the reaction rate, achieving nearly 100% selectivity to α-pinene oxide.

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Development of rapid and selective epoxidation of α-pinene using single-step addition of H2O2 in an organic solvent-free process

/pdf/biodiesel-production-by-in-situ-transesterification-a-review-java2uf3xe.pdf

Adam Harvey

Papers

Removal of toluene as a toxic VOC from methane gas using a non-thermal plasma dielectric barrier discharge reactor

A reactive coupling process for co-production of solketal and biodiesel

Techno-economic comparison of a high- temperature heat pump and an organic Rankine cycle machine for low-grade waste heat recovery in UK industry

Development of rapid and selective epoxidation of α-pinene using single-step addition of H2O2 in an organic solvent-free process

Biodiesel production by in situ transesterification – a review