Method for integrating separate steam production systems

Abstract

A method of integrating steam systems of first and second chemical plants, which includes transferring steam from at least one lower pressure steam header of a first steam production and transport system in the first plant to at least one lower pressure steam header of a second steam production and transport system in the second plant, such that steam produced by the first steam production and transport system is transferred to the second steam production and transport system in the second plant, which can reduce the GHG emissions of the combined first and second plants.

Description

METHOD FOR INTEGRATING SEPARATE STEAM PRODUCTION SYSTEMSTECHNOLOGICAL FIELD

[0001] The present disclosure relates to methods and systems for producing steam for industrial processes.BACKGROUND

[0002] Natural gas is one of the major combustion fuels used throughout the world. It is mainly used to generate industrial and utility electric power, produce industrial process steam and heat, and heat residential and commercial space. Natural gas consists of a high percentage of methane (generally above 85 percent) and varying amounts of ethane, propane, butane, and inerts (typically nitrogen, carbon dioxide, and helium).

[0003] Watertube boilers and firetube boilers are two major types of boilers used for natural gas combustion in an industrial setting. Watertube boilers are designed to pass water through the inside of heat transfer tubes while the outside of the tubes is heated by direct contact with the hot combustion gases and through radiant heat transfer. Watertube boilers are used for a variety of applications, ranging from providing large amounts of process steam, to providing hot water or steam for space heating, to generating high-temperature, high-pressure steam for producing electricity. Firetube boilers are designed such that the hot combustion gases flow through tubes, which heat the water circulating outside of the tubes. These boilers are used primarily for space heating systems, industrial process steam, and portable power boilers. Industrial boilers can also be classified as wall-fired or tangential-fired. Wall-fired units are characterized by multiple individual burners located on a single wall or on opposing walls of the furnace, while tangential units have several rows of air and fuel nozzles located in each of the four corners of the boiler.

[0004] Energy efficiency and greenhouse gas (GHG) reduction are among the top priorities for chemical / petrochemical companies. One of the major energy consumers in any chemical plant is the steam grid wherein natural gas is used in auxiliary boilers to produce high grade steam, which is then used in turbines to produce power. Low grade steam leaving the turbines is eventually used in reboiler heat exchangers, ejectors, and as process steam. There remains a need in the art to enhance the efficiency of steam generation systems to reduce natural gas consumption and GHG emissions.BRIEF SUMMARY

[0005] To improve overall energy consumption, the present disclosure provides steam integration between different plants. Such integration can reduce total boiler load and thereby reduce natural gas consumption and CO2 emissions. Extra steam available in one plant can be transferred to another nearby plant with minimal capital expenditure. The natural gas saved in the boiler may be used to produce valuable chemicals like methanol (MeOH) or to increase the existing capacity of existing MeOH plants.

[0006] The present disclosure includes, without limitation, the following embodiments.

[0007] Embodiment 1 : A method of integrating separate steam systems, comprising: providing a first steam production and transport system comprising a first steam source, a first high pressure steam header transporting steam and in fluid communication with the first steam source, and at least one lower pressure steam header transporting steam and in fluid communication with the first high pressure steam header, the steam transported in the at least one lower pressure steam header having a lower temperature and / or pressure than the steam transported in the first high pressure steam header;

[0008] providing a second steam production and transport system comprising a second steam source, a second high pressure steam header transporting steam and in fluid communication with the second steam source, and at least one lower pressure steam header transporting steam and in fluid communication with the second high pressure steam header, the steam transported in the at least one lower pressure steam header having a lower temperature and / or pressure than the steam transported in the second high pressure steam header; and

[0009] transferring steam from the at least one lower pressure steam header of the first steam production and transport system to the at least one lower pressure steam header of the second steam production and transport system such that steam produced by the first steam production and transport system is transferred to the second steam production and transport system.

[0010] Embodiment 2: The method of Embodiment 1, wherein the first steam production and transport system and the second steam production and transport system are housed within the same or separate chemical plant facilities or complexes adapted to produce different chemicals.

[0011] Embodiment 3: The method of Embodiment 1 or 2, wherein the steam transported in the first high pressure steam header has a higher pressure than the steam transported in the second high pressure steam header, and / or wherein the at least one lower pressure steam headerof the first steam production and transport system has a higher pressure than the at least one lower pressure steam header of the second steam production and transport system.

[0012] Embodiment 4: The method of any one of Embodiments 1 to 3, wherein the steam transported in both the first and second high pressure steam headers has a temperature in the range of about 300 to about 550 °C, such as about 350 to about 475 °C, and / or a pressure in the range of about 35 to about 125 bar, such as about 40 to about 110 bar.

[0013] Embodiment 5: The method of any one of Embodiments 1 to 4, wherein the steam transported in the at least one lower pressure steam header of both the first and second steam production and transport systems has a temperature in the range of about 110 to about 350 °C, such as about 130 to about 325 °C, and a pressure in the range of about 2 to about 45 bar, such as about 5 to about 35 bar, and optionally wherein the difference in pressure of the at least one lower pressure steam header of the first steam production and transport system and the at least one lower pressure steam header of the second steam production and transport system is about 5 bar or higher.

[0014] Embodiment 6: The method of any one of Embodiments 1 to 5, wherein each of the first and second steam production and transport systems has two or more lower pressure steam headers.

[0015] Embodiment 7: The method of any one of Embodiments 1 to 6, wherein each of the first and second steam production and transport systems further comprises a condensate header in fluid communication with one or more of the lower pressure steam headers, and wherein a rate of condensate flow into the condensate header of the first steam production and transport system is reduced due to said transferring step, such as a reduction in flow rate of about 20% or higher, such as about 25% or higher or about 30% or higher.

[0016] Embodiment 8: The method of any one of Embodiments 1 to 7, wherein each of the first and second steam sources comprises a boiler steam drum and process steam, and wherein a steam production rate of the boiler steam drum of the second steam source is reduced due to said transferring step, such as a reduction in steam production rate of about 5% or higher, such as about 7.5% or higher or about 10% or higher.

[0017] Embodiment 9: The method of any one of Embodiments 1 to 8, wherein each of the first and second steam sources comprises a boiler steam drum and process steam, wherein the first and second steam sources transfer a total steam flow rate into the respective high pressuresteam header, and wherein the total steam flow rate of the first steam production and transport system is higher than the total steam flow rate of the second steam production and transport system.

[0018] Embodiment 10: The method of any one of Embodiments 1 to 9, wherein the second steam production and transport system is substantially or completely free of let down steam from the second high pressure steam header.

[0019] Embodiment 11 : An integrated steam system, comprising:

[0020] a first steam production and transport system comprising a first steam source, a first high pressure steam header transporting steam and in fluid communication with the first steam source, and at least one lower pressure steam header transporting steam and in fluid communication with the first high pressure steam header, the steam transported in the at least one lower pressure steam header having a lower temperature and pressure than the steam transported in the first high pressure steam header;

[0021] a second steam production and transport system comprising a second steam source, a second high pressure steam header transporting steam and in fluid communication with the second steam source, and at least one lower pressure steam header transporting steam and in fluid communication with the second high pressure steam header, the steam transported in the at least one lower pressure steam header having a lower temperature and pressure than the steam transported in the second high pressure steam header; and

[0022] a pipeline fluidly connecting the at least one lower pressure steam header of the first steam production and transport system with the at least one lower pressure steam header of the second steam production and transport system and adapted for transport of steam produced by the first steam production and transport system to the second steam production and transport system.

[0023] Embodiment 12: The integrated steam system of Embodiment 11, wherein the first steam production and transport system and the second steam production and transport system are housed within the same or separate chemical plant facilities or complexes adapted to produce different chemicals.

[0024] Embodiment 13: The integrated steam system of Embodiment 11 or 12, wherein the second steam production and transport system is substantially or completely free of let down steam from the second high pressure steam header.

[0025] Embodiment 14: The integrated steam system of any one of Embodiments 11 to 13, wherein each of the first and second steam sources comprises a boiler steam drum and process steam.

[0026] Embodiment 15: The integrated steam system of any one of Embodiments 11 to 14, wherein the first and second steam sources use natural gas for steam production and wherein integration between the first steam production and transport system and the second steam production and transport system results in a reduction in natural gas usage for steam production such that additional natural gas is available for other uses such as methanol or syngas production.

[0027] These and other features, aspects, and advantages of the present disclosure will be apparent from a reading of the following detailed description together with the accompanying figures, which are briefly described below. The present disclosure includes any combination of two, three, four or more features or elements set forth in this disclosure, regardless of whether such features or elements are expressly combined or otherwise recited in a specific example implementation described herein. This disclosure is intended to be read holistically such that any separable features or elements of the disclosure, in any of its aspects and example implementations, should be viewed as combinable, unless the context of the disclosure clearly dictates otherwise.

[0028] It will therefore be appreciated that this Brief Summary is provided merely for purposes of summarizing some example implementations to provide a basic understanding of some aspects of the disclosure. Accordingly, it will be appreciated that the above described example implementations are merely examples and should not be construed to narrow the scope or spirit of the disclosure in any way. Other example implementations, aspects and advantages will become apparent from the following detailed description taken in conjunction with the accompanying figures which illustrate, by way of example, the principles of some described example implementations.BRIEF DESCRIPTION OF THE FIGURES

[0029] Having thus described aspects of the disclosure in the foregoing general terms, reference will now be made to the accompanying figures, which are not necessarily drawn to scale, and wherein:

[0030] FIG. 1 is a schematic representation of two separate steam systems operating independently;

[0031] FIG. 2 is a schematic representation of the two steam systems of FIG. 1 integrated according to an example implementation of the present disclosure;

[0032] FIG. 3 is a schematic representation of two separate steam systems of the general type set forth in FIG. 1 and modeled in the Experimental Section herein; and

[0033] FIG. 4 is a schematic representation of two integrated steam systems of the general type set forth in FIG. 2 and modeled in the Experimental Section herein.DETAILED DESCRIPTION

[0034] Some implementations of the present disclosure will now be described more fully hereinafter with reference to the accompanying figures, in which some, but not all implementations of the disclosure are shown. Indeed, various implementations of the disclosure may be embodied in many different forms and should not be construed as limited to the implementations set forth herein; rather, these example implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like reference numerals refer to like elements throughout.

[0035] Unless specified otherwise or clear from context, references to first, second or the like should not be construed to imply a particular order. A feature described as being above another feature (unless specified otherwise or clear from context) may instead be below, and vice versa; and similarly, features described as being to the left of another feature else may instead be to the right, and vice versa. Also, while reference may be made herein to quantitative measures, values, geometric relationships or the like, unless otherwise stated, any one or more if not all of these may be absolute or approximate to account for acceptable variations that may occur, such as those due to engineering tolerances or the like.

[0036] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., ranges of “up to 25%, or, more specifically, 5%to 20%”, is inclusive of the endpoints and all intermediate values of the ranges of “5% to 25%, ” etc.).

[0037] Combination” is inclusive of blends, mixtures, alloys, reaction products, and the like.

[0038] As used herein, unless specified otherwise or clear from context, the “or” of a set of operands is the “inclusive or” and thereby true if and only if one or more of the operands is true, as opposed to the “exclusive or” which is false when all of the operands are true. Thus, for example, “[A] or [B]” is true if [A] is true, or if [B] is true, or if both [A] and [B] are true. Further, the articles “a” and “an” mean “one or more,” unless specified otherwise or clear from context to be directed to a singular form.

[0039] The present disclosure relates to a method and system for integrating two separate steam systems to improve efficiency. Steam is typically generated from auxiliary boilers, which is then fed to a plurality of steam headers. Headers at different pressures provide the steam requirements of various turbines, heat exchangers, process steam, ejectors, and the like within the chemical plant supported by the steam system. Total load on the boilers will be dictated by the header that has maximum steam consumption. When there is excess steam available in a header in one plant, the current practice is either to vent it or to condense it and use it as boiler feed water. Depending on the specific plant, this steam wastage can be between 0-50 tons per hour (TPH). This eventually ends up in wastage of energy and higher GHG emissions.

[0040] The present disclosure addresses this problem by using the extra steam from one plant in another plant having a need for steam at similar pressure. Accordingly, the present disclosure involves the integration of two separate steam production and transport systems. As used herein, a separate steam production and transport system is one with its own steam source (e.g., steam boiler), which is adapted to meet the steam requirements of a specific chemical plant facility or portion thereof. The present disclosure refers to the separate steam production and transport system that exports steam as a steam exporter system and refers to the separate steam production and transport system that imports the steam from the steam exporter system as a steam importer system. The steam exporter system and the steam importer system are typically located in relatively close proximity such that connecting the two separate systems by pipeline is not cost- prohibitive. The steam exporter system and the steam importer system can be part of the same or different chemical plant facilities or complexes. Typically, the steam exporter system and thesteam importer system are associated with separate chemical production processes producing different chemical products.

[0041] In some embodiments, each of the two integrated steam systems will comprise a high pressure steam header transporting steam and in fluid communication with a steam source, and at least one lower pressure steam header transporting steam and in fluid communication with the high pressure steam header. The steam transported in the at least one lower pressure steam header has a lower temperature and / or pressure than the steam transported in the high pressure steam header.

[0042] In some embodiments, the high pressure steam headers of each steam system will operate at a temperature in the range of about 300 to about 550 °C, such as about 350 to about 475 °C, and at a pressure in the range of about 35 to about 125 bar, such as about 40 to about 110 bar. In some embodiments, the at least one lower pressure steam header of each steam system will operate at a temperature in the range of about 110 to about 350 °C, such as about 130 to about 325 °C, and at a pressure in the range of about 2 to about 45 bar, such as about 5 to about 35 bar.

[0043] Each of the steam systems typically has two or more lower pressure steam headers and a condensate header in fluid communication with one or more of the lower pressure steam headers. In some embodiments, the rate of condensate flow into the condensate header of the steam exporter system is reduced due to integration with the steam importer system, such as a reduction in flow rate of about 20% or higher, such as about 25% or higher or about 30% or higher (e.g., a flow rate reduction of about 20% to about 50% or about 25% to about 40%).

[0044] Example steam sources for each steam system include a boiler steam drum and process steam. As used herein in reference to a steam source, “process steam” refers to steam generated by one or more unit operations within the chemical plant to which the steam system is attached. In some embodiments, the integration of the two steam systems can result in reduction in steam production rate of the boiler steam drum of the steam importer system, such as a reduction in steam production rate of about 5% or higher, such as about 7.5% or higher or about 10% or higher (e.g., a steam production rate reduction of about 5% to about 20% or about 7.5% to about 15%).

[0045] In some embodiments, each of the steam systems include a boiler steam drum and process steam and transfers a total steam flow rate into the respective high pressure steam header.The total steam flow rate of the exporter steam system is typically higher than the total steam flow rate of the importer steam system. In some embodiments, the importer steam system is substantially or completely free of desuperheating of steam from its high pressure steam header, resulting in greater steam use efficiency as explained further below. In this context, “substantially free” mean s that the importer steam system desuperheats no more than about 5% of the total steam flow produced in the boiler steam drum of the importer steam system, such as no more than 2.5% or no more than 1.0% (e.g., about 0.5 to about 5%).

[0046] This export of steam from the steam exporter system has the potential to reduce the boiler load in the steam importer system. This will aid the chemical plant as a whole to meet carbon neutrality targets and also reduce GHG emissions. Conventionally, there is wastage of lower pressure steam in many chemical plants and reduction of such steam waste will reduce GHG emissions of the chemical plant.

[0047] FIG. 1 schematically illustrates a conventional steam production and transport system for two separate chemical plants, Plant- 1 and Plant-2. As shown, there is no integration between the two steam systems, each of which include a boiler 10, 10’, a high pressure steam header 12, 12’, a medium pressure steam header 14, 14’, a low pressure steam header 16, 16’, and a condensate header 18, 18’. Plant- 1 has an additional intermediate pressure steam header 15. The number of steam headers is not particularly limiting and will depend on the steam needs of the specific plant. Typically, there are between two and five steam headers including two, three, four, or five steam headers, each carrying superheated steam. As shown, the feed to each high pressure steam header 12, 12’ is a combination of steam produced in the boiler 10, 10’ and process steam 20, 20’ produced as a byproduct of the chemical plant.

[0048] The temperature and pressure of the steam in each successive steam header will typically decline as the steam proceeds from the high pressure header 12, 12’ to the lower pressure steam headers. The difference in pressure and temperature between successive steam headers can vary. In some embodiments, the difference in pressure between each successive steam header will be about 5 bar or more or about 8 bar or more, such as a pressure difference of about 5 bar to about 100 bar or about 8 bar to about 75 bar. However, in some cases, the pressure of two successive steam headers will be approximately the same, but the temperature will decline. In some embodiments, the difference in temperature between each successivesteam header will be about 20 °C or more or about 50 °C or more, such as a temperature difference of about 20 °C to about 150 °C or about 50 °C to about 140 °C.

[0049] Each box Ul, U2, U3, and U4 of Plant-1 and each box UT, U2’, U4’ of Plant-2 fed from each steam header represents all of the equipment that uses steam from a particular steam header. As shown, as the steam produces work or otherwise loses energy, the steam users produce lower pressure steam that is fed to a lower pressure steam header based on the pressure of the produced steam. For example, as shown, some high pressure steam users Ul, Ul’ produce medium pressure steam fed to medium pressure steam header 14, 14’ and some produce lower pressure steam fed to either the intermediate pressure steam header 15 (in the case of Plant- 1) or the low pressure steam header 16’ (in the case of Plant-2). Similarly, some medium pressure steam users U2, U2’ produce low pressure steam fed to the low pressure steam header 16, 16’. Additionally, some medium pressure steam users U2 of Plant- 1 produce lower pressure steam sent to intermediate pressure steam header 15 and some medium pressure steam users U2’ of Plant-2 produce condensate fed to the condensate header 18’. Some intermediate pressure steam users U3 of Plant- 1 produce lower pressure steam sent to low pressure steam header 16 or produce condensate fed to condensate header 18. The low pressure steam users U4, U4’ produce condensate fed to the condensate header 18, 18’.

[0050] Where a particular steam header has excess steam beyond the needs of the steam users of that header, particularly with respect to lower pressure steam headers, the excess steam is typically either vented to atmosphere as vented steam V, V’ or released as condensate flows C, C’ to the condensate header 18,18’. These flows represent inefficiency as the energy of the steam is lost through venting or condensation. Depending on steam requirements of the plant, these losses can be on the order of 5 to 50 tons of steam per hour (TPH) for a typical chemical plant. Additionally, when a higher pressure steam header has excess steam beyond the needs of the steam users of that header, it is let down to a lower pressure header using a desuperheater D, D’. In some embodiments, a desuperheater reduces the temperature and pressure of the steam by letting down the steam in a valve and by injecting water 22, 22’ (typically boiler feed water) into a portion of the steam. The desuperheating process is also referred to as steam letdown. This also represents an inefficiency in the system as the desuperheating process converts a higher pressure steam to lower pressure steam with a lesser energy without performing any useful work in the system.

[0051] FIG. 2 illustrates an example implementation of the present disclosure based on the same general steam system configuration of FIG. 1, and which is modified such that the two systems are integrated, with excess steam from Plant- 1 being transported to Plant-2 to improve overall efficiency of steam usage of the two plants. As shown, the medium pressure steam header 14 of Plant-1 is integrated with the medium pressure steam header 14’ of Plant-2 via a connecting pipeline 30. In this manner, excess steam from medium pressure steam header 14 can be used in medium pressure steam header 14’, which can result in a reduction in the amount of vented steam V and condensate flow C of Plant- 1. This also can result in a reduction in the amount of let down steam passing through desuperheater D’ from the high pressure steam header 12’ of Plant-2, and a reduction in the amount of let down steam passing through desuperheater D from the medium pressure steam header 14 of Plant- 1 and the desuperheater D from the intermediate pressure steam header 15. This integration results in more efficient steam use in the combined systems due to less loss of steam through venting, condensation, and desuperheating. The overall impact of this integration is a reduction in natural gas usage for steam production, which frees the saved natural gas for other uses, such as use in commercially important chemical processes requiring natural gas as a reagent (e.g., methanol or syngas production).

[0052] For the sake of illustration, FIG. 2 shows integration between medium pressure steam header 14 and medium pressure steam header 14’, but integration could occur between any two steam headers of separate steam generation systems so long as the pressure of the exporting steam header of the exporter steam system is higher than the pressure of the importing steam header of the importer steam system. The difference in steam pressure between the two steam headers can vary, but is typically about 5 bar or more, or about 7.5 bar or more, or about 10 bar or more, such as a steam pressure difference of about 5 bar to about 25 bar or about 10 bar to about 20 bar.EXPERIMENTAL

[0053] Two existing steam production systems of two different chemical plants of the general type, denoted as Plant- 1 and Plant-2 in FIGS. 1 and 2, were modeled using Aspen to measure the impact of integrating the two steam production systems. The case where the two plants are not integrated is shown in FIG. 3 with steam, water, and condensate flows, as well as consumption of steam from each header, shown in tons per hour (TPH). The pressure and temperature of each steam header are provided.

[0054] The Plant- 1 steam system of FIG. 3 has excess steam that is let down from the medium and low pressure steam headers 4, 16, with some of this steam eventually ending up as vented steam (11-12 TPH) or condensate (9-10 TPH). Plant-2 steam system is in need of additional medium pressure steam that is fulfilled by letting down steam from the high pressure steam header 12’ (15 TPH). The FIG. 3 configuration with no steam system integration results in total make-up water use of 205-206 TPH and total natural gas consumption of 540 GJ / hr.

[0055] FIG. 4 illustrates the same two plants as shown in FIG. 3 with integration between a medium pressure steam header of each steam system. In particular, as shown, 15 TPH of steam is transferred from the medium pressure steam header 14 of Plant-1 to the medium pressure steam header 14’ of Plant-2. For the integrated system of FIG. 4, total make-up water use is reduced to 191-193 TPH and total natural gas consumption is reduced to 505 GJ / hr.Additionally, the integration in FIG. 4 reduces the boiler load in Plant-2 from 95 TPH to 82 TPH, which is equivalent to a natural gas savings of 0.27 million British thermal units (MMBTU) / Yr. This extra steam can be used in ejectors, compressors, heat exchangers, or as process steam within the plant. The only required capital expenditure is for a connection line from the steam system of Plant- 1 to the steam system of Plant-2 and optionally a letdown valve. Vent loss and condensate loss in Plant- 1 steam system can be reduced, which has a potential to reduce the make-up water requirement in the complex by 12-14 TPH.

[0056] The integrated approach of FIG. 4 leads to a number of benefits, including: (1) CO2 emissions reduction of 13-16 kilotons per annum (KTA); (2) overall energy consumption reduction of 0.2-0.3 million British thermal units (MMBTU) / Yr; (3) generation of additional methanol equivalent to 10-14 KTA where saved natural gas is used for MeOH production; (4) net water savings of 110-115 KTA; and (5) additional cash-flow of 2-4 $MM / Yr, assuming that saved natural gas is used for MeOH generation.

[0057] In general, the invention may alternately comprise, consist of, or consist essentially of, any appropriate components herein disclosed. The invention may additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any components, materials, ingredients, adjuvants or species used in the prior art compositions or that are otherwise not necessary to the achievement of the function and / or objectives of the present invention.

[0058] Many modifications and other implementations of the disclosure will come to mind to one skilled in the art to which this disclosure pertains having the benefit of the teachings presented in the foregoing descriptions and the associated figures. Therefore, it is to be understood that the disclosure is not to be limited to the specific implementations disclosed herein and that modifications and other implementations are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

CLAIMS1. A method of integrating separate steam systems, comprising:(a) providing a first steam production and transport system comprising a first steam source, a first high pressure steam header transporting steam and in fluid communication with the first steam source, and at least one lower pressure steam header transporting steam and in fluid communication with the first high pressure steam header, the steam transported in the at least one lower pressure steam header having a lower temperature and / or pressure than the steam transported in the first high pressure steam header;(b) providing a second steam production and transport system comprising a second steam source, a second high pressure steam header transporting steam and in fluid communication with the second steam source, and at least one lower pressure steam header transporting steam and in fluid communication with the second high pressure steam header, the steam transported in the at least one lower pressure steam header having a lower temperature and / or pressure than the steam transported in the second high pressure steam header; and(c) transferring steam from the at least one lower pressure steam header of the first steam production and transport system to the at least one lower pressure steam header of the second steam production and transport system such that steam produced by the first steam production and transport system is transferred to the second steam production and transport system.

2. The method of claim 1, wherein the first steam production and transport system and the second steam production and transport system are housed within the same or separate chemical plant facilities or complexes adapted to produce different chemicals.

3. The method of claim 1, wherein the steam transported in the first high pressure steam header has a higher pressure than the steam transported in the second high pressure steam header, and / or wherein the at least one lower pressure steam header of the first steam production and transport system has a higher pressure than the at least one lower pressure steam header of the second steam production and transport system.

4. The method of any one of claims 1 to 3, wherein the steam transported in both the first and second high pressure steam headers has a temperature in the range of about 300 to about550 °C, such as about 350 to about 475 °C, and / or a pressure in the range of about 35 to about 125 bar, such as about 40 to about 110 bar.

5. The method of any one of claims 1 to 3, wherein the steam transported in the at least one lower pressure steam header of both the first and second steam production and transport systems has a temperature in the range of about 110 to about 350 °C, such as about 130 to about 325 °C, and a pressure in the range of about 2 to about 45 bar, such as about 5 to about 35 bar, and optionally wherein the difference in pressure of the at least one lower pressure steam header of the first steam production and transport system and the at least one lower pressure steam header of the second steam production and transport system is about 5 bar or higher.

6. The method of any one of claims 1 to 3, wherein each of the first and second steam production and transport systems has two or more lower pressure steam headers.

7. The method of any one of claims 1 to 3, wherein each of the first and second steam production and transport systems further comprises a condensate header in fluid communication with one or more of the lower pressure steam headers, and wherein a rate of condensate flow into the condensate header of the first steam production and transport system is reduced due to said transferring step, such as a reduction in flow rate of about 20% or higher, such as about 25% or higher or about 30% or higher.

8. The method of any one of claims 1 to 3, wherein each of the first and second steam sources comprises a boiler steam drum and process steam, and wherein a steam production rate of the boiler steam drum of the second steam source is reduced due to said transferring step, such as a reduction in steam production rate of about 5% or higher, such as about 7.5% or higher or about 10% or higher.

9. The method of any one of claims 1 to 3, wherein each of the first and second steam sources comprises a boiler steam drum and process steam, wherein the first and second steam sources transfer a total steam flow rate into the respective high pressure steam header, and wherein the total steam flow rate of the first steam production and transport system is higher than the total steam flow rate of the second steam production and transport system.

10. The method of any one of claims 1 to 3, wherein the second steam production and transport system is substantially or completely free of let down steam from the second high pressure steam header.

11. An integrated steam system, comprising:(a) a first steam production and transport system comprising a first steam source, a first high pressure steam header transporting steam and in fluid communication with the first steam source, and at least one lower pressure steam header transporting steam and in fluid communication with the first high pressure steam header, the steam transported in the at least one lower pressure steam header having a lower temperature and pressure than the steam transported in the first high pressure steam header;(b) a second steam production and transport system comprising a second steam source, a second high pressure steam header transporting steam and in fluid communication with the second steam source, and at least one lower pressure steam header transporting steam and in fluid communication with the second high pressure steam header, the steam transported in the at least one lower pressure steam header having a lower temperature and pressure than the steam transported in the second high pressure steam header; and(c) a pipeline fluidly connecting the at least one lower pressure steam header of the first steam production and transport system with the at least one lower pressure steam header of the second steam production and transport system and adapted for transport of steam produced by the first steam production and transport system to the second steam production and transport system.

12. The integrated steam system of claim 11, wherein the first steam production and transport system and the second steam production and transport system are housed within same or separate chemical plant facilities or complexes adapted to produce different chemicals.

13. The integrated steam system of claim 11, wherein the second steam production and transport system is substantially or completely free of let down steam from the second high pressure steam header.

14. The integrated steam system of claim 11, wherein each of the first and second steam sources comprises a boiler steam drum and process steam.

15. The integrated steam system of claim 11, wherein the first and second steam sources use natural gas for steam production and wherein integration between the first steam production and transport system and the second steam production and transport system results in a reduction in natural gas usage for steam production such that additional natural gas is available for other uses such as methanol or syngas production.

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