METHODOLOGY FOR TREATING BIOMASS, COAL, MSW/ANY KIND OF WASTES AND SLUDGES FROM SEWAGE TREATMENT PLANTS TO PRODUCE CLEAN/UPGRADED MATERIALS FOR THE PRODUCTION OF HYDROGEN, ENERGY AND LIQUID FUELS-CHEMICALS

Abstract

The present invention refers to a method for treating agricultural or forestry or urban origin biomass or mixture of different origin's biomass feedstocks, low quality coal such as peat, lignite or subbituminous or/and bituminous coal, or/and mixtures of them, garbage and urban/industrial wastes, solid and/or liquid state, as well as sewage treatment plant sludges by means of removal of inorganic elements, such as silica, potassium, sodium, chlorine, sulfur, phosphorus, nitrogen and heavy metals such as zinc, mercury, copper, lead, chromium, etc., and the addition of new inorganic elements such as calcium, magnesium, titanium, zirconium, yttrium, aluminum and ammonium, in order to produce a purified and upgraded solid and/or liquid material which can be used as raw material in thermochemical conversion processes such as combustion, flash (t<1 sec)/fast pyrolysis (1<t<10 sec), as well as in the gasification for the production of energy, and/or hydrogen-rich gas and liquid hydrocarbons.

Claims

1. Method for removing inorganic components (Si, K, Na, Cl, S, P, and heavy metals such as zinc, mercury, copper, lead, chromium, etc.) from raw material for the production of clean and upgraded materials, where the raw material is biomass or coal or garbage or waste or sludges or mixtures of them, during which the process is performed in a first stage by leaching of the raw material with an aqueous solution containing strong alkaline agents such as potassium, sodium bases, and/or their salts, followed in a second phase by washing the feedstock with an aqueous solution containing inorganic and/or organic salts containing one or more of the following cations of calcium, magnesium, ammonium, aluminum, titanium, zirconium and yttrium, and where the reactions take place under pressure and at elevated temperatures over 100 C.

2. Method according to claim 1, where the leaching of the raw material takes place only with aqueous solution containing organic and/or inorganic salts of calcium, magnesium, ammonium, aluminum, titanium, zirconium and yttrium, when the silicon concentration in the ash of the treated material is less than 10% and consequently silicon removal from the treated material is not required.

3. Method according to one of claim 1 or 2, where the leaching of the raw material in the second process step is done with an aqueous solution containing organic and/or inorganic salts and organic and/or inorganic acids.

4. Method according to one of claim 1 or 2, and 3 where the process is carried out under pressure in two steps using the reactor of FIG. 1.

5. Method according to claim 4 where the process is carried out under pressure at one stage, when the silicon removal from the material is not necessary, using the reactor of FIG. 1.

6. Method according to one of claim 1 or 2, 3 and 4 where the concentration of strong basic agents for silicon removal ranges from 0.5-1.5% weight basis.

7. Method according to one of claim 1 or 2, 3 and 4 where the concentration of the salts and/or the salt/acid mixtures for the removal of alkali metals, chlorine, sulfur, phosphorus, heavy metals and nitrogen ranges from 0.5-4% weight basis.

8. Method according to one of claims 1 to 7, where the conditions during which the treatment is carried out in the first stage is temperature 110-150 C. and pressure 2-atm if the material is biomass while temperature 130-195 C. and pressure 4-20 atm if the treated material is coal, garbage/waste for less than 5 minutes in case of biomass and less than 20 minutes in case of coal, garbage/waste.

9. Method according to one of claims 1 to 7, where the conditions during which the treatment is carried out in the second stage is temperature 110-160 C. and pressure 2-10 atm if the treated material is biomass, temperature 140-195 C. and pressure 4-20 atm if the treated material is coal, garbage/waste while pressure 4-45 atm and temperature (140-245 C.) in case of plastics/polymer materials especially when they contain structural chlorine, for less than 5 minutes in case of biomass and less than 20 minutes in case of coal, garbage/waste and plastic/polymer materials.

10. Method according to one of claims 1 to 9 where all water-soluble organic/inorganic salts of calcium, magnesium, titanium, zirconium, yttrium, aluminum and ammonium in proportions of 0.07% up to 4% weight basis of the aqueous solution are used as organic and/or inorganic compounds according to the type of the treated material.

11. Method according to one of claims 1 to 9 where in case of biomass, the solvent concentration is limited below 1.5%, while in case of coal and garbage/waste ranges from 0.5-4%.

12. Method according to one of claims 1 to 9 where both organic and inorganic acid/salt mixtures are used in the second step of the process to achieve the desired result considering that the proportion of acid is limited to less than 30% of the total mixture weight basis and preferably the extent of which does not lead to the creation of acidic conditions having a pH less than 5 in the pressurized solution.

13. Method according to one of claims 1 to 12, where the production of the aqueous solution takes place with water regardless its origin, while leaching is carried out at raw material/aqueous solution ratio from 15 grams per liter to 800 grams per liter.

14. Method according to one of claims 1 to 13, where leaching is carried out at raw material/aqueous solution ratio from 15 grams per liter to 400 grams per liter, temperature from 110 C. up to 245 C., and pressure from 2 atm to 45 atm during both stages of treatment depending on the material treated, while the leaching time ranges from 2.5 minutes to 20 minutes.

15. Method according to claim 14, where leaching is carried out at temperatures ranging from 110 C. to 150 C., in each stage, while the leaching time ranges from 2.5 minutes to 4.99 minutes when the treated material is biomass.

16. Method according to claim 13, where leaching is carried out at temperatures ranging from 130 C. to 195 C., in each stage, while the leaching time ranges from 5 minutes to 20 minutes when the treated material is coal, garbage/waste.

17. Method according to claim 13, where leaching is carried out at temperatures ranging from 140 C. to 245 C., in each stage, while the leaching time ranges from 5 minutes to 20 minutes when the treated material is a plastic/polymer material.

18. Method according to one of claims 1 to 17, where the raw material consists of particles and where the particle size ranges from a few micrometers to 5 millimeters.

19. Method according to one of claims 1 to 17, where the raw material consists of particles and where the particle size is less than 2 millimeters.

20. Method according to claims 1 to 17 where the aqueous residue remaining after separation of the alkali compounds used to create the aqueous solvent for the pretreatment of various materials in step 1 of the treatment process is rich in silicon and is utilized for the production of pure silicon.

21. Method according to claims 1 to 17 where the aqueous residue remaining after separation of the organic and/or inorganic compounds used to create the aqueous solvent for the pretreatment of various materials in step 2 of the pretreatment process is rich in alkali metals, chlorine, sulfur and phosphorus and is utilized as high quality fertilizer.

22. Method according to claims 1 to 17 where the high pressure reactor consists of two separate reactors in a parallel mode. Each reactor contains an initial pressure vessel where initially the treated material and the aqueous solution are mixed under atmospheric conditions and ambient temperature with material/aqueous phase ratio from 15 grams per liter to 800 grams per liter and solvent concentration range between 0.5-1.5% weight basis depending on the material used.

23. Method according to claims 1 to 17 and 22 where the material is treated during the first reaction stage in the first pressurized compartment of the reactor with an aqueous alkali solution (base and/or salt), sodium, potassium, at temperature range of 110-150 C. and pressure 2-10 atm when the treated material is biomass while temperature 130-195 C. and pressure 4-20 atm when the treated material is coal, garbage/waste for less than 5 minutes in case of biomass and less than 20 minutes in case of coal, garbage/waste.

24. Method according to claims 1 to 17, 22 and 23 where each pressure vessel according to FIG. 1 is equipped with a direct discharge valve which communicates with the interior of the reactor via a pipeline at the end of which there is a 40 micron diameter solids filter. The immediate depressurization caused by the discharge valve opening after the end of the treatment process results in solid/liquid separation letting the liquid to be concentrated and cooled in the recover tank before being recycled into the process as shown in FIG. 1 while the solid product is removed in the second phase and is transferred to the second pressurized vessel by opening the valve of the pressurized reactor's bottom.

25. Method according to claims 1 to 17, 22, 23 and 24 where the parallel reactor operates one step back from the initial reactor in order to realize a process which is semi-batch but in progress at any time.

26. Method according to claims 1 to 17, 22, 23, 24 and 25 where the second compartment of the pressurized reactor is used for the second pretreatment stage by washing the material with an aqueous solution of inorganic and/or organic salts.

27. Method according to claims 1 to 17, 22, 23, 24, 25 and 26 where the conditions in the second compartment of the reactor is temperature between 110-160 C. and pressure 2-10 atm if the treated material is biomass, temperature between 140-195 C. and pressure 4-20 atm if the treated material is coal, garbage/waste and pressure 4-45 atm and temperature between 140-245 C. in case of plastics/polymer materials especially when they contain structural chlorine, for less than 5 minutes in case of biomass and less than 20 minutes in case of coal, garbage/waste as well as plastic/polymer materials.

28. Method according to claims 1 to 17, 22, 23 and 24 where 80-99% of the silicon is removed from the ash of the treated material during the first leaching stage.

29. Method according to claims 1 to 17, 22, 23, 25, 26 and 27 where the calcium and/or magnesium and/or aluminum and/or titanium and/or zirconium and/or yttrium, and/or ammonium ions are absorbed in the structure of the treated material in the second process step.

30. Method according to claims 1 to 16, where the nitrogen in the treated material which consists of biomass and/or coal and/or garbage/waste is removed in the second leaching stage.

31. Method according to claims 1 to 17 where leaching is carried out by applying elevated pressures and temperatures using commercially available reactors operating at high pressures 2-30 atm and temperatures 110-350 C.

32. Method according to claim 1, where the raw material is biomass or coal or garbage or waste or sludges or mixtures of them, during which the leaching of the raw material with an aqueous solution containing strong alkali agents such as strong bases and/or their salts is performed in a first stage, followed in a second stage by washing of the feedstock with an aqueous solution containing inorganic and/or organic salts containing one or more of the following cations: calcium, magnesium, ammonium, aluminum, titanium, zirconium and yttrium, where the reactions take place in two steps under pressure 2-200 atm and elevated temperatures 110-345 C. using suitable high pressure reactors. The process involves the silicon removal from the ash of the treated material during the first leaching stage, and the incorporation of calcium and/or magnesium and/or aluminum and/or titanium and/or zirconium and/or yttrium and/or ammonium ions in the structure of the treated material in the second process step realizing the simultaneous removal of chlorine, alkali metals, sulfur, phosphorus, heavy metals, and nitrogen from the treated material.

Description

EXAMPLE 1

[0038] Wheat straw is treated at elevated pressure using the reactor shown in FIG. 1. Since this material contains a large proportion of silicon in the ash, its pretreatment is focused in the first stage on trying to remove the silicon from the ash. In order to achieve that, the sample is treated in the first stage using sodium hydroxide in the first compartment of the pressurized reactor. The applied conditions are the following: Temperature 147 C., pressure 5-9 atm, solid/liquid ratio 10% w/w dry basis, leaching time 4.8 minutes, solvent concentration 1% w/w, material particle size <1 mm. After the first step of pretreatment the sample is moved to the second pressurized compartment where it is treated in the second step aiming at the removal of alkali metals, phosphorus, chlorine, sulfur, as well as the deactivation of components remaining in the material structure after the end of the process by means of appropriate salts so that they will be no longer a problem for the further thermochemical treatment of the treated material. The applied conditions are the following: Temperature 148 C., pressure 5-9 atm. solid/liquid ratio 10% w/w dry basis, leaching time 4.9 minutes, solvent concentration 1.2% w/w and calcium chloride as solvent. After the pretreatment, the sample is dried at 50 C. The final solid sample appears to have increased ease of milling requiring 30-40% less energy than the original raw wheat straw while it favors the production of greater strength pellets requiring reduced energy consumption by 30-50% compared again to the original raw straw. The ash content of the final treated material appears to be reduced by more than 30%, the silicon concentration appears to be reduced by 80%, while the concentrations of chlorine and active alkali metals are practically zero. The sulfur and phosphorus concentrations appear significantly reduced by 60-70% for sulfur and from 60% up to 70% for phosphorous. At the same time, the calcium concentration is significantly increased and is now more than 60% of the treated material ash. Both raw and treated material ash is thermally treated in a high temperature oven starting from 600 C. followed by 50 C. steps. Table 2 shows the results of thermal treatment. It is clear that the ash of the treated material appears to have significantly increased thermal resistance while the ash melting point is increased to 1550 C., from 800 C. in case of raw material.

EXAMPLE 2

[0039] Olive kernel is treated at elevated pressure using the reactor shown in FIG. 1. Since this material contains a large proportion of silicon in the ash, its pretreatment is focused in the first stage on trying to remove the silicon from the ash. In order to achieve that, the sample is treated in the first stage using potassium hydroxide in the first compartment of the pressurized reactor. The applied conditions are the following: Temperature 147 C., pressure 5-9 atm, solid/liquid ratio 10% w/w dry basis, leaching time 4.2 minutes, solvent concentration 0.8% w/w, material particle size <1 mm. After the first step of pretreatment the sample is moved to the second pressurized compartment where it is treated in the second step aiming at the removal of alkali metals, phosphorus, chlorine, sulfur, as well as the deactivation of components remaining in the material structure after the end of the process by means of appropriate salts so that they will be no longer a problem for the further thermochemical treatment of the treated material. The applied conditions are the following: Temperature 138 C., pressure 5-7 atm, solid/liquid ratio 15% w/w dry basis, leaching time 4.9 minutes, solvent concentration 1.2% w/w and calcium nitrate as solvent. After the pretreatment, the sample is dried at 50 C. The final solid sample appears to have increased ease of milling requiring 30-40% less energy than the original raw olive kernel while it favors the production of greater strength pellets requiring reduced energy consumption by 30-50% compared again to the original raw olive kernel. The ash content of the final treated material appears to be reduced by more than 40%, the silicon concentration appears to be reduced by 90%, while the concentrations of chlorine and active alkali metals are practically zero. The sulfur and phosphorus concentrations appear significantly reduced by 40% for sulfur and from 60% up to 80% for phosphorous. The concentration of nitrogen is reduced by 45%. At the same time, the calcium concentration is significantly increased and is now more than 60% of the treated material ash. Both raw and treated material ash is thermally treated in a high temperature oven starting from 600 C. followed by 50 C. steps. Table 2 shows the results of thermal treatment. It is clear that the ash of the treated material appears to have significantly increased thermal resistance while the ash melting point is increased to 1450 C., from 850 C. in case of raw material.

[0040] Then both the untreated and the treated material are used in fast pyrolysis tests (t=2 sec) at 600 C. These tests showed that the material conversion into gaseous and liquid products was increased from 80% to 93% at 600 C. after pretreatment. At the same time, although SO.sub.2 was produced in the final gaseous and liquid products during pyrolysis of the raw material, there was no presence of SO.sub.2 in case of the treated material. Additionally, the production of liquid hydrocarbons appears to be decreased by more than 85% in case of the treated sample while the primary end product is a gas mixture rich in H.sub.2, CO, CH.sub.4, and other hydrocarbons.

EXAMPLE 3

[0041] Coal (HSMc) from a US Mine is treated at elevated pressure using the reactor shown in FIG. 1. Since this material contains a large proportion of silicon in the ash, its pretreatment is focused in the first stage on trying to remove the silicon from the ash. In order to achieve that, the sample is treated in the first stage using sodium hydroxide in the first compartment of the pressurized reactor. The applied conditions are the following: Temperature 165 C., pressure 10-20 atm, solid/liquid ratio 35% w/w dry basis, leaching time 19 minutes, solvent concentration 3.8% w/w, material particle size <1 mm. After the first step of pretreatment the sample is moved to the second pressurized compartment where it is treated in the second step aiming at the removal of alkali metals, phosphorus, chlorine, sulfur, as well as the deactivation of components remaining in the material structure after the end of the process by means of appropriate salts so that they will be no longer a problem for the further thermochemical treatment of the treated material. The applied conditions are the following: Temperature 195 C., pressure 18-20 atm, solid/liquid ratio 35% w/w dry basis, leaching time 20 minutes, solvent concentration 4% w/w and calcium chloride as solvent. After the pretreatment, the sample is dried at 50 C. The ash content of the final treated material appears to be reduced by more than 35%, the silicon concentration appears to be reduced by 70%, while the concentrations of chlorine and active alkali metals are practically zero. The sulfur concentration appears to be significantly reduced by 50-70%, nitrogen concentration is reduced by 55%, while the concentration of heavy metals such as Hg, Pb, Ni, Cd, As, etc. appears to be reduced by 60-95%. At the same time, the calcium concentration is significantly increased and is now more than 50% of the treated material ash. Both raw and treated material ash is thermally treated in a high temperature oven starting from 800 C. followed by 50 C. steps. Table 2 shows the results of thermal treatment. It is clear that the ash of the treated material appears to have significantly increased thermal resistance while the ash melting point is increased to 1450 C., from 1300 C. in case of raw material.

[0042] Then both the untreated and the treated material are used in fast pyrolysis tests (t=2 sec) at 600 C. and 800 C. These tests showed that the material conversion into gaseous and liquid products was increased from 41 to 75% at 600 C. and from 70 to 85% at 800 C. after pretreatment. At the same time, although SO.sub.2 was produced in the final gaseous and liquid products during pyrolysis of the raw material, there was 90% reduction in the presence of SO.sub.2 in case of the treated material. Additionally, the production of liquid hydrocarbons appears to be decreased by more than 80% in case of the treated sample while the primary end product is a gas mixture rich in H.sub.2, CO, CH.sub.4, and other hydrocarbons.

EXAMPLE 4

[0043] Coal (EBWM) from a US Mine is treated at elevated pressure using the reactor shown in FIG. 1. Since this material contains a large proportion of silicon in the ash, its pretreatment is focused in the first stage on trying to remove the silicon from the ash. In order to achieve that, the sample is treated in the first stage using sodium hydroxide in the first compartment of the pressurized reactor. The applied conditions are the following: Temperature 185 C., pressure 15-20 atm, solid/liquid ratio 28% w/w dry basis, leaching time 15 minutes, solvent concentration 3% w/w, material particle size <1 mm. After the first step of pretreatment the sample is moved to the second pressurized compartment where it is treated in the second step aiming at the removal of alkali metals, phosphorus, chlorine, sulfur, as well as the deactivation of components remaining in the material structure after the end of the process by means of appropriate salts so that they will be no longer a problem for the further thermochemical treatment of the treated material. The applied conditions are the following: Temperature 195 C., pressure 18-20 atm, solid/liquid ratio 28% w/w dry basis, leaching time 15 minutes, solvent concentration 2.5% w/w and calcium nitrate/calcium chloride ratio: 50/50 as solvent. After the pretreatment, the sample is dried at 50 C. The ash content of the final treated material appears to be reduced by more than 40%, the silicon concentration appears to be reduced by 80%, while the concentrations of chlorine and active alkali metals are practically zero. The sulfur concentration appears to be significantly reduced by 60-70%, while the concentration of heavy metals such as Hg, Pb, Ni, Cd, As, etc. appears to be reduced by 60-98%. At the same time, the calcium concentration is significantly increased and is now more than 50% of the treated material ash. Both raw and treated material ash is thermally treated in a high temperature oven starting from 800 C. followed by 50 C. steps. Table 2 shows the results of thermal treatment. It is clear that the ash of the treated material appears to have significantly increased thermal resistance while the ash melting point is increased to 1450 C., from 1300 C. in case of raw material.

[0044] Then both the untreated and the treated material are used in fast pyrolysis tests (t=2 sec) at 600 C. and 800 C. These tests showed that the material conversion into gaseous and liquid products was increased from 48 to 73% at 600 C. and from 65 to 80% at 800 C. after pretreatment. At the same time, although SO.sub.2 was produced in the final gaseous and liquid products during pyrolysis of the raw material, there was 92% reduction in the presence of SO.sub.2 in case of the treated material. Additionally, the production of liquid hydrocarbons appears to be decreased by more than 80% in case of the treated sample while the primary end product is a gas mixture rich in H.sub.2, CO, CH.sub.4, and other hydrocarbons.

EXAMPLE 5

[0045] Used car tires are treated at elevated pressure using the reactor shown in FIG. 1 utilizing calcium nitrate as solvent. Since this material does not contain a large proportion of silicon in the ash, the pretreatment is focused on the removal of alkali metals, phosphorus, chlorine, sulfur, as well as the deactivation of components remaining in the material structure after the end of the process by means of appropriate salts so that they will be no longer a problem for the further thermochemical treatment of the treated material. The applied conditions are the following: temperature 147 C., pressure 5-7 atm, solid/liquid ratio 20% w/w dry basis, leaching time 7.5 minutes, solvent concentration 3% w/w, material particle size <3 mm. After the pretreatment, the sample is dried at 50 C. After the pretreatment, 2.1% weight increase of the treated dry material is noticed because of the calcium absorption by the material. Sample analysis by electron microscopy SEM-EDX confirms the significantly increased calcium concentration in the sample as well as the absence of chlorine and alkali metals while the sulfur concentration appears to be significantly reduced by 17-35%. Then both the untreated and the treated material are used in fast pyrolysis tests (t=2 sec) at 600 C. and 800 C. These tests showed that the material conversion into gaseous and liquid products was increased from 37 to 75% at 600 C. and from 73 to 93.5% at 800 C. after pretreatment. At the same time, although SO.sub.2 was produced in the final gaseous and liquid products during pyrolysis of the raw material, there was no presence of SO.sub.2 in case of the treated material. Additionally, the production of liquid hydrocarbons appears to be decreased by more than 80% in case of the treated sample while the primary end product is a gas mixture rich in H.sub.2, CO, CH.sub.4, and other hydrocarbons.

TABLE-US-00001 TABLE 1 Ash analysis and characterization of biomass, coal Pretreated Pretreated Pretreated Pretreated Analysis Wheat Wheat Olive Olive Coal Coal Coal Coal (%) Straw Straw Kernel Kernel (HSMc) (HSMc) (EBWM) (EBWM) Ash 8.34 5.6 4.3 2.5 8.58 6.4 15.12 10.3 Content *K.sub.2O 1.31 0.2 1.22 0.16 0.14 0.03 0.45 0.04 *Na.sub.2O 0.56 0.09 0.03 0.02 0.07 0.02 0.12 0.019 SiO.sub.2 5 1 0.57 0.07 3.38 0.83 6.8 0.78 CaO 0.39 2.9 0.97 1.7 0.23 3.6 0.74 5.7 P.sub.2O.sub.5 0.35 0.05 0.2 0.05 nd nd nd nd SO.sub.3 0.13 0.02 0.05 0.03 0.35 0.1 0.73 0.21 Cl 0.13 0.00 0.12 0.00 0.047 0.00 0.15 0.00 Analysis (ppm) Cd nd nd nd Nd 0.38 0.039 1.2 0.12 As nd nd nd Nd 5.7 0.95 5.98 0.32 Ni nd nd nd Nd 31.9 2.15 33.86 1.55 Hg nd nd nd Nd 0.2 0.04 0.17 0.04 Zn nd nd nd Nd 34.18 4.76 55.78 2.59 Pb nd nd nd Nd 155.7 1.32 9.96 0.71 Cr nd nd nd Nd 11.77 4.01 27.89 2.18 Cu nd nd nd Nd 81.66 2.88 41.83 1.47 nd: not detected, *non reactive forms in the case of the pretreated sample

TABLE-US-00002 TABLE 2 Thermal behavior of ash from raw and pretreated biomass types and coal Ash samples Melting point ( C.) Raw olive kernel 850 Pretreated olive kernel 1450 Raw wheat straw 800 Pretreated wheat straw 1550 Raw coal (HSMc) 1300 Pretreated coal (HSMc) 1450 Raw coal (EBWM) 1300 Pretreated coal (EBWM) 1450