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
  • C10L5/08—Methods of shaping, e.g. pelletizing or briquetting without the aid of extraneous 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
  • C10L5/00—Solid fuels
  • C10L5/02—Solid fuels such as briquettes consisting mainly of carbonaceous materials of mineral or non-mineral origin
  • C10L5/34—Other details of the shaped fuels, e.g. briquettes
  • C10L5/36—Shape
  • C10L5/361—Briquettes
• • 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
  • C10L5/40—Solid fuels essentially based on materials of non-mineral origin
  • C10L5/44—Solid fuels essentially based on materials of non-mineral origin on vegetable substances
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E50/00—Technologies for the production of fuel of non-fossil origin
  • Y02E50/10—Biofuels, e.g. bio-diesel
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E50/00—Technologies for the production of fuel of non-fossil origin
  • Y02E50/30—Fuel from waste, e.g. synthetic alcohol or diesel

Definitions

• THIS INVENTION relates to combustible briquettes formed of a mixture of sawdust or wood particles and a carbonaceous material such as coal, coke, charcoal or coalchar.
• the invention resides in a method of producing a combustible briquette which comprises mixing sawdust or wood particles and a carbonaceous material such as coal, coke, charcoal or coalchar, pressing the mixture at a temperature and pressure sufficient to remove excess moisture from the mixture, to substantially eliminate the elasticity of the mixture, to substantially eliminate springback and to bind the components of the mixture together.
• a carbonaceous material such as coal, coke, charcoal or coalchar
• the sawdust used was typical hardwood sawdust from kiln dried wood or green sawdust dried as required. Its moisture content was 13.5 percent although this was adjusted by the addition of water for some tests.
• the bulk density of the sawdust was 200 kilograms per cubic -3 metre (kg m ) when the container was loosely filled and
• Cylindrical briquettes were formed in two steel moulds with diameters of 28.64 and 41.54mm respectively.
• the maximum load that could be applied to the smaller mould was 25 tons, equivalent to a pressure of 386 MPa (56000 psig).
• the maximum load that could be applied to the large mould was 30 tons, equivalent to a pressure of 221 MPa (32000 psig) .
• the first and greatest of these elastic movements is referred to as "springback" and was measured with a scale and pointer fixed to the base plate of the mould and the piston respectively.
• the second and third indications of elasticity were measured with vernier calipers and are much smaller than springback measurements.
• Elasticity is a physical property of matter which allows it to deform under pressure and return to its original dimensions (more or less) when the deforming stress is removed.
• elasticity values calculated for the purpose of this specification were derived in particular experimental conditions and should not be construed as absolute values of the elasticity of the materials under test.
• the sawdust as received containing about 12-13 percent of moisture, was screened on square mesh laboratory screens of aperture 600 and 300 micrometres.
• the sawdust being used was hardwood sawdust with 12-13 percent of moisture. A quantity of sawdust with sufficient added water to raise the moisture content to 25 percent was left in a sealed plastic bag for about 18 hours to equilibrate. Portions of this wet sawdust were dried to different levels of moisture content and spring- back measurements were made for an applied pressure of 386MPa. Other portions of sawdust were completely dried at 110°C or heated to 200°C and 300°C before similar springback measurements were made. The results are shown in Table 2.
• briquettes As they were expelled from the mould, briquettes expanded in both height and diameter. For sawdust (12-13 percent moisture) pressed at 386MPa, the expansion immediately after expulsion was about 5-10 percent in height and less than 1 percent in diameter. As the briquettes aged they expanded more, about 15 percent in height and less than 1 percent in diameter. This expansion was less when briquettes were pressed at 221MPa.
• the briquettes made with sawdust containing different levels of moisture were observed over a period of six days.
• a briquette has its maximum specific gravity and minimum dimensions under pressure (386MPa) in the mould. The dimensions increase immediately on expulsion from the mould so that the specific gravity decreases. The dimensions increase again as the briquette ages and the final specific gravity is affected by these dimensional changes and any changes in moisture content. The following values were noted:
• the properties of sawdust-coal briquettes might be expected to be similar to those of sawdust briquettes because the major value component is sawdust and coal is also elastic in the briquetting conditions employed. Some briquettes were made with mixtures of sawdust and coal with various moisture contents. The briquetting details are shown in Table 4 and the properties of the briquettes are shown in Table 5 with corresponding item numbers to assist interpretation (see below).
• the testwork has shown that the elasticity of the materials increases the dimensions of sawdust-coal briquettes from the moment that the moulding pressure is released until the briquettes stabilise on free-standing. These dimensional changes are aggravated by changes in the moisture content of the briquettes until equilibrim with ambient conditions is attained. In the cirucmstances of this testwork, the dimensional changes due to both causes were minimised when the moisture contents of the sawdust and coal were each about 10-12 percent. It is probable that the moisture content of the sawdust is more critical than that of the coal because the sawdust is the major volume component of the mixutre. The particle size of the sawdust does not appear to be a significant factor.
• Each bag contained approximately 5 kilograms of sawdust and coal mixed on a mass ratio of 1:1.
• the moisture contents marked on the samples were 25%, 12% and 3% respectively.
• the first series of trials used a manually operated 100 tonne press.
• a high tensile steel mould and piston were manufactured for the trials to facilitate the manufacture of the briquettes.
• the external size of the mould was 150mm height x 149mm diameter, and the internal size was 150mm height x 82mm diameter, giving the mould wall a thickness of 33.5mm.
• the piston measure 79mm height x 82mm diameter.
• holes were drilled vertically down the piston from face to face.
• the six holes were drilled to 4mm in diameter at 60 pitch circule diameter, each at 60 points of the piston face.
• a seventh hole was drilled down the centre of the piston.
• Vernier Calipers were used to measure the respective heights of briquettes during the trials.
• Varying quantities of mixtures were pressed in the mould in order to determine the ideal pressure per square inch required to destroy elasticity of the mixture.
• the elasticity of 1:1 mixture of sawdust and coal is directly related to the pressure applied for compaction, and the moisture level of the mix, both during compaction and at completion of compaction.
• Test results indicate that a variation of moisture level of the mixture, heat, compaction pressure, and duration of compaction pressure; directly cause a change in the hard ⁇ ness of the briquette and its Gross Specific Energy.
• Collie Coal as mined may contain 24-28 percent moisture and 3-8 percent ash.
• the Gross Specific Energy of that coal would be approximately 19.9 Mgj/kilogram.
• Coal with a moisture content of 12.5 percent would have a Gross Energy Value of about 24.75 Mgj/kilogram.
• a commercial plant as envisaged for production of the briquettes would need to dry economically the sawdust/coal mixture to about 12 percent moisture, before manufacture of the briquette.
• Briquettes produced would have Gross Energy Values of between 23-24 Mgj/kilogram and an ash content of some 2 percent.
• Much of the further drying process of the mix is carried out during the briquettes' manufacture, by the process of heat and pressure to produce a briquette containing a moisture level of some 5 percent.
• the briquette demonstrated great elasticity and spring ⁇ back, and finally broke into several pieces.
• a lOJjoz mixture was pressed at 100 Tonne for twenty seconds and left in the mould for three minutes without constant pressure being reapplied. When expelled from the mould, the briquette contained too much elasticity, and crazed laterally.
• the first of the Trials "Tr?" used 4oz of mix at 25% moisture content.
• the moisture escape holes blocked up, and when the briquette was expelled from the mould, the moisture content caused springback in the top section of the briquette. Cores of the mix were extruded from the moisture escape holes.
• Trial "T20 ** used 4oz of 25% moisture mix, compacted at a pressure of 12 Tonnes for a period of eight minutes-, at a mould commencement temperature of 170 C and mould temper ⁇ ature o * f 136°C at completion.
• the briquette showed no signs of . springback after twenty-four hours following manufacture, prior to being pulped up for laboratory analysis.
• Trial n T2Z n was designed to prove the duration of time of pressure under compaction was relative to the quantity of mix to be briquetted.
• Trial “T24” was a repeat of Trial ⁇ * T20", although the mould completion temperature had dropped to 118°C compared to 136°C in Trial ** T20". No springback was recorded, and the briquette has been kept.
• the moisture level of the mix determines at what pressure and temperature the mix needs to be manufactured, to destroy elasticity and springback.
• a moisture content of 3% will produce a briquette at 120 Tonnes pressure held for 3-5 minutes, at a temperature of 170 C at commencement of moulding, (see Trial 19).
• a temperature of 120 C is not adequate for a 3% moisture mix and results in the briquette developing lateral cracks, (see Trial 22).
• Trial 18 produced a good briquette when 4oz of 12% moisture mix was compacted under 120 Tonne for a period of 3-5 minutes at a mould commencement temperature of 170 C.
• Trial 21 demonstrated that a mould commencement temper ⁇ ature of 120 C was not satisfactory and the briquette produced, developed lateral cracks caused by springback.
• the mix must be briquetted at a temperature of some 150 C to 170°C, and a compaction pressure of 12 Tonnes (32,480 p.s.i.) must be maintained for a period of two minutes per loz of mix.
• the temperature of the mould should be in excess of 120 c and preferable no greater than 195°C although temperatures of up to 285 C may be required with coalchar.

Landscapes

• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Geology (AREA)
• Solid Fuels And Fuel-Associated Substances (AREA)

Applications Claiming Priority (1)

Publications (2)

Family

ID=3762112

Family Applications (1)

Country Status (5)

Families Citing this family (4)

Family Cites Families (6)

• 1985
  • 1985-04-18 WO PCT/AU1985/000085 patent/WO1986006091A1/en not_active Application Discontinuation
  • 1985-04-18 EP EP19850901925 patent/EP0218579A4/de not_active Withdrawn
• 1986
  • 1986-12-11 NO NO86864996A patent/NO864996L/no unknown
  • 1986-12-16 DK DK605286A patent/DK605286D0/da not_active Application Discontinuation
  • 1986-12-17 FI FI865152A patent/FI865152A0/fi not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events