METHOD FOR PROCESSING MEAT-AND-BONE MEAL

Abstract

A method for processing meat-and-bone meal for obtaining ashes includes steps of: feeding a catalytic fluidized bed gasifier with a meat-and-bone meal and an orthosilicate with a gas stream comprising oxygen, for obtaining a synthetic gas stream and ashes, wherein the catalytic fluidized bed gasifier is at a temperature from 400 C. to 1000 C.; grinding the obtained ashes; feeding a thermal boiler with the ground ashes, the obtained synthetic gas and a gas stream comprising oxygen for separating the ashes from the orthosilicate, wherein the thermal boiler is at a temperature from 600 C. to 2000 C.; and collecting the separated ground ashes.

Claims

1. A method for processing meat-and-bone meal for obtaining ashes, comprising the following steps: feeding a catalytic fluidised bed gasifier with a meat-and-bone meal and an orthosilicate with a gas stream comprising oxygen, for obtaining a synthetic gas stream and ashes, wherein the catalytic fluidized bed gasifier is at a temperature from 400 C. to 1000 C.; grinding the obtained ashes yielding ground ashes; feeding a thermal boiler with the ground ashes, the obtained synthetic gas, and a gas stream comprising oxygen for separating the ashes from the orthosilicate, wherein the thermal boiler is at a temperature from 600 C. to 2000 C.; and collecting the separated ground ashes.

2. The method according to claim 1, wherein the synthetic gas stream is a hydrogen riched gas.

3. The method according to claim 1, wherein the catalytic fluidized bed gasifier is fed with a water steam.

4. The method according to claim 1, wherein the stream comprising oxygen is an air stream or an oxygen stream.

5. The method according to claim 1, further comprising feeding a cyclone with the synthetic gas of the catalytic fluidized bed gasifier for obtaining fine ashes.

6. The method according to claim 5, further comprising feeding the thermal boiler with the fine ashes obtained in the cyclone.

7. The method according to claim 1, wherein the thermal boiler is further fed with an amount of synthetic gas.

8. The method according to claim 6, further comprising feeding a silo with the fine ashes from the thermal boiler.

9. The method according to claim 1, wherein the reactor is at a pressure from 90 kPa to 110 kPa.

10. The method according to claim 1, wherein the catalytic fluidised bed gasifier is at a temperature from 450 C. to 950 C.

11. The method according to claim 1, wherein the grinding of the ashes is made in a mill.

12. The method according to claim 1, wherein the thermal boiler is at a temperature from 750 C. to 1500 C.

13. The method according to claim 1, wherein orthosilicate is selected from any of Dolomite, Alkaline metal, Olivine, Nickel or their mixtures.

14. The method according to claim 1, further comprising feeding a buffer with the ground ashes for retaining the ground ashes before the feeding the thermal boiler.

15. The method according to claim 1, wherein the amount of ground ashes obtained is 20 to 25% (wt/wt.sub.meat and bone meal).

16. The method according to claim 1, wherein the dimension of the ground ashes less than 3 mm.

17. The method according to claim 5, wherein the dimension of the fine ashes is from 0.5 to 5 micrometres.

18. Ashes obtained by the method according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The following figures provide preferred embodiments for illustrating the disclosure and should not be seen as limiting the scope of invention.

[0038] FIG. 1: Schematic representation of an embodiment of the method for processing meat-and-bone meal.

[0039] FIG. 2: Schematic representation of an embodiment of the method for processing meat-and-bone meal.

[0040] FIG. 3: Flow chart of an embodiment of the method for processing meat-and-bone meal.

DETAILED DESCRIPTION

[0041] The present invention relates to a method for processing meat-and-bone meal for obtaining ashes, comprising the following steps: [0042] feeding a catalytic fluidised bed gasifier with a meat-and-bone meal and an orthosilicate with a gas stream comprising oxygen, for obtaining a synthetic gas stream and ashes, wherein the catalytic fluidised bed gasifier is set at a temperature from 400 C. to 1000 C.; [0043] grinding the obtained ashes; [0044] feeding a thermal boiler with the ground ashes, the obtained synthetic gas, and a gas stream comprising oxygen for separating the ashes from the orthosilicate, wherein the thermal boiler is at a temperature from 600 C. to 2000 C.; and [0045] collecting the separated ground ashes.

[0046] For better results, a catalyst is added to speed-up the reaction, such as orthosilicate. In the fluidised bed reactor, there is thermal contact between the biomass, namely the meat-and-bone meal, and the orthosilicate.

[0047] In an embodiment, the orthosilicate recirculates from the reactor to extract/degrade the fine ashes and is introduced again to the reactor jointly with the catalyst. Preferably, the orthosilicate is selected from Dolomite, Alkaline metal, Olivine, Nickel or their mixtures.

[0048] For better results, the ashes from the reactor are ground or crushed in the mill so that the ashes with a higher dimension will be totally burned in the next step, namely, in the thermal boiler. Also, the griding of the ashes enables the catalyst to be removed from the ashes.

[0049] In an embodiment the thermal boiler burns the synthetic gas and the ashes are obtained from the reactor. The thermal boiler burns the organic material that is still present in the ground ashes and also enables the amount of chlorides to be kept at a low level on the ground or fine ashes.

[0050] In an embodiment, the process further comprises the step of feeding a cyclone with the synthetic gas of the reactor for obtaining fine ashes.

[0051] In an embodiment, the process further comprises the step of feeding the thermal boiler with the fine ashes obtained in the cyclone.

[0052] In an embodiment, the process further comprises the step of feeding a silo with the fine ashes from the thermal boiler and decanting the fine ashes.

[0053] In an embodiment, the process further comprises a previous step of dehydrating the meat-and-bone meal before feeding the reactor.

[0054] In an embodiment, the reactor is at a pressure from 99325 to 102325 Pa. In some embodiments, the reactor pressure is in a preferred range of 99900 to 101525 Pa. In other implementations, the reactors is in a more preferred range of 100100 to 101225 Pa. These pressures allow enable output of the syngas from gasifier.

[0055] In an embodiment, the reactor is at a temperature from 450 C. to 950 C. In some embodiments, the reactor is at a more preferable temperature of 720 C. to 870 C.

[0056] In an embodiment, the reactor is a gasification reactor. In the gasification reactor a synthetic gas with H.sub.2 and CO is obtained.

[0057] In an embodiment, the gasification reactor is a fluidised bed gasification reactor. Preferably the fluidised bed is in counter-current.

[0058] In an embodiment, the thermal boiler is at a temperature from 750 C. to 1500 C. In some implementations, the thermal boiler is at a more preferable temperature of 850 C. to 1050 C.

[0059] In an embodiment, the method comprises an air-water exchanger for the production of water steam in the boiler and an air/air exchanger to recover the heat from the combustion gases to heat the air of the reactor.

[0060] In an embodiment, the process further comprises the step of feeding a buffer with the ground ashes for retaining the ground ashes before the feeding the thermal boiler.

[0061] In an embodiment, the amount of ground ashes obtained is from 20 to 25% (wt/wt.sub.total of meat-bone meal).

[0062] Ashes are obtained by the method for processing meat-and-bone meal to obtain ashes. The ashes can be used in several applications such as agriculture.

[0063] FIG. 1 shows a schematic representation of an embodiment of the method where: 1 represents the wet biomass input; 2 represents an output of dehydrated biomass, preferably the meat-and-bone meal; 3 represents dry biomass storage silo; 4 represents exit of biomass from the silo to be directed to the gasification reactor; 5 biomass input of the gasification reactor; 6 represents catalyst inlet; 7 represents air; 8 represents water vapour; 10 represents H.sub.2/CO Synthetic gas outlet; 11 represents air; 12 represents water steam; 13 represents an ash output; 14 represents a mill-entrance; 15 represents a crushed/micronized ash output; 16 represents an input for the ground ash buffer; 17 represents an ground ash output; 18 represents an inlet for synthetic H.sub.2/CO gas entering in the cyclone filter; 19 represents synthetic gas outlet from the cyclone filter; 20 represents an exit of the fine ash from the cyclone filter; 21 represents an inlet for storage of fine ash and 22 represents a fine ash outlet to the thermal oxidiser.

[0064] FIG. 2 shows a schematic representation of an embodiment of continuation of the method where 23 represents synthesis Gas Inlet H.sub.2/CO; 24 represents entry of evaporates; 25 represents an entry of natural gas; 26 represents an air; 27 represents an injection of fine plus ground ash; 28 represents the thermal boiler suitable for operation with Synthetic Gas; 29 represents a Temperature control >=850 C.; 30 represents ground ash output; 31 represents an exit of combustion gases; 32 represents an inlet to the silo to capture the fine ash, which can be used for a P-phosphorus rich fertilizer manufacturing process; 33 represents an escape; 34 represents the fine ash output; 35 represents the chimney entrance; 36 represents the exit of gases to atmosphere; and 37 represents the atmosphere.

[0065] FIG. 3 shows a flow diagram of an embodiment of the method for processing meat-and-bone meal using the system components and arrangement discussed above. In a first step 100 a fluidized bed gasifier is fed with meat-and-bone meal and orthosilicate, and with a gas stream to obtain a synthetic gas stream and ashes. In a following step 110, the ashes are ground, for example in a mill. In step 120, a thermal boiler is fed with the ground ashes, the obtained synthetic gas, and a gas stream including oxygen to separate the ashes from the orthosilicate. The separated ashes are collected in step 130. In the depicted embodiment, after the ashes have been collected a cyclone is fed with the ashes and synthetic gas from step 110, and fine ashes are output form the cyclone in step 140. In step 150, the thermal boiler is fed with the fine ashes produced by the cyclone.

[0066] The following pertains to the ash characterization.

[0067] In an embodiment, the ash content is depending on the ash temperature. The ash content at 750 C. is 18.8 wt.-% (water free), at 850 C. it is 18.62 wt.-%. The ash content decreases with increasing ash temperature due to volatilisation of components like carbonates.

[0068] In an embodiment, the sulphur content of 0.66 wt.-% in total splits up into 0.02 wt.-% of ash sulphur and 0.64 wt.-% of combustible sulphur.

[0069] The calorific value is determined by burning the sample with oxygen in a bomb calorimeter. The higher heating value is a calculated quantity. The higher heating value (HHV) and the lower heating value (LHV) determined for the animal meal sample are listed below in Table 1, being ar: the sample as received; wf: water free biomass:

TABLE-US-00001 TABLE 1 Higher and lower heating value W HHV LHV ar ar wf ar wf Sample wt.-% kJ/kg 5484 0.8 20.831 20.999 19.501 19.678

[0070] The water free biomass sample is a sample that was dried in a dryer.

[0071] The ash melting behaviour is determined by optical tracking of changes in form of a pressed pellet of sample ash. At characteristic form changes, the temperature is noted (e.g. spheric temperature). The melting behaviour was determined under oxidizing as well as reducing temperature. The 550 C. ash showed optical changes at approximately 880 C. (oxidizing atmosphere) and 960 C. (reducing atmosphere). For both atmospheres, no characteristic changes could be observed up to 1,592 C. (maximum temperature of the used lab equipment).

[0072] To gain insights of the chemical composition of mineral phases and the sulphur species distribution, an x-ray diffractometry was carried out. The results are shown in Table 2.

TABLE-US-00002 TABLE 2 Results of X-ray diffractometry Phase Name Phase formula wt.-% RietveId Quartz SiO.sub.2 2.1 Hydroxylapatite, syn Ca.sub.5[OH|(PO.sub.4).sub.3] 69.0 Merrillite, syn Ca.sub.9NaMg(PO.sub.4).sub.7 7.8 Anhydrite CaSO.sub.4 0.5 Dolomite CaMg(CO.sub.3).sub.2 1.1 Langbeinite K.sub.2Mg.sub.2[SO.sub.4].sub.3 1.3 Sylvite KCl 5.9 Calcium Phosphate Ca.sub.3(PO.sub.4).sub.2 1.5 Illite 2M1 K.sub.0.65Al.sub.2.0Al.sub.0.65Si.sub.3.35O.sub.10(OH).sub.2 1.2 Amorphous 9.66 Sum 100.0

[0073] The term comprising whenever used in this document is intended to indicate the presence of stated features, integers, steps, components, but not to preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0074] The disclosure should not be seen in any way restricted to the embodiments described and a person with ordinary skill in the art will foresee many possibilities to modifications thereof. The above described embodiments are combinable.

[0075] The following claims further set out particular embodiments of the disclosure.