NL1035853C

NL1035853C - Combustible materials

Info

Publication number: NL1035853C
Application number: NL1035853A
Authority: NL
Inventors: Erik Alexander Bijpost
Original assignee: Holland Novochem B V
Priority date: 2008-08-21
Filing date: 2008-08-21
Publication date: 2010-03-10
Also published as: NL1037217C

Description

Titel: COMBUSTIBLE MATERIALS

INTRODUCTION

Fireplaces have been used in homes over the years for providing heat as well as to provide a desired ambience. While 5 wood and coal have been the primary fuels for burning in fireplaces, there is an increasing demand for manufactured or artificial fireplace logs. These logs are typically easier to purchase and store, provide better heating values than wood or coal, are easier to light, safer to use with virtually no 10 maintenance during burning, and can be used to build fires of a known duration, generally from 2 hours to more than 4 hours. Artificial firelogs are typically manufactured by combining a carrier material, usually particles of cellulosic origin, with a combustible binder/fuel. The cellulosic material may be 15 sawdust, or a mixture of sawdust with other combustible materials of varying proportion. The binder/fuel typically consists of a suitable blend of waxes, typically a flammable wax such as paraffin or slack wax, flammable vegetable oils, such as stearic and/or palmitic acid or other fatty acids or 20 esters which can be used either alone or in combination with other combustible materials. Additives imparting desired combustion characteristics, appearance, and other attributes may be combined with the basic ingredients. Such additives may include chemicals designed to color or otherwise modify or 25 retard the flame, add aroma or crackling sounds or otherwise change the burning characteristics to more closely mimic the burning of natural logs. Following thorough mixing of the ingredients, the resulting mixture is formed into suitable, log-like shapes by extrusion, molding or compression, in 30 either a batch or continuous process.

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Firelog base waxes should have physical characteristics (e.g. melting point, hardness and/or malleability) that permit the material to be readily formed into firelogs having a pleasing appearance and/or feel to the touch, as well as 5 having desirable olfactory properties. Artificial firelogs are typically manufactured from blends of about 50% to about 60% (by weight) petroleum waxes and about 40% to 50% (by weight) cellulosic fibers. The petroleum wax constituent, which may include paraffin wax or slack wax by way of example, provides 10 the principal fuel content for the firelog and contains about twice the BTU (British thermal unit) energy value per unit mass as the cellulosic fibers.

In recent years, there has been dramatic inflation in the cost of petroleum products, including refined products, such 15 as petroleum waxes. Consequently, the application of petroleum-based products is much less economic for firelog manufacturers. Furthermore, paraffin wax material is derived from non-renewable petroleum fossil fuel, and thus the byproducts of burning such fuel can contribute to the 20 Greenhouse Effect.

The most common binder component of synthetic firelogs is a petroleum slack wax or a synthetic polymer of high molecular weight which provides good adhesion with cellulosic fibers. Saturated fatty acids, such as palmitic or stearic acids, can 25 be used to raise the melting point of the wax blend or to solidify the binder. Unsaturated, oily fatty acids are generally excluded because they are liquid at room temperature and lack the binding characteristics required for firelogs. A liquid or soft wax binder material, such as that disclosed in 30 U.S. Patent No. 4,326,854, must be solidified with the fibres using chemical processes, such as polymerization or neutralization in order to form a firelog, which can significantly increase the cost and complexity of production.

WO 2008/076456 teaches an artificial firelog comprising a 35 combustible cellulosic material and a combustible non- 3 petroleum wax, derived from a plant oil, a vegetable oil, an animal fat, a rosin, a pitch and combinations thereof. As a result more environmental friendly artificial firelogs can be produced. However, the prices of natural oils are increasing 5 very rapidly due to the use as starting material for the production biodiesel.

A pricewise friendly alternative is offered by using corn by-products from ethanol production, marketed under the brand name alluma™. Typically these corn-based mixtures comprise 10 starch, yeast cells and proteins. These compounds possess a significantly lower energy value than the traditional petroleum waxes, owing the lower carbon content in the molecules. In addition, proteins contain nitrogen atoms, which can be upon combustion transformed into NOx compounds. These 15 products are known to be toxic.

OBJECTIVE OF THE INVENTION

It means that there is a need for more affordable, 20 efficient and low toxic binder materials for the production of artificial firelogs. In addition, it is advantageous when extra additives can be admixed to provide other characteristics, e.gr. the addition of sodium bicarbonate can give rise to lowering the CO emission upon burning the firelog 25 (WO 02/090472).

DESCRIPTION OF THE INVENTION

The invention relates to a method, composition and 30 products providing new firelogs having (a) 30% to about 70% by weight of a combustible non-petroleum additive and (b) about 30% to about 70% by weight of combustible cellulosic or fibre material constituent, possibly admixed with a petroleum wax, saturated fatty acid or salt, for a total of about 100 parts. 35 The non-petroleum additives of choice are selected from either 4 used deep fat (huge waste material in the Benelux) or residues, originating from distillation processes of biodiesel (methyl- and/or ethylesters of natural fatty acids) and related products, such as glycerol esters (mono-, di- en 5 triesters), pentaerythritol esters (mono-, di-, tri- en tetra esters) and sorbitan esters (mono-, di- en triesters). Typically, the residues contain, apart from the original (monomer) ester, high amounts polymeric compounds, including hydrolysable esters. These products are usually well-available 10 and affordable, while they are hardly applied yet on industrial scale other than a cheap fuel source. Owing to the high carbon level, the energy value of the esters is high.

Applicant has claimed in another patent that abovementioned fatty ester-based polymers can be used a 15 protective/preventive coating for maintaining storage and handling quality of solids, such as fertilizer granules.

Moreover, applicant has found that the selected fatty ester-based residues can be admixed with the traditional petroleum waxes. The solidification properties of the firelog 20 end product can further be adjusted by using saturated fatty acids, such as palmitic acid and stearic acid and mixtures thereof. Surprisingly, up to 10% (w/w) inorganic salts, such as sodium bicarbonate can be dissolved in the fatty acid ester residues. WO 02/090472 claims that this specific salt decrease 25 the CO emission upon combusting a firelog. In addition, it appeared that the addition of either sodium hydroxide or potassium hydroxide to the fatty ester residue leads to a strong increase of the viscosity. Moreover, the flame retardation can be adjusted by admixing various compounds, 30 such as used deep fat and inorganic salts. Consequently, the application of fatty ester residues as firelog constituent offers the producer very attractive opportunities: it matches with the traditional petroleum waxes, whereas it can also be tuned at wish by addition.of e.g. used deep fat or inorganic 35 salts.

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Examples of combustible cellulosic or fiber material that may be used include, without limitation, wood particles, pulp, shavings or chips, sawdust, ground bark, shredded paper or cardboard, waxed cardboard, charcoal powder, sphagnum moss, 5 and agricultural waste materials such as straw, grass clippings, leaves, cotton linter, rice hulls, peanut, almond, walnut or other nut shells and hulls, distillers grain or other cereal grain by-products and coffee grounds, and blends of any two or more of the foregoing.

10 The petroleum wax of a firelog material may be derived from a variety of sources, including without limitation those having a petroleum or non-petroleum base. A petroleum wax can contain one or more suitable wax or waxy materials, including without limitation combustible paraffin's, petrolatum's, 15 microcrystalline and waxy crude oils, consisting of any one of the following, in whole or part of a blend, including; slack wax, scale wax, residual wax, olefins, and resins.

The invention will be explained below with a number of examples, with the use of methods which are representative for 20 handling and testing of the new raw materials for artificial firelogs. These examples exclusively serve to explain and not to limit the claimed protective scope of the present invention.

25 EXAMPLES

To test the potential of new raw materials, artificial firelogs have been prepared on lab scale. The procedure starts by admixing saw dust (110 mesh) with fatty acid ester residue, 30 possibly followed by petroleum wax, saturated fatty acid (or its metal salt), inorganic salt or mixtures thereof (total amount of 20 grams) in a glass beaker at a temperature of approximately 90 °C. The components are thoroughly mixed by means of a spatula. The mixture is warmed up to 90 °C for 30 35 minutes and again thoroughly mixed. A plastic cylinder with a 6 diameter of 3.0 cm and a length of 14 cm is filled with the combustible mixture. Afterwards a piston is put in the cylinder at a pressure of 2 bar for 1 minute. The resulting firelog (3 cm high, 3 cm diameter) is allowed to cool down to 5 room temperature and subjected to a 5 minute burning test (Table 1). A mixture of saw dust and slack wax is used as reference.

Table 1. Compositions and characteristics of several firelogs 10

Raw materials Ratio Results

Reference: Saw dust, slack 50/50 Stable firelog.

wax (m.p. 65 °C, oil content After 5 minutes 25% (w/w)) burning, 2 mm of firelog outside is black.

Saw dust, used deep fat 50/50 , . . Stable firelog.

(polymerized triglyceride 10% , ., ,, After 5 minutes (w/w), triglycerides 80% ., burning only half (w/w), fatty acid 10% (w/w)) of the cylinder is burned (flame retardation).

Saw dust, biodiesel polymer 50/50 Stable firelog.

ester residue (polymerized After 5 minutes triglyceride 30% (w/w), non- burning, 6 mm of hydrolysable 50% (w/w), long firelog outside chain methyl ester 20% (w/w)) is black.

Saw dust, used deep fat, 50/25/25 Stable firelog.

biodiesel polymer fatty ester After 5 minutes residue burning, 2 mm of firelog outside is black.

Saw dust, biodiesel polymer 50/25/25 Stable firelog. fatty ester residue, slack After 5 minutes 7 wax burning, 2 mm of firelog outside is black.

Saw dust, biodiesel polymer 50/50 Stable firelog. fatty ester residue, After 5 minutes petrolatum (m.p. 85 °C, oil burning, 2 mm of content 10% (w/w/)) firelog outside is black.

Saw dust, biodiesel polymer 50/25/25 Stable firelog, fatty ester residue, some cracks, saturated stearic acid After 5 minutes burning, 3 mm of firelog outside is black.

Saw dust, biodiesel polymer 50/25/25 Stable firelog. fatty ester residue, After 5 minutes magnesium stearate burning, 2 mm of firelog outside is black.

Saw dust, biodiesel polymer 50/48/2 Stable firelog. fatty ester residue, sodium After 5 minutes bicarbonate burning, 2 mm of firelog outside is black.

Saw dust, biodiesel polymer 50/45/5 Stable firelog. fatty ester residue, sodium Upon burning, the hydroxide (33% aq) flame strongly retarded.

Saw dust, biodiesel polymer 50/45/5 Stable firelog. fatty ester residue, Upon burning, the potassium hydroxide (50% aq) flame strongly retarded.

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Saw dust, pentaerythritol 50/50 Stable firelog.

tetrastearate ester After 5 minutes burning, 3 mm of firelog outside is black.

Saw dust, sorbitan 50/50 Stable firelog.

tristearate ester After 5 minutes burning, 3 mm of firelog outside is black.

It can be concluded that both used deep fat, fatty esters and its polymerized distillation residues act as good binder 5 and combustion additive for artificial firelogs. It has been shown that the physical properties of fatty ester-based polymers can further be adjusted by either admixing other fatty esters or addition of petroleum waxes, saturated fatty acids, saturated fatty acid salts and/or inorganic salts.

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Claims

A combustible material containing a combination of combustible cellulose and combustible fatty acid ester derivatives.

2. Material according to claim 1, wherein the combustible material consists of 30 to 70% (m / m) cellulose, 30 to 70% (m / m) fatty acid ester derivatives with a final total of 100% (m / m).

3. Material according to one or more of claims 1 to 2, wherein the material is further provided with a petroleum wax or mixtures thereof.

4. Material according to one or more of claims 1 to 3, wherein the material consists of 30 to 70% (m / m) cellulose, 0.1 to 70% (m / m) fatty acid ester derivatives and 0.1 to 70 % (m / m) petroleum wax with a final total of 100% (m / m).

5. Material according to one or more of claims 1 to 4, wherein the material is furthermore provided with a saturated fatty acid, in particular hexadecanic acid, octadecanic acid or mixtures thereof.

6. Material according to one or more of claims 1 to 5, wherein the material consists of 30 to 70% (m / m) cellulose, 0.1 to 70% (m / m) fatty acid ester derivatives and 0.1 to 70 % (m / m) saturated fatty acid with a final total of 100% (m / m).

7. Material according to one or more of claims 1 to 6, wherein the material consists of 30 to 70% (m / m) cellulose, 0.1 to 70% (m / m) fatty acid ester derivatives, 0.1 to 70 % (m / m) petroleum wax and 0.1 to 70% (m / m) saturated fatty acid, with a final total of 100% (m / m).

8. Material according to one or more of claims 1 to 7, wherein the material is furthermore provided with a metal salt of fatty acid, in particular aluminum stearate and 1035853 magnesium stearate or mixtures thereof.

A material according to any one of claims 1 to 8, wherein the material consists of 30 to 70% (m / m) cellulose, 0.1 to 70% (m / m) fatty acid ester derivatives and 0.1 to 70 % (m / m) metal salts of fatty acid with a final total of 100% (m / m).

10. Material according to one or more of claims 1 to 9, wherein the material consists of 30 to 70% (m / m) cellulose, 0.1 to 70% (m / m) fatty acid ester derivatives, 0.1 to 70 % (m / m) petroleum wax, 0.1 to 70% (m / m) saturated fatty acid and 0.1 to 70% (m / m) metal salts of fatty acid with a final total of 100% (m / m).

The material according to one or more of claims 1 to 10, wherein the material further comprises an inorganic salt or mixtures thereof.

12. Material according to one or more of claims 1 to 11, wherein the material consists of 30 to 70% (m / m) cellulose, 30 to 70% (m / m) fatty acid ester derivatives and 0.1 to 10% ( m / m) inorganic salt, with a final total of 100% (m / m).

13. Material according to one or more of claims 1 to 12, wherein the material consists of 30 to 70% (m / m) cellulose, 0.1 to 70% (m / m) fatty acid ester derivatives, 0.1 to 70 % (m / m) petroleum wax, 0.1 to 70% (m / m) saturated fatty acid, 0.1 to 70% (m / m) metal salts of fatty acid and 0.1 to 10% (m / m) inorganic salt, with a final total of 100% (m / m). 30

A material according to any one of claims 11 to 13, wherein the inorganic salt contains sodium bicarbonate.

Material according to one or more of claims 11 to 14, wherein the inorganic salt contains a hydroxide, in particular sodium hydroxide and potassium hydroxide.

Material according to one or more of claims 1 to 15, wherein the combustible cellulose is from an organic source, in particular wood flour and sawdust.

The material of any one of claims 1 to 16, wherein the fatty acid ester derivative contains frying fat waste. 5

18. Material according to one or more of claims 1 to 17, wherein the combustible fatty acid ester derivative contains a residue from the distillation processes of biodiesel (methyl and / or ethyl esters of natural fatty acids) or methyl ester, ethyl ester, glycerol esters (mono-, di- and triesters), pentaerythritol esters (mono-, di-, tri- and tetraesters) and sorbitan esters (mono-, di- and triesters) or mixtures thereof.

19. Material according to one or more of claims 1 to 18, wherein the fatty acid ester derivative comes from the production of biodiesel.

20. Method for making combustible material in which a mixture is made of a combustible cellulose and combustible fatty acid ester derivatives.

A method according to claim 20, wherein the combustible material consists of 30 to 70% (m / m) cellulose, 30 to 70% (m / m) fatty acid ester derivatives with a final total of 100% (m / m).

A method according to any one of claims 20 to 21, wherein the material further comprises a petroleum wax or mixtures thereof. 30

A method according to any one of claims 20 to 22, wherein the material consists of 30 to 70% (m / m) cellulose, 0.1 to 70% (m / m) fatty acid ester derivatives and 0.1 to 70% (m / m) petroleum wax with a final total of 100% (m / m). 35

A method according to any one of claims 20 to 23, wherein the material is further provided with a saturated fatty acid, in particular hexadecanic acid, octadecanic acid or mixtures thereof.

A method according to any of claims 20 to 24, wherein the material consists of 30 to 70% (m / m) cellulose, 0.1 to 70% (m / m) fatty acid ester derivatives and 0.1 to 70% (m / m) 5 saturated fatty acid with a final total of 100% (m / m).

A method according to any one of claims 20 to 25, wherein the material consists of 30 to 70% (m / m) cellulose, 0.1 to 70% (m / m) fatty acid ester derivatives, 0.1 to 70% (m / m) 10 petroleum wax and 0.1 to 70% (m / m) saturated fatty acid, with a final total of 100% (m / m).

27. Method according to one or more of claims 20 to 26, wherein the material is further provided with a metal salt of fatty acid, in particular aluminum stearate and magnesium stearate or mixtures thereof.

A method according to any one of claims 20 to 27, wherein the material consists of 30 to 70% (m / m) cellulose, 0.1 to 70% (m / m) fatty acid ester derivatives and 0.1 to 70 % (m / m) metal salts of fatty acid with a final total of 100% (m / m).

29. Method according to one or more of claims 20 to 28, wherein the material consists of 30 to 70% (m / m) cellulose, 0.1 to 70% (m / m) fatty acid ester derivatives, 0.1 to 70 % (m / m) petroleum wax, 0.1 to 70% (m / m) saturated fatty acid and 0.1 to 70% (m / m) metal salts of fatty acid with a final total of 100% (m / m).

The method of any one of claims 20 to 29, wherein the material further comprises an inorganic salt or mixtures thereof.

A method according to any one of claims 20 to 30, wherein the material consists of 30 to 70% (m / m) cellulose, 30 to 70% (m / m) fatty acid ester derivatives and 0.1 to 10% ( m / m) inorganic salt, with a final total of 100% (m / m).

A method according to any of claims 20 to 31, wherein the material consists of 30 to 70% (m / m) cellulose, 0.1 to 70% (m / m) fatty acid ester derivatives, 0.1 to 70% (m / m) petroleum wax, 0.1 to 70% (m / m) saturated fatty acid, 0.1 to 70% (m / m) metal salts of fatty acid and 0.1 to 10% (m / m) inorganic salt, with a final total of 100% (m / m).

The method of any one of claims 30 to 32, wherein the inorganic salt contains sodium bicarbonate.

The method of any one of claims 30 to 33, wherein the inorganic salt contains a hydroxide, in particular sodium hydroxide and potassium hydroxide.

A method according to any one of claims 20 to 34, wherein the combustible cellulose is from an organic source, in particular wood flour and sawdust.

The method of any one of claims 20 to 35, wherein the fatty acid ester derivative contains frying fat waste. 20

37. A method according to any one of claims 20 to 36, wherein the combustible fatty acid ester derivative contains a residue from the distillation processes of biodiesel (methyl and / or ethyl esters of natural fatty acids) or methyl ester, ethyl ester, glycerol esters (mono-, di- and triesters), pentaerythritol esters (mono-, di-, tri- and tetraesters) and sorbitan esters (mono-, di- and triesters) or mixtures thereof.

The method of any one of claims 20 to 37, wherein the fatty acid ester derivative is from the production of biodiesel.

39. Material obtainable by the method according to any of claims 20-38. 35

40. A method for making a combustible product, wherein use is made of a material according to any of claims 1-19 or 39 or of a material obtained by the method according to any of claims 20-38, wherein the material is pressed, preferably in a mold, and the material is allowed to cure to a product with the desired shape.

A product obtainable by the method according to claim 40.

A product obtained by the method according to claim 40.

The product of claim 41 or 42, wherein the product is a hearth block. 1035853