Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L5/00—Solid fuels
  • C10L5/02—Solid fuels such as briquettes consisting mainly of carbonaceous materials of mineral or non-mineral origin
  • C10L5/06—Methods of shaping, e.g. pelletizing or briquetting
  • C10L5/10—Methods of shaping, e.g. pelletizing or briquetting with the aid of binders, e.g. pretreated binders
  • C10L5/14—Methods of shaping, e.g. pelletizing or briquetting with the aid of binders, e.g. pretreated binders with organic binders
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L9/00—Treating solid fuels to improve their combustion
  • C10L9/10—Treating solid fuels to improve their combustion by using additives
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L2200/00—Components of fuel compositions
  • C10L2200/02—Inorganic or organic compounds containing atoms other than C, H or O, e.g. organic compounds containing heteroatoms or metal organic complexes
  • C10L2200/0254—Oxygen containing compounds
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L2230/00—Function and purpose of a components of a fuel or the composition as a whole
  • C10L2230/06—Firelighters or wicks, as additive to a solid fuel
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L2230/00—Function and purpose of a components of a fuel or the composition as a whole
  • C10L2230/14—Function and purpose of a components of a fuel or the composition as a whole for improving storage or transport of the fuel
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L2250/00—Structural features of fuel components or fuel compositions, either in solid, liquid or gaseous state
  • C10L2250/04—Additive or component is a polymer

Definitions

• This invention relates to methods and compositions for inhibiting the air oxidation and spontaneous combustion of coal, low-ranked coal, and in particular sub-bituminous coal.
• Sub-bituminous coal forms within fresh water peat bogs that do not get washed out into the sea and therefore have unique chemical properties. Due to the differences in its formation, sub- bituminous coal has a loose pore structure and retains high levels of water. As a result it is a less efficient fuel than other coals such as anthracite or bituminous coal, and can require as much as double the amount of coal mass to produce the same amount of energy.
• Sub-bituminous coal also contains large pyrite particles which tend to foul and slag furnace walls before they completely combust, ft is not surprising then that historically, sub-bituminous coal has been recognized to be a lower value, less desired feedstock fuel for power generation.
• sub-bituminous coals have far lower levels of undesirable coiistituenis such, as sulfur, mercury or arsenic.
• subbituniinous coars high Calcium Oxide and Magnesium Oxide levels cause sub-bituminous coal combustion to produce tar less boiler slag.
• strict environmental laws have made it more suitable to use sub-bituminous coal than other sources of coal, even though they might be of higher fuel content.
• sub-bituminous coal tonnage has greatly increased over the past decade and subbituminous coal producers are actively seeking methods for safe shipment in massive ocean - going vessels and acknowledge the urgent need for technology to address the dangers in spontaneous combustion of this coal.
• At least one embodiment of the invention is directed towards a method of inhibiting the spontaneous combustion of a pile of low-ranked coal
• the method comprises the step of applying to the coal an inhibitor composition.
• the composition comprises crude glycerin and a VAE copolymer or a PVA copolymer in a ratio of between 90: 10 and 10:90.
• the low-ranked coal may be left undisturbed for a period of time in which it is probable that bu t for the presence of the composition, the pile would have spontaneously combusted,
• the low-ranked coal may be exposed to air or an oxidizing atmosphere for a period of at least 5 days prior to the coal being positioned into a pile.
• the coal may be handled by an apparatus comprising at least pinch point through which the coal will pass and wherein portions of the coal will accumulate and persist.
• the coal may be loaded into ship's hold and remain undisturbed in a pile of at least 30,000 tons for at least 10 days.
• the coal may be sub- bitumi ous coal.
• the composition may inhibit the spontaneous combustion at a rate greater than that of a mixture of VAE mixed with pure glycerin.
• the pile may be within a ship's bold.
• the method may exclude the use of a FIFO method in handling the pile.
• the composition may prevent the oxidation of carbonyl groups within the coal for at least 60 days and but for the composition the carbonyl groups would have undergone at least a 50% Encrea.se in the oxidation of the coaPs carbonyl groups.
• FIG. 1 is a graph illustrating how the invention affects the oxidation of aliphatic portions of coal.
• FIG. 2 is a graph illustrating how the invention affects the formation and oxidation of carbonyl containing portions of coal.
• FIG. 3 is a graph illustrating how the invention affects the adiabatic temperature of coal Detailed Description of the Invention
• “Arching 1 * means an obstruction in the flow of coal material through a portion of a coal handling process formed out of coal material which has agglomerated into the form of an arch, the arching can be cohesive (formed by particle to particle bonds), interlocking (formed by particles which are large relative to the size of an outlet it passes through and are compacted together by mechanical force suach as a collapsing rathole), or both,
• As-shipped means a rocky composition of matter which has been removed from the ground, substantially all of which has been ground into particles having a volume of no more than 3 inches -1 , and has not had removed from it the naturally occurring moisture present when the composition was in the ground.
• ""Crude glycerin" means a by-product derivative from a transesterificatlon reaction involving triglycerides including transesterification reactions involving biodiesel manufacturing processes, in which the by-product comprises glycerin and at least one component selected from the list consisting of: fatty acids, esters, salt, methanol, tocopherol, sterol, mono-giycerides, di- giycerides, and triglycerides.
• Low Ranked Coat means coal which has a gross calorific value limit of no greater than 9,500 BTU/lb on a moist mineral-included as-shipped basis.
• Low ranked coal includes sub-bituminous coals, lignite coals, and high volume or highly oxidized bituminous coals.
• Moiig means non glycerol organic materia! and typically consists of soaps, free tatty acids, and other impurities,
• Porate material' means a material that has a tendency to form dust particles when handled, processed, or contacted, which includes but is not limited to coa!, dirt, wood chips, agricultural products, fruits, fertilizers, ores, mineral ores, fine materials, sand, gravel, soil, fertilizers, or other dust generating material, and any combination thereof.
• ' ' -Pinch Point means a piece of equipment or portion thereof present in an industrial process through which there is a general flow of coal material but dae to the shape of the piece of equipment or portion thereof, the flow of a portion of the material becomes impinged and that portion remains stationary for a period of time
• exemplary industrial processes include but are not limited to coal processing, coal refining, coal handling, coal grinding, coal transporting, coal loading, coal storing, and coal unloading
• exemplar ⁇ ' types of equipment include but are not limited to chutes, bent or curved pipes, channels, or ducts (elbows), or spaces small enough such that bridges of agglomerated materials collect. Pinch points can cause arching and ratholing of the flowing coal material.
• “Powder River Basin” means the geological region (approximately 1 0 km east- west by 320 km north-south) which is a rich source of naturally occurring Sub-Bituminous Coal located in in southeastern Montana and north eastern Wyoming in the vicinity of the cities of Gillette, Wyoming, Sheridan Wyomine * and Miles Citv Montana.
• PVA polyvinyl acetate polymer
• Mathoiing v means the obstructing of the flow of coal material through a portion of a coal handling process formed out of coal material which has cohesive strength (formed by particle to particle bonds) such that while some of the material flows along a channel within the mass of material, material which is outside of the channel becomes stagnant and does not flow. Ratholes may collapse in the presence of external force such as vibration and when they collapse they may reform into arches.
• Sub-Bituminous Co P means the compositions of matter bearing this name as defined in ASTM D388-05, it includes naturally occurring coal compositions which have a gross calorific value limit of between 1 1,500 BTU/ib and 8,300 BTU/ib on a moist, mineral-matter-free basis, it typically has an as-shipped gross calorific value limit of 8400-8800 BTU/ib, it includes but is not limited to Powder River Basin Coal
• VAE means vinyl acetate ethylene co-polymer, hi at least one embodiment the repeating units of VAE are selected from one of formula 1, 11, 111, IV, and any combination thereof wherein:
• n Is the number of cross linking units
• m is the number of first chain units
• o is the number of second chain units
• either, some, or ail of n, m, and o can be 1 or more, although m and o will frequently be 2 or 3 or 4 or more, either or both of the first and second chain units can be left side end (terminal) units of a polymer chain and/or right side end
• VAE (terminal) units of a polymer chain
• VAE can also comprise co-polymers containing additional cross linking units and can comprise additional polymer chains
• the surface of a pile- of low-ranked coal is treated with an inhibiting composition to inhibit the spontaneous combustion of the pile.
• the inhibitor is a composition comprising crude glycerin and VAE copolymer and/or a PVA copolymer.
• the crude glycerin is derived from a transesterification reaction involving triglycerides,
• Coal dust (which can result from all coal not just low-ranked coal) is highly mixed with atmospheric oxygen and can be a cause of a spontaneous explosion.
• Unique to low- ranked coal is its high propensity to oxidize which can cause fires within the coal piles itself Low-ranked coal can oxidize and suffer from non-explosion fires within the pile even when substantially ail airborne dust has been removed from the presence of the mass of coal.
• the pile is in the proximity of substantially no dust so it is substantially not at risk of an airborne explosion, but the low ranked-eoal is at risk of an oxidation, induced fire.
• the presence of dust is excluded.
• the presence of coal which is non-low grade is excluded, in at least one embodiment a substantial risk of an airborne explosion is excluded while the risk of oxidation, and oxidation induced combustion is substantial
• Biodiesel is typically made through a chemical process called transesterification in which vegetable oil or animal fats are converted to tatty acid alkyi esters and crude glycerin byproduct.
• Fatty acids and fatty acid alkyi esters can be produced from oils and fats by base- catalyzed transesterification of the oil, direct acid-catalyzed esterification of the oil and conversion of the oil to fatty acids and subsequent esterification to biodiesel.
• fatty acid aikyl esters are produced by the base-catalyzed method, In general, any base may be used as the catalyst used for transesterification of the oil to produce biodiesel, however sodium hydroxide or potassium hydroxide are used in most commercial processes.
• oils and fats can be filtered and preprocessed to remove water and contaminants. If free fatty acids are present, they can be removed or transformed into biodiesel using special pretreatment technologies, such as acid catalyzed esterification.
• the pretreated oils and fats can then be mixed with an alcohol and a catalyst (e.g. base).
• the base used for the reaction is typically sodium hydroxide or potassium hydroxide, being dissoived in the alcohol used (typically ethanol or methanol) to form the corresponding alkoxide, with standard agitation or mixing. It should be appreciated that any suitable base can he used.
• the alkoxide may then be charged into a closed reaction vessel and the oils and fate are added.
• the system can then be closed, and held at about 71 degrees C (160 degrees F) for a period of about 1 to 8 hours, although some systems recommend that the reactions take place at room temperature,
• oil molecules e.g. triglycerides
• two major products are produced: 1) a crude fatty acid alkyl esters phase (i.e. biodiesel phase) and 2) a crude glycerin phase
• the crude fatty acid alkyl ester phase forms a layer on top of the denser crude glycerin phase.
• the two can be gravity separated, For example, the crude glycerin phase can be simply drawn off the bottom of a settling vessel in some cases, a centrifuge may be employed to speed the separat ion of the two phases.
• the crude glycerin phase typically consists of a mixture of glycerin, methyl esters, methanol, mottg and inorganic salts and water.
• Methyl esters are typically present in an amount of about 0.01. to about 5 percent by weight.
• methanol can be present in the crude glycerin in an amount greater than about 5 weight percent to about 30 weight percent, In at least one embodiment, the crude glycerin comprises about 30 to about 95 weight percent of glycerin.
• VAE is a copolymer in which multiple vinyl acetate polymers contain ethylene side branches which fbnn cross linkages and connect the polymers to each other forming copolymer networks.
• the composition comprises between 90: 0 and 0:90 of VAE copolymer to crude glycerin by mass, fti at least one embodiment the composition further comprises water. In at least one embodiment the composition comprises water and the crude glycerin both prevents the freezing of the water and prevents its evaporation thereby reducing the tendency of oxidation to occur.
• composition is applied according to any one of the methods or apparatuses of US 5,441 ,566.
• the components of the inhibiting composition may be mixed immediately before addition to the low-grade coal or may be pre-mixed or some components may be pre-mixed and other components may be mixed immediately before addition.
• the material may be applied in liquid form by a spray boom having one or more spray heads. In at least one embodiment the composition is applied to the material to be coated by at least one of the methods disclosed in US Patent 5,622,561.
• composition is applied as the pile is being formed.
• the composition can be applied to the material before and/or as it is poured or dumped into a pile.
• the material passes along a conveyer belt before it is poured or dumped and the composition is applied to the material as it travels along the belt.
• the composition functions as a tackifier which helps to hold together the material in the form of larger clumps that are less likely to launch as airborne dust.
• the inhibitor is applied such that one or more of the standard safety protocols can be omitted from the handling of Sub-Bituminous Coal or low-rank coal
• the inhibitor treated sub-bitumous or low rank coal can be safely processed through a legacy coal handling apparatus having one or more pinch points.
• the inhibitor treated low-rank coal can be allowed to remain undisturbed for longer than is allowed for untreated low-ranked coal or it is handled in a non-FIFO manner even though this will result in a pile of low-ranked coal remaining in inventory longer than the safety protocols recommend.
• the sub-bitumous coal is mined from the Powder River Basin and is handled, stored, and transported according to a legacy coal handling method.
• the inhibitor treated low-ranked coal is loaded into the hold of a ship where it will sit for at least 1 1 days undisturbed.
• the coal is loaded onto the ship after it has sat within a railcar for 1-20 days also undisturbed.
• the crude glycerin forms hydrogen bonds with the coal's hydroxy! groups and carbonyl groups which reduces the reactivity of these groups with oxygen while simultaneously the VAE and/or PVA copolymer serves to sea! the surfaces of the treated coal.
• the crude glycerin forms hydrogen bonds with the coal's hydroxy! groups and carbonyl groups which reduces the reactivity of these groups with oxygen while simultaneously the VAE and/or PVA copolymer serves to sea! the surfaces of the treated coal.
• impurities within the crude glycerin (such as but not limited to fatty acid methyl esters, partially hydrolyzed fatty acid methyl esters, and inorganic salts) perform better than pure glycerin because they produce a physical barrier along the surface of the coal piles which further bars the oxidation processes of the treated coal .
• the composition inhibits combustion caused by the re-filling of the voids within the coal particles. Because moisture does not only flow in one direction voids formed by evaporation sometimes become re-filled by condensing moisture. The process of refilling the moisture, however, generates heat which accelerates oxidation and thus may in its own right, cause spontaneous combustion. In at least one embodiment the invention retains the moisture and thereby prevents the re-filling of the coal with heat laden moisture.
• the composition is used on low ranked coal passing through a funnel shaped piece of processing equipment or other pinch point containing equipment.
• Funnels are characterized as having sloped side walls which slope down to a small opening, Because of the frictional properties of the sloped walls, the innate autogenous/cohesive properties of the low ranked coal, and/or the magnitude of the slope, coal particles adjacent to the walls will have a different flow rate than particles farther from the walls and closer to a region directly over the opening.
• one of the: frictional properties, slope magnitude, size of the opening, size of the coal material particles, and autogenous cohesive properties of the coal particles, and any combination thereof is such that but for the presence of the composition the coal particles would form a rathole and only flow through a channel and would oxidize but with the composition such oxidation does not occur.
• ratholes, arches, and other pinch points can be dislodged or broken up by applying energy such as vibrations. These vibrations however can be dangerous, expensive, and may cause explosions or damage the equipment and as a result they are undesirable.
• the method excludes the appl ication of energy (including but not limited to vibration) to break up a rathole or arch in the piece of equipment that forms a rathole and/or arch for a period of time over which otherwise a user would have applied.
• the application of energy is excluded for a period of time extending from between 1 week to 12 months.
• Low-ranked coals typically contain higher moisture contents than higher ranked coals and are therefore expected to be more likely to form ratholes, arches or manifest other pinch points than higher ranked coals.
• the low-ranked coal is passed through a piece of equipment in which in the absence of the composition., due to its moisture content the low ranked coal would form an arch, rathole, or pinch point, but a higher ranked coal would not form an arch, rathole, or pinch point, and because of the presence of the composition, the moisture laden low ranked coal does not oxidize or is inhibited from oxidizing,
• the coal processing equipment contains a crack in which low ranked coal particles collect, become stagnant and may oxidize but in the presence of the composition such oxidation is inhibited and/or does not occur,
• the low ranked coal passes through the coal processing equipment in the absence, of one added item selected from the list consisting of: water, wetting agents, foams, micelle encapsulating agents, C ⁇ 3 ⁇ 4, 2 , and any combination thereof.
• Coal oxidation takes place in a series of steps including the oxidation of functional groups of the coal by oxygen, the build-up of oxygen containing oxidation product groups within the coal and the formation of gaseous carbon monoxide and carbon dioxide as the ultimate oxidation products.
• infrared spectroscopy it is possible to monitor the first two processes over time as a sample of coal is oxidized in air.
• FlGs. 1 and 2 there are shown samples of treated and untreated sub-bituminous coal which are compared using Fourier Transform Infrared Spectroscopy (FTt ).
• FTt Fourier Transform Infrared Spectroscopy
• the treated sub-bituminous coal displays a steady increase in carbonyl species as expected from the oxidation of the aliphatic groups.
• the untreated sub-bituminous coal displays a relatively unchanged level of carbonyl species over the course of the test. The latter is an indication that the untreated sub-bituminous coal oxidation process is producing gaseous carbon monoxide and carbon dioxide at. a much fester rate than in the treated sub-bituminous coal.
• overall oxidation of the treated sub-bituminous coal takes place more slowly than the untreated sub-bituminous coal
• FIG. 3 there is shown the results of testing the semi- adiabatic oxidation levels of treated and untreated sub-bitumous coal .
• selected sub-bitumous coal samples were prepared under an inert atmosphere prior to use and placed in a dewar flask equipped with a thermocouple for measuring the temperature of the coal and with a gas inlet tube to deliver gas directly to the coal and a gas outlet tube to allow gas to escape from the flask.
• One flask contained treated sub-bituminous coal and another flask contained an untreated portion of the same sub-bituminous coal.
• the flasks were sealed and placed in a controlled temperature oven under constant nitrogen flow within the flask.
• the rate of heat build-up within the flasks is related to the rate of oxidation of the material within the flask.
• the change in temperature within the flasks provides an indirect measure of the tendency of the contents to resist oxidation
• the invention encompasses any possible combination of some or all of the various embodiments described herein and/or incorporated herein.
• the invention encompasses any possible combination of some or all of the various embodiments described herein and/or incorporated herein.
• the invention encompasses any possible combination of some or all of the various embodiments described herein and/or incorporated herein.

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• 2013
  • 2013-04-04 CA CA2865453A patent/CA2865453C/en active Active
  • 2013-04-04 JP JP2015504711A patent/JP2015512470A/ja active Pending
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