Synthesis gas preparation process

Abstract

The invention relates to the technical field of synthesis gas, in particular to a process for preparing synthesis gas. According to the synthesis gas preparation process provided by the invention, the slurry containing lignin with a certain concentration is used as a gasification raw material for the first time, and the problem that high-concentration slurry cannot be prepared by conventional biomass gasification is solved by carrying out three-element separation, modification and utilization on biomass, so that the biomass solid content in the gasification slurry raw material is increased, and the production cost is reduced. Meanwhile, the technical prejudice that lignin usually needs to be separated in a conventional technology for preparing synthesis gas from biomass through slurry is abandoned, the characteristics that lignin in the slurry is low in oxygen content and high in heat value are fully utilized, the process cost of synthesis gas preparation is reduced, the volume fraction of the prepared effective synthesis gas (carbon monoxide and hydrogen) is larger than or equal to 63 vol%, and the method is suitable for industrial production. In the synthesis gas, the content of carbon monoxide is greater than 30 vol%, the content of carbon dioxide is 18-32 vol%, and the content of hydrogen is 32-41 vol%.

Description

Technical Field

[0001] The present invention relates to the technical field of syngas, and particularly relates to a process for preparing syngas. Background Art

[0002] Facing increasingly severe global problems such as climate change, environmental pollution, and energy shortage, promoting the energy consumption structure transformation from being dominated by fossil energy to being led by clean and low-carbon energy has become the consensus of mankind. At the same time, reducing the carbon dioxide emissions during the production process has become an important means for green chemical industry to save energy and reduce carbon.

[0003] As a renewable energy source, biomass is also a main force in the energy transformation. On the one hand, some biomass itself can absorb carbon dioxide in the atmosphere. On the other hand, it can be widely used in green chemical production to produce a series of green downstream products. From the perspective of biomass utilization, biomass gasification to prepare syngas is a common production process, including fluidized bed gasification process and entrained flow gasification process.

[0004] For the fluidized bed gasification process, since the gasification temperature is set above 1000°C, it is easy to cause incomplete pyrolysis of biomass, resulting in a certain amount of methane, which in turn affects the synthesis of subsequent downstream organic products from syngas. For the entrained flow gasification process, due to the high gasification temperature of the entrained flow bed, the volatile matter will be fully pyrolyzed, with high thermal efficiency and carbon conversion rate. No methane is produced during the production process, and no tar is produced either. Therefore, it is widely used in the production of syngas by biomass gasification.

[0005] In the prior art, patent document CN115125036A discloses a method and system for preparing methanol from biomass. This method uses biomass as a raw material and conducts hydrothermal treatment on it. Since a large amount of hemicellulose degrades during the hydrothermal process, the cell wall structure of biomass is damaged, causing lignin to migrate to the cell wall surface. Then, the water-soluble lignin is removed with water, and part of the insoluble lignin is released into the liquid phase. Finally, after solid-liquid separation, the hydrothermal biomass is used as the raw material for the subsequent gasification process for gasification. It can be seen that in this process, the key step is to completely remove lignin by hydrothermal treatment, so that the raw material hydrothermal biomass finally entering the subsequent gasification process contains as little lignin as possible, including water-soluble lignin and insoluble lignin. This is also the consensus in the field regarding the use of biomass in the gasification process. It is precisely because of the above technical prejudice that the content of syngas prepared during the gasification process using biomass is relatively low. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention lies in the problem that the content of syngas prepared by the biomass gasification process in the prior art is relatively low. Furthermore, a process for preparing syngas is provided, which on the one hand increases the content of syngas, and on the other hand makes full use of lignin in biomass, and the use of biomass containing lignin is more abundant.

[0007] To this end, the present invention provides a process for preparing syngas, wherein the gasification raw material is a slurry containing biomass lignin, and the content of lignin is greater than or equal to 3 wt%.

[0008] Preferably, the content of lignin is greater than or equal to 8 wt%.

[0009] More preferably, the content of lignin is 8 - 60 wt%.

[0010] In some embodiments, the slurry includes a liquid product separated by heating a biomass treatment liquid. Preferably, the components in the treatment liquid include at least one of metal inorganic salts and metal hydroxides. More preferably, the slurry is formed after concentration of the liquid product.

[0011] In some embodiments, the content of solids in the slurry is greater than or equal to 10 wt%. Preferably, the content of solids in the slurry is 10 - 60 wt%, and the content of solids in the slurry is 50 - 60 wt%.

[0012] In some embodiments, the viscosity of the slurry is less than or equal to 2000 mPa·s. Preferably, the viscosity of the slurry is less than or equal to 1200 mPa·s. More preferably, the viscosity of the slurry is 700 - 1200 mPa·s.

[0013] In some embodiments, the dry - basis ash content in the slurry is less than or equal to 45 wt%. Preferably, the dry - basis ash content in the slurry is less than or equal to 40 wt%. More preferably, the dry - basis ash content in the slurry is less than or equal to 25 wt%.

[0014] In some embodiments, the lignin accounts for 9 - 90 wt% of the solids.

[0015] In some embodiments, the slurry further includes a carbon - containing fuel. Preferably, the carbon - containing fuel includes coal, and the proportion of coal in the solids in the slurry is 5 wt - 95 wt%.

[0016] Preferably, the carbon - containing fuel includes liquid waste or gaseous waste soluble in liquid, and the proportion of liquid waste or gaseous waste soluble in liquid in the slurry is 0.5 wt - 30 wt%.

[0017] In some of these embodiments, the biomass includes at least one of wood, herbaceous plants, agricultural waste, agricultural residues, agricultural crops, livestock and poultry waste, or industrial biomass processing waste.

[0018] In some of these embodiments, the particle size of the biomass is less than or equal to 5 mesh. Preferably, the particle size of the biomass is less than or equal to 4000 μm, and more preferably less than or equal to 850 μm.

[0019] In some of these embodiments, the water content of the biomass is 10-70 wt%, preferably 10-50 wt%.

[0020] In some of these embodiments, the biomass includes at least one of straw, corn cobs, wood chips, sugarcane, bagasse, human and animal feces.

[0021] In some of these embodiments, the metal inorganic salt includes at least one of metal sulfide salts, metal sulfite salts, metal bisulfite salts, and metal nitrate salts.

[0022] In some of these embodiments, the metal sulfide salt includes at least one of sodium sulfide, potassium sulfide, and calcium sulfide.

[0023] Preferably, the metal sulfite salt includes at least one of sodium sulfite, potassium sulfite, and calcium sulfite.

[0024] Preferably, the metal hydroxide is at least one of sodium hydroxide, potassium hydroxide, and calcium hydroxide.

[0025] Preferably, the metal bisulfite salt includes calcium bisulfite.

[0026] Preferably, the metal nitrate salt includes calcium nitrate.

[0027] Optionally, the treatment liquid is prepared by passing an acidic gas into a metal hydroxide solution. Optionally, the acidic gas includes acidic waste gas generated during the production process.

[0028] In some of these embodiments, the acidic waste gas is at least one of hydrogen sulfide or sulfur dioxide.

[0029] In some of these embodiments, the mass ratio of the metal sulfide salt to the metal hydroxide in the treatment liquid is 1:(2-4), and the pH value of the treatment liquid is 13-14.

[0030] In some of these embodiments, the mass ratio of the metal sulfite salt to the metal hydroxide in the treatment liquid is 1:(0.4-2), and the pH value of the treatment liquid is 10-12.

[0031] In some of these embodiments, the concentration of metal bisulfite in the treatment liquid is 8-10 wt%.

[0032] In some of these embodiments, the temperature for heating the biomass and the treatment liquid is 105-200 °C, and the heating time is 30 min-5 h.

[0033] In some of these embodiments, the ratio of the biomass to the treatment liquid is 1:(1-10), with the unit being g:mL.

[0034] In some of these embodiments, the ratio of the biomass to the treatment liquid is 1:(1-6), with the unit being g:mL.

[0035] In some of these embodiments, sulfur dioxide is injected into the calcium hydroxide solution to form a treatment liquid, and the pH value of the treatment liquid is 4.5-5.5.

[0036] In some of these embodiments, the temperature for heating the biomass and the treatment liquid is 120-160 °C, the heating time is 45 min-3 h, and the ratio of the biomass to the treatment liquid is 1:(4-6), with the unit being g:mL.

[0037] In some of these embodiments, the slurry further includes introducing an acidic gas into the liquid product to adjust the pH value of the liquid product to 9-11, separating to obtain a precipitate, and formulating the precipitate into a slurry. The acidic gas includes hydrogen sulfide.

[0038] In some of these embodiments, the liquid after separating the precipitate is recycled.

[0039] In some of these embodiments, the gasification temperature for gasifying the gasification raw material is 850-1500 °C. Preferably, the gasification temperature is 1050-1300 °C; the gasification pressure for gasifying the gasification raw material is 0.05-8.0 MPa. Preferably, the gasification pressure is 2.5-6.9 MPa; the gasification residence time for gasifying the gasification raw material is 1 s-5 s.

[0040] In some of these embodiments, the gasification of the gasification raw material further includes a desulfurization and purification step.

[0041] In some of these embodiments, the gasification raw material is gasified by a entrained flow bed.

[0042] The technical solution of the present invention has the following advantages:

[0043] 1. A syngas preparation process provided by the present invention firstly proposes to use a slurry containing a certain concentration of lignin as a gasification raw material, solves the problem that conventional biomass gasification cannot produce a high-concentration slurry, increases the biomass solid content in the gasification slurry raw material, and at the same time abandons the technical prejudice that lignin usually needs to be separated in the technology of preparing syngas from conventional biomass through slurry. It makes full use of the characteristics of low oxygen content and high calorific value of lignin in the slurry. On the one hand, it reduces the process cost of syngas preparation. On the other hand, the volume fraction of the effective syngas (carbon monoxide and hydrogen) prepared is greater than or equal to 63 vol%, the carbon monoxide content in the syngas is greater than 30 vol%, the carbon dioxide content is 18 - 32 vol%, and the hydrogen content is 32 - 41 vol%.

[0044] 2. The present invention provides a syngas preparation process. The slurry includes the liquid product separated by heating and treating the biomass with a treating liquid, and the treating liquid includes at least one of metal inorganic salts and metal hydroxides. The present invention uses the liquid product separated by heating and treating the biomass with the treating liquid as the gasification raw material. By heating and treating the biomass in the treating liquid, cellulose and hemicellulose can be effectively separated to obtain a slurry containing lignin. Through the separation, modification and utilization of the three components of biomass, on the one hand, the residual liquid after heat treatment of biomass can be fully recycled, and on the other hand, the syngas produced by using the recycled residual liquid has a high yield, and the contents of methane, carbon dioxide and other impurities in the syngas are low, greatly improving the carbon reduction effect of biomass in the preparation of green chemical products.

[0045] 3. The present invention provides a syngas preparation process. An acidic substance is introduced into the liquid product to adjust the pH value to 9 - 11, and a precipitate is separated. The precipitate is formulated into a slurry, and the solid content in the slurry is greater than or equal to 10 wt%. The present invention uses the acidic substance to lower the pH of the liquid product to obtain a precipitate mainly composed of lignin, which can effectively control the lignin content in the slurry and avoid the instability of the syngas component content caused by uncontrollable slurry concentration. At the same time, the present invention limits the solid content in the slurry to be greater than or equal to 10 wt%, which can not only reduce the energy consumption and cost of preparing the slurry, but also increase the yield of the prepared syngas.

[0046] 4. A syngas preparation process provided by the present invention recycles the liquid after separating the precipitate. By introducing an acidic substance into the liquid product, the precipitate obtained after separation is used as the raw material for preparing the slurry, and the filtrate obtained after separation can be used as the alkaline solution in the preparation process of the liquid product, realizing repeated use, reducing waste and lowering costs. Description of the Drawings

[0047] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0048] Figure 1 It is a process flow diagram of a specific example of the production method of syngas in Embodiment 1 of the present invention;

[0049] Figure 2 It is a process flow diagram of a specific example of the production method of syngas in Embodiment 2 of the present invention;

[0050] Figure 3 It is a process flow diagram of a specific example of the production method of syngas in Embodiment 8 of the present invention;

[0051] Figure 4 It is a process flow diagram of a specific example of the production method of syngas in Embodiment 9 of the present invention;

[0052] Figure 5 It is a process flow diagram of a specific example of the production method of syngas in Embodiment 15 of the present invention;

[0053] Figure 6 It is a process flow diagram of a specific example of the production method of syngas in Embodiment 16 of the present invention;

[0054] Figure 7 It is a process flow diagram of a specific example of the production method of syngas in Embodiment 22 of the present invention;

[0055] Figure 8 It is a process flow diagram of a specific example of the production method of syngas in Embodiment 23 of the present invention. Specific Embodiments

[0056] The following embodiments are provided to better further understand the present invention, which are not limited to the best embodiments, and do not limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior art features falls within the protection scope of the present invention.

[0057] For those not indicating specific experimental steps or conditions in the embodiments, the operations or conditions of the conventional experimental steps described in the literature in this field can be followed. For the reagents or instruments not indicating the manufacturers, they are all conventional reagent products that can be obtained through commercial purchase.

[0058] Embodiment 1

[0059] See Figure 1 As shown, this embodiment provides a method for producing syngas, and the specific steps and parameters are as follows:

[0060] (1) Pass hydrogen sulfide into sodium hydroxide solution to prepare an alkaline solution (treatment solution) with a mass ratio of sodium sulfide to sodium hydroxide of 1:2, and the pH value of the alkaline solution is 13;

[0061] (2) Mix straw with an average particle size of 15 mesh and a water content of 20 wt% with the alkaline solution prepared in step (1). Among them, the ratio of straw to alkaline solution is 1:3, with the unit of g:mL. Cook the mixture of straw and alkaline solution at 160 °C for 3 h;

[0062] (3) Filter the mixture after cooking in step (2). The filtered liquid product is biomass for generating syngas, and the solid product is cellulose. Among them, the solid product cellulose can be dissolved and enzymatically hydrolyzed to produce pentose or hexose, and then fermented to obtain bioethanol, or it can be used for papermaking or producing other cellulose products;

[0063] (4) Pass hydrogen sulfide into the liquid product obtained in step (3) and adjust the pH value to 9 to obtain a precipitate and residual alkali solution. The residual alkali solution can be used as the alkaline solution in step (2), and the precipitate is a slurry raw material mainly composed of lignin;

[0064] (5) Mix the precipitate obtained in step (4) with water to prepare a slurry. The viscosity of the slurry is 1173 mPa·s, the content of solids in the slurry is 60 wt%, the lignin in the slurry accounts for 98.2 wt% of the solids, and the dry basis ash content of the slurry is 23.27 wt%. In a entrained flow bed, gasify the slurry at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. Desulfurize and purify the gasified product to obtain syngas and by-product hydrogen sulfide;

[0065] The by-product hydrogen sulfide can be used in the preparation of the alkaline solution in step (1) or for adjusting the pH of the liquid product in step (4). The waste heat generated during the gasification process can be used in the cooking process of step (2).

[0066] Example 2

[0067] Please refer to Figure 2As shown, this embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 1, except that in step (5), the precipitate obtained in step (4), water, and coal are mixed to prepare a slurry. The viscosity of the slurry is 1062 mPa·s, the content of solids in the slurry is 60 wt%, among which lignin in the slurry accounts for 9.82 wt% of the solids, coal accounts for 90 wt% of the solids, the dry basis ash content of the slurry is 8.48 wt%. In a entrained flow bed, the slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. The gasified product is subjected to desulfurization and purification treatment to obtain syngas and by-product hydrogen sulfide.

[0068] Embodiment 3

[0069] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 1, except that in step (5), the precipitate obtained in step (4), water, and coal are mixed to prepare a slurry. The viscosity of the slurry is 1075 mPa·s, the content of solids in the slurry is 60 wt%, among which lignin in the slurry accounts for 19.64 wt% of the solids, coal accounts for 80 wt% of the solids, the dry basis ash content of the slurry is 10.13 wt%. In a entrained flow bed, the slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. The gasified product is subjected to desulfurization and purification treatment to obtain syngas and by-product hydrogen sulfide.

[0070] Embodiment 4

[0071] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 1, except that in step (5), the precipitate obtained in step (4), water, and coal are mixed to prepare a slurry. The viscosity of the slurry is 1099 mPa·s, the content of solids in the slurry is 60 wt%, among which lignin in the slurry accounts for 39.28 wt% of the solids, coal accounts for 60 wt% of the solids, the dry basis ash content of the slurry is 13.41 wt%. In a entrained flow bed, the slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. The gasified product is subjected to desulfurization and purification treatment to obtain syngas and by-product hydrogen sulfide.

[0072] Embodiment 5

[0073] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 1, except that in step (5), the precipitate obtained in step (4), water and coal are mixed to prepare a slurry. The viscosity of the slurry is 1124 mPa·s, the content of solids in the slurry is 60 wt%, wherein lignin in the slurry accounts for 58.92 wt% of the solids, coal accounts for 40 wt% of the solids, the dry basis ash content of the slurry is 16.70 wt%. In a entrained flow bed, the slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa, and the gasification time is 2 s. The gasified product is subjected to desulfurization and purification treatment to obtain syngas and by-product hydrogen sulfide.

[0074] Embodiment 6

[0075] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 1, except that in step (5), the precipitate obtained in step (4), water and coal are mixed to prepare a slurry. The viscosity of the slurry is 1148 mPa·s, the content of solids in the slurry is 60 wt%, wherein lignin in the slurry accounts for 78.56 wt% of the solids, coal accounts for 20 wt% of the solids, the dry basis ash content of the slurry is 19.98 wt%. In a entrained flow bed, the slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa, and the gasification time is 2 s. The gasified product is subjected to desulfurization and purification treatment to obtain syngas and by-product hydrogen sulfide.

[0076] Embodiment 7

[0077] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 1, except that in step (5), the precipitate obtained in step (4), water and coal are mixed to prepare a slurry. The viscosity of the slurry is 1161 mPa·s, the content of solids in the slurry is 60%, wherein lignin in the slurry accounts for 88.38 wt% of the solids, coal accounts for 10 wt% of the solids, the dry basis ash content of the slurry is 21.63 wt%. In a entrained flow bed, the slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa, and the gasification time is 2 s. The gasified product is subjected to desulfurization and purification treatment to obtain syngas and by-product hydrogen sulfide.

[0078] Embodiment 8

[0079] See Figure 3 shown, this embodiment provides a method for producing syngas. The specific steps and parameters are as follows:

[0080] (1) Hydrogen sulfide is introduced into a sodium hydroxide solution to prepare an alkaline solution with a mass ratio of sodium sulfide to sodium hydroxide of 1:2, and the pH value of the alkaline solution is 13;

[0081] (2) Mix the straw with an average particle size of 15 mesh and a water content of 20% with the alkaline solution prepared in step (1). The ratio of straw to the alkaline solution is 1:3, in units of g:mL. Cook the mixture of straw and the alkaline solution at 160 °C for 3 h;

[0082] (3) Filter the mixture after cooking in step (2). The liquid product obtained after filtration is the biomass for generating syngas, and the solid product is cellulose. The solid product cellulose can be hydrolyzed by enzymes to obtain pentose or hexose, and then bioethanol can be obtained through fermentation. It can also be used for papermaking or producing other cellulose products;

[0083] (4) Concentrate the liquid product obtained in step (3) to obtain a slurry. The viscosity of the slurry is 1098 mPa·s, the content of solids in the slurry is 60 wt%, the lignin in the slurry accounts for 93.4 wt% of the solids, and the dry basis ash content is 32.04 wt%. In a entrained flow bed, gasify the slurry at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. Desulfurize and purify the gasified product to obtain syngas and by-product hydrogen sulfide;

[0084] The by-product hydrogen sulfide can be used in the preparation of the alkaline solution in step (1), and the waste heat generated during the gasification process can be used in the cooking process of step (2).

[0085] Example 9

[0086] Please refer to Figure 4 As shown, this example provides a method for producing syngas. The specific steps and parameters are the same as those in Example 8, except that in step (4), the liquid product obtained in step (3) is concentrated and mixed with coal to form a slurry. The viscosity of the slurry is 1055 mPa·s, the content of solids in the slurry is 60 wt%, the lignin in the slurry accounts for 9.34 wt% of the solids, the coal accounts for 90 wt% of the solids, and the dry basis ash content is 9.36 wt%. In a entrained flow bed, gasify the coal-water slurry at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. Desulfurize and purify the gasified product to obtain syngas and by-product hydrogen sulfide.

[0087] Example 10

[0088] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 8, except that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. The viscosity of the slurry is 1060 mPa·s, the content of solids in the slurry is 60 wt%, among which lignin in the slurry accounts for 18.68 wt% of the solids, coal accounts for 80 wt% of the solids, and the dry basis ash content is 11.88 wt%. In a entrained flow bed, the water-coal slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. The gasified product is subjected to desulfurization and purification treatment to obtain syngas and by-product hydrogen sulfide.

[0089] Example 11

[0090] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 8, except that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. The viscosity of the slurry is 1069 mPa·s, the content of solids in the slurry is 60 wt%, among which lignin in the slurry accounts for 37.36 wt% of the solids, coal accounts for 60 wt% of the solids, and the dry basis ash content is 16.92 wt%. In a entrained flow bed, the water-coal slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. The gasified product is subjected to desulfurization and purification treatment to obtain syngas and by-product hydrogen sulfide.

[0091] Example 12

[0092] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 8, except that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. The viscosity of the slurry is 1079 mPa·s, the content of solids in the slurry is 60 wt%, among which lignin in the slurry accounts for 56.04 wt% of the solids, coal accounts for 40 wt% of the solids, and the dry basis ash content is 21.96 wt%. In a entrained flow bed, the water-coal slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. The gasified product is subjected to desulfurization and purification treatment to obtain syngas and by-product hydrogen sulfide.

[0093] Example 13

[0094] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 8, except that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. The viscosity of the slurry is 1088 mPa·s, the content of solids in the slurry is 60 wt%, where lignin in the slurry accounts for 74.72 wt% of the solids, coal accounts for 20 wt% of the solids, and the dry basis ash content is 27 wt%. In a entrained flow bed, the water-coal slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. The gasified product is subjected to desulfurization and purification treatment to obtain syngas and by-product hydrogen sulfide.

[0095] Example 14

[0096] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 8, except that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. The viscosity of the slurry is 1093 mPa·s, the content of solids in the slurry is 60 wt%, where lignin in the slurry accounts for 84.06 wt% of the solids, coal accounts for 10 wt% of the solids, and the dry basis ash content is 29.52 wt%. In a entrained flow bed, the water-coal slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. The gasified product is subjected to desulfurization and purification treatment to obtain syngas and by-product hydrogen sulfide.

[0097] Example 15

[0098] See Figure 5 As shown, this embodiment provides a method for producing syngas. The specific steps and parameters are as follows:

[0099] (1) Catalytically oxidize hydrogen sulfide to obtain sulfur dioxide, and introduce the sulfur dioxide into a sodium hydroxide solution to prepare an alkaline solution with a mass ratio of sodium sulfite to sodium hydroxide of 1:2, and the pH value of the alkaline solution is 9;

[0100] (2) Mix straw with a particle size of 15 mesh and a water content of 20% with the alkaline solution prepared in step (1). The ratio of straw to the alkaline solution is 1:3, in units of g:mL. The mixture of straw and the alkaline solution is cooked at 160 °C for 3 h;

[0101] (3) Filter the mixture after cooking in step (2). The filtered liquid product can be used as biomass for generating syngas, or can be separated and purified to obtain sulfonated lignin and other products. The solid product is cellulose. The solid product cellulose can be dissolved and enzymatically hydrolyzed to produce pentose or hexose, and then fermented to obtain bioethanol, or can be used for papermaking or producing other cellulose products;

[0102] (4) Concentrate the liquid product obtained in step (3) to form a slurry. The viscosity of the slurry is 726 mPa·s, the solid content in the slurry is 60 wt%, the lignin in the slurry accounts for 95.3 wt% of the solids, the dry basis ash content is 18.46 wt%. In a entrained flow bed, gasify the slurry at a temperature of 1300 °C and a pressure of 6.9 MPa for 1 s. Purify the gasified product to obtain syngas and by-product hydrogen sulfide;

[0103] The by-product hydrogen sulfide can be used in step (1) to produce sulfur dioxide through catalytic oxidation, for the preparation of alkaline solutions or for the preparation of sulfur. The waste heat generated during the gasification process can be used in the cooking process of step (2).

[0104] Example 16

[0105] Please refer to Figure 6 As shown, this example provides a method for producing syngas. The specific steps and parameters are the same as those in Example 15, except that in step (4), the liquid product obtained in step (3) is concentrated and mixed with coal to form a slurry. The viscosity of the slurry is 1018 mPa·s, the solid content in the slurry is 60 wt%, the lignin in the slurry accounts for 9.53 wt% of the solids, the coal accounts for 90 wt% of the solids, the dry basis ash content is 8 wt%. In a entrained flow bed, gasify the coal-water slurry at a temperature of 1300 °C and a pressure of 6.9 MPa for 1 s. Purify the gasified product to obtain syngas and by-product hydrogen sulfide.

[0106] Example 17

[0107] This example provides a method for producing syngas. The specific steps and parameters are the same as those in Example 15, except that in step (4), the liquid product obtained in step (3) is concentrated and mixed with coal to form a slurry. The viscosity of the slurry is 985 mPa·s, the solid content in the slurry is 60 wt%, the lignin in the slurry accounts for 19.06 wt% of the solids, the coal accounts for 80 wt% of the solids, the dry basis ash content is 9.16 wt%. In a entrained flow bed, gasify the coal-water slurry at a temperature of 1300 °C and a pressure of 6.9 MPa for 1 s. Purify the gasified product to obtain syngas and by-product hydrogen sulfide.

[0108] Example 18

[0109] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 15, except that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. The viscosity of the slurry is 920 mPa·s, the content of solids in the slurry is 60 wt%, where lignin in the slurry accounts for 38.12 wt% of the solids, the coal is 60 wt% of the solids, and the dry basis ash content is 11.49 wt%. In a entrained flow bed, the water-coal slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 1 s, and the gasified product is purified to obtain syngas and by-product hydrogen sulfide.

[0110] Embodiment 19

[0111] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 15, except that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. The viscosity of the slurry is 856 mPa·s, the content of solids in the slurry is 60 wt%, where lignin in the slurry accounts for 57.18 wt% of the solids, the coal is 40 wt% of the solids, and the dry basis ash content is 13.81 wt%. In a entrained flow bed, the water-coal slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 1 s, and the gasified product is purified to obtain syngas and by-product hydrogen sulfide.

[0112] Embodiment 20

[0113] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 15, except that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. The viscosity of the slurry is 791 mPa·s, the content of solids in the slurry is 60 wt%, where lignin in the slurry accounts for 76.24 wt% of the solids, the coal is 20 wt% of the solids, and the dry basis ash content is 16.14 wt%. In a entrained flow bed, the water-coal slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 1 s, and the gasified product is purified to obtain syngas and by-product hydrogen sulfide.

[0114] Embodiment 21

[0115] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 15, except that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. The viscosity of the slurry is 758 mPa·s, the content of solids in the slurry is 60 wt%, where lignin in the slurry accounts for 85.77 wt% of the solids, coal accounts for 10 wt% of the solids, and the dry basis ash content is 17.30 wt%. In a entrained flow bed, the coal-water slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 1 s, and the gasified product is purified to obtain syngas and by-product hydrogen sulfide.

[0116] Embodiment 22

[0117] See Figure 7 As shown, this embodiment provides a method for producing syngas. The specific steps and parameters are as follows:

[0118] (1) Catalytically oxidize hydrogen sulfide to obtain sulfur dioxide, and introduce the sulfur dioxide into calcium hydroxide solution to obtain a treatment solution. The pH value of the treatment solution is 5, and the mass fraction of calcium bisulfite in the treatment solution is 8%;

[0119] (2) Mix straw with a particle size of 15 mesh and a water content of 20% with the treatment solution prepared in step (1). The ratio of straw to the treatment solution is 1:5, in units of g:mL. The mixture of straw and the treatment solution is cooked at 160 °C for 3 h;

[0120] (3) Filter the mixture after cooking in step (2). The filtered liquid product can be used as biomass for generating syngas, or can be separated and purified to obtain sulfonated lignin and other products. The solid product is cellulose. The solid product cellulose can be dissolved and enzymatically hydrolyzed to produce pentose or hexose, and then fermented to obtain bioethanol, or can be used for papermaking or producing other cellulose products;

[0121] (4) Concentrate the liquid product obtained in step (3) to form a slurry. The viscosity of the slurry is 931 mPa·s, the content of solids in the slurry is 60 wt%, lignin in the slurry accounts for 94.7 wt% of the solids, and the dry basis ash content is 41.78 wt%. In a entrained flow bed, the slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s, and the gasified product is purified to obtain syngas, by-product hydrogen sulfide and quicklime;

[0122] The by-product hydrogen sulfide can be used in step (1) to be catalytically oxidized to obtain sulfur dioxide, for the preparation of alkaline solutions or for the preparation of sulfur. The waste heat generated during the gasification process can be used for the cooking process in step (2).

[0123] Embodiment 23

[0124] Please refer to Figure 8 As shown, this embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 22. The difference is that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. Among them, the viscosity of the slurry is 1038 mPa·s, the content of solids in the slurry is 60 wt%, among which lignin in the slurry accounts for 9.47 wt% of the solids, coal is 90 wt% of the solids, and the dry basis ash content is 10.33 wt%. In a entrained flow bed, at a temperature of 1300 °C and a pressure of 6.9 MPa, the slurry is gasified for 2 s, and the gasified product is purified to obtain syngas, by-product hydrogen sulfide, and quicklime.

[0125] Embodiment 24

[0126] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 22. The difference is that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. Among them, the viscosity of the slurry is 1026 mPa·s, the content of solids in the slurry is 60 wt%, among which lignin in the slurry accounts for 18.94 wt% of the solids, coal is 80 wt% of the solids, and the dry basis ash content is 13.83 wt%. In a entrained flow bed, at a temperature of 1300 °C and a pressure of 6.9 MPa, the slurry is gasified for 2 s, and the gasified product is purified to obtain syngas, by-product hydrogen sulfide, and quicklime.

[0127] Embodiment 25

[0128] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 22. The difference is that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. Among them, the viscosity of the slurry is 1002 mPa·s, the content of solids in the slurry is 60 wt%, among which lignin in the slurry accounts for 37.88 wt% of the solids, coal is 60 wt% of the solids, and the dry basis ash content is 20.82%, in a entrained flow bed, at a temperature of 1300 °C and a pressure of 6.9 MPa, the slurry is gasified for 2 s, and the gasified product is purified to obtain syngas, by-product hydrogen sulfide, and quicklime.

[0129] Embodiment 26

[0130] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 22, except that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. The viscosity of the slurry is 979 mPa·s, the content of solids in the slurry is 60 wt%, among which lignin in the slurry accounts for 56.82 wt% of the solids, coal accounts for 40 wt% of the solids, and the dry basis ash content is 27.80 wt%. In a entrained flow bed, the slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. The gasified product is purified to obtain syngas, by-product hydrogen sulfide, and quicklime.

[0131] Embodiment 27

[0132] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 22, except that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. The viscosity of the slurry is 955 mPa·s, the content of solids in the slurry is 60 wt%, among which lignin in the slurry accounts for 75.76 wt% of the solids, coal accounts for 20 wt% of the solids, and the dry basis ash content is 34.79 wt%. In a entrained flow bed, the slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. The gasified product is purified to obtain syngas, by-product hydrogen sulfide, and quicklime.

[0133] Embodiment 28

[0134] This embodiment provides a method for producing syngas. The specific steps and parameters are the same as those in Embodiment 22, except that in step (4), the liquid product obtained in step (3) is concentrated and then mixed with coal to form a slurry. The viscosity of the slurry is 943 mPa·s, the content of solids in the slurry is 60 wt%, among which lignin in the slurry accounts for 85.23 wt% of the solids, coal accounts for 10 wt% of the solids, and the dry basis ash content is 38.29 wt%. In a entrained flow bed, the slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. The gasified product is purified to obtain syngas, by-product hydrogen sulfide, and quicklime.

[0135] Embodiment 29

[0136] This embodiment provides a method for producing syngas. The specific steps and parameters are as follows:

[0137] (1) Hydrogen sulfide is introduced into a sodium hydroxide solution to prepare an alkaline solution with a mass ratio of sodium sulfide to sodium hydroxide of 1:4, and the pH value of the alkaline solution is 13.5.

[0138] (2) Mix sawdust with a particle size of 15 mesh and a water content of 15% with the alkaline solution prepared in step (1). The ratio of sawdust to the alkaline solution is 1:6, with the unit being g:mL. Cook the mixture of straw and the alkaline solution at 105 °C for 5 h;

[0139] (3) Filter the mixture after cooking in step (2). The liquid product obtained after filtration is the biomass for generating syngas, and the solid product is cellulose. The solid product cellulose can be hydrolyzed by enzymes to obtain pentose or hexose, which can be fermented to obtain bioethanol after that, or can also be used for papermaking or producing other cellulose products;

[0140] (4) Pass hydrogen sulfide into the liquid product obtained in step (3) to adjust the pH value to 11, obtaining a precipitate and residual lye. The residual lye can be used as the alkaline solution in step (2), and the precipitate is a slurry raw material mainly composed of lignin;

[0141] (5) Prepare a slurry with the precipitate obtained in step (4). The viscosity of the slurry is 1068 mPa˙s, the solid content in the slurry is 50%, lignin in the slurry accounts for 14.78 wt% of the solids, coal accounts for 85 wt% of the solids, and the dry basis ash content is 9.30 wt%. In a entrained flow bed, gasify the slurry at a temperature of 1250 °C and a pressure of 8 MPa for 3 s. Purify the gasified product to obtain syngas and by-product hydrogen sulfide;

[0142] The by-product hydrogen sulfide can be used in the preparation of the alkaline solution in step (1), and the waste heat generated during the gasification process can be used in the cooking process of step (2).

[0143] Example 30

[0144] This example provides a method for producing syngas. The specific steps and parameters are as follows:

[0145] (1) Pass hydrogen sulfide into sodium hydroxide solution to prepare an alkaline solution with a mass ratio of sodium sulfide to sodium hydroxide of 1:4, and the pH value of the alkaline solution is 13.8;

[0146] (2) Mix corn cob with a particle size of 20 mesh and a water content of 15% with the alkaline solution prepared in step (1). The ratio of corn cob to the alkaline solution is 1:6, with the unit being g:mL. Cook the mixture of straw and the alkaline solution at 190 °C for 30 min;

[0147] (3) Filter the mixture after cooking in step (2). The liquid product obtained after filtration is the biomass for generating syngas, and the solid product is cellulose. The solid product cellulose can be hydrolyzed by enzymes to obtain pentose or hexose, which can be fermented to obtain bioethanol after that, or can also be used for papermaking or producing other cellulose products;

[0148] (4) The liquid product obtained in step (3) is concentrated and then mixed with coal to prepare a water - coal slurry. Among them, the content of solids in the slurry is 60%, lignin in the slurry accounts for 42.03 wt% of the solids, coal accounts for 55 wt% of the solids, the viscosity of the slurry is 1072 mPa·s, the dry - basis ash content is 18.18 wt%. In a entrained - flow bed, at a temperature of 1500 °C and a pressure of 2.5 MPa, the water - coal slurry is gasified for 1 s. The gasified product is purified to obtain syngas and by - product hydrogen sulfide;

[0149] The by - product hydrogen sulfide can be applied to the preparation of the alkaline solution in step (1), and the waste heat generated during the gasification process can be used for the cooking process in step (2).

[0150] Example 31

[0151] This example provides a method for producing syngas. The specific steps and parameters are as follows:

[0152] (1) Catalytic oxidation of hydrogen sulfide is carried out to obtain sulfur dioxide. The sulfur dioxide is introduced into sodium hydroxide solution to prepare an alkaline solution with a mass ratio of sodium sulfite to sodium hydroxide of 1:1.5, and the pH value of the alkaline solution is 10;

[0153] (2) Straw with a particle size of 15 mesh and a water content of 20% is mixed with the alkaline solution prepared in step (1). Among them, the ratio of straw to the alkaline solution is 1:8, with the unit of g:mL. The mixture of straw and the alkaline solution is cooked at 130 °C for 2 h;

[0154] (3) The mixture after cooking in step (2) is filtered. The filtered liquid product can be used as biomass for generating syngas, or can be separated and purified to obtain sulfonated lignin and other products. The solid product is cellulose. The solid - state product cellulose can be dissolved and enzymatically hydrolyzed to produce pentose or hexose, and then fermented to obtain bio - ethanol, or can be used for papermaking or producing other cellulose products;

[0155] (4) The liquid product obtained in step (3) is concentrated and then mixed with coal to prepare a slurry. Among them, the content of solids in the slurry is 60%, lignin in the slurry accounts for 14.3 wt% of the solids, the content of coal in the slurry accounts for 85 wt% of the solids, the viscosity of the slurry is 1001 mPa·s, the dry - basis ash content is 8.58 wt%. In a entrained - flow bed, at a temperature of 1200 °C and a pressure of 2.5 MPa, the water - coal slurry is gasified for 1 s. The gasified product is purified to obtain syngas and by - product hydrogen sulfide;

[0156] The by - product hydrogen sulfide can be catalytically oxidized in step (1) to produce sulfur dioxide, which can be used for the preparation of alkaline solutions or for the preparation of sulfur. The waste heat generated during the gasification process can be used for the cooking process in step (2).

[0157] Example 32

[0158] This example provides a method for producing syngas, and the specific steps and parameters are as follows:

[0159] (1) Catalytically oxidize hydrogen sulfide to produce sulfur dioxide, and pass the sulfur dioxide into calcium hydroxide solution to obtain a treatment liquid. The pH value of the treatment liquid is 4.5, and the mass fraction of calcium bisulfite in the treatment liquid is 10%;

[0160] (2) Mix straw with a particle size of 15 mesh and a water content of 20% with the treatment liquid prepared in step (1). Among them, the ratio of straw to the treatment liquid is 1:6, with the unit of g:mL. Cook the mixture of straw and the treatment liquid at 120 °C for 1 h;

[0161] (3) Filter the mixture after cooking in step (2). The filtered liquid product can be used as biomass for generating syngas, or can be separated and purified to obtain sulfonated lignin and other products. The solid product is cellulose. The solid product cellulose can be dissolved and enzymatically hydrolyzed to produce pentose or hexose, and then fermented to obtain bio - ethanol, or can be used for papermaking or producing other cellulose products;

[0162] (4) Concentrate the liquid product obtained in step (3) and mix it with coal to obtain a slurry. Among them, the content of solids in the slurry is 60 wt%, the lignin in the slurry accounts for 42.62 wt% of the solids, the coal in the slurry is 55 wt% of the solids, the viscosity of the water - coal slurry is 996 mPa·s, the dry - basis ash content is 22.56 wt%. In a entrained - flow bed, at a temperature of 1200 °C and a pressure of 3.4 MPa, gasify the slurry for 5 s. Purify the product after gasification to obtain syngas and by - product hydrogen sulfide;

[0163] The by - product hydrogen sulfide can be catalytically oxidized in step (1) to produce sulfur dioxide, which can be used for the preparation of alkaline solutions or for the preparation of sulfur. The waste heat generated during the gasification process can be used for the cooking process in step (2).

[0164] The slag in the entrained - flow bed in step (4) of this example contains a large amount of quicklime and can be used for cement preparation.

[0165] Example 33

[0166] This example provides a method for producing syngas, and the specific steps and parameters are as follows:

[0167] (1) Catalytically oxidize hydrogen sulfide to obtain sulfur dioxide, and pass the sulfur dioxide into a calcium hydroxide solution to obtain a treatment liquid with a pH value of 5.5 and a mass fraction of calcium bisulfite in the treatment liquid of 6%;

[0168] (2) Mix straw with a particle size of 15 mesh and a water content of 20% with the treatment liquid prepared in step (1). Among them, the ratio of straw to the treatment liquid is 1:4, with the unit of g:mL. Cook the mixture of straw and the treatment liquid at 150 °C for 45 min;

[0169] (3) Filter the mixture after cooking in step (2). The filtered liquid product can be used to generate biomass for synthesis gas or can be separated and purified to obtain sulfonated lignin and other products. The solid product is cellulose. The solid product cellulose can be dissolved and enzymatically hydrolyzed to produce pentose or hexose, and then fermented to obtain bioethanol, or can be used for papermaking or producing other cellulose products;

[0170] (4) Concentrate the liquid product obtained in step (3) and mix it with coal to obtain a slurry. Among them, the content of solids in the slurry is 60 wt%, the lignin in the slurry accounts for 18.94 wt% of the solids, the coal in the slurry is 80 wt% of the solids, the viscosity of the slurry is 1026 mPa˙s, and the dry basis ash content is 13.83 wt%. In a gasifier, at a temperature of 1050 °C and a pressure of 3.8 MPa, gasify the slurry for 12 s. Purify the gasified product to obtain synthesis gas and by-product hydrogen sulfide;

[0171] The by-product hydrogen sulfide can be used in step (1) to be catalytically oxidized to obtain sulfur dioxide, used for the preparation of alkaline solutions or for the preparation of sulfur. The waste heat generated during the gasification process can be used for the cooking process in step (2).

[0172] In step (4) of this example, the slag in the gasifier contains a large amount of quicklime and can be used for cement preparation.

[0173] Comparative Example 1

[0174] This comparative example provides a synthesis gas preparation process, and the specific steps and parameters are as follows:

[0175] Mix the solid product cellulose obtained in step (3) of Example 1 with water to obtain a slurry. The viscosity of the slurry is 1512 mPa˙s, the content of cellulose in the slurry is 60 wt%, and the dry basis ash content of the slurry is <1 wt%. In a gasifier, at a temperature of 1300 °C and a pressure of 6.9 MPa, gasify the slurry for 2 s. Purify the gasified product to obtain synthesis gas.

[0176] Comparative Example 2

[0177] This comparative example provides a syngas preparation process. The specific steps and parameters are the same as those in Example 2, except that in step (5), the solid content in the slurry is 25 wt%, where lignin in the slurry accounts for 9.82 wt% of the solids, coal accounts for 90 wt% of the solids, the dry basis ash content in the slurry is 8.48 wt%, the viscosity is 117.5 mPa·s, and the slurry is gasified at a temperature of 1300 °C and a pressure of 6.9 MPa for 2 s. The gasified product is purified to obtain syngas.

[0178] Comparative Example 3

[0179] Corn stover is used as the raw material for pulping and gasification. The gasification conditions are a pressure of 6.9 MPa and a temperature of 1300 °C. Among them, the solid content of the slurry is 30%, the viscosity is 1621 mPa·s, and the dry basis ash content is 5.17 wt%.

[0180] The following method is used for corn stover pulping: First, the corn stover is dried to reduce the moisture content to 12 wt%. The dried stover is screened to remove impurities such as sediment and metal to ensure the purity of the raw material. Subsequently, a hammer mill is used to crush the stover into particles with a size of 2 mm. The crushed corn stover is ground to obtain a particle size distribution suitable for entrained flow gasification. The ground stover powder is mixed with an appropriate amount of water to make a slurry with a solid content of 30%.

[0181] Experimental Example 1

[0182] The contents of each component in the syngas generated by gasification in Examples 1 - 33 and Comparative Examples 1 - 3 are detected. The detection results are shown in Table 1.

[0183] The detection method uses gas chromatography (GC) for detection.

[0184] Table 1 Detection Results of Component Contents in Syngas

[0185]

[0186]

[0187]

[0188] According to the data in Table 1, compared with the component content results of the synthesis gas in Comparative Examples 1-3, the present invention can use the slurry containing lignin as the gasification raw material, and the synthesized gas generated by gasification has a high content and a low carbon dioxide content. This is because, compared with cellulose or hemicellulose, lignin has a low oxygen content, a high calorific value, and a low content of hydrophilic groups. Therefore, it is difficult to prepare a pulp using lignin as a raw material, and the content of lignin or the solid substance formed by lignin and coal in the prepared slurry is high, and the content of the synthesized gas obtained after gasification is high; while in Comparative Example 1, a solid product is used to form a slurry, the lignin content in the slurry in Comparative Example 2 is lower than 3wt%, and in Comparative Example 3, corn straw is directly pulped, resulting in a low content of effective synthesis gas and a high carbon dioxide content after gasification.

[0189] Obviously, the above embodiments are merely examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. The obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. A synthesis gas preparation process, characterized in that: The gasification raw material is a slurry containing biomass lignin, and the content of lignin is greater than or equal to 3wt%.

2. The synthesis gas preparation process according to claim 1, characterized in that: The content of lignin is greater than or equal to 8wt%; and / or, the slurry comprises a liquid product obtained by heating and separating the biomass and the treatment liquid, The components in the treatment solution include at least one of a metal inorganic salt and a metal hydroxide.

3. The synthesis gas preparation process according to claim 1, characterized in that: The content of lignin is 8-60wt%; and / or, the solid content in the slurry is greater than or equal to 10 wt %; and / or, the viscosity of the slurry is less than or equal to 2000 mPa˙s; And / or, the dry basis ash content in the slurry is less than or equal to 45wt%.

4. The synthesis gas production process according to claim 2 or 3, characterized in that: The solid content in the slurry is 10-60wt%; The lignin accounts for 9-90wt% of the solid matter; and / or, the viscosity of the slurry is less than or equal to 1200 mPa˙s; and / or, the slurry further comprises a carbonaceous fuel; The dry ash content of the slurry is less than or equal to 40 wt %.

5. The synthesis gas preparation process according to claim 4, characterized in that: The solid content in the slurry is 50-60wt%; The dry ash content of the slurry is less than or equal to 25wt%; The viscosity of the slurry is 700-1200 mPa˙s; and / or, the carbon-containing fuel comprises coal, and the proportion of coal to solid matter in the slurry is 5wt%-95wt%; And / or, the carbon-containing fuel includes liquid waste or gaseous waste soluble in liquid, and the proportion of the liquid waste or gaseous waste soluble in liquid in the slurry is 0.5wt-30wt%.

6. The synthesis gas preparation process according to claim 2, characterized in that: The biomass comprises at least one of wood, herbaceous plants, agricultural waste, agricultural residues, agricultural crops, aquaculture waste or industrial biomass processing waste; And / or, the particle size of the biomass is less than or equal to 4000 μm, preferably less than or equal to 850 μm; And / or, the water content of the biomass is 10-70 wt%, preferably 10-50 wt%.

7. The synthesis gas preparation process according to claim 6, characterized in that: The biomass includes at least one of straw, corn cobs, wood chips, sugarcane, bagasse, and human and animal feces.

8. The synthesis gas preparation process according to claim 2, characterized in that: The metal inorganic salt includes at least one of metal sulfide salts, metal sulfites, metal bisulfites, and metal nitrates.

9. The synthesis gas production process according to claim 8, characterized in that: The metal sulfide salt includes at least one of sodium sulfide, potassium sulfide and calcium sulfide; and / or, the metal sulfite comprises at least one of sodium sulfite, potassium sulfite and calcium sulfite; and / or, the metal bisulfite comprises calcium bisulfite; And / or, the metal nitrate comprises calcium nitrate.

10. The synthesis gas production process according to claim 2, characterized in that: The metal hydroxide is at least one of sodium hydroxide, potassium hydroxide or calcium hydroxide.

11. The synthesis gas production process according to claim 2, characterized in that: The treatment liquid is prepared by passing acidic gas into a metal hydroxide solution. Optionally, the acidic gas includes acidic waste gas generated during the production process.

12. The synthesis gas production process according to claim 11, characterized in that: The acidic waste gas is at least one of hydrogen sulfide and sulfur dioxide.

13. The synthesis gas production process according to claim 8, characterized in that: The mass ratio of the metal sulfide salt to the metal hydroxide in the treatment solution is 1:(2-4), and the pH value of the treatment solution is 13-14; and / or, the mass ratio of the metal sulfite to the metal hydroxide in the treatment solution is 1:(0.4-2), and the pH value of the treatment solution is 10-12; And / or, the concentration of the metal bisulfite in the treatment solution is 8-10 wt %.

14. The synthesis gas production process according to claim 2, characterized in that: The heating temperature of the biomass and the treatment liquid is 105-200°C, and the heating time is 30min-5h; And / or, the ratio of the biomass to the treatment liquid is 1:(1-10), in units of g:mL.

15. The synthesis gas production process according to claim 2, characterized in that: The ratio of the biomass to the treatment liquid is 1:(1-6), in units of g:mL.

16. The synthesis gas production process according to claim 11, characterized in that: Sulfur dioxide is injected into the calcium hydroxide solution to form a treatment solution, and the pH value of the treatment solution is 4.5-5.5; The temperature for heating the biomass and the treatment liquid is 120-160° C., the time for heating is 45 min-3 h, and the ratio of the biomass to the treatment liquid is 1:(4-6), in units of g:mL.

17. The synthesis gas production process according to claim 2, characterized in that: The slurry also includes the steps of introducing acidic gas into the liquid product, adjusting the pH value of the liquid product to 9-11, separating to obtain a precipitate, and preparing the precipitate into a slurry, wherein the acidic gas includes hydrogen sulfide.

18. The synthesis gas production process according to claim 17, characterized in that: The liquid after separation of the precipitate is reused.

19. The process for preparing synthesis gas according to any one of claims 1 to 18, characterized in that: The gasification temperature for gasifying the gasification raw material is 850-1500° C., preferably, the gasification temperature is 1050-1300° C.; and / or, the gasification pressure for gasifying the gasification raw material is 0.05-8.0 MPa, preferably, the gasification pressure is 2.5-6.9 MPa; And / or, the gasification time for gasifying the gasification raw material is 1s-30s, preferably, the gasification time is 1s-5s.

20. The synthesis gas production process according to claim 19, characterized in that: The method also includes the step of desulfurizing and purifying the gasified product.

21. The synthesis gas production process according to claim 1, characterized in that: The gasification raw material is gasified by an entrained bed.

Images