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
  • C10L5/40—Solid fuels essentially based on materials of non-mineral origin
  • C10L5/46—Solid fuels essentially based on materials of non-mineral origin on sewage, house, or town refuse
• • 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

• the present invention relates to a method for producing fuel from the biomass component of waste, in particular from organic wet fraction (OWF) .
• OPF organic wet fraction
• the organic wet fraction (OWF) amounts to about 40% of the total non- KGW domestic refuse. OWF is non-combustible and at the moment is still disposed of to landfill. The amount of presented OWF will increase sharply in the coming years . OWF already forms a problem at the moment for a number of reasons. Firstly, composting or fermenting is not worthwhile. Diverse studies have shown that the compost from OWF does not comply with legal requirements. The reason for this is that the heavy metal content is too high according to legal standards currently in force. In addition, OWF is too wet and contains too much sand to make direct incineration possible. Disposal of OWF to landfill is often only permitted under exemption, wherein additional charges are also made.
• the organic wet fraction can be obtained in per se known ways, for instance by removing metals, for instance by means of a metal separator, from the waste, particularly domestic waste, and by removing the coarse fraction from said waste by means of a separation to size .
• Drying of the organic wet fraction advantageously takes place at least partially by means of composting. Moisture is consumed in the composting process, whereby the composted material becomes drier.
• the cut-off point used as limit in the separation to size depends on the starting material and the properties thereof. It has been found that in the case of standard domestic refuse a cut-off point of 10 mm is very suitable in finally arriving at an acceptable fuel.
• the first fraction with dimensions above the cut-off point preferably consists of material with a size between roughly 10 and roughly 40 mm.
• the second fraction has dimensions below the cut-off point, i.e. of less than about 10 mm.
• the separation into fractions on the basis of at least diameter, and optionally density, can take place in different ways. Separation on the basis of diameter alone can be performed by screening when glass is present in particles smaller than the lighter organic particles.
• the technique of air separation is also suitable. This technique is further elucidated in the example. It is however particularly recommended to apply a ballistic separating process, such as for instance by placing the material for processing on a high speed conveyor belt which is disposed horizontally.
• the conveyor belt is situated at a minimum height of 4.5 m.
• the belt has a minimum speed of 8 m/s.
• the material is thrown off in horizontal direction. Heavier particles of a determined diameter are thrown further than particles with a lower density of the same diameter.
• the invention further relates to a fuel to be obtained from waste by performing the method according to one or more of the foregoing claims.
• figure 1 shows the distribution of dry and organic matter in fractions of dried OWF
• figure 2 is a schematic representation of an air separator with zigzag distribution
• figure 3 shows particle size distribution after air separation of the heavy fraction at 10 m/s
• figure 4 shows particle size distribution after air separation of the light fraction at 10 m/s
• figure 5 shows a comparison of the particle size distribution in the light fraction and the heavy fraction after air separation
• figure 6 is a schematic representation of an ASTER installation
• figure 7 shows the distribution of dry and organic matter in the 0-10 mm fraction after ASTER separation
• figure 8 shows the distribution of dry and organic matter in the 10-40 mm fraction after ASTER separation
• figure 9 shows the mass balance of the method according to the invention.
• the OWF After extraction of an organic wet fraction from a quantity of standard domestic refuse, the OWF is first dried, whereby it loses much weight. The material is then separated in order to remove from the OWF as much inert material as possible, such as stones, glass and sand. After separation the material is pelletized and incinerated. Pelletizing can optionally be omitted.
• the OWF can be dried by means of composting.
• the composition of the organic matter of the OWF was determined.
• the OWF was analysed for the quantity of cellulose, lignin, protein, starch, fats and other carbohydrates (see table 1) . If the organic matter content is higher than 30% of the dry matter and the lignin content is lower than 20% of the organic matter, the waste is theoretically compostable . Table 1
• composition of the organic matter shows that the OWF particularly contains less quickly degradable substances such as crude cellulose, fats and lignin. If the lignin content is lower than 20%, performing of the composting experiment is worthwhile. Table 1 shows that this is the case here.
• the first composting experiment was carried out with 300 litres of OWF with a weight of 162 kg, although without feedback of the air. The experiment stood for 15 days. The temperature was round 60 °C for two days and thereafter lower.
• Table 2 shows the mass balance over the first composting experiment.
• the table shows that 75% of the water has evaporated, whereby the dry matter content has risen by 30%.
• the total weight has decreased by 35%.
• the second composting experiment was carried out with 162.6 kg of OWF and stood for 19 days. In contrast to the first composting experiment, this composting experiment was performed with feedback of the used air.
• the advantage hereof is that the fed-back air is warmer than fresh air. Warm air absorbs more water, whereby the OWF dries more quickly.
• the temperature was round 60°C only for the first few days and thereafter the temperature falls and fluctuates round 27°C. This is roughly equal to the temperature in the CAT space.
• the mass balance of this CAT experiment can be found in table 3.
• Air separation is a much used method of separating plastic and paper from domestic refuse. Since air separation also appeared to be a good method to separate the lighter (organic) material from the heavier (inert) material in OWF, an air separation experiment was carried out, wherein use was made of a so-called zigzag separator. This air separator separates particularly on the basis of the falling behaviour, the density and the surface area of a particle.
• Figure 2 shows a schematic view of the used air separator.
• the material is fed in at the top 1 of zigzag part 2.
• the embodiment shown is a rise separator, i.e. the separator does not blow but sucks.
• the lighter material is carried by the suction force to cyclone 3.
• the light fraction 4 comes out at the bottom of cyclone 3.
• the heavy fraction 5 enters zigzag part 2 and falls downward into a container (not shown) .
• the zigzag part contains six bends 6 of 120° . In a zigzag channel 7 the classification takes place at the position of each individual bend.
• the sequence of bends makes repeated classification possible.
• the separation performance is determined by the separation characteristic of a single bend and the particle exchange between the bends.
• the run-down of the particle movements at a bend generally depends not only on the process conditions, particle properties and bend geometry, but also on the direction in which the particles approach the bend.
• a total of about 70 kg OWF with a dry matter content of 85% is air separated.
• the air separation experiments were performed at two different air speeds, i.e. 10 m/s and 12.5 m/s. Visually the better separation appeared to take place at the air speed of 12.5 m/s. From the analysis results, however, it was found that the separation was better at the air speed of 10 m/s.
• the topflow or overflow of the air separator particularly contains much fine material and very light material such as thin plastic.
• the underflow contains stones and glass, but also the heavier and larger pieces of plastic, wood and pieces of paper.
• a possible drawback is that parts of the OWF are caked to each other. These lumps are heavy and always move to the underflow. This problem is however quite simple to solve, for instance by transporting the material using a screw. Table 5 shows a mass balance of the air separation experiment.
• the heavy fraction contains little material smaller than 1 mm.
• the finer material in the heavy fraction is probably material which was adhered to the larger portions and which has been detached by the vibration of the screens.
• the lighter material contains almost no material > 35 mm. This is because this material is too heavy to be sucked upward.
• the air separator separates the OWF particularly to particle size.
• the large particles end up in the heavy fraction and the small particles in the light fraction.
• a flow of light material with a higher organic matter content is indeed obtained by means of air separation.
• this organic flow is only 47% of the dry OWF, whereby 53% is thus left which must be disposed of to landfill or processed in other manner.
• a more efficient separation is achieved when the dried OWF is first separated into different fractions. During screening the larger chunks present in the OWF also fall apart .
• the dried OWF is now pre-separated into two fractions, i.e. the fraction >10 mm and the fraction between 0-10 mm.
• ASTERTM technology An example of a ballistic separating method is the so-called ASTERTM technology. Such a technique will be referred to hereinbelow with the general term "ballistic system” .
• This technique separates according to density, shape and size. The technique is based on the force of gravity and uses about 20 times less energy than an air separator. This method is also cheaper to purchase.
• the installation for use in this technique (figure 6) operates as follows. Via the infeed 8 the material is carried onto a conveyor belt 9. The conveyor belt has a ribbed profile so that the material remains properly in place, and rotates at high speed (maximum 10 m/s) . The material is hereby flung from the belt at great speed. The material is collected behind the belt in a closed collecting space 10.
• this is 7 m high and 5.5 m long, and is divided into five different compartments 12-15.
• the lightest material thus enters the first container 12, the heaviest material ends up in the last container 15.
• a blower 16 is suspended just behind the conveyor belt which blows the light material into a separate first collecting container 11. When the collecting space is long enough, container 11 is unnecessary.
• fraction 1 is the lightest, fraction 5 the heaviest
• fraction 1 is the lightest, fraction 5 the heaviest
• the analysis results show that the OWF is separated into an inert and an organic flow.
• Light fractions >10 mm in particular have a high organic matter content.
• the light fractions of 0-10 mm have a somewhat lower organic matter content. This is because the material ⁇ 10 mm in the starting material also has a lower organic matter content .
• the fractions 1-3 of the fraction 0-10 mm and the fractions 1-4 of the fraction 10-40 mm were mixed and then incinerated. When these fractions are mixed there results a fuel with an organic matter content of 55% .
• the fraction ⁇ 2 mm could be separated beforehand. In this manner material with an organic matter content of 66% can be obtained.
• fractions 4 and 5 of the fraction 0-10 mm and the fraction 5 of the fraction 10-40 mm consist largely of stones and glass. These fractions can for instance be marketed as rubble or gravel.
• the concentration of sodium + potassium lies round 8,000 mg/kg. It is known that clogging takes place at a sodium + potassium content of 10,000 mg/kg. The calorific value will be round 18 MJ/kg.
• the invention therefore provides a method to make a fuel from OWF and analogous waste flows, such as non-KGW domestic refuse, the organic fraction from industrial waste, green waste, grounds maintenance waste, the organic fraction from construction and demolition waste, the organic fraction from "old” excavated waste landfills, by choosing drying and separation such that the fuel to be formed can be processed in different types of incineration plant .
• a minimum of 12% of the fine inert fraction ⁇ 2 mm consisting particularly of glass
• the techniques of screening and ballistic separation are applied. It is generally the case that if the glass content of dried material is greater than 0 and the organic matter content (of the dry matter) is more than 60%, a ballistic separation is required to remove at least some of the glass. When the glass content is less than 1% and the organic matter content less than 60%, glass can be removed using an additional screening step (e.g. mesh width 4 mm) . The small particle fraction contains inert (non-combustible) parts. If the glass content of dried material is less than 1% of the dry matter and the organic matter content more than 60%, a screening step is then only necessary to separate the fine fraction (e.g. mesh width ⁇ 4 mm) .
• an additional screening step e.g. mesh width 4 mm

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Solid Fuels And Fuel-Associated Substances (AREA)
• Processing Of Solid Wastes (AREA)

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• 1999
  • 1999-12-23 AU AU20071/00A patent/AU2007100A/en not_active Abandoned
  • 1999-12-23 EP EP99963699A patent/EP1060233A1/de not_active Withdrawn
  • 1999-12-23 WO PCT/NL1999/000803 patent/WO2000039255A1/en not_active Application Discontinuation

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