Nanoscience and Nanotechnology | Open Access Articles

Air Quality Regulation Policy In Portugal, João F. Gomes Jan 2004

Air Quality Regulation Policy In Portugal, João F. Gomes

João F Gomes

Ten years after the publication of first air quality laws in Portugal, and seven years after the publication of the respective emission limits, it seems appropriate to analyse the degree of law enforcement by the Portuguese manufacturing industry. Therefore, based on the emission measurements made regularly by ISQ, as the only officially accredited laboratory, a set of about 400 sources is analysed in terms of the compliance with the emission limits regarding total suspended particulate, sulphur dioxide, nitrogen oxides and VOCs. The compliance is evaluated through a non-dimensional parameter and plotted versus the emission flow rate to derive conclusions: it …

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Emission And Odour Control In Kraft Pulp Mills, João F. Gomes Jan 2003

Emission And Odour Control In Kraft Pulp Mills, João F. Gomes

João F Gomes

This paper describes systematic work done in the field of atmospheric emissions from Portuguese Kraft pulp mills, focused mainly on the gaseous emissions responsible for its characteristic odour. These mal-odorous gases, which were identified as hydrogen sulphide, methyl mercaptan, deimethyl mercaptan and dimethyl-disulphide, were experimentally quantified and classified into groups so that alternatives for abatement could be devised. The considered abatement techniques were evaluated economically and it was concluded that the costs to be incurred by pulp mills for an efficient abatement of TRS gases are not dramatic and could be easily covered by this industry, resulting in an evident …

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Diagnostic Of Critical Circuits Of Kraft Pulp Production Process Considering The Environmental Aspects, João F. Gomes Jan 2002

Diagnostic Of Critical Circuits Of Kraft Pulp Production Process Considering The Environmental Aspects, João F. Gomes

João F Gomes

This paper describes systematic work done in the field of atmospheric emissions from Portuguese Kraft pulp mills. This study led to the determination of emission factors from stationary sources that proved to be an important tool to assess the need for investment on air pollution abatement equipment, namely in what concerns mal-odorous gases.

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Characterisation Of Non-Condensable Sulphur Containing Gases From Kraft Pulp Mills (2), João F. Gomes Jan 2001

Characterisation Of Non-Condensable Sulphur Containing Gases From Kraft Pulp Mills (2), João F. Gomes

João F Gomes

This paper describes work performed on the sampling and analysis of non-condensable gases (NCG) emitted from diffuse sources of a Portuguese Kraft pulp mill, which is the background information for a NCG collection, treatment and disposal system. The variability found in the composition of the gaseous compounds showed the existence of gaseous streams other than typical total reduced sulphur (TRS) compounds as usually described. From the measured TRS concentrations and the gas flow rate from each source it was possible to calculate the emission flow rate, E, of each source. These emission flow rates were then divided into 3 categories …

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Practical Determination Of Efficiency Of Electrostatic Precipitators, João F. Gomes Jan 1999

Practical Determination Of Efficiency Of Electrostatic Precipitators, João F. Gomes

João F Gomes

Electrostatic precipitators are one of the most efficient particulate pollution control equipments used mainly for the treatment of gaseous effluents at high flow rates. Consequently electrostatic precipitators are widely used in thermal power plants, cement plants and pulp mills. Apart from a high efficiency other advantages are related with the fact that this type of equipment has a considerable low payback time in industrial plants where the particulate recovered from the gases has commercial value and can be recycled within the industrial process itself or even sold to other industrial companies. Where sulphate (Kraft) pulp mills are concerned an electrostatic …

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Characterisation Of Non-Condensable Sulphur Containing Gases From Kraft Pulp Mills, João F. Gomes Jan 1998

Characterisation Of Non-Condensable Sulphur Containing Gases From Kraft Pulp Mills, João F. Gomes

João F Gomes

This paper describes work performed on the sampling and analysis of non-condensable gases (NCG) emitted from diffuse sources of a Portuguese kraft pulp mill, which is the background information for a NCG collection, treatment and disposal system. The variability found in the composition of the gaseous compounds showed the existence of gaseous streams other than typical total reduced sulphur (TRS) compounds as usually described.

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A Simple Way To Measure Particle Size, João F. Gomes Jan 1998

A Simple Way To Measure Particle Size, João F. Gomes

João F Gomes

The size range of particles is an important parameter for subsequent dispersion estimates and sometimes is quite useful for analysing the performance of combustion equipment as well as dedusting equipment efficiency. So far, no standard method has been developed but several laboratories use laser-beam techniques which are usually quite expensive ones. In this paper a method is presented where the particles are collected isokinetically in a filter from gases circulating in a stack as described in USEPA method 5. Afterwards particles are observed at an optical microscope and measured. In spite of some limitations this appears to be an inexpensive …

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Pollutant Atmospheric Emissions From Portuguese Kraft Pulp Mills, João F. Gomes Jan 1997