A kind of method of utilizing gramineous straw to prepare true qualities paper pulp
Technical field
The invention belongs to stalk slurrying field, be specifically related to a kind of method of utilizing gramineous straw to prepare true qualities paper pulp.
Background technology
Continuous expansion along with paper industry, constantly opening up of pulp applications is wide, supply falls short of demand gradually for the former timber that is used as main paper making raw material, cause forest overcut, influence ecological environment, on the other hand, agricultural crop straw but causes a large amount of wastes owing to can not get the utilization of effective science as inexhaustible resource.
Existing stalk slurrying majority is white slurry, production technology is all chemical method, its principle is that the compositions such as lignin in stalk are decomposed by chemical agent, retain fiber, the compositions such as the lignin decomposing run off with pulp-making waste-water, conventional chemical agent is as caustic soda, Anthraquinones auxiliary agent and hypochlorite etc., because consumption is very large, so become the main pollution source of papermaking wastewater, the composition such as xylogen degradation not only in degradation process simultaneously, also there is quite a few fiber can divide and take off simultaneously, reduced yield, cause the waste of raw material; In addition, chemical degradation process need High Temperature High Pressure, so energy consumption is higher.The technique that has occurred at present some stalk true qualities slurrying, its essence or chemical method boiling, decompose lignin, just at bleaching stage, changed original technique, such as having replaced tri-stage bleaching with oxygen delignification, the whiteness of pulping is reduced greatly, but bleaching process is more serious to fibre damage, cause beating degree higher, affect the result of use of molding.
Summary of the invention
The problem existing for prior art, the invention provides a kind of method of utilizing gramineous straw to prepare true qualities paper pulp, to adopt high-density paste mill once to grind pulping through take the gramineous straw that profit that ethylene glycol, NaOH, glycerine forms as raw material opens agent preimpregnation, then through washing, screening, the concentrated pulping of purified treatment.Technique of the present invention is simple, gained paper pulp yield is high, drainability good, intensity is large, cost is low, and pulping process does not need extra heating, and energy consumption is low, few and the institute's sewer of sewage flow rate is easy to process, and prepared paper pulp can be applicable to the true qualities paper pulp that paper mould manufacture, paper for daily use are manufactured.
The concrete technical scheme of the present invention is:
Utilize gramineous straw to prepare a method for true qualities paper pulp, concrete steps are as follows:
(1) water is warmed to 50-80 ℃, adds a profit agent, be mixed with presoak, standby;
(2) by straw cutting, be 2-5cm, be delivered in presoak and soak, dehydration;
(3) step (2) is dewatered resulting stalk grinds, and obtains slightly slurry;
(4) the thick slurry of step (3) gained is washed, screened, press filtration obtains filter cake, i.e. true qualities paper pulp.
The described profit of step (1) is opened agent and is comprised of sodium hydroxide solution, ethylene glycol and glycerine.
The mass percent of described sodium hydroxide solution is 10%-35%.
Due to NaOH can with stalk in lignin reaction, from reducing costs consideration, adopt sodium hydroxide solution can slough part lignin, contribute to stalk softening; Described glycerine is a kind of material that is relatively applicable to stalk fibre profit, and abundant natural degradation, contributes to naturally locating of preimpregnation waste water; Described ethylene glycol, as the solvent of glycerine, can make glycerine in presoak, disperse fully, make to process evenly, and ethylene glycol is also to belong to polyhydroxy substance, also has certain profit Zhang Zuoyong.
The percetage by weight that the addition of described sodium hydroxide solution accounts for over dry stalk is 1%-5%, and the percetage by weight that the addition of described ethylene glycol accounts for over dry stalk is 0.1%-0.4%, and the percetage by weight that the addition of described glycerine accounts for over dry stalk is 0.05%-0.3%.The profit forming is like this opened agent and just can be made stalk fibre moisten Zhang Pengsong completely, the yield of guarantee paper pulp and quality.
The described stalk of step (2) is gramineous straw, is preferably one or more in wheat straw waste or reed straw or rice straw.
For reinforced convenient, soak evenly, save energy consumption, by straw cutting, be that 2-5cm is delivered in soak and soaks, its objective is and make stalk fibre profit Zhang Pengsong.
The described stalk weight of step (2) and presoak volume t/m
3ratio be 1:5-10.Can make like this stalk soak profit Zhang Pengsong completely, contribute to follow-up grinding.If stalk is too much, stalk soaks not exclusively, will affect follow-up grinding, even affects paper pulp yield and quality; If soak is too much, cause the waste of raw material.
The addition of the described water of step (1) first calculates respectively the rise addition of each component in agent of profit according to rise percetage by weight that each component in agent accounts for over dry stalk of profit, then the weight by presoak deducts the addition of moistening each component in the agent of rising, and is the addition of water.
The described soaking temperature of step (2) is 50 ℃-80 ℃.At such temperature, soak, just can make stalk fibre moisten Zhang Pengsong completely.If excess Temperature, causes energy consumption waste, if temperature is too low, do not reach the effect of immersion.
The described soak time of step (2) is 50min-70min, preferably 60min.If long soaking time, increases the production cycle, increase energy consumption, if soak time is too short, can not make stalk fibre profit Zhang Pengsong, affect paper pulp yield and quality.
The equipment that the described dehydration of step (2) adopts is inclined helix dehydrator, is existing equipment, and said dehydration is here natural-dehydration, and the material concentration that enters equipment is 2%-5%, and the material concentration after dehydration is 16%-23%.
Described in step (3), grinding the equipment adopting is high-density paste mill, is existing equipment, and its model is YC-600.
Described in step (4), washing is to open agent in order to wash residual profit off, and the water lotion obtaining after described washing is delivered to dosing operation, can be used for preparing presoak, supplements the presoak reducing.
The equipment that described in step (4), screening adopts is closed rotary-wing pressure sieve, is commonly called as pressurized screen, is papermaking common equipment, and its screening concentration is 1%-3%.In 1 cubic metre of pulp solution of concentration 1% finger here, contain paper pulp 10Kg, in 1 cubic metre of pulp solution of concentration 3% finger, contain paper pulp 30Kg.The inlet outlet pressure differential of described closed rotary-wing pressure sieve is 0.1-0.3MPa, is preferably 0.2MPa.
The equipment that press filtration described in step (4) adopts is Double-screen filter press, and it enters to starch concentration is 3%-5%, in 1 cubic metre of pulp solution of concentration 3% finger here, contains paper pulp 30Kg, in 1 cubic metre of pulp solution of concentration 5% finger, contains paper pulp 50Kg.
Institute's sewer is discharged from raw material preimpregnation, because the major pollutants that contain are stalk residues of silt and loss, by coarse filtration, tackle solid content, burning disposal together with mixing with coal, main matter after burning is carbon dioxide and water, pollution-free, remaining sewage can reach discharge standard by cesspool left and right autoxidation degraded in 7 days, and its COD is 60mg/L.
Technique of the present invention is simple, gained paper pulp yield is high, drainability good, intensity is large, cost is low, and pulping process does not need extra heating, and energy consumption is low, few and the institute's sewer of sewage flow rate is easy to process, and prepared paper pulp can be applicable to the true qualities paper pulp that paper mould manufacture, paper for daily use are manufactured.
The specific embodiment
Embodiment 1
Utilize gramineous straw to prepare a method for true qualities paper pulp, concrete steps are as follows:
(1) water is warmed to 50 ℃, adds a profit agent, be mixed with 5m
3presoak, standby;
(2) 1t wheat straw waste is cut to 2cm, is delivered to 5m
3presoak in, in temperature, be to soak 50min at 50 ℃, adopt inclined helix dehydrator to dewater;
(3) step (2) is dewatered resulting wheat straw waste adopts high-density paste mill to grind, and obtains slightly slurry;
(4) the thick slurry of step (3) gained is washed, adopted the pressurized screen that screening concentration is 1%, inlet outlet pressure differential is 0.1MPa to screen, the Double-screen filter press that to adopt into slurry concentration be 3% carries out press filtration, obtains filter cake, i.e. true qualities paper pulp.
The described profit of step (1) is opened agent and is comprised of sodium hydroxide solution 10Kg, ethylene glycol 1 Kg and glycerine 0.5 Kg.
The mass percent of described sodium hydroxide solution is 10%.
The performance of gained finished pulp is: fracture length 4.5km, beating degree 15
osR, yield 52.5%.
Embodiment 2
Utilize gramineous straw to prepare a method for true qualities paper pulp, concrete steps are as follows:
(1) water is warmed to 80 ℃, adds a profit agent, be mixed with 10m
3presoak, standby;
(2) 1t reed straw is cut to 5cm, is delivered to 10m
3presoak in, in temperature, be to soak 70min at 80 ℃, adopt inclined helix dehydrator to dewater;
(3) step (2) is dewatered resulting reed straw adopts high-density paste mill to grind, and obtains slightly slurry;
(4) the thick slurry of step (3) gained is washed, adopted the pressurized screen that screening concentration is 3%, inlet outlet pressure differential is 0.3MPa to screen, the Double-screen filter press that to adopt into slurry concentration be 5% carries out press filtration, obtains filter cake, i.e. true qualities paper pulp.
The described profit of step (1) is opened agent and is comprised of sodium hydroxide solution 50Kg, ethylene glycol 4Kg and glycerine 3Kg.
The mass percent of described sodium hydroxide solution is 35%.
The performance of gained finished pulp is: fracture length 5km, beating degree 14
osR, yield 55%.
Embodiment 3
Utilize gramineous straw to prepare a method for true qualities paper pulp, concrete steps are as follows:
(1) water is warmed to 65 ℃, adds a profit agent, be mixed with 8m
3presoak, standby;
(2) 1t rice straw is cut to 3cm, is delivered to 8m
3presoak in, in temperature, be to soak 60min at 65 ℃, adopt inclined helix dehydrator to dewater;
(3) step (2) is dewatered resulting rice straw adopts high-density paste mill to grind, and obtains slightly slurry;
(4) the thick slurry of step (3) gained is washed, adopted the pressurized screen that screening concentration is 2%, inlet outlet pressure differential is 0.2MPa to screen, the Double-screen filter press that to adopt into slurry concentration be 4% carries out press filtration, obtains filter cake, i.e. true qualities paper pulp.
The described profit of step (1) is opened agent and is comprised of sodium hydroxide solution 30Kg, ethylene glycol 2Kg and glycerine 1Kg.
The mass percent of described sodium hydroxide solution is 20%.
The performance of gained finished pulp is: fracture length 5.5km, beating degree 13.4
osR, yield 57.8%.
Embodiment 4
Utilize gramineous straw to prepare a method for true qualities paper pulp, concrete steps are as follows:
(1) water is warmed to 70 ℃, adds a profit agent, be mixed with 6m
3presoak, standby;
(2) 1t wheat straw waste and reed straw are cut to 4cm, are delivered to 6m
3presoak in, in temperature, be to soak 65min at 70 ℃, adopt inclined helix dehydrator to dewater;
(3) step (2) is dewatered resulting wheat straw waste and reed straw adopts high-density paste mill to grind, and obtains slightly slurry;
(4) the thick slurry of step (3) gained is washed, adopted the pressurized screen that screening concentration is 1%, inlet outlet pressure differential is 0.3MPa to screen, the Double-screen filter press that to adopt into slurry concentration be 3% carries out press filtration, obtains filter cake, i.e. true qualities paper pulp.
The described profit of step (1) is opened agent and is comprised of sodium hydroxide solution 40Kg, ethylene glycol 3Kg and glycerine 2Kg.
The mass percent of described sodium hydroxide solution is 25%.
The performance of gained finished pulp is: fracture length 5.4km, beating degree 14.3
oSR, yield 56%.
Embodiment 5
Utilize gramineous straw to prepare a method for true qualities paper pulp, concrete steps are as follows:
(1) water is warmed to 75 ℃, adds a profit agent, be mixed with 7m
3presoak, standby;
(2) 1t wheat straw waste, reed straw and rice straw are cut to 3cm, are delivered to 7m
3presoak in, in temperature, be to soak 55min at 75 ℃, adopt inclined helix dehydrator to dewater;
(3) step (2) is dewatered resulting wheat straw waste, reed straw and rice straw adopts high-density paste mill to grind, and obtains slightly slurry;
(4) the thick slurry of step (3) gained is washed, adopted the pressurized screen that screening concentration is 2%, inlet outlet pressure differential is 0.2MPa to screen, the Double-screen filter press that to adopt into slurry concentration be 4% carries out press filtration, obtains filter cake, i.e. true qualities paper pulp.
The described profit of step (1) is opened agent and is comprised of sodium hydroxide solution 20Kg, ethylene glycol 2Kg and glycerine 1.5Kg.
The mass percent of described sodium hydroxide solution is 30%.
The performance parameter of gained finished pulp is: fracture length 5.6km, beating degree 13.7
osR, yield 57%.
Paper pulp in existing industry is generally white slurry, and its performance parameter is: fracture length is at 3500-4000m, and beating degree is 28
osR, yield is 40%, because existing paper pulp is produced for papermaking application, so higher to white background requirement, but more serious to fibre damage in bleaching process, cause beating degree higher, so existing paper pulp is used for manufacturing moulding article, the result of use of molding will be affected.
The true qualities paper pulp that embodiment 1-5 adopts gramineous straw to prepare, can be applicable to paper mould manufacture, paper for daily use manufacture, be particularly useful for paper mould manufacture, beating degree is low, easily dehydration, reduced the oven dry cost in paper mould manufacturing technique, yield is high, has reduced the production cost of paper pulp.