Fuel Composition

Abstract

Disclosed herein are compositions of matter having valuable combustion properties. The compositions are particularly desirable in combinations having enhanced ignition and continued combustion properties in forms based on natural source and manmade (reconstituted) firewood and briquettes for heating, cooking and the like. The compositions involved contain mixtures of straight chain and branched chain olefins and paraffins of selected molecular weight with preference for the co-presence of higher alcohols, the latter being particularly effective components for purposes of enhancing the fabrication and burning characteristics of some of the compositions.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention pertains to compositions of combustibles containing mixtures of aliphatic olefins and paraffins and which preferably contain some form of porous cellulose or carbon and significant quantities of aliphatic alcohols. The alcohols preferred for inclusion in the compositions are in two principal categories with control of the proportioning of the alcohols between the two categories being useful to enhance certain desired properties. One category is mixed normal and branched primary alcohols which include and range upward from about eicosanol to about triancontanol, especially those ranging from eicosanol to tetracosanol. The other category is mixed normal and branched primary alcohols of lighter molecular weight than eicosanol ranging from about butanol to about octadecanol with particular preference for alcohols of the molecular weight from octanol to dodecanol. Mixtures as regards molecular weight and branching appear to provide more gradual "release" due to variations in physical properties.

The compositions outlined in the foregoing have numerous uses but of particular significance are those uses connected with fuels and combustion enhanced "solid" fuels such as fireplace logs of wood, natural as well as artificial; charcoal, in natural or compacted form, such as coke, and the like. The high content of olefinic and alcoholic molecules appears to enhance luminosity and minimize soot. In certain instances as in the production of light or of heat for cooking, certain categories of the compositions are useful as principal or as sole fuels because of properties of ease of ignition, of complete but prolonged combustion and of virtual absence of characteristic "natural petroleum" odors. Where the combustion is largely of a decorative or convenience nature as frequently is the case with the combustion of natural or manmade logs or briquettes in a fireplace or grill, certain compositions of the present invention provide logs which have improved ignition properties and enhanced resistance to deterioration caused by various factors such as insects, moisture, fungus, and the like. Certain categories of the compositions are useful in controlled-release combustion enhancement; particularly with dense logs such as some natural wood logs or strongly compressed manmade logs based on oak, fir or pine sawdust or chips. In many instances, it is difficult to maintain combustion of logs without controlled release combustion adjuvants as with large individual logs in fireplaces of where the logs are stored prior to use under conditions where moisture pickup is not prevented. Problems of the latter categories are minimized using teachings of the present application.

2. Description of the Prior Art

In combustion applications such as those outlined in the foregoing, petroleum-based materials of various forms and compositions have been used in various ways for a long time. Such petroleum-based materials are subject to certain limitations and have numerous undesired characteristics. One of the principal undesired characteristics in most instances is odor. As a practical matter, one cannot use kerosene without imparting the widely-known undesirable odor thereof to any environment involved. The present class of materials is characterized by unique odor properties and some of the compositions have desirable odors characteristic of coconut oil. The significance of this is that the average user of materials of the present class is familiar, and adversely so, with the odor of kerosene but is unfamiliar with the odor of the present material in such usage. Such a user soon comes to regard the materials involving the present compositions as something different and superior to "kerosene" containing materials, particularly with respect to matters associated with clean burning, safety, and absence of kerosene or gasoline odors.

Manmade logs based on various forms of cellulose such as compacted sawdust or wood chips, are not only difficult to ignite but are highly susceptible to rapid damage from moisture. Thus, in most prior art involving manmade logs, it has been common practice to dip or spray the manmade logs with "wax" molecular weight materials of approximately 20-30 carbon atoms per molecule. In general, this approach is of only limited effectiveness with regard to enhancing the moisture resistance properties of the materials as a surface coating because of cracks and pin holes and is not particularly effective in long-term combustion enhancement or in ignition because the waxes are surface coatings that are not particularly easy to ignite and which melt rapidly and drop off when heat is applied.

In some processes for making artificial logs, "wax" materials are incorporated into the logs as they are being compressed so that the wax type materials are caused to be present throughout the mass rather than merely being present on the surface. Although this can be fairly effective for combustion adjuvant purposes, the compressing processes generally involve significant heat providing hazardous manufacturing conditions and leading to recognition of a need for a better manufacturing process.

SUMMARY

In accordance with the principles of the present invention, compositions are provided which have highly desirable properties as principal fuels or as adjuvants to enhance the ignition and/or combustion of other fuel materials. The materials are characterized by clean burning properties, freedom from "petroleum" odors either prior to or during combustion and ease of application to co-present natural as well as manmade combustible materials. Exemplary of the natural materials usable with the present invention are natural wood logs such as those cut from trees, particularly hardwood materials such as oak, ash and the like which natural materials readily absorb liquid compositions and components of the present invention and which respond favorably to combustion as compositions of the present invention.

The fireplace use of natural wood logs involves several difficulties under ordinary circumstances. In the first place, fireplace combustion is frequently a "decorative" operation with the actual utilitarian purpose of developing heat being a secondary result. Thus, there are many instances in which one does not desire a roaring fire involving many logs simultaneously but rather prefers the economy of a single easily and quickly ignited long-burning log. Long-burning usually requires a dense natural log of considerable size, say 6-10 inches diameter. An untreated oak log of such size, alone, is difficult to ignite safely and to maintain in combustion and normally requires considerable preparation including the development of coals or fire from logs of lesser size. When such large logs are used as parts of compositions of the present invention, ignition is easy and the slow progressive or controlled release of pore-contained or capillary-contained liquid materials of the present invention prolongs and maintains combustion even without prior or continued co-presence of coals and heat baffling structures.

DISCUSSION

Typical compositions in accordance with the teachings of the present invention contain a compact porous carbonaceous body of organic or inorganic or a combination nature. Typical organic nature materials are cellulose in forms of natural wood logs and artificial or manmade bodies of a "log-type" configuration having for example a circular, split circular, polygonal, rectangular or a generally triangular or a semicircular cross section. Preferred natural wood logs are those of the "furniture" category of "hard woods" such as oak, ash, hickory; however, since the principal matter of importance for a compact porous carbonaceous body for the present in relationship to natural wood is the suitability for combustion in a house-type fireplace where the environment is low temperature as contrasted to an enclosed furnace. It is evident that the principles of the present invention apply to materials which are not necessarily considered hardwood for furniture purposes, additional typical suitable woods being fir, spruce, redwood, cypress, poplar, sycamore, cedar, pine, locust and the like.

Manmade or artificial logs are typically some form of compact natural-grown cellulose and which may or may not be of a "reconstituted" variety such as wood pulp, reclaimed newspapers, and magazines. Typical compacted natural cellulose materials are based on some form of sub-divided wood such as sawdust, chips, shavings, and the like. These materials are desired because of their "waste" nature which is conducive to low cost. Typical compacted natural cellulose materials are obtained from planing refuse, sawmill waste, bark, leaves, and sub-divided vegetable fibers. A typical sub-divided vegetable fiber is bagasse, which is a residue of the milling of sugar cane after the bulk of the sugar has been removed. Another vegetable fiber is corn stalks particularly in particulate form produced by grinding, shredding, pulverizing, and the like.

Other forms of compact porous carbonaceous bodies include "inorganic" materials composed largely of carbon such as by-products of the manufacture of carbon black, by-products of petroleum refining operations, and residues resulting from the generation of gas and other materials. In this last category of carbon-base materials is included materials well known by appearance or composition as petroleum or coal "coke," as charcoal briquettes, and the like, used for cooking.

It will be recognized that the foregoing recitation of typical compact porous carbonaceous bodies represents cellulose and carbon materials which are combustible but which are in general not particularly easy to ignite requiring either prolonged heating with ignition materials such as loose chips of wood, paper and the like or use in conjunction with a well-developed bed of fiery coals. It will be recognized that one would not give even momentary consideration to igniting such materials in the compacted form with merely a match; however, when those materials are combined with other materials as hereinafter recited to provide certain preferred compositions according to the present invention, the resulting compositions are capable of ignition quickly and cleanly upon the mere contact with the flame of the match, yet they do not drop or flash suddenly upon ignition.

The compositions of matter in accordance with the teachings of the present invention include a combination of a compact porous carbonaceous body and pore contained combustion and ignition adjuvant consisting essentially of aliphatic hydrocarbons preferably with aliphatic alcohols also present, the aliphatic hydrocarbons containing only carbon and hydrogen and being mixtures of olefins and paraffins having predominately from about eight to about 24 carbon atoms per molecule and having an olefin/paraffin weight per ratio from about 1:1 to about 10:1, the alcohols containing predominantly only one hydroxyl group per molecule, said group being primary, the alcohols having predominantly from about four to about 30 carbon atoms per molecule, the weight ratio of hydrocarbons to alcohol being from about 1:0 to about 1:1.

Particularly preferred compositions in accordance with the foregoing are those wherein the weight ratio of hydrocarbons to alcohol is from about 201 to about 1:1.

A further characterization of preferred compositions of matter includes that wherein the olefin/paraffin weight ratio is about 2:1. In preferred compositions in accordance with the present invention, the hydrocarbons are predominantly mono-olefinic, particularly where the olefins are predominantly straight chain alpha olefins. In certain preferred compositions of the present invention the paraffins include about 10 percent by weight of branched chain paraffins, the balance being unbranched.

EXAMPLE I

Fir sawdust or particle size ranging about one one-hundredth to one-fourth inch resulting from planar mill operations (circular saws, band saws, jointers, planers, shapers, etc.) is compressed under pressure of approximately 25,000 lbs./sq. inch to a volume of about one-third that of the loose material in a cylindrical form of approximately 4 inches diameter. Upon cooling and removing the pressure, the cylinders have considerable mechanical strength even where the only binder is the residual resin in the sawdust. (Finished length is approximately 16 inches). The compressed sawdust artificial logs are usable for combustion purposes directly but are difficult to ignite. The logs have a hard glossy exterior surface but the artificial logs are highly susceptible to damage from moisture because the surface is not impervious to moisture and because a significant portion of the compression pressure is retained as internal forces. Such a log disintegrates completely to a loose soggy mass within approximately 5 minutes upon insertion in water.

Artificial logs prepared as in the foregoing procedure were soaked for 5 hours at 25.degree. C. in a preferred olefin-paraffin composition having the following wt. percent analysis as determined by Vapor Phase Chromatography.

VPC Analysis n- Br- n- Br- (Atoms/Molecule) Paraffins Paraffins Olefins Olefins __________________________________________________________________________ 10 2.23 - 7.32 0.44 12 12.10 0.34 16.58 4.29 14 6.85 0.62 8.26 4.01 16 3.21 0.74 4.44 3.44 18 1.35 0.62 2.74 2.64 20 0.39 0.15 1.53 1.18 22 0.23 0.07 1.94 1.68 24 0.23 0.11 1.89 2.86 26 0.15 0.06 1.08 2.65 28 - - 0.21 1.37 26.74 2.71 45.99 24.56 __________________________________________________________________________

In a five-hour soak period, the artificial log which previously weighed approximately 6 lbs picked up approximately 11/2 pounds of the olefin-paraffin composition.

The foregoing log, although usable immediately, was allowed to stand for approximately 24 hours to age and achieve uniformity of distribution of the olefin-paraffin material. It was then placed on a pair of andirons in a fireplace with no other combustible material present. The log was ignited at both ends with a single match. The log ignited quickly, the fire spreading across most of the surface in about 1 minute. The log burned continuously with a pleasantly luminous flame and with little visible smoke for about 2 hours and 15 minutes.

Without the foregoing olefin-paraffin mixture, it is usually necessary to stack three logs together and break up a fourth to get ignition.

EXAMPLE II

Example I is repeated with reconstituted fir, pine, and other types of wood. Similar desirable results are obtained.

EXAMPLE III

Example I is repeated with natural oak, fir pine, etc., logs in various sizes and shapes as material with which hydrocarbon and alcohol adjuvant materials recited is combined. Similar long burning and ease of ignition are experienced.

EXAMPLE IV

Example I is repeated with coke, natural and artificial, and with charcoal briquettes as material with which hydrocarbon and alcohol adjuvant materials recited are combined. Similar long burning and ease of ignition are experienced.

EXAMPLE V

Example I is repeated with waste paper, magazines, newspapers, bagasse, cornstalks as the material used to produce a compact porous carbonaceous body with which hydrocarbon and alcohol adjuvant materials are combined. Similar long burning and ease of ignition are experienced.

EXAMPLE VI

The preceding examples are repeated wherein the adjuvant compositions are according to the following ratios by weight. Similar desirable results are obtained.

Adjuvant from about 5 to about 25 percent by weight of pore-contained organic combustible consisting essentially of aliphatic hydrocarbons and aliphatic alcohols in combinations of the following tabulation:

Ratios: Hydrocarbon/Alcohol 100/0 95/5 90/10 85/15 80/20 75/25 70/30 60/40 50/50 Hydrocarbons: (predominantly C.sub.10.sup.-14) Olefin/Paraffin 90/10 85/15 80/20 50/50 Alcohols Alcohols C.sub.8 -C.sub.18 Alcohols (C.sub.20 -C.sub.24) 1/0 3/1 2/1 1/1 1/2 1/3 0/1

example vii

example VI is repeated with hydrocarbons being predominantly eight to 24 carbon atoms per molecule and alcohols being predominantly four to 30 carbon atoms per molecule, the low and high alcohol categories being split between C.sub.18 and C.sub.20 as in Example VI. Similar desirable results are obtained.

EXAMPLE VIII

Compositions of paraffin, olefins and alcohols as tabulated in Example VI are burned as sole fuels in a wick-type combustion device, a glass chimney "kerosene" lantern. Excellent flame luminosity is obtained with little soot and with absence of characteristic "kerosene" odor. In this example the highest ratio of hydrocarbon to alcohol is 95/5 (about 20/1).

Claims

We claim:

1. In combination, a compact porous combustible carbonaceous body selected from the group consisting of cellulose and carbon and, additionally,

from about 5 to about 25 percent by weight of pore-contained organic combustible contained with the pores of the carbonaceous body consisting essentially of aliphatic hydrocarbons and aliphatic alcohols,

the aliphatic hydrocarbons containing only carbon and hydrogen and being a mixture of olefins and paraffins having predominantly from about eight to about 24 carbon atoms per molecule and having an olefin/paraffin weight ratio from about 1:1 to about 10:1,

the alcohols consisting essentially of molecules having from about four to about 30 carbon atoms and having only one hydroxyl group per molecule, said group being primary,

the weight ratio of aliphatic hydrocarbons to alcohol being from about 1:0 to about 1:1.

2. The combination of claim 1 wherein the compact porous carbonaceous body consists essentially of compacted particles of cellulose.

3. The combination of claim 2 wherein the compacted particles consist essentially of subdivided wood.

4. The combination of claim 2 wherein the compacted particles consist essentially of wood sawdust.

5. The combination of claim 2 wherein the compacted particles are obtained from paper.

6. The combination of claim 2 wherein the compacted particles consist essentially of vegetable fiber.

7. The combination of claim 6 wherein the compacted particles consist essentially of particulate corn stalks.

8. The combination of claim 1 wherein the compact porous carbonaceous body consists essentially of compacted particles of carbon.

9. The combination of claim 1 wherein the compacted particles consist essentially of coke.

10. The combination of claim 1 wherein the compacted particles consist essentially of petroleum coke.

11. The combination of claim 1 wherein the compacted particles consist essentially of coal coke.

12. The composition of claim 1 wherein the weight ratio of hydrocarbons to alcohol is from about 20:1 to about 1:1 and the alcohols are predominantly alcohols having from about eight to about 24 carbon atoms per molecule.

13. The composition of claim 1 wherein the weight ratio of hydrocarbons to alcohol is from about 20:1 to about 1:1 and the alcohols are predominantly alcohols having from about 20 to about 24 carbon atoms per molecule.

14. The composition of claim 1 wherein the weight ratio of alcohols having up to 18 carbon atoms per molecule to alcohols having 20 and more carbon atoms per molecule is about 1:1.

15. The composition of claim 1 wherein the hydrocarbons are predominantly olefinic hydrocarbons.

16. The composition of claim 1 wherein olefin/paraffin weight ratio is about 2:1.

17. The composition of claim 1 wherein the olefins are predominantly straight chain alpha olefins.

18. The composition of claim 1 wherein the straight chain alpha olefins are about two-thirds of the total olefins on a weight basis.

19. The composition of claim 1 wherein the paraffins are predominantly straight chain.

20. The composition of claim 1 wherein the paraffins include about 10 percent by weight of branched chain paraffins.

21. The composition of claim 1 wherein the hydrocarbon/alcohol weight ratio is about 3/1.

22. The composition of claim 1 wherein the hydrocarbon/alcohol weight ratio is about 3/1 and the alcohols are predominantly alcohols having from 20 to 24 carbon atoms per molecule.

23. The composition of claim 1 wherein the hydrocarbon/alcohol weight ratio is about 1/1, about half of the alcohols by weight having from about 20 to about 24 carbon atoms per molecule.