Encyclopedia of Renewable Energy. James G. Speight
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Baghouse Filter
Baghouse fabric filters are generally used where higher removal efficiency is required for particles smaller than approximately 10 microns. Thus, the filter is an air pollution control device and dust collector that removes particulates or gas released from commercial processes. A large number of bag-shaped filters would be needed to clean large gas flows. In general, all of the filters would be enclosed in the same structure (a baghouse) and would share input and output gas manifolds.
As a gas stream passes through the baghouse, dust is removed by one or more of the following physical phenomena: intersection, impingement, diffusion, gravitational settling, or electrostatic attraction. The initial filtration creates a layer of dust on the bag fabric. This layer is primarily responsible for this method’s high removal efficiency; the filter cloth serves mainly as a support structure.
The efficiency of a baghouse filter depends on the particle size distribution, the particle density and chemistry, and moisture. Under most conditions, a well-designed and well-operated baghouse will achieve a removal efficiency of at least 99% for particles as small as 1 micron. In the renewable energy industry, baghouse filters are likely to be used for dust removal from crushers, screens, transfer points, and storage bins.
Fabric life may be substantially shortened in the presence of high acid or alkaline atmospheres, especially at elevated temperatures; also, the maximum operating temperature is limited to 285°C (550°F), unless special fabrics are used.
See also: Baghouse, Centrifugal Separation, Cyclone Separation.
Barrel
The standard oil barrel of 42 US gallons is used in the United States as a measure of crude oil and other crude oil products. The 42 US gallon size of barrel as a unit of measure is largely confined to the American oil industry, since other sizes of barrel were used by other industries in the United States, and nearly all other countries use the metric system. Many oil-producing countries that did not have the technical expertise to develop their own domestic oil industry standards use the American oil barrel because their oil industries were founded by US oil companies.
Outside of the United States, oil is commonly measured in cubic meters (m3) or in tonnes (1 tonne = 2,204.6 lbs), with tonnes more often being used by European oil companies. International companies listed on American stock exchanges tend to convert their oil production volumes to barrels for global reporting purposes, and those listed on European exchanges tend to convert their production to tonnes.
The wooden oil barrel of the late 1800s is different from the modern day 55-gal steel drum (known as the 44-gal drum in Britain and the 200-L drum in Australia). The 42-US gallon oil barrel is a unit of measure, and is no longer used to transport crude oil – most crude oil is moved in pipelines or oil tankers.
The barrel of oil equivalent (BOE) is a unit of energy based on the approximate energy released by burning one barrel (42 US gallons) of crude oil. The Internal Revenue Service of the United States defines the barrel of oil equivalent as equal to 5.8 × 106 Btu. A barrel of oil equivalent is approximately 6,000 ft3 of typical natural gas.
Other conversion data are the BBOe, (also BBOE), or billion barrel of oil equivalent, representing 109 (US billion) barrels of oil, used to measure crude oil reserves, and million barrels per day, MMbd (or MMBD), used to measure daily production and consumption. Also used is the Mtoe (not middle toe but millions of tonnes of oil equivalent), a metric measurement equivalent to approximately 0.006841 billion barrels of oil equivalent.
The barrel of oil equivalent is used by oil and gas companies in their annual financial statements as a way of combining oil reserves and natural gas reserves as well as production into a single measure.
See also: Barrel of Oil Equivalent.
Barrel of Oil Equivalent
A barrel of oil equivalent (BOE or a barrel of crude oil equivalent, BCOE) is a used to summarize the amount of energy that is equivalent to the amount of energy found in a barrel of crude oil. Thus, a barrel of crude oil is a liquid measure equal to 42 US gallons (35 Imperial gallons or 158.9873 L). The BOE is the amount of energy contained in a barrel of crude oil; a barrel of crude oil is approximately (because of the difference in crude oil properties and character) equivalent to 5.8 million Btu. Also, approximately 7.2 barrels of oil are equivalent to one ton of oil. A BOE is approximately roughly 6,000 ft3 of natural gas.
A commonly used multiple of the BOE is the kilo-barrel of oil equivalent (kboe or kBOE), which is 1,000 times larger. Other common multiples are the billion BOE, representing 109 barrels of oil, used to measure crude oil reserves, and million barrels per day (MMbd or MMBD), used to measure daily production and consumption. Also used is the million tons of oil equivalent (Mtoe) which is a metric measurement equivalent to approximately 0.006841 billion barrels of crude oil equivalent.
The BOE is used by oil and gas companies in their financial statements as a way of combining crude oil reserves and natural gas reserves and production into a single measure.
See also: Barrel, Resources And Reserves.
Basic Nitrogen
Nitrogen in liquid fuels (renewable fuels are included here) may be classified arbitrarily as basic and non-basic (Table B-1). The basic nitrogen compounds, which are composed mainly of pyridine-type homologs and occur throughout the boiling ranges of organic compounds, which are usually of the pyrrole, indole, and carbazole types, have a decided tendency to exist in the higher boiling fractions and crude oil residua and in liquids from alternative energy sources such as biomass and organic waste.
Organic nitrogen-containing compounds have many important roles in nature (hence, also in biomass) and display an enormous structural diversity, in which the nitrogen atoms can form part of simple functional groups or complex heterocyclic systems. The basic nitrogen compounds also have varying degrees of substitution and oxidation. The most noteworthy of these naturally occurring molecules are proteins, and most vitamins and hormones. Furthermore, nitrogen compounds in liquids produced from a variety of sources (including biomass and organic waste) can have a deleterious effect on any catalysts used to upgrade the liquid.
Basic nitrogen compounds with a relatively low molecular weight can be extracted with dilute mineral acids; equally strong bases of higher molecular weight remain unextracted because of unfavorable partitioning between the oil and aqueous phases. A method has been developed in which the nitrogen compounds are classified as basic or non-basic, depending on whether they can be titrated with perchloric acid in a 50:50 solution of glacial acetic acid and benzene.
Table B-1 Non-basic and basic nitrogen types.
Nitrogen compounds extractable with dilute mineral acids from renewable fuels typically consist of alkyl pyridine derivatives, alkyl quinoline derivatives, and alkyl isoquinoline derivatives carrying alkyl substituents, as well as pyridine derivatives in which the substituent was a cyclopentyl or cyclohexyl group. The compounds that cannot be extracted with dilute mineral acids contain the greater part of the nitrogen in crude oil and are generally of the carbazole, indole, and pyrrole types.
Thus, the presence of the various types of nitrogen compounds in any feedstock must be monitored because they can critically affect aquatic ecosystems, especially their high levels can cause eutrophication under certain conditions. Ammonia, organic species, nitrate derivatives (-NO3), and nitrite derivatives (-NO2) can be present in wastewaters. In general, ammonia and organic species are the most common in raw