Sulphur content of fuels

Directive 1999/32/EC on the reduction of the sulphur content of several liquid fuels and Directive 2003/17/EC. The latter obliges the refining sector to reduce the sulphur content of fuels, increasing energy consumption and CO2 emissions. 

This focuses the spotlight on the sulphur content of fuels since the combustion of fuels which contain sulphur in any form will result in the formation of the stable combustion product which is sulphur dioxide. 

The present chapter describes the service conditions at the flame tube of an intermittent operating recirculation burner measured in a burner rig (maximum temperature experienced by the material 1000°C). Three different austenitic high temperature Ni-base alloys are being tested in the rig in an ongoing experiment. The effect of the parameters material temperature, duration of the air ventilation after burner shutdown and sulphur content of fuel on the structure and growth of the oxide scale on the alloys after 50 h exposure time have been investigated. 

EC Directive amending 93/12/EC on the sulphur content of liquid fuels... 

EC Directive relating to a reduction in the sulphur content of certain liquid fuels and amending... 

SI 2000/1460 The Sulphur Content of Liquid Fuels (England and Wales) Regulations... 

Typical sulphur content values for various fossil hydrocarbon fuels are shown in Table I. The very high associated sulphur content of many of the deep gas deposits is readily seen. Fortunately, however, this sulphur content is present as relatively easily removed H2S although the presence of such large quantities at elevated temperatures and pressures can pose... 

The ratio of limestone to fuel required for effective desulphurisation depends upon both the mineral and sulphur content of the coal. It may be possible to burn low sulphur (<0.8%) western coal directly with 90% sulphur retention thus avoiding the necessity for flue gas desulphurisation and still meeting environmental SO2 emission regulations (18). Fluidyne (19) have indicated that a 3.65% Illinois coal with 0.3 lbs. of dolomite added per pound of coal in a fluidised bed combustor can reduce SO2 emission to less than 1.2 lbs. of SO2 per million BTU thermal output thus meeting U.S. EPA limits for large plants. 

Sulphur content of certain liquid fuels. Amended in 1987 EC Directive 87/219/EEC (1) The motor and oil fuel... 

Thermofuel-based fuel produces much lower sulphur oxides (SO ) than conventional diesel since sulphnr levels in the fnel are typically less than 0.01% (100 ppm) as compared with conventional diesel which has sulphur around 400-500 ppm. SO emissions for Thermofuel diesel are thus correspondingly 4-5 times lower than that of conventional diesel. Furthermore the Thermofuel incorporates an integrated desulphurization plant to ensure the sulphur content of the diesel produced is always within specification. 

Combustion of the mixed oils may generate less pollutant compounds such as NO, PAH and SO, . The hot corrosion caused by the vanadium contained in the usual gas turbine fuel might also be inhibited by the presence of some metals contained in the biofuels [17]. The sulphur content of the mixed oils is expected to be lower than that of conventional petroleum friels. 

For the first preliminary experiments, a standard fuel oil burner system was purchased. Due to several reasons, however, a new pump and atomisation system was required, viz. a dedicated fuel punqp and a different spray nozzle. In this new set-up, primary air for a proper fiiel atomisation and secondary air for the combustion could be controlled separately. Furthermore, pumping and combustion of heavy fuel oil (sulphur content of 3.35 wt.% and a viscosity of 180 cP) was possible only, when mixed with diesel in a ratio of 60 40 (dicsehheavy firel oil). Besides, the flame tuimel had to be preheated to approx. TSO C using ordinary diesel or ethanol as a start-up fuel. When a steady state operation was observed (after approximately 10 minutes), the diesel flow to the flame tunnel could be replaced by a mixture of heavy fiiel oil and diesel (40 60), and the emissions of SOj are recorded (approx. 400 ppm). Then CEB is injected and subsequently the SO2 levels are recorded every 30 s. Usually, almost instantly a sharp decrease in the SOj concentration was observed, due to the reaction of the Ca wifti SO2. The experiments were carried out at various fiiel flow rates, ranging from 0.5 to 3 kg/hr, and at a CEB flow rate corresponding to Ca S ratios from 0 to 3. 

Regional performance demand Different geographical regions have different market requirements. European oils tend to be for longer drain applications, up to 30,000 miles between oil drains, whereas North American market lubricants tend to be changed every 3000-10,000 miles. Additionally, differences between developed and developing markets have an effect on the required lubricant performance and hence the formulation and the lubricant drain interval. Local fuel variation also needs to be considered, e.g. the sulphur content of diesel, overall fuel quality based upon refinery processing and contamination of fuel. 

A manufacturer s range of trunk piston engine oils will include products with base numbers from approximately 15 to 50. The appropriate oil is then selected to match the sulphur content of the fuel being used. In service, the initial BN will fall fairly rapidly but will then stabilise. The stabilised BN is normally rather more than half the original value of new oil, ensuring good corrosion protection. 

Fuel quality is the major problem, the official sulphur content of diesel is... 

European Environment Bureau, European Federation for Transport Environment, Seas at Risk, The Swedish NGO Secretariat on Acid Rain, Environmental NGO Recommendation on COM (002) 595 as Regards the Sulphur Content of Marine Fuels, 5 February 2003, http //www.eeb.org/ activities/air/Joint position paper S marine fuels Sept 03.pdf. 

Diesel fuels also contain sulphur compounds, namely thiophenes. Their combustion leads to sulphur oxides from which acid rains originate. Thus, the sulphur content of diesel fuels is becoming more and more strictly regulated. 

Carbons black includes several types of carbons, such as acetylene black, channel black, furnace black, lamp black. Commonly, their names are referred to the process or the source material from which they are made. Among those, the production of furnace black is the most important. Its production process consists in feeding a furnace with natural gas and aromatics oils as feedstock, where is vaporized and then pyrolyzed. Vulcan XC-72 (a furnace black from Cabot Corporation) is the most widely used catalyst support for low-temperature fuel cells due to their low cost and high availability, being this material used as standard to compare other types of carbons. Vulcan XC-72, formed by nanoparticles of 20-40 nm, has an electrical conductivity of 4 S cm a sulphur content of 0.05 %, and a negligible oxygen content [13]. Within the textural properties Vulcan carbon has a superficial area of 252 m g with a total pore volume of 0.63 cm g and a pore size distribution around 15 nm [14]. 

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