Method for reducing the emission of greenhouse gasses from livestock into the atmosphere

Technical field of the invention

The invention relates to a method for reducing the emission of methane and possible other carbonaceous gasses from livestock into the atmosphere. The invention also relates to an animal feed composition for reducing the emission of methane and possible other carbonaceous gasses from livestock into the atmosphere. Furthermore, the invention relates to a method for manufacturing such animal feed composition.

Background of the invention

Negative environmental and health effects, such as global warming, smog, and respiratory problems in humans caused by the emission of harmful pollutants, such as methane, N ₂ 0 and carbon dioxide (C0 ₂ ), have resulted in countries, states, and territories throughout the world regulating the amount of emissions permitted by businesses and industries. Some scientists claim that the C0 ₂ emissions are causing global warming under the theory that the emissions create a greenhouse effect. The source of these and other emission pollutants can come from a myriad of industries, such as industries breeding livestock.

Cattle typically lose 6% of their ingested energy as eructated methane, and further greenhouse gasses are developed and emitted from the manure. Animal science nutrition research has focused on finding methods to reduce methane emissions because of its inefficiency not because of the role of methane in global warming. However, because methane can affect climate directly through its interaction with long-wave infrared energy and indirectly through atmospheric oxidation reactions that produce C0 ₂ , a potent greenhouse gas, more recent attention has been given to its potential contribution to climatic change and global warming. Eructation of methane by cattle begins approximately 4 weeks after birth when solid feeds are retained in the reticulorumen. Fermentation and methane production rates rise rapidly during reticulorumen development. Estimates of yearly methane production of the typical beef and dairy cow range from 60 to 71 kg and 10 to 126 kg, respectively.

Various countries have agreed to reduce their C0 ₂ emissions under the Kyoto Protocol. The Kyoto Protocol is a protocol to the international Framework

Convention on Climate Change with the objective of reducing greenhouse gases in an effort to prevent anthropogenic climate change.

As of May 2008, 182 parties have ratified the protocol. One hundred thirty seven developing countries have ratified the protocol, including Brazil, China and India, but have no obligation beyond monitoring and reporting emissions. Thirty six developed C.G. countries including the EU as a party in its own right are required to reduce greenhouse gas emissions to the levels specified for each of them in the treaty (representing over 61.6% of emissions from Annex I countries. The United States is the only developed country that has not ratified the treaty and is one of the significant greenhouse gas emitters. With that aim, it will provide a complex system which will allow some countries to buy emission credits from others.

The emission credits (or carbon credits) are measured in "equivalent metric tons of carbon dioxide", the main heat-trapping gas blamed by scientists for climate change. Thus, one credit is equal to one tonne of C0 ₂ -equivalent. This means that all other greenhouse gasses have to be converted into C0 ₂ -equivalents.

Under the Kyoto Protocol, the Conference of the Parties decided (decision 2/CP.3) that the values of "Global Warming Potential" calculated for the IPCC Second Assessment Report are to be used for converting the various greenhouse gas emissions into comparable C0 ₂ equivalents when computing overall sources and sinks. GWP is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming. It is a relative scale which compares the gas in question to that of the same mass of carbon dioxide, whose GWP is by definition 1. The Clean Development Mechanism (CDM) is an arrangement under the Kyoto Protocol allowing industrialised countries with a greenhouse gas reduction commitment (called Annex 1 countries) to invest in projects that reduce emissions in developing countries as an alternative to more expensive emission reductions in their own countries. A crucial feature of an approved CDM carbon project is that it has established that the planned reductions would not occur without the additional incentive provided by emission reductions credits, a concept known as

"additionality". Absorbing methane and other gasses formed from liquid manure or slurry of partly liquids, partly solid manure (semi-liquid manure) is known in different aspects. Often methane and other gasses are collected in closed tanks, or the manure is added a catalyser or the like to eliminate formation of methane and/or other carbonaceous gas by electrochemical ion bonding.

Forming carbonaceous solid matter in a pyrolytic process is also known. It is also known that the pyrolytic matter has voids so that the pyrolyzed lignocellulotic composition has certain porosity. Often, a pyrolytic process is used for burning gasses formed during the pyrolytic process. The solid matter formed during pyrolysis may be disposed of, either by being burned for energy or by being recycled as fertilizer.

WO2009/049631 discloses a method for absorbing methane gas or other carbonaceous volatile gasses formed from organic waste material. The method comprises

- loading of a solid pyrolyzed lignocellulotic composition into a vessel,

- loading the volatile gas to be absorbed into the vessel,

- said gas being a free constituent or an ionic constituent of an organic waste material such as excrements of livestock, preferably being an ionic constituent of a liquid phase of excrements of livestock, and

- said method using pyrolyzed lignocellulotic composition as absorbent being formed by subjecting plant material to temperatures of at the maximum 700°C in a pyrolytic process thereby forming the pyrolyzed lignocellulotic composition having a solid structure. WO2011/044905 discloses an animal feed composition for reducing the emission of methane and possible other carbonaceous gasses from livestock into the atmosphere. Furthermore, the invention relates to a method and an apparatus for manufacturing such animal feed composition.

Summary of the invention

One object of the present invention is to provide a method, which gives a possibility to reduce the emission of methane, possible other carbonaceous gasses, and possible N ₂ 0 from livestock into the atmosphere.

Another object of the present invention is to provide an animal feed capable of reducing the emission of methane, possible other carbonaceous gasses, and possible N ₂ 0 from livestock into the atmosphere. Surprisingly, the inventors of the present invention experienced that animal feed comprising a pyrolyzed lignocellulotic composition may catch fire during the pelleting process. Hence, another object of this invention is to provide a method for producing an animal feed comprising a pyrolyzed lignocellulotic composition. Another object of this invention is to minimize the energy consumption during the pelleting process.

The method according to the invention, for reducing the emission into the atmosphere of methane and possible other carbonaceous gasses being produced during processing of feed in the bowel of livestock, has the advantage that the emission is reduced in a manner where only products produced on a farm may be employed. Furthermore, the method according to the invention adsorbs methane and possible other carbonaceous gasses before the methane and possible other carbonaceous gasses are out of the one or more stomachs of the livestock.

The amount of carbon-dioxide produced is limited to the very lowest amount possible. Pyrolysis is a process forming a limited amount of carbon-dioxide due to the raw material not being fully burned. The emission of other greenhouse gasses is also limited to the very minimum. Especially methane emission is sought reduced, since methane is about twenty times more harmful than carbon-dioxide as a pollutive greenhouse gas.

Thus, one aspect of the invention relates to a method for producing an activated pyrolyzed lignocellulotic composition, said method comprising :

providing a lignocellulotic material,

- subjecting said lignocellulotic material to pyrolysis, thereby forming a

pyrolyzed lignocellulosic material

- exposing said pyrolyzed lignocellulosic material to a superheated steam, thereby forming an activated pyrolyzed lignocellulotic composition.

Another aspect of the present invention relates to a method for producing a pelletized feed product comprising :

- providing a feed component selected from the group consisting of cereal straws, legume straws, canola/rape straws, cereal hays, legume hays, grass hays, corn stalks/ stover, other suitable stalky materials or mixtures thereof,

- providing an activated pyrolyzed lignocellulotic composition,

mixing said one or more feed components and said activated pyrolyzed lignocellulotic composition, thereby forming a feed mix,

- feeding the feed mix into a conditioner where it is exposed to steam,

passing the steam treated feed mix through a pelletizing mill,

- optionally, cooling and drying the prepared pellets; wherein the dry matter weight ratio between the feed component and the activated pyrolyzed lignocellulotic composition is 2-20;

wherein said pyrolyzed lignocellulotic composition has a methane adsorption capacity of at least 0.1 mmol/g at 298 K and at a pressure in the range of 0.9-1.2 atmosphere.

Yet another aspect of the present invention relates to a feed product comprising :

- a feed component selected from the group consisting of cereal straws, legume straws, canola/rape straws, cereal hays, legume hays, grass hays, corn stalks/stover, other suitable stalky materials or mixtures thereof, and - an activated pyrolyzed lignocellulotic composition; wherein said pyrolyzed lignocellulotic composition has a methane adsorption capacity of at least 0.1 mmol/g at 298 K and at a pressure in the range of 0.9- 1.2 atmosphere.

Brief description of the figures

Fig. 1 shows the total gas produced per gram incubated dry feed. AC (activated carbon), G (gassification biochar), P (placebo), SH (strawbased biochar, high dose), SL (strawbased biochar, low dose) and W (woodbased biochar).

The present invention will now be described in more detail in the following.

Detailed description of the invention

One aspect of the invention relates to a method for producing an activated pyrolyzed lignocellulotic composition, said method comprising :

providing a lignocellulotic material,

- subjecting said lignocellulotic material to pyrolysis, thereby forming a

pyrolyzed lignocellulosic material

- exposing said pyrolyzed lignocellulosic material to a superheated steam, thereby forming an activated pyrolyzed lignocellulotic composition.

In the present context, the term "lignocellulosic material" refers to plant biomass that is composed of cellulose, hemicellulose, and lignin. The carbohydrate polymers (cellulose and hemicelluloses) are tightly bound to the lignin.

The raw material for the pyrolysis process may be corn, straw, wood or other organic material. Using corn, straw, wood or other organic material has the advantage that the raw material for the pyrolysis process may be products produced on a farm, in forestry or at another agricultural production site.

In the present context, the term "pyrolysis" refers to a thermochemical decomposition of organic material at elevated temperatures in the absence of oxygen. The pyrolysis of lignocellulosic materials starts at 200-300°C. In one embodiment of the present invention, the pyrolysis is performed at 200- 700°C and at a pressure in the range of 0.9-1.2 atmosphere. In the present context, the term "superheated steam" refers to steam at a temperature higher than water's boiling point at a given pressure. If saturated steam is heated at constant pressure, its temperature will rise, producing superheated steam. This will occur if saturated steam contacts a surface with a higher temperature. The steam is then described as superheated by the number of degrees it has been heated above saturation temperature. For superheating to take place one of two things must occur. Either all of the liquid water must have evaporated or, in the case of steam generators (boilers), the saturated steam must be conveyed out of the steam drum before superheating can occur, as steam cannot be superheated in the presence of liquid water.

There are three stages of heating to convert liquid water to superheated steam. First the liquid water's sensible temperature is raised. Then latent heat (this heat does not raise the temperature of the fluid) is added. After all of the liquid is evaporated or the saturated steam is taken from the steam drum sensible heat is again added superheating the steam.

In one embodiment of the present invention, the superheated steam is provided at a temperature within the range of 150-1000°C, such as within the range of 200-900°C, e.g. 250-800°C, such as within the range of 280-700°C, e.g. 300- 600°C, such as within the range of 325-500°C, e.g. 350-450°C.

The pressure of the superheated steam is desirably above atmospheric pressure. In one embodiment of the present invention, the pressure of the superheated steam is within the range of 1-500 psig, such as 5-400 psig, e.g. 10-300 psig, such as 20-250 psig, e.g. 30-200 psig, such as 50-150 psig, e.g. 75-100 psig.

Psig (pound-force per square inch gauge) is a unit of pressure relative to the surrounding atmosphere.

In another embodiment of the present invention, the superheated steam is provided at a pressure of 1-500 psig, such as within the range of 5-450 psig, e.g. 10-400 psig, such as within the range of 15-350 psig, e.g. 20-300 psig, such as within the range of 25-250 psig, e.g. 30-200 psig, such as within the range of 35- 150 psig, e.g. 50-100 psig. The inventors of the present invention have found that a reduced pressure treatment may enhance the adsorption of greenhouse gasses. Such reduced pressure treatment can be performed in a vacuum chamber. A vacuum chamber is a rigid enclosure from which air and other gases are removed by a vacuum pump. The resulting low pressure is commonly referred to as a vacuum.

In the present context the term "reduced pressure treated pyrolyzed

lignocellulotic composition" refers to a pyrolyzed lignocellulotic composition being treated with a pressure below 1 atmosphere, such as within the range of 0-0.9 atmosphere.

In one embodiment of the present invention, the process further comprises exposing said activated pyrolyzed lignocellulotic composition to a reduced pressure treatment within the range of 0-0.9 atmosphere, such as 0.1-0.8 atmosphere, e.g. 0.2-0.7 atmosphere, such as 0.3-0.6 atmosphere, e.g. 0.4-0.5 atmosphere. Without being bound by a specific theory, the inventors speculate that fine particles are released from the porous structure, thereby increasing the pore volume accessible to the greenhouse gasses. The duration of the treatment may vary from seconds to hours or days, such as within a range of 1 second to 5 days, e.g. 7 seconds to 1 day, such as within a range of 15 seconds to 75 minutes, e.g. 1-60 minutes, such as within a range of 10-45 minutes, e.g. 35 minutes - depending on the force of the vacuum pump and the amount of fine particles to be released.

In another embodiment of the present invention, the reduced pressure treatment is kept within a range of 0-0.5 atmosphere for at most 60 minutes, such as within a range of 1 second to 45 minutes, e.g. 5 seconds to 30 minutes, such as within a range of 10 seconds to 15 minutes, e.g. 30 seconds to 10 minutes, such as within a range of 45 seconds to 5 minutes, e.g. 1-4 minutes. In another embodiment of the present invention, the reduced pressure treatment is kept within a range of 0-0.8 atmosphere, such as within a range of 0.01-0.7 atmosphere, e.g. 0.05-0.6 atmosphere, such as within a range of 0.1-0.5 atmosphere, e.g. 0.2-0.4 atmosphere.

In another embodiment of the present invention, the lignocellulotic material is selected from the group consisting of corn, straw, wood, other organic material, or combinations thereof olive pits, vine cuttings, bagasse, oil palm waste. One aspect of the present invention relates to an activated pyrolyzed

lignocellulotic composition obtained by the method of the present invention.

The adsorption capacity of a porous material may be different depending on the gas being used, i.e. the size of the molecule. Among the various descriptions of the sizes of molecules, that most applicable to transport phenomena is called the "kinetic diameter" of molecules. The kinetic diameter is a reflection of the smallest effective dimension of a given molecule. It is easy to visualize that a given molecule can have more than one dimension, which characterizes its size, if the molecule is not spherical. 0 ₂ and N ₂ are diatomic molecules (two atoms joined by a chemical bond or bonds), not spheres in shape but rather cylindrical in shape, akin to the shape of a tiny jelly bean. Thus, a "length" dimension of the cylindrical shape is a larger dimension than the smaller "waistline" diameter of the cylindrical shape. In transport phenomena, the molecule with the smallest effective waistline diameter is that which behaves as the smallest molecule, i.e., has the smallest kinetic diameter.

The kinetic diameters of selected molecules are as follows: oxygen = 0.346 nm, ammonia = 0.26 nm, water = 0.265 nm, NO = 0.316 nm, N ₂ 0 = 0.33 nm, methane = 0.38 nm, nitrogen = 0.36 nm, carbon dioxide = 0.33 nm, hydrogen = 0.29 nm and propane = 0.43 nm.

The porous texture characterisation of an activated pyrolyzed lignocellulotic composition can be carried out by physical adsorption of gases (N ₂ at 77 K and C0 ₂ at 273 K) using an automatic volumetric adsorption system. The micropore volume (size smaller than 2 nm) can be calculated from the application of the Dubinin-Radushkevich (DR) equation to the N ₂ adsorption at 77 K up to P/P ₀ ≤ 0.1. The volume of narrow micropores (size smaller than 0.7 nm) can be assessed from C0 ₂ adsorption at 273 K, and the volume of mesopores (size between 2 and 50 nm) obtained from N ₂ , adsorption at 77 K and mercury porosimetry. The volume of super micropores (size between 0.7 and 2 nm) can be calculated from the difference between the micropore volume obtained from N ₂ adsorption at 77 K and the volume of narrow microporosity (Alcahiz-Monge et al. 1994 and 1997).

In one embodiment of the present invention, the activated pyrolyzed

lignocellulotic composition has a volume of super micropores of at least 0.005 cm ³ /g, such as within a range of 0.01-1.0 cm ³ /g, e.g. 0.02-0.4 cm ³ /g, such as within a range of 0.03-0.35 cm ³ /g, e.g. 0.04-0.3 cm ³ /g, such as within a range of 0.05-0.25 cm ³ /g, e.g. 0.06-0.2 cm ³ /g, such as within a range of 0.07-0.15 cm ³ /g, e.g. 0.08-0.1 cm ³ /g. In another embodiment of the present invention, the activated pyrolyzed lignocellulotic composition has a volume of super micropores of at least 0.01 cm ³ /g, such as within a range of 0.015-5.0 cm ³ /g, e.g. 0.02-4.0 cm ³ /g, such as within a range of 0.03-3.00 cm ³ /g, e.g. 0.04-2.0 cm ³ /g, such as within a range of 0.05-1.5 cm ³ /g, e.g. 0.06-1.4 cm ³ /g, such as within a range of 0.07-1.3 cm ³ /g, e.g. 0.08-1.1 cm ³ /g.

In another embodiment of the present invention, the activated pyrolyzed lignocellulotic composition has a volume of narrow micropores of at least 0.005 cm ³ /g, such as within a range of 0.015-5.0 cm ³ /g, e.g. 0.02-4.0 cm ³ /g, such as within a range of 0.03-3.00 cm ³ /g, e.g. 0.04-2.0 cm ³ /g, such as within a range of 0.05-1.5 cm ³ /g, e.g. 0.06-1.4 cm ³ /g, such as within a range of 0.07-1.3 cm ³ /g, e.g. 0.08-1.1 cm ³ /g.

In yet another embodiment of the present invention, the activated pyrolyzed lignocellulotic composition has a micropore volume (size smaller than 2 nm) of at least 0.01 cm ³ /g, such as within a range of 0.015-5.0 cm ³ /g, e.g. 0.02-4.0 cm ³ /g, such as within a range of 0.03-3.00 cm ³ /g, e.g. 0.04-2.0 cm ³ /g, such as within a range of 0.05-1.5 cm ³ /g, e.g. 0.06-1.4 cm ³ /g, such as within a range of 0.07-1.3 cm ³ /g, e.g. 0.08-1.1 cm ³ /g. Another problem with pyrolyzed lignocellulotic composition formed by a pyrolytic process is that a large part of the pore volume may be too narrow for e.g. the methane molecule to enter. Hence, a large part of the surface area is inaccessible and results in an inefficient methane adsorption capacity.

The inventors of the present invention have found a method to alleviate the above mentioned problems. By the method according to the invention, the methane is absorbed in a reduced pressure treated pyrolyzed lignocellulotic composition. The reduced pressure treated pyrolyzed lignocellulotic composition comprising adhered greenhouse gasses, such as methane, may subsequently be burned off, thereby producing carbon-dioxide as all burning will do. Alternatively, the reduced pressure treated pyrolyzed lignocellulotic composition comprising adhered methane may be used as a soil improving agent, e.g. as an enriched fertilizer not only having the fertilising benefits of the pyrolyzed lignocellulotic composition itself, but also having the fertilising advantages of the adhered methane.

Methane adsorption at 298 K can be carried out in a DMT high-pressure

microbalance (Sartorius 4406) connected to a computer for data acquisition (Alcahiz-Monge et al. 1997). The balance is equipped with a pressure indicator and a thermocouple mounted in the sample housing as well as with a rotary pump. The experimental results may be corrected for buoyancy effects related to the displacement of gas by the sample, sample holder, adsorbed phase and pan. The corrections due to the sample holder and pan may be obtained with a blank experiment carried out with the sample holder empty. The buoyancy due to the sample, which results in an apparent loss of weight, may be estimated as the product of the skeletal volume of the sample and gas density. The buoyancy effect related to the adsorbed phase may be corrected to obtain the absolute adsorption isotherms. In yet another embodiment of the present invention, the pyrolyzed lignocellulotic composition has a methane adsorption capacity of at least 0.05 mmol/g at 298 K and at a pressure in the range of 0.9-1.2 atmosphere, such as in the range of 0.07-5.0 mmol/g, e.g. at least 0.1 mmol/g, such as in the range of 0.3-4.0 mmol/g, e.g. at least 0.5 mmol/g, such as in the range of 0.6-3.0 mmol/g, e.g. at least 0.7 mmol/g, such as in the range of 0.8-2.5 mmol/g, e.g. at least 1.0 mmol/g at a pressure in the range of 0.9-1.2 atmosphere.

Another aspect of the present invention relates to an activated pyrolyzed lignocellulotic composition according to the present invention for use as a medicament.

Yet another aspect of the present invention relates to an activated pyrolyzed lignocellulotic composition according to the present invention for use as a medicament for treatment of belching.

Still another aspect of the present invention relates to an activated pyrolyzed lignocellulotic composition according to the present invention for use as a medicament for treatment of methane generating micro-organisms in an animal.

Another object of the present invention is to provide an animal feed capable of reducing the emission of methane, possible other carbonaceous gasses, and possible N ₂ 0 from livestock into the atmosphere. Another object of this invention is to minimize the energy consumption during the pelleting process.

The present invention is directed to a process for forming pelleted animal feeds. As used herein, the term animal feeds includes, but is not limited to pelleted feeds for livestock such as beef and dairy cattle, pigs, sheep, etc., poultry, fish, cats, dogs and the like. The principle behind this invention can be applied to any animal feed whether in block, pellet, wafer, cube, crumble or briquet form, and may also be used for extrusion products. Feed ingredients are normally first hammered to reduce the particle size of the ingredients. Ingredients are then batched, and then combined and mixed thoroughly by a feed mixer. Feed mixers are used for the mixing of feed

ingredients and premixes. The mixer plays a vital role in the feed production process, with efficient mixing being the key to good feed production. If feed is not mixed properly, ingredients and nutrients will not be properly distributed. This means that the feed will not have even nutritional benefit. Once the feed has been prepared to this stage the feed is ready to be pelletized.

Pelletizing is done in a pellet mill, where feed is normally conditioned and thermal treated in the fitted conditioners of a pellet mill. The feed is then pushed through the holes in the pellet die and exit the pellet mill as pelleted feed.

After pelleting, the pellets are cooled with a cooler to bring the temperature of the feed down. Other post pelleting applications include post-pelleting conditioning, sorting via a screen and maybe coating if required.

In the conditioning step, live steam is injected into the feed mash as it is conveyed through the conditioner which generally consists of a cylindrical tube with a rotating shaft upon which numerous paddles or picks are mounted. The condensing steam increases the temperature and moisture content of the mash.

Pellets, which are used as food stuffs for animals, have been made for many years using the conventional manufacturing process comprising the steps of mixing the components of the pellet, which may include meat or fish meal, soya meal, flour or other components and normally comprise twelve to fourteen percent of water, and then feeding these components into a conditioner where they are exposed to steam. The addition of steam heats the mixture, improves production rates, reduces die wear, and improves pellet quality. Subsequently, the mixture is passed through a pelletizing mill, which causes further heating. Finally, the prepared pellets are cooled and dried.

Surprisingly, the inventors of the present invention experienced that animal feed comprising a pyrolyzed lignocellulotic composition may catch fire during the pelleting process of conventional feed. Hence, another object of this invention is to provide a safe method for producing an animal feed comprising a pyrolyzed lignocellulotic composition. The inventors have found that the temperature of the steam treated feedmix should be at most 60 degrees Celsius prior to entering the pelletizing mill in order not to auto-ignite during the pelleting procedure in the pelletizing mill. Thus, one aspect of the invention relates to a method for producing a pelletized feed product comprising :

- providing a feed component selected from the group consisting of cereal straws, legume straws, canola/rape straws, cereal hays, legume hays,

5 grass hays, corn stalks/ stover, other suitable stalky materials or mixtures thereof,

- providing an activated pyrolyzed lignocellulotic composition,

mixing said one or more feed components and said activated pyrolyzed lignocellulotic composition, thereby forming a feed mix,

10 - feeding the feed mix into a conditioner where it is exposed to steam,

passing the steam treated feed mix through a pelletizing mill,

- optionally, cooling and drying the prepared pellets; wherein the dry matter weight ratio between the feed component and the

15 activated pyrolyzed lignocellulotic composition is within the range of 1-20;

wherein the temperature of the steam treated feedmix is at most 60 degrees Celsius prior to entering the pelletizing mill.

In one embodiment of the present invention, the steam treated feedmix is at most 20 60 degrees Celsius prior to entering the pelletizing mill, such as within a range of 20-60 degrees Celsius, e.g. 25-55 degrees Celsius, such as within the range of 30-50 degrees Celsius, e.g. 35-45 degrees Celsius prior to entering the pelletizing mill.

25 In another embodiment of the present invention, the dry matter weight ratio

between the feed component and the activated pyrolyzed lignocellulotic

composition is within the range of 1-20, such as within the range of 1-10, e.g. 1- 5, such as within the range of 2-4.

30 In yet another embodiment of the present invention, the dry matter weight ratio between the feed component and the activated pyrolyzed lignocellulotic

composition is within the range of 6-20, such as within the range of 7-15, e.g. 10- 12. Furthermore, the inventors have found that the feedmix should be mixed with water when the dry matter weight ratio between the feed component and the activated pyrolyzed lignocellulotic composition is within the range of 1-5. In another embodiment of the present invention, the dry matter weight ratio between the feed component and the activated pyrolyzed lignocellulotic composition is within the range of 1-5; wherein, prior to the steam treatment, the feed mix is further mixed with at least 1% w/w water based on the feed mix, such as in the range of 2-20% w/w, e.g. 3-15% w/w, such as in the range of 4-14% w/w, e.g. 5-13% w/w, such as in the range of 6-12% w/w, e.g. 7-11% w/w, such as in the range of 8-10% w/w based on the feed mix.

In another embodiment of the present invention, the steam treated feed mix comprises at least 5% w/w water, such as in the range of 10-20% w/w, e.g. 15% w/w water.

In yet another embodiment of the present invention, wherein the dry matter weight ratio between the feed component and the activated pyrolyzed

lignocellulotic composition is above 5; wherein the steam treated feed mix comprises at least 10% w/w water.

In yet another embodiment, the invention relates to a method for producing an animal feed, said method comprising mixing activated pyrolyzed lignocellulotic composition with animal feed, and forming the mixture into animal feed composition of a desired structure, shape and size. The activated pyrolyzed lignocellulotic composition may be mixed with animal feed, either during manufacture of the feed, at a site between manufacture and a site of feeding, or at the site of feeding the livestock with feed added the animal feed composition. The amount, possibly also the grain size, of the activated pyrolyzed lignocellulotic composition may be adjusted depending on which kind of livestock is fed, and depending on whether the livestock being fed are newly born, half-grown, or full- grown livestock. According to an aspect of the invention the concentration of said activated pyrolyzed lignocellulotic composition in said animal feed is from about 0.1% w/w to about 50% w/w. Said animal feed composition may further be used as a medicament. The animal feed composition used as a medicament may reduce the amount of bacteria producing methane in one or more stomachs of the livestock.

Said animal feed composition may further be used for the manufacture of a medicament. Using solid pyrolyzed lignocellulotic composition in an animal feed composition for the manufacture of a medicament results in a new medicament for livestock.

The animal feed composition might be embodied in any substance suitable for feeding to animals (particularly to ruminants) in admixture with other feedstuffs, for example in compound feeds, feed blocks, liquid feed supplements, drenches or slow-release pellets. The substances may each fulfill one or more useful functions; for example, they may act as methane inhibitors, they may control rumen fermentation (which, in turn, leads to enhanced animal performance), they may act as sources of energy, they may act as preservatives for animal feedstuffs.

In a specific embodiment, the invention further provides an animal feed

composition wherein said pyrolyzed lignocellulotic composition is having a largest size of less than 5 mm, preferably a largest size less than 4 mm, more preferred a largest size of less than 2 mm, even more preferred a largest size of less than 1 mm, possible a largest size of less than 0.5 mm, and having a smallest size more than 0.1 mm. Selecting the size of the animal feed composition according to the above results in a biasing between the livestock's ability to eat the feed

composition and the feed composition's ability to absorb methane and possible other carbonaceous gasses.

In yet another specific embodiment, the invention further relates to an animal feed composition wherein the activated pyrolyzed lignocellulotic composition is being formed during a pyrolysis process of plant raw material, possibly raw material from wood such as conifer, even possibly raw material from crops such as maize, even more possibly raw material from organic waste material. Using plant raw material, possibly raw material from wood such as conifer, even possibly raw material from crops such as maize, even more possibly raw material from organic waste material has the advantage that the activated pyrolyzed lignocellulotic composition may be produced from products on a farm, in forestry or at another agricultural or industrial production site.

In another embodiment, the invention relates to use of an animal feed

composition as an additive in compound feeds, feed blocks, liquid feed

supplements, drenches, slow release pellets and/or ensiled green fodder, hay and grain. The animal feed composition may be added to feed for livestock, either during manufacture of the livestock feed, at a site between manufacture and a livestock feeding location, or at the livestock feeding location.

One aspect of the present invention relates to a feed product comprising :

- a feed component selected from the group consisting of cereal straws, legume straws, canola/rape straws, cereal hays, legume hays, grass hays, corn stalks/stover, other suitable stalky materials or mixtures thereof, and - an activated pyrolyzed lignocellulotic composition; wherein said activated pyrolyzed lignocellulotic composition has a methane adsorption capacity of at least 0.05 mmol/g at 298 K and at a pressure in the range of 0.9-1.2 atmosphere.

In one embodiment of the present invention, the amount of the activated pyrolyzed lignocellulotic product in the feed product is within the range of 5-50% w/w on a dry matter basis, such as within the range of 10-45% w/w, e.g. 15-40% w/w water, such as within the range of 20-35% w/w, e.g. 25-30% w/w on a dry matter basis.

In one embodiment of the present invention, the amount of water content in the feed product is within the range of 1-20% w/w, such as within the range of 1- 15% w/w, e.g. 1-10% w/w, such as within the range of 2-9% w/w, e.g. 3-8% w/w. At the present time, most animal feed manufacturers use some form of pelleting aid when producing their feed compositions. A major concern among animal feed manufacturers is the production of fines that occurs in the pellet mill, conveyers, coolers, sifters, bins, packers, etc. Recycling of fines is expensive since it greatly reduces production rates. In addition to concern about the expense, the repeated steaming and compression-temperature effects aggravate existing stability problems of vitamins and other additives. The importance of minimizing fines is therefore apparent.

One method of reducing fines in the production process is to decrease the pellet diameter of the pelleting die. However, this process requires a greater

expenditure of energy, slows the production process, and causes more heat to be developed within the pellet which seriously affects the stability of certain labile ingredients within the feed formulation.

The other alternative is to incorporate a binding agent into the pellet composition. It is known in the prior art that binders and hardening agents can be utilized in the production of pelleted animal feeds to reduce the degree of fines. For example, present day manufacturing processes of pelleted animal feeds commonly use such binders as sodium or calcium bentonite (a tri-layered aluminum silicate, montmorillonite), collagen protein derivatives, cane or wood molasses, various starches obtained as the by-products from whole grain processing, natural gums and fatty acids, spray dried calcium lignosulfonates, cellulose gums, hemicellulose extract as the by-product in the production of pressed wood, lignin sulfonates comprising one or a combination of the ammonium, calcium, magnesium or sodium salts of the extract of spent sulfite liquor drained from the sulfite digestion of wood, abaca or sisal. These commonly used pellet binders and their methods of use are well known in the art. However, many of these pellet binders have serious disadvantages. For example, the use of many of the above binders such as lignin sulfonate or wood molasses are unpalatable to some animals and thus actually decrease the nutritional value of the animal feed to which they are added. This is of particular importance in feeds for monogastric animals such as swine, which require a feed with high nutritional value. From an economic standpoint, animal feed manufacturers would prefer to produce pelleted feeds at the lowest energy input. Adding binders to their feed

compositions has proven to be an acceptable way of producing more durable pellets that are able to withstand the rough handling experienced during the manufacturing, packaging and transportation operations. However, the binders themselves add additional costs to the feed composition in the form of an additional ingredient that must be ordered, stocked, inventoried, and added as a separate step in the manufacturing process. It would therefore be a major advantage for an animal feed manufacturer to use as a binder a substance that has the ability to provide the necessary pellet hardening properties and also supply the necessary nutrients to the feed composition. That is, if the binder could also act as a source of important mineral requirements, substantial savings would result. In another embodiment of the present invention, at most 10% w/w of the feed component selected from the group consisting of cereal straws, legume straws, canola/rape straws, cereal hays, legume hays, grass hays, corn stalks/ stover, other suitable stalky materials or mixtures thereof, have a fibre length in the range of 25 mm to 90 mm, and advantageously, in the range of 30 mm to 80 mm. This part is intended to enhance digestion.

When the prepared feed is prepared for feeding to fully grown ruminants, in particular, cows, cattle and the like with relatively large muzzles, the lengths of the fibres of the digestion enhancing forage material of the prepared feed will be of the longer range, while in prepared feeds for smaller ruminants, for example, calves, sheep, goats and the like, with relatively small muzzles, the length of the fibres of the digestion enhancing forage material of the prepared feed will be of the shorter ranges. In one embodiment of the invention the prepared feed is adapted for feeding to a lactating cow, and in an alternative embodiment of the invention the prepared feed is adapted for feeding to a dry cow. In a further alternative embodiment of the invention the prepared feed is adapted for feeding to a beef producing animal. Another aspect of the present invention relates to a feed product according to the present invention for use as a medicament.

Yet another aspect of the present invention relates to a feed product according to the present invention for use as a medicament for treatment of belching.

Still another aspect of the present invention relates to a feed product according to the present invention for use as a medicament for treatment of methane generating micro-organisms in an animal.

Another aspect of the present invention relates to use of a feed product according to the present invention as an animal feed.

The pyrolyzed lignocellulotic composition used as adsorbent may be formed by subjecting plant material to temperatures of at the maximum 700°C in a pyrolytic process. Utilising low pyrolyse temperature reduces energy consumption when manufacturing the pyrolyzed lignocellulotic composition.

The activated pyrolyzed lignocellulotic composition according to the invention can function as a greenhouse gas sink, where greenhouse gas can be absorbed from the stomach, the intestines and subsequently the faeces of livestock.

Simultaneously, the activated pyrolyzed lignocellulotic composition according to the invention can function as an inhibitor of methane and carbon dioxide forming micro bacteria in the faeces of livestock, thereby additionally reducing the discharge of the greenhouse gas into the atmosphere.

By the method according to the invention, the methane in the faeces is adsorbed in the activated pyrolyzed lignocellulotic composition. The activated pyrolyzed lignocellulotic composition may subsequently be burned off, thereby producing carbon-dioxide as all burning will do. Alternatively, the activated pyrolyzed lignocellulotic composition may be used as a soil improving agent, e.g. as an enriched fertilizer not only having the fertilising benefits of the activated pyrolyzed lignocellulotic composition itself, but also having the fertilising advantages of the methane absorbed in the activated pyrolyzed lignocellulotic composition. The method according to the invention may also be used by private, by industrial entities and by governments to fulfill the Kyoto Protocol. The Kyoto Protocol is a 'cap and trade' system that imposes national caps on the emissions of greenhouse gasses. Although these caps are national-level commitments, in practice most countries will devolve their emissions targets to individual industrial entities, such as a farm with livestock. Outside of the Kyoto Protocol a substantial voluntary market exists. It trades VCU's, voluntary carbon units, that are not connectied to any quota or emissions target system. The possible buyers of Credits may be privates and industrial entities that expect their emissions to exceed their quota. Typically, they will purchase Credits directly from another party with excess allowances, from a broker, or from an Energy Saving Company (ESCO). Carbon Credits are tradable instruments with a transparent price and with a measurable amount for trading. The market is expected to grow substantially, with banks, brokers, funds, arbitrageurs, ESCOs and private traders eventually participating. The greenhouse gas intended for being absorbed by the activated pyrolyzed lignocellulotic composition, when used as a greenhouse gas sink, may be a mixture of different greenhouse gases, preferably a mixture of methane and C0 ₂ , or the greenhouse gas intended for being absorbed by the activated pyrolyzed lignocellulotic composition, when used as a greenhouse gas sink, may be one greenhouse gas only, preferably methane only.

The method according to the invention may also be used by private, by industrial entities and by governments to fulfill the Kyoto Protocol. The Kyoto Protocol is a 'cap and trade' system that imposes national caps on the emissions of greenhouse gasses. Although these caps are national-level commitments, in practice most countries will devolve their emissions targets to individual industrial entities, such as a farm with livestock.

According to an aspect of the invention, the pyrolyzed lignocellulotic composition is used as a greenhouse gas sink, said greenhouse gas having been absorbed in or being chemically bound in excrements of livestock, and said greenhouse gas being stored until further processing, said greenhouse gas being stored in pyrolyzed lignocellulotic composition functioning as an inhibitor of methane and carbon dioxide forming micro bacteria in the excrements of livestock, thereby additionally reducing the emission of the greenhouse gas into the atmosphere.

The possible amount of greenhouse gas sink is within the interval of 10 mg to 1000 metric tonnes, such as 500 mg to 1 metric tonnes, such as 1 gram to 100 kg, such as 50 gram to 10 kg, preferably the predefined amount of said

greenhouse gas sink is 1 kg. The choice of amount of greenhouse gas sink may differ depending on different parameters individually or in combination such as: the organic waste material in question, the concentration of greenhouse gas in the organic waste material, the certainty needed or desired of the measuring being performed within the period of time and possible other parameters.

The possible amount of manure is within the interval of 10 mg to 1000 kg, such as 1 gram to 100 kg, such as 5 gram to 50 kg, such as 10 gram to 30 kg, preferably the predefined amount of said amount manure is 10 kg. The choice of amount of manure may differ depending on different parameters individually or in combination such as: the organic waste material in question, the concentration of greenhouse gas in the organic waste material, the certainty needed or desired of the measuring being performed within the period of time and possible other parameters. The greenhouse gas intended for being absorbed by pyrolyzed lignocellulotic composition, when used as a greenhouse gas sink, may be a mixture of different greenhouse gases, preferably a mixture of methane and C0 ₂ , or the greenhouse gas intended for being absorbed by pyrolyzed lignocellulotic composition, when used as a greenhouse gas sink, may be one greenhouse gas only, preferably methane only.

Selecting raw material which is derived from plants results in a farm possible having the raw material ready at hand for performing the pyrolysis process for forming the solid pyrolyzed lignocellulotic composition for the method according to the invention. Selecting a substance containing methane or other carbonaceous gasses from excrements of livestock results in a farm being able, at first hand, to reduce emission of greenhouse gasses by the method according to the invention.

It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention. All patent and non-patent references cited in the present application, are hereby incorporated by reference in their entirety.

The invention will now be described in further details in the following non-limiting examples.

Examples

Effect of biochar and activated carbon on in vitro rumen fermentation and methane production.

Treatments with activated carbon or biochar resulted in a smaller amount of gas produced during 48 hour in vitro rumen fermentation of feed (table 1). The difference is statistically significant (P=0.0056 (P<0.05 is significant)).

Table 1 : Average amount of total gas produced during 48 hours of in vitro rumen fermentation of cattle feed with and without biochar or activated carbon.

Treatment N Average Standard deviation cumulative

pressure after 48

hours (PSI)

AC (activated carbon) 5 24.18 1.27

G (gassification biochar) 4 24.56 0.80

P (placebo) 5 27.03 1.14

SH (strawbased biochar, high dose) 4 25.20 1.63

SL (strawbased biochar, low dose) 5 26.42 1.23

W (woodbased biochar) 4 24.12 1.27 Note that the dosing of strawbased biochar was lower than originally intended and lower than for the other additives. This was because the dry matter content in the strawbased biochar was much lower than in the other additives (see table 2) and this was not known at the time of sample preparation. Samples of the additives were subsequently dried using standard procedures and all data recalculated to a dry matter basis.

Table 2: Average dry matter content of additive products

Because different doses of additives and differing amounts of feed dry matter were incubated, gas production per unit dry matter in the feed and per unit dry additive is of interest (table 3). NOTE: that the treatments'^", "AC" and "W" produced significantly less gas per g feed and significantly more gas per g additive than "P" and "SL", suggesting less fermentation activity.

Table 3: Average amount of total gas produced per g dry feed and additive. Values followed by differing letters are significantly different (P<0.05)

The average percentage of methane in the produced gas from the in vitro rumen fermentations is numerically higher in the "placebo" treatment than in the treatments with biochar and activated carbon (table 2). The difference between treatments is significant (P=0.0423). However, only treatment "G" produced a significantly less percentage of methane when compared to the "P", "SH" and "SL" treatments.

Table 4: Average percentage of methane in the gas produced during 48 hours of in vitro rumen fermentation of cattle feed with and without biochar or activated carbon. Values followed by differing letters are significantly different (P<0.05)

Again, because of different dry matter contents the methane production per unit dry matter feed and dry matter additive is shown in table 5. The "G" treatment produced significantly less methane per gram feed and per g additive than the "P" or "SH" or "SL" treatments.

Table 5: Average ml methane produced per g feed and additive. Values followed by differing letters are significantly different (P<0.05)

The results from tables 3-5 are graphically presented in figure 1. Fiber analysis was undertaken in order to evaluate fiber digestibility. Another correction was necessary in the fiber analyses process because of a differential solubility/permeability of the biochar products during washing with water and NDS (see table 6). This correction assumes that the loss of biochar/ AC from the bag was the same in the fermented and the non-fermented samples. The difference in dry-matter content between placebo and treatments is the amount of biochar/ AC (which is calculated on a dry matter basis). The difference in DM between treatments and placebo after NDF wash is therefore compared to the amount of DM biochar/ AC added before wash.

This solubility/permeability was tested in a subsequent trial using 2 quantities of additive. The results of this test are shown in table 6, and show a large variation based on the additive as well as a differential solubility/permeability per unit additive to surface area of the bag. Therefore the correction comparing each set of additive samples with the "P" treatment as done in the first trial was deemed most correct. This correction factor is shown in the final column of table 6.

Table 6: Test results of permeability/solubility of biochar and activated charcoal products water or NDS

*CV= coefficient of variation - a measure of how much variation exists between the results of the 5 replicates . These values indicated that the differences found from the repeated values are quite acceptable.

Using this correction the methane production per g digested fiber fraction and total dry matter was calculated (table 7). The "G" treatment produced significantly less methane per gram digested feed than did the "P", "SH", and "SL" treatment. However, no significant differences were seen in the average methane produced per digested fiber fraction. The fiber fraction is assumed to be the primary reason of methane production and therefore these final results are surprising.

Table 7. Average ml methane produced per g digested feed and digested fiber fraction. Values followed by differing letters are significantly different (P<0.05)

CONCLUSION : The "W" "AC" and "G" treatments behaved similarly with respects to total gas produced (per g feed and additive) - suggesting an equal digestibility. Likewise, these three treatments produced similar (not significantly different) proportions of methane and a similar volume of methane per g digested feed. Surprisingly there was no significant difference in the amount of gas produced per g digested fiber. This can be due to biological/chemical mechanisms of the additives that interact with the feed components or sample variation (as discussed above). Further studies could be undertaken to determine this fiber/methane anomaly.

References

Alcahiz-Monge et al. ; Carbon, Vol. 32, No. 7, pp. 1277-1283, 1994.

Alcahiz-Monge et al. ; Carbon Vol. 35, No. 2, pp. 291-297, 1997.