PL244101B1 - Pellet made from a mixture of hay and dry sewage sludge - Google Patents

Abstract

The subject of the invention is a pellet made of a mixture of hay and dry sewage sludge with improved mechanical strength, refined with a composition of additives containing quicklime and calcium lignosulfonate, characterized by the fact that it is a mixture of hay and dry sewage sludge, containing dry sewage sludge and hay in the mass ratio of dry sewage sludge. sewage to hay ranging from 1: 99 to 1: 4, containing from 0.5 to 2% (m/m) of a composition of quicklime and calcium lignosulfonate based on the mass of pellets, in which composition the mass ratio of quicklime to calcium lignosulfonate is 1:1.

Description

TECHNICAL FIELD

The subject of the invention is a pellet made of a mixture of hay and dry sewage sludge, with improved mechanical strength, refined with a composition of additives.

STATE OF TECHNOLOGY

Unprocessed plant biomass is characterized by a relatively low bulk density, which makes its transport, storage and use in practice difficult; hence it is necessary to thicken it, e.g. in the form of pellets or briquettes. They are produced from dry, crushed biomass under high pressure and elevated temperature, most often without the addition of a binder. The forces and temperature occurring during agglomeration cause a significant amount of raw material to be compacted in a small volume. This results in a decrease in water content, an increase in mass and energy concentration, and significantly increases the comfort of distribution and use of biofuel.

The quality of pellets, determined on the basis of several physical properties, such as bulk density, calorific value, mechanical strength, moisture content and caloric value, depends on the quality of the raw material and their production parameters. One of the most important parameters regarding pellets is mechanical strength.

Mechanical strength means the ability of the thickened biofuel to remain intact during technological operations and transport, therefore it is one of the most important quality parameters for both the manufacturer and the customer.

In order to obtain adequate mechanical strength, it may be necessary to use binding substances in the pellet production process - the so-called binder. Typically, substances of organic origin - plants or animals - are used as binders so that their addition does not reduce the biomass content in the fuel. Binders are added to the biomass in the range of 0.5% to 5.0% by mass.

Authors of the articles [W. Li, Y. Jiang, S. Rao, X. Yin, E. Jiang. Parameter optimization of corn stover blended with sawdust and sodium lignosulphonate compression experiments, Transactions of the Chinese Society of Agricultural Engineering, 2018, 34, 1, 108-203; M. Thomas, D.J. van Zuilichem, A.F.B. van der Poel. Physical quality of pelleted animal feed. 2. Contribution of processes and their conditions, Animal Feed Science and Technology, 1997, 64, 173-192; O.C. Chin, K.M. Siddiqui, Characteristics of some biomass briquettes prepared under modest die pressures, Biomass Bioenergy, 2000, 18, 223228] and patent description US6013116 presented research results which showed that the addition of calcium lignosulfonate increases the mechanical strength of the pellets, and at the same time allows for lowering the operating temperature of the device pelletizing.

In several studies on the impact of additives on mechanical properties, calcium oxide is described as having the highest effectiveness in increasing the mechanical strength and hardness of pellets among all those tested [L.C. Tabil, Jr. S. Sokhansanj, R.T. Tyler, Performance of different binders during alfalfa pelleting, Canadian Agricultural Engineering, 1997, 39, 17-23; L. Kong, S.H. Tian, Z. Li, R. Luo, D. Chen, Y.T. Tu, Y. Xiong, Conversion of recycled sawdust into high HHV and low NOx emission bio-char pellets using lignin and calcium hydroxide blended binders, Renewable energy, 2013, 60, 559-565]. Also in the patent description PL 171208, binders for obtaining briquettes and pellets using calcium oxide are presented.

Polish patent application PL395378 presents fuel pellets for the production of which dried sewage sludge was used.

The patent description PL214121 describes a method for obtaining fuel in the form of pellets using animal meat and bone meal and feathers, with the addition of bran, straw, oil cake and oil plant meals, and using animal and plant fats as binders.

The patent description PL215280 presents a method for obtaining fuel pellets from biomass, in which the pellet uses a post-fermentation substrate resulting from the biogas process as a binder.

The authors of the Polish patent application PL421069 described a method of obtaining pellets from sawdust with rye bran.

The Polish patent application PL127593 discloses a method of obtaining fuel in the form of pellets consisting of wood shavings, sewage sludge and grass straw in various weight ratios.

The Polish patent application PL380210 discloses a method for producing pellets from bran from mills, malt houses or distilleries.

The patent description JP 2019172766 presents a method for obtaining pellets from biomass - bamboo, in which sewage sludge is used as a binder.

The authors of patent description TW 201833314 presented a method of obtaining thickened fuel from food remains and organic sediments combined with a binder, which can be selected from one or a combination of the following substances: kitchen waste, sweet potato flour, corn starch, rice, oatmeal.

The patent description EP 2865736 presents a solid fuel obtained from a mixture of biodegradable municipal waste and/or industrial fibrous materials from natural textiles and fibers, and/or industrial waste cellulosic products, phytomass from farming, preferably straw, waste from hydroponic cultivation, dust from the grinding of all types of cereals and/or dried fruit and/or dried flowers and/or dried vegetables after their expiry date and/or pomace and other waste from plant production and/or tobacco waste and/or cork waste.

Patent description KR 101539224 discloses a solid fuel consisting of biomass and organic sludge from sewage treatment plants. In order to improve the mechanical properties of the fuel, a binder was used, which may be: saccharified waste solution, seaweed extract concentrate, chitosan solution, corn starch and their mixture, and is used in an amount from 0.1 to 2.0% by weight. on the total mass of the fuel mixture.

The patent US 2011197501 discloses the composition of a solid fuel consisting of coal dust and biomass, for the production of which a binder was used, which is a substance from: lignin, emulsion of lignin and asphalt, wheat starch, calcium lignosulfonate, tall oil, coal tar, polyvinyl alcohol ), phenolic resin, paper slime, molasses, lime, gaur gum, polymeric material and mixtures thereof.

The purpose of the present invention is to obtain a pellet from a mixture of hay and dry sewage sludge with improved mechanical strength, which will be characterized by higher mechanical strength than a pellet from a mixture of hay and dry sewage sludge, the mechanical strength of which has not been improved.

Surprisingly, it was found that such properties are possessed by the pellet in accordance with the present invention, made of a mixture of hay and dry sewage sludge, refined with a composition of additives, which is characterized by higher mechanical strength than pellets without a composition of enriching additives.

ESSENCE OF THE INVENTION

Pellet made of a mixture of hay and dry sewage sludge, with improved mechanical strength, refined with a composition of additives that contains quicklime and calcium lignosulfonate, is characterized by the fact that the mixture of hay and dry sewage sludge containing dry sewage sludge and hay in the mass ratio of dry sewage sludge to hay ranging from 1:99 to 1:4, contains from 0.5 to 2% (m/m) of the composition of quicklime and calcium lignosulfonate based on the mass of pellets, in which the mass ratio of quicklime to calcium lignosulfonate is 1: 1.

It turned out during the research that refining pellets made of a mixture of hay and dry sewage sludge with a composition of additives allows for improving the mechanical strength of the pellet from over 5 to over 10% compared to pellets made from a mixture of hay and dry sewage sludge not containing an additive composition.

The present invention is presented in embodiments from 1 to 13, illustrating the composition, method of production and test results for assessing the mechanical strength of pellets made of a mixture of hay and dry sewage sludge refined with a composition of additives, therefore they cannot be considered as limiting the essence of the invention, because they are only illustrative. character.

PL 244101 Β1

EXAMPLES

Example 1 - comparative example

1485 g of hay with properties from Table 1 and 15 g of dry sewage sludge with properties from Table 2 were weighed. Hay and dry sewage sludge were mixed and then granulated in a ZLSP-150B pelleting device from Haven Polska Sp. z o. o. using a matrix with a mesh diameter of 6 mm.

Table 1. Characteristics of the hay used for testing.

Parameter Unit Value Appearance — the nature of the tourist is common Moisture content % 10 14 Ash content % 5.7 Opal value MJ/kg 13.1 - 17.2 Table 2. Characteristics of dry sewage sludge used for testing. Parameter rlodnostka Value Appearance — dark gray powder The content of orioles<x:i % 11.0 Ash content % 35, vol Opal value MJ/kg 12.1

Example 2

1,477.575 g of hay with the properties from Table 1, 14.925 g of dry sewage sludge with the properties from Table 2, 3.750 g of quicklime with the properties from Table 3 and 3.750 g of calcium igniosulfonate with the properties from Table 4 were weighed. All components and additives were mixed and then they were granulated in the ZLSP-150B pelleting device from Haven Polska Sp. z o. o. using a matrix with a mesh diameter of 6 mm.

Table 3. Characteristics of quicklime used for testing.

Parameter Unit Value Appearance — White powder Density. 20°C g/cm3 3.31 Solubility in water. 20°C g/l00 ml 0.13 pi l of saturated solution. 20°C — 11 - 12

PL 244101 Β1

Table 4. Characteristics of lime lignosulfonate used for testing.

Parameter Unit Value Appearance — Brownish powder Thickness. 2(X< gA:m3 0.52 Solubility in water. 20°C g/100 ml Soluble dl 10% solution in water. 20°C — 3.5 - 5.1

Example 3

1470.15 g of hay with properties from Table 1, 14.85 g of dry sewage sludge with properties from Table 2, 7.50 g of quicklime with properties from Table 3 and 7.50 g of calcium ligniosulfonate with properties from Table 4 were weighed. All components and additives were mixed and then granulated in the ZLSP-150B pelletizing device from Haven Polska Sp. z o. o. using a matrix with a mesh diameter of 6 mm.

Example 4

1462.65 g of hay with properties from Table 1, 7.35 g of dry sewage sludge with properties from Table 2, 15.00 g of quicklime with properties from Table 3 and 15.00 g of calcium liniosulfonate with properties from Table 4 were weighed. All components and additives were mixed and then granulated in the ZLSP-150B pelletizing device from Haven Polska Sp. z o. o. using a matrix with a mesh diameter of 6 mm.

Example 5 - comparative example

1350 g of hay with properties from Table 1 and 150 g of dry sewage sludge with properties from Table 2 were weighed. Hay and dry sewage sludge were mixed and then granulated in a ZLSP-150B pelleting device from Haven Polska Sp. z o. o. using a matrix with a mesh diameter of 6 mm.

Example 6

1343.25 g of hay with properties from Table 1, 149.25 g of dry sewage sludge with properties from Table 2, 3.75 g of quicklime with properties from Table 3 and 3.75 g of calcium ligniosulfonate with properties from Table 4 were weighed. All components and additives were mixed and then granulated in the ZLSP-15013 pelleting device from Haven Polska Sp. z o. o. using a matrix with a mesh diameter of 6 mm.

Example 7

1336.50 g of hay with properties from Table 1, 148.50 g of dry sewage sludge with properties from Table 2, 7.50 g of quicklime with properties from Table 3 and 7.50 g of calcium ligniosulfonate with properties from Table 4 were weighed. All components and additives were mixed and then granulated in the ZLSP-150B pelletizing device from Haven Polska Sp. z o. o. using a matrix with a mesh diameter of 6 mm.

Example 8

1323.00 g of hay with properties from Table 1, 147.00 g of dry sewage sludge with properties from Table 2, 15.00 g of quicklime with properties from Table 3 and 15.00 g of calcium ligniosulfonate with properties from Table 4 were weighed. All components and additives were mixed and then granulated in the ZLSP-150B pelletizing device from Haven Polska Sp. z o. o. using a matrix with a mesh diameter of 6 mm.

Example 9 - comparative example

1200 g of hay with properties from Table 1 and 350 g of dry sewage sludge with properties from Table 2 were weighed. Hay and dry sewage sludge were mixed and then granulated in a ZLSP-150B pelleting device from Haven Polska Sp. z o. o. using a matrix with a mesh diameter of 6 mm.

Example 10

1194.00 g of hay with properties from Table 1, 298.50 g of dry sewage sludge with properties from Table 2, 3.75 g of quicklime with properties from Table 3 and 3.75 g of calcium ligniosulfonate with properties from Table 4 were weighed. All components and additives were mixed and then granulated in the ZLSP-150B pelletizing device from Haven Polska Sp. z o. o. using a matrix with a mesh diameter of 6 mm.

Example 1 1

1188.00 g of hay with properties from Table 1, 297.00 g of dry sewage sludge with properties from Table 2, 7.50 g of quicklime with properties from Table 3 and 7.50 g of calcium ligniosulfonate with properties from Table 4 were weighed. All components and additives were mixed and then granulated in the ZLSP-150B pelletizing device from Haven Polska Sp. z o. o. using a matrix with a mesh diameter of 6 mm.

Example 12

1176.00 g of hay with properties from Table 1, 294.00 g of dry sewage sludge with properties from Table 2, 15.00 g of quicklime with properties from Table 3 and 15.00 g of calcium ligniosulfonate with properties from Table 4 were weighed. All components and additives were mixed and then granulated in the ZLSP-150B pelletizing device from Haven Polska Sp. z o. o. using a matrix with a mesh diameter of 6 mm.

Example 13

The mechanical strength of the products from examples 1 to 12 was tested. The tests were carried out according to PN-EN ISO 17831 ·1:2016 ·02 (Solid biofuels - Determination of the mechanical strength of pellets and briquettes - Part 1: Pellets) in the "PELTEST" apparatus manufactured by the company TESTCHEM.

The test consisted of placing approximately 500 g of tested pellets, sieved on a 3.15 mm sieve, in a steel cuboid rotating at 50 rpm, after 10 minutes, separating the crushed pellets again on the same sieve and weighing the residue on the sieve. The following equation is used to calculate the strength of the tested pellet sample.

DU=(mA/mE)-100 where:

DU - mechanical strength, % mA - mass of the sample after the test, g mE - mass of the sample before the test, g

The obtained results of mechanical strength tests are presented in Table 5.

PL 244101 Β1

Table 5. Mechanical strength according to PN-EN ISO 17831-1:2016 02

Tested sample Mechanical strength |%I Product from example 1 (comparison example) 84.2G Product from example 2 88.97 Product from example 3 87.13 Product.from example 4 92.18 Product from example 5 (fertilizer example) 85.0G Product, from example G 91.84 Product from example 7 94/11 Product from example 8 93.50 Product from example 9 (comparison example) 84.37 Product from example 10 89.52 Product from example 11 92/10 Product from example 12 93.32

The above examples present the composition of pellets made of a mixture of hay and dry sewage sludge with improved strength according to the invention and demonstrate the effectiveness of improving its mechanical strength in test trials, proving its industrial applicability.

The results of tests on the mechanical strength of pellets made of a mixture of hay and dry sewage sludge with improved strength according to the invention were compared with the results of tests on pellets made from a mixture of hay and dry sewage sludge containing no additives.

Claims (1)

1. Pellet made of a mixture of hay and dry sewage sludge, with improved mechanical strength, refined with a composition of additives containing quicklime and calcium lignosulfonate, characterized in that the mixture of hay and dry sewage sludge containing dry sewage sludge and hay in the mass ratio of sewage sludge to hay is from 1:99 to 1:4, contains from 0.5 to 2% (m/m) of the composition of quicklime and calcium lignosulfonate based on the mass of pellets, in which the mass ratio of quicklime to calcium lignosulfonate is 1:1.