[001] This disclosure relates to methods and apparatus for transporting bulk material, more particularly, but not exclusively, to methods and apparatus for transporting bulk combustible material.

[002] There are health & safety risks associated with the transportation of bulk combustible material, particularly in the case of particulate material intended for burning as a fuel.

[003] The cost of transporting bulk combustible materials from source can also affect the competitive advantage of bulk combustible materials intended for burning as a fuel, e.g. in the case of coal materials intended for use as a fuel in locations significantly remote from the source (e.g. in overseas territories).

[004] An object of the methods and apparatus in this disclosure is to overcome or mitigate one or more problems associated with the prior art.

[005] According to a first aspect of the disclosure, there is provided a method of transporting bulk material, the method comprising the following steps:

providing a container having a chamber for receiving bulk material;

carrying out a material charging step, wherein said chamber is charged with bulk material at a first location;

carrying out an initial carbon dioxide charging step, wherein said chamber is charged with carbon dioxide to a predetermined level; and

transporting said container to a second location;

wherein the method includes the further steps of:

monitoring the carbon dioxide level within the chamber during transportation of the container to said second location; and

carrying out an additional carbon dioxide charging step, as required, wherein the chamber is charged with additional carbon dioxide, in order to maintain the carbon dioxide level at or above said predetermined level during transportation of the container to said second location.

[006] It is known to transport perishable foodstuff by gas-tight container, and provide a supply of carbon dioxide to the container, in order to control a desired level of oxygen within the container (necessary to keep said foodstuff in good condition). However, in exemplary embodiments herein, the method can be used to fill all available space within the chamber with as much carbon dioxide as possible, in order to expel oxygen from the bulk material prior to transportation. Advantageously, exemplary embodiments utilise filling the available space with carbon dioxide under pressure, to further assist in expelling oxygen from the chamber. Moreover, exemplary embodiments of the method provide additional charging of carbon dioxide into said chamber, as required, to prevent ingress of oxygen from the atmosphere during transportation. Aspects of the disclosure therefore serve to provide a safe, controlled environment for the storage and transportation of bulk material within a container.

[007] In exemplary embodiments, the bulk material is a mineral material, e.g. coal fly- ash.

[008] In exemplary embodiments, the bulk material is a combustible material. In exemplary embodiments, the bulk material is a coal material, e.g. lignite. In exemplary embodiments, the coal material is provided in particulate or powdered form (e.g. particulate or powdered lignite). In other exemplary embodiments, coal material is provided in block or briquette form (e.g. lignite in block or briquette form). It will be understood that aspects of the disclosure therefore serve to provide a safe, controlled environment for the storage and transportation of combustible material within a container.

[009] In exemplary embodiments, the chamber is of a kind configured to be gas-tight during transportation (e.g. after charging with material at a first location and prior to discharge of said material at a second location). This reduces the likelihood of oxygen ingress during storage or transportation. In exemplary embodiments, the container is a freight or shipping container having a chamber for receiving bulk material, which is configured to be gas-tight during transportation. Examples of such containers are well known in the freight and shipping industries. Of course, it will be understood that such gas-tight chambers are sometimes prone to air-ingress (or loss of pressure, in the case of pressurised chambers).

[010] In exemplary embodiments, the container is provided with a discrete source of carbon dioxide, advantageously, for ready discharge of carbon dioxide to the chamber.

[Oil] In exemplary embodiments, the chamber and discrete source of gas form part of a system for monitoring the pressure level of said gas in the chamber during transportation of the chamber, and for controlling a discharge of gas from said discrete source if said monitored pressure level drops below a predetermined level. [012] In exemplary embodiments, the discharge of carbon dioxide from said discrete source of carbon dioxide is controlled according to a predetermined protocol. In exemplary embodiments, said control is performed automatically, e.g. via a computer signal or other control signal from a control device, such as a computer processor or the like.

[013] In exemplary embodiments, the discrete source of carbon dioxide is a dedicated container (e.g. a bottle or cylinder) of carbon dioxide (e.g. in a compressed gas state or a liquefied gas state). The use of liquefied gas will reduce the required size of the discrete source for any given duration of transportation from the first location to the second location (compared to the use of carbon dioxide in a compressed gas state), thereby reducing the impact on potential storage capacity within the chamber.

[014] In exemplary embodiments, the discrete source of gas is a dedicated container mounted at or arranged for communication with an upper region of the chamber, for discharge of gas from said discrete source into an upper region of said chamber.

[015] In exemplary embodiments, the initial carbon dioxide charging step is carried out to create a saturated carbon dioxide environment within the chamber. Such an environment minimises the risk of combustion within the chamber during transportation of the bulk material to the second location, particularly in the case of transporting potentially combustible bulk material, such as lignite.

[016] In exemplary embodiments, said predetermined level of said initial carbon dioxide charging step is a fluid pressure level. In exemplary embodiments, said predetermined level of said initial carbon dioxide charging step is a fluid pressure level greater than atmospheric pressure (i.e. above 1 atm or above 1013.25 hPa). Advantageously, said predetermined carbon dioxide fluid pressure level is greater than atmospheric pressure, at a level suitable to prevent the ingress of oxygen or atmospheric air into the chamber (not least due to the difference in specific gravity between carbon dioxide and oxygen), thereby significantly reducing the risk of any combustion or explosion of the bulk material under transportation within the chamber. However, it will be understood that excessive levels of fluid pressure above atmospheric pressure will be undesirable in most practical instances, since this will could create problems for sealing the chamber in which the bulk material and carbon dioxide is to be transported.

[017] In exemplary embodiments, the volume of said chamber is substantially filled with bulk material during the material charging step. The objective in such embodiments is to try to maximise the volume of bulk material product that can be transported within container, whilst minimising the volume of carbon dioxide required to create said predetermined carbon dioxide level within the chamber.

[018] In exemplary embodiments, the discrete source of carbon dioxide is mounted within the chamber, e.g. in an upper region of the chamber. In exemplary embodiments, the chamber has a base, side walls extending up from said base, and a ceiling extending between said side walls at a location above said base. In exemplary embodiments, the discrete source of carbon dioxide is spaced away from the base, e.g. mounted on or adjacent the ceiling of the chamber. Advantageously, the specific gravity of carbon dioxide is greater than the specific gravity of air, and so the carbon dioxide can descend within the chamber from the upper region, e.g. displacing air within the chamber.

[019] In alternative embodiments, the discrete source is external to the chamber but is arranged in communication with the upper region of the chamber, for discharge of carbon dioxide from the discrete source into the upper region of the chamber, e.g. via a conduit extending in fluid communication between the discrete source and the chamber.

[020] In exemplary embodiments, the monitoring of the fluid pressure is carried out using a valve forming part of or mounted on the discrete source of carbon dioxide, wherein the valve is operable to release carbon dioxide from said discrete source of carbon dioxide, e.g. to maintain the fluid pressure above said predetermined level. Other pressure monitoring methods are within the contemplation of the invention, and will be apparent to the skilled person having regard for the content of this disclosure.

[021] In exemplary embodiments, the initial carbon dioxide charging step involves obtaining carbon dioxide from a separate source remote from the container. That is to say, in exemplary embodiments, the discrete source of carbon dioxide is not used for the initial carbon dioxide charging step. However, it will be understood that the discrete source of carbon dioxide could be used to finally prime the chamber to the desired level, i.e. after a significant proportion of the desired level has been obtained from the separate source. An examples of a suitable separate sources is a power generating plant, such an electricity generating power station. In exemplary embodiments, carbon dioxide is harvested from the power generating plant and stored on site (e.g. in suitable tanks), for later use in said initial carbon dioxide charging step.

[022] In exemplary embodiments, the material charging step is carried out at an original source for said bulk material in a raw state, e.g. at a coal mine, or is carried out at a coal processing plant or coal storage location. [023] In exemplary embodiments, the material charging step is carried out at a processing plant for said bulk material, e.g. at a material processing plant or a material drying plant.

[024] In exemplary embodiments, the second location is a site where the bulk material is intended to be used as a fuel source, such as a power generation location, e.g. a combined cycle gas turbine plant.

[025] In exemplary embodiments, the first location is bulk material drying plant (e.g. a plant for drying particulate coal materials), and the second location is a power generation location, wherein the bulk material is supplied for use as a fuel source for use in a power generation cycle at said power generation location. The bulk material may be stored at said second location, prior to use as a fuel source.

[026] In exemplary embodiments, the container is transported by rail and/or road and/or by ocean-going vessel.

[027] In exemplary embodiments, the first location is on a first land mass and the second location is on a second land mass, wherein for at least part of the journey between the first and second locations the container is shipped by ocean from said first land mass to said second land mass.

[028] In exemplary embodiments, the material charging step is carried out concurrently with the initial carbon dioxide charging step, e.g. as a mixture of carbon dioxide and said bulk material. Advantageously, this may reduce the risk of combustion or explosion as the material settles in the chamber.

[029] In exemplary embodiments, the carbon dioxide is recovered from the chamber at said second location, such as by a dedicated recovery step (e.g. prior to discharge of the transported bulk material). In exemplary embodiments, the dedicated recovery step involves a suction operation, which may need to be filtered to prevent the removal of bulk material during the recovery step. In exemplary embodiments, the recovered carbon dioxide can be stored, e.g. in suitable tanks, and transported for safe disposal or reprocessed for use in other applications.

[030] Another aspect of the disclosure provides a method of transporting bulk material, the method comprising the following steps: providing a container having a chamber for receiving bulk material;

carrying out a material charging step, wherein said chamber is charged with bulk material at a first location;

carrying out an initial carbon dioxide charging step, wherein said chamber is charged with carbon dioxide to a predetermined fluid pressure level; and

transporting said container to a second location;

wherein the method includes the further steps of:

monitoring the carbon dioxide fluid pressure level within the chamber during transportation of the container to said second location; and

carrying out an additional carbon dioxide charging step, as required, wherein the chamber is charged with additional carbon dioxide, in order to maintain the carbon dioxide level at or above said predetermined fluid pressure level during transportation of the container to said second location;

optionally, wherein the carbon dioxide is recovered from the chamber at said second location (e.g. prior to discharge of the transported bulk material);

optionally, wherein the predetermined level of said initial carbon dioxide charging step is a fluid pressure level greater than atmospheric pressure.

[031] Another aspect of the disclosure provides a method of transporting bulk bituminous coal material, the method comprising the following steps:

providing a container having a chamber for receiving bulk bituminous coal material;

providing a source of bulk bituminous coal material in particulate form;

conveying the particulate bulk bituminous coal material to the chamber in a gas flow of carbon dioxide;

charging said chamber with said particulate bulk bituminous coal material using said carbon dioxide gas flow;

pressurising the charged chamber with carbon dioxide to a predetermined fluid pressure level; and

transporting said container to a remote location;

wherein the method includes the further steps of:

monitoring the carbon dioxide fluid pressure level within the chamber during transportation of the container to said remote location; and

carrying out an additional carbon dioxide charging step, as required, wherein the chamber is charged with additional carbon dioxide, in order to maintain the carbon dioxide level at or above said predetermined fluid pressure level during transportation of the container to said remote location;

optionally, wherein the carbon dioxide is recovered from the chamber at said second location (e.g. prior to discharge of the transported bulk material); optionally, wherein the predetermined level of said initial carbon dioxide charging step is a fluid pressure level greater than atmospheric pressure;

optionally, wherein the conveying of the particulate bulk bituminous coal material to the chamber in a gas flow of carbon dioxide occurs at a coal mine, wherein the particulate bulk bituminous coal material is obtained from the coal mine and the carbon dioxide is obtained from a power generating plant at or associated with the coal mine.

[032] According to a further aspect of the disclosure, there is provided a method of transporting particulate material from a particulate material source (e.g. to a use location), the method comprising the following steps:

providing a passageway defining a flow path between the particulate material source and a second location;

sending a stream of carbon dioxide along the conduit from the particulate material source to the second location; and

sending particulate material along the conduit in the stream of carbon dioxide.

[033] In exemplary embodiments, a pressure of the stream of carbon dioxide within the conduit is greater than atmospheric pressure.

[034] In exemplary embodiments, the stream of carbon dioxide is provided by a power generation plant; optionally, wherein the power generation plant is part of or is in association with a coal mine or coal processing plant.

[035] In exemplary embodiments, the particulate material source is a drying plant at a coal mine or coal processing plant.

[036] Aspects of the disclosure set out above refer specifically to the use of carbon dioxide. Alternatively, the carbon dioxide may be provided in the form of a gas mixture which is rich in carbon dioxide, i.e. a mixture of carbon dioxide and other inert gases. In exemplary embodiments, said other inert gases should not contain oxygen, in order to minimise the risk of a combustion reaction - especially, if the method is to be used for transporting carbon rich materials, such as brown coals and bituminous coals. It may also be desirable that said other inert gases should not contain hydrogen, because carbon and hydrogen can sometimes react to form methane under pressure.

[037] In other aspects of the disclosure, the carbon dioxide of the above aspects and exemplary embodiments of the disclosure is replaced with another inert gas or mixture of inert gases. In exemplary embodiments, said other inert gases should not contain oxygen (i.e. dioxygen), in order to minimise the risk of a combustion reaction - especially, if the method is to be used for transporting carbon rich materials, such as brown coals and bituminous coals. It may also be desirable that said other inert gases should not contain hydrogen (i.e. dihydrogen), because carbon and hydrogen can sometimes react to form methane under pressure.

[038] For example, in other aspects of the disclosure, the carbon dioxide of the above aspects and exemplary embodiments of the disclosure is replaced with nitrogen, or a gas mixture which is rich in nitrogen, e.g. a mixture of nitrogen and other inert gases. In exemplary embodiments, said other inert gases should not contain oxygen, in order to minimise the risk of a combustion reaction - especially, if the method is to be used for transporting carbon rich materials, such as brown coals and bituminous coals. It may also be desirable that said other inert gases should not contain hydrogen, because carbon and hydrogen can sometimes react to form methane under pressure. Nitrogen is more readily available than carbon dioxide, and so may provide a cheaper or more convenient transportation medium.

[039] It will be understood that the use of carbon dioxide (whether pure or in a gaseous mixture), other inert gases (such as nitrogen), or inert gaseous mixtures referred to above is primarily concerned with ensuring that pressurised coal materials (e.g. brown coals and bituminous coals) do not react so as to combust during transportation. Accordingly, any suitable combinations of inert gases which can achieve this result are within the contemplation of the methods and apparatus described herein.

[040] A particular advantage is achieved, in the case of brown coals and bituminous coals, if the inert gases are sourced from traditional waste gas products associated with the mining or processing of said brown coals and bituminous coals.

[041] As such, according to another aspect of the disclosure, there is provided a method of transporting bulk material, the method comprising the following steps:

providing a container having a chamber for receiving bulk material;

carrying out a material charging step, wherein said chamber is charged with bulk material at a first location;

carrying out an initial gas charging step, wherein said chamber is charged with gas to a predetermined level; and

transporting said container to a second location;

wherein the method includes the further steps of:

monitoring the gas within the chamber during transportation of the container to said second location; and carrying out an additional gas charging step, as required, wherein the chamber is charged with additional gas, in order to maintain the gas level at or above said predetermined level during transportation of the container to said second location.

[042] In exemplary embodiments, the gas is an inert gas (e.g. nitrogen or carbon dioxide) or a gaseous mixture of inert gases (e.g. comprising nitrogen and/or carbon dioxide). Nitrogen is more readily available than carbon dioxide, and so may provide a cheaper or more convenient transportation medium. Other suitable inert gases may be applicable.

[043] In exemplary embodiments, said gas or gaseous mixture is devoid of oxygen. That is to say, the gas or gaseous mixture does not comprise oxygen gas (i.e. dioxygen), in order to minimise the risk of a combustion reaction - especially, if the method is to be used for transporting carbon rich materials, such as brown coals and bituminous coals. It may also be desirable that said gas or gaseous mixture is devoid of hydrogen. That is to say, the gas or gaseous mixture does not comprise hydrogen gas (i.e. dihydrogen), because carbon and hydrogen can sometimes react to form methane under pressure.

[044] According to a still further aspect of the disclosure, there is provided a method of transporting particulate material from a particulate material source, the method comprising the following steps:

providing a passageway defining a flow path between the particulate material source and a second location;

sending a stream of inert gas along the conduit; and

sending particulate material along the conduit in the stream of inert gas.

[045] In exemplary embodiments, the stream of inert gas comprises a stream of a single inert gas (e.g. carbon dioxide of nitrogen) or a gaseous mixture of multiple inert gases (e.g. comprising nitrogen and/or carbon dioxide). Nitrogen is more readily available than carbon dioxide, and so may provide a cheaper or more convenient transportation medium. Other suitable inert gases may be applicable.

[046] In exemplary embodiments, said inert gas or gaseous mixture is devoid of oxygen.

That is to say, the inert gas or gaseous mixture does not comprise oxygen gas (i.e. dioxygen), in order to minimise the risk of a combustion reaction - especially, if the method is to be used for transporting carbon rich materials, such as brown coals and bituminous coals. It may also be desirable that said inert gas or gaseous mixture is devoid of hydrogen. That is to say, the inert gas or gaseous mixture does not comprise hydrogen gas (i.e. dihydrogen), because carbon and hydrogen can sometimes react to form methane under pressure.

[047] In exemplary embodiments, said inert gas or gaseous mixture comprises carbon dioxide and/or nitrogen.

[048] In exemplary embodiments, a pressure of the stream of inert gas is greater than atmospheric pressure.

[049] In exemplary embodiments, the stream of inert gas is provided by a power generation plant; optionally, wherein the power generation plant is part of or in association with a coal mine or coal processing plant.

[050] In exemplary embodiments, the particulate material source is a drying plant at a coal mine or coal processing plant.

[051] According to a further aspect of the disclosure, there is provided a method of transporting carbon dioxide, the method comprising the following steps:

providing a container at a first location, the container containing bulk material and carbon dioxide;

separating the carbon dioxide from the bulk material;

storing the separated carbon dioxide in a vessel; and

transporting the vessel from the first location to a second location.

[052] In exemplary embodiments, separating the carbon dioxide from the bulk material comprises pumping the carbon dioxide out of the container.

[053] In exemplary embodiments, the method further comprises processing the separated carbon dioxide to remove traces of the bulk material, prior to storing in the vessel.

[054] In exemplary embodiments, processing the separated carbon dioxide comprises providing a filter between the container and the vessel and pumping the carbon dioxide through the filter.

[055] In exemplary embodiments, the second location is a material charging location at which the container is re-charged with bulk material and carbon dioxide; optionally, wherein the material charging location is a drying plant at a coal mine. [056] In exemplary embodiments, transporting the vessel from the first location to the second location comprises at least one of: transporting the vessel via road, transporting the vessel via rail, and/or shipping the vessel via the ocean.

[057] The method according to this aspect of the disclosure is also applicable to the handling of containers containing bulk material and other gases of the kind mentioned above, i.e. single inert gases such as nitrogen, or gaseous mixtures of multiple inert gases (e.g. comprising nitrogen and/or carbon dioxide). Other suitable inert gases may be applicable.

[058] According to a still further aspect of the disclosure, there is provided a freight or shipping container, the container having a chamber for receiving bulk material, optionally, configured to be gas-tight during transportation of said container; wherein the container is provided with a discrete source of gas, for discharge of gas into the chamber if the gas level drops below a predetermined level during transportation of the container, and wherein the gas is inert gas, optionally comprising nitrogen and/or carbon dioxide, or wherein the gas is a gaseous mixture of inert gases, optionally comprising nitrogen and/or carbon dioxide.

[059] In exemplary embodiments, the chamber and discrete source of gas form part of a system for monitoring the pressure level of said gas in the chamber during transportation of the chamber, and for controlling a discharge of gas from said discrete source if said monitored pressure level drops below a predetermined level.

[060] In exemplary embodiments, the discrete source of gas is a dedicated container mounted at or arranged for communication with an upper region of the chamber, for discharge of gas from said discrete source into an upper region of said chamber.

[061] It will be understood that the methods described herein provide safer transportation opportunities for combustible materials, such as brown coals and bituminous coals. Moreover, the methods described herein provide significant cost-saving opportunities, when compared with conventional transportation and shipping methods for bulk materials, in particular conventional methods for shipping of coal materials.

[062] Other aspects and features of the disclosure will be apparent from the appended claims and the following description of exemplary embodiments, made with reference the accompanying drawings, in which :

[063] Figure 1 is a schematic view of a container for transport of bulk materials; [064] Figure 2 is a schematic flow diagram of a transportation route;

[065] Figure 3 is a schematic diagram of an advantageous transportation route; and

[066] Figure 4 is a schematic diagram of a further advantageous transportation route.

[067] Referring firstly to Figure 1, a container for use in a method of transporting bulk material is indicated generally at 10. The container 10 has a chamber 12 for receiving bulk material to be transported (indicated generally at 14).

[068] In this embodiment, the container has 12 an inlet 16 through which the chamber 12 is intended to be charged with bulk material 14 at a first location. The container 12 also has an 18 outlet through which the bulk material 14 is intended to be discharged from the chamber 12 (e.g. at a second location, remote from the first location). It will be understood that the container 10 may have a combined inlet/outlet for charging/discharging operations, in other embodiments.

[069] In the illustrated embodiment, the container 10 is a freight or shipping container of the kind having a chamber 12 configured to be gas-tight during transportation (e.g. after charging with bulk material at a first location). Examples of such containers are well- known in the freight and shipping industries, such as intermodal freight shipping containers in accordance with IS0688. The width of such containers is standardised, so as to be interchangeable when transporting between ships and road/rail options in different international territories (e.g. between Australia and Japan). IS01496-1 provides an alternative standard for such freight containers.

[070] Of course, it will be understood that such gas-tight chambers are sometimes prone to air-ingress (or loss of pressure, in the case of pressurised chambers). However, one aspect of this disclosure relates generally to the transportation of bulk materials in an inert gas environment. Accordingly, the container 10 is provided with a discrete source 20 of inert gas, in particular carbon dioxide. The discrete source 20 is in the form of a dedicated container (e.g. a bottle or cylinder) of carbon dioxide (e.g. in a compressed gas state or a liquefied gas state).

[071] In exemplary embodiments, the discrete source 20 of carbon dioxide is mounted within the chamber 12, e.g. advantageously, in an upper region 22 of the chamber 12, for discharge of carbon dioxide into the upper region of the chamber 12. In exemplary embodiments, the chamber 12 has a base 24, side walls 26 extending up from said base 24, and a ceiling 28 extending between said side walls 26 at a location above said base 24. In exemplary embodiments, the discrete source 20 of carbon dioxide is spaced away from the base 24, e.g. mounted on or adjacent the ceiling 28 of the chamber 12. Advantageously, the specific gravity of carbon dioxide is greater than the specific gravity of air, and so the carbon dioxide can descend within the chamber 12 from the upper region 22, e.g. displacing air within the chamber 12. In alternative embodiments, the discrete source 20 is external to the chamber 12 but is arranged in communication with the upper region of the chamber 12, for discharge of carbon dioxide from the discrete source 20 into the upper region of the chamber 12, e.g. via a conduit extending in fluid communication between the discrete source 20 and the chamber 12.

[072] In exemplary embodiments, the chamber 12 and the discrete source 20 form part of a system for monitoring the level of said carbon dioxide in the chamber during transportation of the chamber, and for controlling a discharge of gas from said discrete source if said monitored level drops below a predetermined level (e.g. pressure level monitoring to detect whether the pressure level drops below a predetermined pressure level).

[073] In exemplary embodiments, discharge of carbon dioxide from said discrete source 20 of carbon dioxide is controlled according to a predetermined protocol, performed automatically, via a computer signal or other control signal from a control device 30, such as a computer processor or the like. In this embodiment, the control device 30 is provided on the container 10, but may be remote from the container 10 in other embodiments.

[074] In exemplary embodiments, the monitoring of the carbon dioxide level is carried out by monitoring the fluid pressure level within the chamber 12. For example, the fluid pressure in the chamber 12 may be monitored using a valve 30 forming part of or mounted on the discrete source 20 of carbon dioxide, wherein the valve 30 is operable to release carbon dioxide from said discrete source 20 of carbon dioxide, e.g. to maintain the fluid pressure above a predetermined level.

[075] Methods of transportation of bulk material using the container 10 will now be described, with reference to Figures 1 and 2.

[076] Firstly, the container 10 is provided at a first location, where a bulk material charging step is to be carried out. Accordingly, the chamber 12 is charged with bulk material 14 at said first location, e.g. via the inlet 16. [077] An initial carbon dioxide charging step is carried out, wherein said chamber 12 is charged with carbon dioxide to a predetermined level. Advantageously, the initial carbon dioxide charging step is carried out at said first location, e.g. after the bulk material charging step. However, as will be described in more detail below, it may be advantageous to carry out the bulk material charging step and the initial carbon dioxide charging step concurrently.

[078] In exemplary embodiments, the bulk material 14 is a combustible material. In exemplary embodiments, the bulk material 14 is a coal material, e.g. brown coal, such as lignite. In exemplary embodiments, the coal material is provided in particulate or powdered form (e.g. particulate or powdered lignite). In other exemplary embodiments, coal material is provided in block or briquette form (e.g. lignite in block or briquette form). In the case of bituminous coal materials, it may be advantageous for the coal material to be provided in a crushed form (i.e. after raw coal material has undergone a crushing operation), to reduce the maximum particle diameter of the coal material (e.g. to a size suitable for gas-transportation purposes).

[079] In other embodiments, the bulk material is a mineral material, e.g. coal fly-ash.

[080] In exemplary embodiments, the volume of the chamber 12 is substantially filled with bulk material 14 during the material charging step. The objective is to try to maximise the volume of bulk material 14 that can be transported within container 10, whilst minimising the volume of carbon dioxide required to obtain a predetermined level within the chamber 12.

[081] Advantageously, the initial carbon dioxide charging step may be carried out to create a saturated carbon dioxide environment within the chamber 12. Such an environment minimises the risk of combustion within the chamber 12 during transportation of the bulk material 14 within the container 10 (e.g. from the first location to the second location), particularly in the case of transporting potentially combustible bulk material, such as lignite.

[082] It is known to transport perishable foodstuff by sealed, gas-tight container, and provide a supply of carbon dioxide to the sealed container, in order to control a desired level of oxygen within the sealed container (necessary to keep said foodstuff in good condition). However, in exemplary embodiments of the disclosure, the method is intended to fill all space within the chamber 12 with as much carbon dioxide as possible, under pressure, in order to expel oxygen from the bulk material 14 prior to transportation. Moreover, in exemplary embodiments, the method is intended to provide additional charging of carbon dioxide into said chamber, as required, in order to maintain the carbon dioxide at a predetermined level. This can be advantageous in preventing the ingress of oxygen from the atmosphere during transportation of the container 10.

[083] In exemplary embodiments, the predetermined level of said initial carbon dioxide charging step is a fluid pressure level. Hence, the fluid pressure level is monitored during transportation of the container 10 to the second location. Fluid pressure monitoring provides a very simple option for monitoring the level of carbon dioxide within the chamber 12. In exemplary embodiments, the predetermined fluid pressure level is above atmospheric pressure, i.e. greater than 1 atm (or greater than 1013.25 hPa), e.g. at a level suitable to prevent the ingress of oxygen or atmospheric air into the chamber 12 (not least due to the difference in specific gravity between carbon dioxide and oxygen), thereby significantly reducing the risk of any combustion or explosion of the bulk material 14 under transportation. It will be understood that excessive levels of fluid pressure above atmospheric pressure will be undesirable in most practical instances, since this will could create problems for sealing the chamber in which the bulk material and carbon dioxide is to be transported.

[084] In exemplary embodiments, the initial carbon dioxide charging step involves obtaining carbon dioxide from a separate source 34 remote from the container 10. That is to say, in exemplary embodiments, the discrete source 20 of carbon dioxide is not used for the initial carbon dioxide charging step. However, it will be understood that the discrete source 20 of carbon dioxide could be used to finally prime the chamber to the desired level, i.e. after a significant proportion of the desired level has been obtained from the separate source 34. An examples of a suitable separate sources is a power generating plant, such an electricity generating power station.

[085] In exemplary embodiments, it is advantageous if the material charging step is carried out at the original source of said bulk material 14 in a raw state, e.g. at a coal mine (in the case of bituminous coals or brown coals, such as lignite). This can increase the overall efficiency of the transportation method, by reducing the number of loading/unloading operations for the bulk material between the source and the intended destination. [086] In an example, illustrated in Figure 3, the container 10 is provided at first location 36, which is a processing plant at the source of a bulk material to be transported, in particular a crushing plant or drying plant 38 at a coal mine 40. In such examples, an electricity or other power generating plant 42 at the coal mine 40 serves as the remote source 34 of carbon dioxide for the initial carbon dioxide charging step. This provides cost-efficiency advantages for the method of transportation, since the carbon dioxide will be readily available and would not need to be purchased or transported from another source. In exemplary embodiments, carbon dioxide is harvested from the power generating plant and stored on site (e.g. in suitable tanks), for later use in said initial carbon dioxide charging step.

[087] Once the container 10 has been charged with bulk material and carbon dioxide to the predetermined level, the container 10 is transported to a second location 44 (i.e. remote from said first location 36), e.g. for discharge of the bulk material 14 from the container 10. In exemplary embodiments, the bulk material is intended to be used at the second location, but may be stored at the second location prior to use. It may be desirable to store the bulk material in the container at said second location, until it is required for use.

[088] It will be understood that gas level monitoring of the kind described above (and subsequent 'topping-up', if necessary) may be carried out while the bulk material is in storage in the container, whether or not the container is in transportation between the first and second locations, or is static at the first or second locations (or any intermediate location).

[089] In exemplary embodiments, the predetermined level of said initial carbon dioxide charging step is a fluid pressure level above atmospheric pressure, i.e. greater than 1 atm (or greater than 1013.25 hPa), e.g. at a level suitable to prevent the ingress of oxygen or atmospheric air into the chamber 12 (not least due to the difference in specific gravity between carbon dioxide and oxygen), thereby significantly reducing the risk of any combustion or explosion of the bulk material 14 under transportation.

[090] During transportation, the chamber 12 is intended to be sealed gas-tight. Moreover, during transportation to said second location 44, the level of carbon dioxide within the chamber 12 is monitored. Any suitable monitoring method may be applicable. In the case of a predetermined fluid pressure level, it may desirable to use pressure sensors within the chamber 12, or a sensor on a valve 32 of the discrete source 20 on the container 10. The objective is to carry out an additional carbon dioxide charging step, as required, such that the chamber 12 is charged with additional carbon dioxide from the discrete source 20, in order to maintain the carbon dioxide level at or above said predetermined level during transportation of the container 10 to said second location 44.

[091] In exemplary embodiments, the second location 44 is a power generation location, e.g. a combined cycle gas turbine plant.

[092] In exemplary embodiments, the carbon dioxide is recovered from the chamber 12 at said second location 44, such as by a dedicated recovery step (e.g. prior to discharge of the transported bulk material). In exemplary embodiments, the dedicated recovery step involves a suction operation, which may need to be filtered to prevent the removal of bulk material during the recovery step. In exemplary embodiments, the recovered carbon dioxide can be stored, e.g. in suitable tanks, and transported for safe disposal or reprocessed for use in other applications.

[093] In a further advantageous example, illustrated in Figure 4, the first location is a bulk material drying plant 46 at a coal mine 48. Coal material 50 is obtained from the coal mine 48 and transferred to the bulk material drying plant 46 in particulate form. The coal material 50 may be processed (e.g. via crushing), if necessary, to reduce the maximum particle size of the coal material to a desired maximum diameter, before being passed through the drying plant 46 (whereby the moisture level of the coal material 48 is reduced). Examples of such drying plants 46 are known from W02012/160320 and WO2018/083485, which are incorporated herein by reference. In such examples, the particulate coal material 50 (e.g. lignite) is conveyed as a gas-entrained flow as it passes through the drying plant 46. Hence, for each type of material, the maximum particle size of the bulk material has to be suitable to be conveyed as a gas-entrained flow.

[094] After drying, the coal material 50 is transported to the container 10 via a further gas-entrainment system 52, which is configured to transport the coal material 50 in a flow of gas. Particularly, the further gas-entrainment system 52 uses carbon dioxide as the gas medium to create the gas flow in which the coal material is to be entrained and transported. Advantageously, the carbon dioxide is received from a power generating plant 54 located at or associated with the coal mine 48 (e.g. from a storage tank of carbon dioxide harvested during operation of the power generating plant, and/or directly operation of the power generating plant). The chamber 12 in the container 10 is charged with coal material (e.g. through the inlet 16 ), advantageously via the gas entrainment system, such that the bulk material charging step and the initial carbon dioxide charging step are carried out concurrently (i.e. with the particulate coal material 50 and carbon dioxide provided as a mixture of gas and solids). The chamber 12 of the container 10 is substantially filled with the coal material 50, and carbon dioxide is provided under pressure, until the fluid pressure level is greater than 1 atm (or greater than 1013.25 hPa), e.g. at a level suitable to prevent the ingress of oxygen or atmospheric air into the chamber 12. The chamber 12 is then sealed gas-tight, prior to transportation.

[095] In accordance with this example, once sealed, the container 10 is transported from the coal mine 48, via rail or road, to a first port 56. At the first port 56, the container 10 is loaded onto a ship 58 (e.g. a container ship). The ship 58 is then transported on water 60 (e.g. an ocean) to a second port 62, where the container 10 is unloaded from the ship 58, before being transported to a second location 64, via rail or road. In this example, the second location 64 is a power generation location (e.g. a combined cycle power plant), wherein the bulk material 50 is supplied as a fuel source for use in a power generation cycle at said second location 64.

[096] During transportation to the second location 64, the objective is to reduce or prevent the risk of combustion of the coal material, by maintaining the level of carbon dioxide within the chamber 12. Hence, the level of carbon dioxide within the chamber 12 is monitored, e.g. via fluid pressure monitoring in a manner previously described herein, so that an additional carbon dioxide charging step can be performed, using a discrete source of carbon dioxide on the container 10, to maintain level of carbon dioxide at said predetermined level.

[097] In exemplary embodiments, the carbon dioxide is recovered from the chamber 12 at said second location 64, such as by a dedicated recovery step (e.g. prior to discharge of the transported bulk material 50). In exemplary embodiments, the dedicated recovery step involves a suction operation, which may need to be filtered to prevent the removal of bulk material during the recovery step. In exemplary embodiments, the recovered carbon dioxide can be stored, e.g. in suitable tanks, and transported for safe disposal or reprocessed for use in other applications.

[098] It will be understood that the methods described herein provide safer transportation opportunities for combustible materials, such as brown coals and bituminous coals. Moreover, the methods described herein provide significant cost-saving opportunities, when compared with conventional transportation and shipping methods, in particular conventional methods for shipping of coal materials. [099] In exemplary embodiments, the material charging step is carried out at a bulk material processing plant or bulk material storage location (e.g. a coal processing plant or coal storage plant, which may or may not be located at a coal mine).

[100] In exemplary embodiments, the second location is a site where the bulk material is intended to be used as a fuel source, such as a power generation location, e.g. a combined cycle gas turbine plant.

[101] In exemplary embodiments, the container is transported from the first location to the second location by one or more methods, such as by rail and/or road and/or by ocean going vessel.

[102] In exemplary embodiments, the first location is on a first land mass and the second location is on a second land mass, wherein for at least part of the journey between the first and second locations the container is shipped by ocean from said first land mass to said second land mass.

[103] Aspects of the disclosure described above refer specifically to the use of carbon dioxide. Alternatively, the carbon dioxide may be provided in the form of a gas mixture which is rich in carbon dioxide, i.e. a mixture of carbon dioxide and other inert gases. In exemplary embodiments, said other inert gases should not contain oxygen, in order to minimise the risk of a combustion reaction - especially, if the method is to be used for transporting carbon rich materials, such as brown coals and bituminous coals. It may also be desirable that said other inert gases should not contain hydrogen, because carbon and hydrogen can sometimes react to form methane under pressure.

[104] In other aspects of the disclosure, the carbon dioxide of the above aspects and exemplary embodiments is replaced with another inert gas or mixture of inert gases. In exemplary embodiments, said other inert gases should not contain oxygen (i.e. dioxygen), in order to minimise the risk of a combustion reaction - especially, if the method is to be used for transporting carbon rich materials, such as brown coals and bituminous coals. It may also be desirable that said other inert gases should not contain hydrogen (i.e. dihydrogen), because carbon and hydrogen can sometimes react to form methane under pressure.

[105] For example, in other aspects of the disclosure, the carbon dioxide of the above aspects and exemplary embodiments of the disclosure is replaced with nitrogen, or a gas mixture which is rich in nitrogen, e.g. a mixture of nitrogen and other inert gases. In exemplary embodiments, said other inert gases should not contain oxygen (i.e. are devoid of oxygen), in order to minimise the risk of a combustion reaction - especially, if the method is to be used for transporting carbon rich materials, such as brown coals and bituminous coals. In exemplary embodiments, said other inert gases should not contain hydrogen (i.e. are devoid of hydrogen), because carbon and hydrogen can sometimes react to form methane under pressure. Nitrogen is more readily available than carbon dioxide, and so may provide a cheaper or more convenient transportation medium.

[106] It will be understood that the use of carbon dioxide (whether pure or in a gaseous mixture), other inert gases (such as nitrogen), or inert gaseous mixtures referred to above is primarily concerned with ensuring that pressurised coal materials (e.g. brown coals and bituminous coals) does not react so as to combust during transportation. Accordingly, any suitable combinations of inert gases which can achieve this result are within the contemplation of the methods and apparatus described herein.

[107] A particular advantage is achieved, in the case of brown coals and bituminous coals, if the inert gases are sourced from traditional waste gas products associated with the mining or processing of said brown coals and bituminous coals.