WO2004035396A1

WO2004035396A1 - Simple biodiesel production device

Info

Publication number: WO2004035396A1
Application number: PCT/AU2003/001352
Authority: WO
Inventors: Terry Shulze
Original assignee: Terry Shulze
Priority date: 2002-10-16
Filing date: 2003-10-14
Publication date: 2004-04-29
Also published as: AU2002952102A0; NZ539920A

Abstract

A hand held device to produce small amounts of biodiesel by a transesterfication process, having a funnel shaped outlet conduit and valve to decant stratified layers through the outlet when the device is titled, a system of level marks on the container for various selective amounts of feedstock and additives and for evaluating the process from the resulting amount of byproduct, and orifices for filling and venting. Tilting means are disclosed A chemical mixture to create a chemical reaction for the transesterfication process is disclosed.

Description

SIMPLE BIODIESEL PRODUCTION DEVICE

Field of the Invention

This invention relates to the production of methyl/ethyl esters (biodiesel), specifically it is a hand held device that allows an individual to produce biodiesel without the need for expensive equipment or significant training.

Discussion of the Related Art

Methyl/ethyl esters, or more commonly referred to as biodiesel, is a diesel fuel obtained from a process called transesterification that makes use of organic fats and oils (feedstock). Biodiesel can be made with either freshly processed fat or oil, or with well used waste cooking oil. The transesterification process makes use of an alcohol (usually methanol or ethanol) and a catalyst (usually Sodium Hydroxide or Potassium Hydroxide) and through the chemical process breaks the bonds of the ester chains in the triglyceride from the glycerol molecule and allows the said alcohol to bond with the freed ester chains. Further any Free Fatty Acids (FF A) that is present in the feedstock is bonded with excess base catalyst to form a soap molecule. Both the newly freed glycerol molecule and the soap molecule are more dense than the resulting biodiesel and therefore precipitate out. The result from the chemical reaction is a layer of biodiesel suspended over the heavier glycerin/soap layer.

The chemical composition needed for the reaction can vary considerably. The stoichiometric ratio of methanol to the triglyceride varies with the feedstock from which the triglyceride is derived. Most oils and fats have stoichiometric ratios which call for around 12.5% of methanol. per volume of oil/fat. However, canola oil produces the best return of biodiesel with the least amount of glycerol with a stoiciometric ratio that gives a mixture of around 11.3% of methanol by volume of oil. Of the common fats/oils found in waste vegetable oil; lard requires about 12.7%, tallow about 12.4%, palm oil about 13%, peanut oil about 12.3%, cottonseed oil about 12.6%, soy been oil about 12.5%. Coconut oil requires much more methanol for a complete reaction, that is, around 16.3% methanol by volume of oil. As can be seen from the various constituents that may be found in waste vegetable oil (WVO), the amount of methanol to arrive at a chemically correct mixture varies with the base oil and what has been cooked within it.

Further, the amount of conversion of the feedstock to biodiesel depends to a great degree on the amount of alcohol in the process, an excess of the stociometric amount is necessary for a good reaction. Generally, if 18% by volume of methanol is used the process will produce biodiesel that is approximately 90% converted from tryglycerides to biodiesel. At 25% by volume the amount of conversion is around 98% biodiesel. The remaining unprocessed feedstock will be composed of various amounts of mono, di and tryglycerides, which remain in the fuel Although commercial grade biodiesel is usually in excess of 96% conversion that level of conversion is not necessarily required for safe usage. It should be noted that the original diesel engine that was built by Rudolf Diesel was designed to run on straight vegetable oil.

There are two further complications in measuring the amount of methanol needed for the reaction in WVO. First, not only does the amount of methanol required for a good reaction increase as the stoichiometric ratio of the oil increases, but the increase in glycerol from the use of these type of oils will also absorb some of the methanol into solution, thereby depriving the reaction of some methanol.

The second complication concerns the amount of FFA that the WVO contains. The more used/heated/older the feedstock the more FFA the feedstock will contain. The higher the FFA, the more soap that is produced into the byproduct and the more methanol that the soap will bond with. Thus, a higher FFA feedstock will require not just more catalyst for the reaction, but will require more methanol as well.

In addition to the said complexities of the chemical process, the commercial production of biodiesel requires multiple vessels, pipes, pumps and machinery to mix the various fluids. The large amount of equipment used in commercial production of biodiesel thus creates an economic barrier to persons who wish to make small amounts of biodiesel from feedstock they may have on hand. Further, the process (called titration) of determining the FFA that may be present in a given feedstock, and which needs to be neutralised, is a complicated and time consuming activity that most lay persons find overly difficult.

Many shop keepers, restaurant owners and other individuals have access to small amounts of feedstock suitable for biodiesel production. However, the small amount of feedstock that they may possess does not lend itself to devoting significant time, energy or capital to the conversion of the feedstock to biodiesel. Presently, there are no simple commercial devices available to the average person to manufacture biodiesel. Even if a person decides to expend the effort to make a small homebuilt biodiesel processor, it usually becomes necessary for the individual to have some basic chemical training and understanding in order to perform the necessary functions.

The invention allows any person to manufacture biodiesel with just a minimum of capital outlay, physical effort and knowledge of chemistry. It is comprised of a vessel of clear or opaque plastic and uses the physical shaking, by hand, of the mixture in the vessel to produce biodiesel. The vessel is fitted with openings that allow the input of fluids and for the careful draining off of stratified layers. The vessel incorporates lined levels on the sides of the vessel to assist the person in calibrating the amount of feedstock and the special blend of alcohol/catalyst (Biodiesel Converter) that will promote the reaction to produce biodiesel.

Further, the opening used to drain off the stratified layers is in the form of a funnel or pipe running into a valve system whereby the person can physically watch the fluids moving through the conduit and thereby quickly cut off the flow at the appropriate time. In UK patent 2 300 560 the funnel so described is essentially a traditional funnel that has been joined to the side of an open basin. The funnel in that design is to reduce spillage from the open basin into another vessel, such as decanting the waste sump oil from a vehicle into another container. The design for the function of the UK patent is considerably different to the longer clear conduit incorporated with the closed vessel that comprises the biodiesel processor, the primary purpose of which is to allow for more precise division of the layers. SUMMARY

The object of the invention is to provide a quick, easy and inexpensive way to produce biodiesel from small amounts of available oil or fat. The invention simplifies the process so that the operator of the invention need not have any formal training in chemistry.

The process is simplified by the elimination of multiple vessels for production as the pre- mixed chemical mixture is already optimized for the invention. The invention also allows the operator to economise during the process by minimizing the amount of chemical mixture used in order to maximize the amount of biodiesel produced. It allows a person to monitor the process to make sure the reaction was adequate for the particular feedstock

It is understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrates embodiments of the invention and together with the description serve to explain the principles of the invention:

In the drawings:

Fig. 1 illustrates a perspective view of the invention;

Fig. 2 illustrates a side view of the invention mentioned in Fig 1 above;

Fig. 3 A illustrates a side view of the invention positioned for decanting using an attached pivot;

Fig. 3B illustrates a side view of the invention positioned for decanting using an object to position the invention;

Fig. 4 illustrates a side view of the invention with the cap off of the vent orifice; Fig. 5 illustrates a perspective view of the invention showing various levels of feedstock on the invention;

Fig. 6 illustrates a close-up corner view of the vessel showing the level lines on the invention;

Fig. 7 illustrates a hypothetical level of biodiesel and byproduct in the invention when using the 15% level of biodiesel converter;

Fig. 8 illustrates a hypothetical level of biodiesel and byproduct in the invention when using the 20% level of biodiesel converter;

Fig. 9A illustrates a bolt hole mounting system for decanting using full length ribs;

Fig. 9B illustrates a bolt hole mounting system for decanting using partial length ribs;

Fig. 9C illustrates a notch mounting system for decanting using partial length ribs;

Fig. 9D illustrates a pivot mounting system for decanting that is folded up against the body of the invention;

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

As stated in the "Discussion of the related art", the production of biodiesel results in two distinct stratified layers. The advantage of the proposed design is that by tilting the vessel (as in Fig. 3A or 3B) the lower layer of glycerin/soap herein referred to as byproduct, will move to the conduit/funnel section of the vessel and be positioned next to the valve/petcock. By use of the valve/petcock the lower layer of byproduct from the chemical reaction can be carefully drained off. Whereas other small vessels may have valves/petcocks for decanting fluid from the vessel, they are not specifically designed to allow the removal of stratified layers. The conduit in the invention is designed without any impediments to the removal of a lower layer of stratified fluid. That is, there are no steps or lips from the manufacturing process to catch and hold any of the lower layer. The conduit section is a smooth continuous egress from the main body of the vessel.

Further, by designing the conduit to flow through a narrow section there will be less volume within the conduit as compared to a large mouth funnel. This allows less fluid to be left in the conduit while increasing the accuracy of the cut-off point that is used to stop the decanting. The conduit section is also designed so that it is clear or opaque and thus the operator can watch the fluids move through the conduit and easily determine the cutoff point.

The petcock (Fig. 2,1) is also designed to work in conjunction with the tapered conduit system. The internal design of the petcock is made without any steps or lips that would catch and hold any of the lower layer. The petcock can be made of clear or opaque material Further, the opening of the petcock can be angled to work in conjunction to the tilting of the vessel. As the vessel is tilted downward, the petcock opening becomes more vertical to the ground. The extended petcock opening is also designed so that a hose may be attached to the open end of the petcock and remain there while a decanting operation is underway.

Another embodiment of the invention is a shorter funnel or conical section on the vessel with the main conduit for egress being provided by the neck of the petcock (Fig. 2,1). In this embodiment the petcock is made of clear or opaque material and the neck of the petcock may be drawn out and narrowed in order to provide a more accurate cut-off point.

As can be seen in drawing Fig. 4 an air vent is incorporated into the processor. The position of the air vent is designed to remain above the fluid level when the processor is tilted to the decanting position (Fig. 3 A or 3B). The operation of the air vent is by way of a screw on cap (Fig. 4,2) that closes off a small orifice into the processor.

During the mixing phase and for a short period after the mixing phase of the process the air vent is kept closed. Keeping the processor closed during this time not only eliminates spillage, but stops methanol evaporation from the processor. Initially, the methanol is warm and will try to evaporate off before it is chemically bound in the reaction. The closed vessel allows the methanol to condense on the inside of the vessel and re-enter the reaction. This condensation process can be seen working during the first part of the reaction. By processing using a closed vessel, the chemical process results in less methanol being needed for the reaction and a safer working environment for the user as free methanol vapors are reduced.

The air vent is only needed when the air pressure in the processor drops below the air pressure out side the processor. This pressure differential begins to occur a few minutes after the mix begins to cool from the reaction and later when the operator begins to decant from the processor.

The aforementioned lined levels allows an operator to accurately add to the vessel the required amount of feedstock and then subsequently the addition of the chemical mixture (Converter) necessary for the chemical reaction. The level marks first designate a given amount of feedstock that has been added to the vessel for processing (say 5 litre, 6 litre, etc). Each level line for a given amount of feedstock is accompanied with its associated Converter and Byproduct levels (Fig. 6). The level lines for the volume of feedstock continue around the sides of the processor, for example, starting at 5 litres and increasing to 14 litres in one litre increments (Fig. 5)

Above the level line for the feedstock is another set of level lines for a given amount of Converter. The Converter fluid will be subsequently added to the feedstock and the volume of Converter fluid will bear a relationship to the amount of feedstock that is present in the vessel. The relationship of the Converter may be designated in amounts of say 15%, 20% and 25% by volume of the feedstock (Fig. 6)

The marks for these various levels may take into consideration the type of feedstock and the extra volume of the feedstock caused by the expansion of the feedstock during heating (usually 50C-55C). The level for the Converter may also take into consideration its volume at ambient temperatures (say 21 C temperate climate, 30C tropical).

The level marks for the byproduct (Fig. 6) of the chemical reaction (the glycerin/soap layer) will be below the level marks for the feedstock. The level marks for the byproduct of the chemical reaction will also have separate levels (say 15%, 20% and 25%) that correspond to the amount of Converter that is used during the reaction.

As stated in the discussion of the related art that canola oil required the lowest stoiciometric ratio of methanol of 11.3. Further, that the average stoiciometric ratio for most oil/fats found in WVO was around 12.5. By designing the byproduct lines to correspond to the stoichiometric ratio requirements of fresh canola oil, the lower range will always set a minimum level for conversion with all available oil/fats. Should a reaction not produce enough byproduct to reach the lower level, then the reaction has been incomplete.

The design of the byproduct line should be done in conjunction with using fresh canola oil and the Converter that is to be used in the processor. It may be that within a locality that only 98% pure methanol is available, or that only 95% pure potassium hydroxide is available. As such, the byproduct line will differ slightly from the byproduct line that would be arrived at by using 100% pure methanol and 100% pure potassium hydroxide.

Although one might assume that the bottom level of the lowest range (say 15%) would be the bottom level of all ranges as the amount of glycerol for a given amount of oil remains the same, however, that is not the case. As more Converter is introduced into the mixture, most of the excess alcohol in the mixture is absorbed into the byproduct, thereby raising the top level of the byproduct. As such, the more Converter that is used, the higher the level of the byproduct range must become. Therefore it is necessary that a specific and distinct byproduct range be designated for each level of Converter volume (Fig. 6)

The need for the various amounts of Converter is explained as follows. An increase in the amount of Converter used will result in both extra catalyst and alcohol being introduced into the mixture. An increase in catalyst allows the Converter to neutralize more FFA. An increase in alcohol allows the Converter to reach a higher level of conversion of the feedstock to biodiesel. Also, as stated in the related art, with certain feedstock with high FFA, there is a need for an increase in both alcohol and catalyst in order to complete the reaction. The formula for the Converter is designed to allow for a multitude of feedstock with variations in FFA content. Further, the byproduct range levels ensures that the operator is provided with adequate information regarding the extent of the transesterification process.

The Converter is composed of methanol and/or ethanol. The use of methanol is the preferred choice as it allows a high conversion of the feedstock and it creates a more reliable reaction. The catalyst is composed of potassium hydroxide and/or sodium hydroxide. The use of potassium hydroxide is generally the preferred choice as it allows the glycerin/soap layer to remain fluid for a much longer period than the sodium hydroxide catalyst. However, in tropical climates the use of sodium hydroxide may be the catalyst of choice as it is less expensive and the higher ambient temperatures will prevent the glycerin/soap layer from solidifying.

The preferred chemical mixture for the Converter may vary with significant changes in feedstock. In the conversion of coconut or palm kernel oil, the blend of the chemical mixture would require more methanol (approximately 25% more) in the reaction because of the need for a higher stoichiometric ratio. The need for more methanol in the reaction of coconut and palm kernel oil sets these two oils apart from the rest of the feedstocks and would likely require entirely different level lines on a specially made model of the invention.

A hypothetical operation of the process may be explained thus; if an operator was to use 15% Converter to a given amount of oil/feedstock and the chemical reaction did not take place, that is, there is no separation of the biodiesel and byproduct, then more Converter must be used. Or in the alternative, if there is separation and the resulting level of the byproduct line is below the minimum (Fig. 7), then again more Converter must be used. The operator should go on to add more Converter to the processor, say to the 20% volume level, then after mixing the contents and waiting a short time, recheck the byproduct level and see if the level reaches or is above the 20% minimum byproduct level (Fig. 8) For most applications, and the preferred embodiment of the invention, the blend of the Biodiesel Converter is 100% pure methanol with 68 grams of pure potassium hydroxide per litre of methanol (however the invention is not limited to this blend of catalyst and alcohol). Changes in the blend may affect the accuracy in using the level lines on the processor, as such, the chemical blend and the processor are rationally linked. The invention is comprised not only of the hand processor, but also includes the chemical blends that would work for a given processor.

Significant changes in feedstock, such as with coconut oil would require a different processor and a different chemical blend to go with that processor. The invention claims all chemical blends that would work with a processor. Chemical blends might be made of 99% pure methanol and 95% pure potassium hydroxide/sodium hydroxide, which would closely mimic in function the above preferred embodiment. Further, a change say from 68 grams of pure potassium hydroxide to 70 grams pure potassium hydroxide would also mimic the preferred embodiment and are included in the claim of the invention.

The above mentioned preferred embodiment of chemical blend is a very strong base mixture with the ability to convert most suitable feedstock containing very high FFA when used at high levels of concentration such as 20% and 25% by volume. However, at 15% by volume the limit of the Converter is for a feedstock containing a more modest amount of FFA. This is in recognition that the better feedstocks for biodiesel require less methanol and catalyst for a good reaction.

The amount of FFA that a mix of 15% of Converter of the said blend would safely neutralize is about 2.6% FFA (WVO with 2% of FFA content is usually available from many diverse supplies). A 20% mix of the said blend would neutralize about 4.2% FFA and a 25% mix would neutralize about 5.9% FFA.

The yield of fuel that results from the use of high FFA decreases markedly as the FFA increases. With 2.6% FFA the yield is approximately 90% of the volume of the WVO. As the FFA increases to 4.2% the yield drops to approximately 79% and at 5.9% FFA the yield drops to approximately 68%. The careful choice of feedstocks becomes evident when considering the economic viability of the process. The higher FFA feedstocks not only require more methanol and catalyst for the reaction, but also release less biodiesel.

"Washing" is the process of mixing water in with the biodiesel to remove any left over soap and methanol. The washing process is not entirely needed as some people have been using "unwashed" biodiesel in their engines for considerable time and no ill effects have been noted. However, all commercial biodiesel is washed and many persons would prefer this extra treatment to their biodiesel.

An example of "washing" is given thus - To wash with the processor is simplified by the use of the decanting funnel. In the first wash; water of a quantity that is 5% of the original volume of feedstock is slowly added down the inside wall of the tilted processor. This allows the water to settle into the bottom with the byproduct. This first addition of water performs several functions, first it allows a slight washing of the biodiesel, it makes the byproduct easier to drain and it frees up any trapped biodiesel in the byproduct. The addition of 5% water to the byproduct can increase the yield of biodiesel as much as 5% in heavy FFA feedstock.

After about an hour, the byproduct/water mix is drained from the processor by the use of the funnel and petcock configuration. After decanting the byproduct and water mixture, the processor is then brought upright and more water is introduced slowly down the inside of the processor. The amount of water used in this second wash can be as much as the processor can safely hold without spilling through the open air vent while in the decanting position. The processor is then sealed and lain on its side. This laying flat position allows more surface area of the water to come in contact with the biodiesel. After leaving for an extended period, perhaps even overnight, the processor is then drained of the water through the funnel and petcock configuration.

The biodiesel can then be used, or if further washing is desired the process can be repeated. By keeping the turbulence low during the initial washing process described above, a person can avoid introducing fine water droplets into the biodiesel. Subsequent washings can be more agitated as the amount of soap remaining in the biodiesel decreases. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided that they come within the scope of the appended claims and their equivalents.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:-

1. A hand held mixing device for producing biodiesel, being a vessel having: a clear or opaque body and a conduit on said vessel leading to an orifice controlled by a valve.

2. A device as claimed in claim 1, further said valve being detachable.

3. A device as claimed in claims 1 and 2, having an inlet, whereby said inlet will allow material to be placed within said vessel.

4. A device as claimed in claims 1 to 3, having an air vent, whereby said air vent will allow the equalization of pressure in said vessel to the outside air.

5. A device as claimed in claims 1 to 4, having liquid level markings incorporated on the sides of said vessel whereby to indicate the amount of feedstock in said vessel.

6. A device as claimed in claims 1 to 5, having liquid level markings incorporated on the sides of said vessel whereby to indicate the amount of chemical mixture to be added to said feedstock.

7. A device as claimed in claims 1 to 6, having liquid level markings incorporated on the sides of said vessel whereby to indicate the minimum amount of byproduct from a resulting chemical reaction of said feedstock and said chemical mixture.

8. A device as claimed in claims 1 to 7, having said valve with an angled outlet.

9. A device as claimed in claims 1 to 8, having a carry handle incorporated into the body of said vessel.

10. A device as claimed in claims 1 to 9, having a fitting, lever, fixture, holes, lip, hook, notch or similar device incorporated onto or into said vessel thereby providing means for said vessel to be held in a position to assist settling and decanting.

11. A chemical mixture of methanol and potassium hydroxide to be added to said vessel in claims 1 to 10, and thereby convert by said chemical reaction said feedstock to biodiesel within said vessel.

12. A chemical mixture of methanol and/or ethanol containing quantities of potassium hydroxide and/or sodium hydroxide to be added to the said vessel in claims 1 to 10, and thereby convert by said chemical reaction said feedstock to biodiesel within said vessel

13. Said chemical mixture as in claims 11 to 12 with the properties of increasing amounts of said chemical mixture resulting in an increase in the rate of conversion of said feedstock to biodiesel, and with increasing amounts of said chemical mixture resulting in an increasing rate of conversion of the free fatty acids to soap within said vessel.

14. Said chemical mixture as in claims 11 to 13 whereby the results from said chemical reaction in said vessel will have a relationship to said level markings on said vessel.

15. A device for producing biodiesel substantially as hereinbefore described with reference to the accompanying drawings.