GB2584714A

GB2584714A - A system for the processing of suitable municipal/general wastes and sewage

Info

Publication number: GB2584714A
Application number: GB1908485.4A
Authority: GB
Inventors: Jackson John
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-06-12
Filing date: 2019-06-12
Publication date: 2020-12-16
Anticipated expiration: 2039-06-12
Also published as: GB2584714B

Abstract

A system for processing sewage and municipal waste comprises a symbiotic system that enables the production of alcohols by fermentation and a system which produces dewatered processed municipal wastes and biosolids that can be combusted to be used as mixed fuels. The CO2 produced by the fermentation can be used to percolate through the medium to create a slightly acidic medium which improves methane output. Alcohol and other volatile compounds may be extracted vis distillation and used as fuel. Bacteria are killed during the heat treatment prior to fermentation. Water produced by the sewage treatment may be used in the municipal waste process, reducing the use of potable water.

Description

Patent application: Title A system for the processing of suitable municipal/general wastes and sewage to make fuels or products efficiently as a co related system.

By John Jackson date 09/06/2019 Introduction/background: Processes to make use of wastes or materials to make biofuels is a technology of importance to enable human activities to both dispose of products safely and to help with environmental and ecology issues that are affected by waste disposal or substrates that can be used as fuels/biofuels.

This system/process defines a system that will offer a greater level of processing options for materials already in use and the possible biomaterials of the future that may be faster degrading than current materials in any fermentation or biodegestion process. It enables a possible three fuels to be made these being an alcohol (ethanol/methanol) and the gas Methane (CH4) ,the alcohol /s having a low boiling point can be distilled off, and any other chemicals extracted with the alcohol/these other chemicals extracted with the alcohol may have uses other than as a fuel, and an inert digestate that can be combusted.

The Methane (CH4) formed in biodegestion, is collected from the digester as a mixture of Carbon Dioxide (CO2). Carbon monoxide (CO)and Methane (CH4) which is conventionally known as Bio Gas, the bio gas is then subjected to a separation process,which can be a gas separation membrane/s or passed through a solvent,usually water,which absorbs the Carbon dioxide and Carbon Monoxide to create a carbonated water and relatively pure stream of Methane (CH4), which is not absorbed by the solvent/water.

Water use and re use in such processing systems of fermentation and Bio digestion can be considerable, typical solids to water ratio of 40% solids to 60% water is considered standard,untreated water back to water courses would cause possible dangerous pollution and toxic pollution,and the system attempts to show that water can be used efficiently and reused efficiently to enable water abstraction to be minimised As most dewatering systems for digestate are mechanical the final product will carry some moisture with it,around 10-20%.

Introduction/background continued:

The process also attempts to make use of CO2 gas by percolating the CO2 through the waste medium, to increase CM production using the anaerobic methanogenesis bacterial pathways, and to help with organic acid formation in the products being bio digested.

The process also attempts to be continuous and recognises some of the time spans of fermentation and Biodegestion, and offer a form of continuous processing that acts as both process and store of digestate where, dewatered digestate would have use as a combustion fuel.

Sewage processing is seen as a complimentary process and the application attempts to show how a waste processing system with fermentation and biodegestion could work together, to consider both bio security and as processes operating independently to produce a final dewatered digestate that can be combined to produce a fuel for combustion or other purpose (dewatered digestate preferred as fuel for combustion).

The conventional term for sewage digestate is bio solids or sewage sludge, and it is understood that the two digestion processes have very different and necessary considerations and processing.Sewage may contain some toxic chemicals,or chemicals harmful to biological function, such as bleach or detergents, as well as bacteria and other organisms that are harmful to humans directly such as bacteria that are pathogens and needs more thorough treatment of waste water and careful handling of the digestate of bio solids.

Combining the relationship between general waste processing and sewage processing, the application attempts to show that a new beneficial relationship is possible, giving greater efficiency and increasing CH4 production compared to systems that do not use the efficiencies.

The specifying in the patent application emphasises the processing of wastes processing clearly, and outlines the process of sewage processing in its key relationship to the waste processing system, but is a little less specific in the sewage processing, as sewage processing has many variations in biodegestion treatments and chemical treatments and

Introduction/background continued:

in most cases returns treated water back to water bodies. The high nitrogen concentrations in sewage are suggested to either be extracted or used as medium to grow plants/microorganisms which in turn can be separated and used as a substrate for biodegestion.

Introduction to Drawings:

Figure 1: A schematic representation of a waste processing system to process suitable non sewage wastes. Key:

S=A waste sorting process to remove products found in the starting waste constituent material,that can be recycled,or are toxic or problematic for processing in the subsequent process, or as final end product digestate to be used as a combustion fuel.

S1=The stream of sorted waste, containing wastes suitable for biological treatment, processing and conversion into fuel /fuels/products.

CW=cold/warm water processing (suggested as rotary drum containing/augmenting waste but may be tank/vessel with mixing at a temperature of 60oC or below fed as heated or heated in vessel) Fl=water feed to CW S2=flow of waste stream from CW to HTN HTW=Hot water treatment (suggested as rotary drum containing /augmenting stream S2 but may be a tank/vessel with mixing at a temperature of 60-100oC and or temperature as required, or heated in vessel) F2=heated water feed from FIX to HTW ADM1=An additional feed to S3 suggested as materials that are pre-approved for introduction as feedstock and are not toxic or problematic for subsequent biological processing, or as a final end product digestate to be used as a combustion fuel, but not supplied by process S e.g. oils/fats, sugars/carbohydrates, and/or acid or alkali for physical breakdown of constituent materials in waste flow 83, from an individual supplier/source S3=Flow of waste stream from HTN to HTST HTST=High temperature steam treatment where steam is directly injected into contained flow S3, to mix and heat flow 83 as required.

Introduction to Drawings continued:

Figure 1 continued: A schematic representation of a waste processing system to process suitable non sewage wastes.

ST=Steam supply for HTST S4=Flow of waste stream from HTST to HX 1IX1=Heat exchanger to remove heat from waste flow 84 and transfer the said heat to water feed F2.

S5=Flow of waste from HX to FM BA=Biological organism/organisms to be added to 85 waste flow contained within FM unit or multiples thereof of the FM unit.

FM=Fermentation vessel/vessels (preferred as continuous system but could be batch) ,with in vessel mixing or size reduction of particles of constituent components of waste stream S5, to which is added biological organism/organisms via feed BA. Said FM process/conditions to facilitate, said biological organism to flourish/multiply and act upon constituent particles of waste flow S5, so as to produce products from biologioal activity and or alter the material of flow 85.(preferred as yeast or bacteria to make ethanol/methanol/alcohol, but may also be a fungi,or combination of one or more of yeast, bacteria or fungi if required processing time thought to be 0-30 days as required).

Cl =flow of Carbon dioxide/carbon monoxide and/or other gases/vapours collected from the FM stage as a gas to filtration/biological treatment, to remove toxins or kill any biological organism transfer from FM, to store CO2.

C4=flow of Carbon dioxide from another source e.g. an exhaust from a combustion system to CO2S.

CO2=A store for gaseous Carbon dioxide /carbon monoxide.

C2=Flow of gaseous Carbon dioxide and Carbon monoxide to the vessel/vessels of the BD section, to percolate through the waste medium.

Introduction to Drawings continued:

C3=Flow of gaseous carbon dioxide /carbon monoxide from the BG unit where membrane separation is used to separate the methane.

S6=Waste stream flow from FM stage to HT stage.

HT=Heat treatment stage of waste flow S6, to induce an alcohol or other organic volatile chemicals/molecules to be released from the waste flow of S6 so being processed as in distillation, these alcohol and volatile vapours then being collected as flow D1 and transferred to item DSFV, leaving the remaining 86 waste flow material to exit the HT stage, as waste stream flow 87.(suggested as direct steam into flow 86 in a suitable vessel to separate vapours and gases from 86,but could be other form of direct/indirect heat) D1=Flow of vapours/gases from HT processing of waste stream S6 DSFV=distillation or fractional distillation to condense out and separate alcohol/alcohols and other collected volatile chemical vapours/substances/gases as products/potential fuels.

AL=collection/store of distilled alcohols from DSFV OV=collection store of other volatile non-alcohol compounds from DSFV S7=waste stream flow from HT to HX2 HX2=Heat exchanger, where said heat is transferred from flow S7 to the water feed WF unit for steam generation and steam return/condensing, (and or other use of heat) and to cool waste outflow flow from HX" unit to flow S8.

WF=water feed for steam generation ST=steam production unit to feed HTST and HT S8=Waste stream flow from HX2 to BD

Introduction to Drawings continued:

ADM2= An additional feed to 68 suggested as materials that are pre-approved for introduction as feedstock and are not toxic or problematic for subsequent biological processing, or as a final end product digestate to be used as a combustion fuel, but not supplied by process S e.g. oils/fats, sugars/carbohydrates, and/or acid or alkali for physical breakdown of constituent materials in waste flow S8, from an individual supplier/source.

BA2= Biological organism/organisms to be added to 88 waste flow contained within BD unit or multiples thereof the BD unit.

BD=Bio digestion process where vessel/vessels (preferred as continuous system but could be batch and is also fed/percolated through with gaseous carbon dioxide and /or carbon monoxide and or other gases or gaseous/chemical mixture) ,with in vessel mixing or size reduction of particles of constituent components of waste stream 88, to which is added biological organism/organisms via feed BA2. Said BD process/conditions to facilitate, said biological organism to flourish/multiply and act upon constituent particles of waste flow 88, so as to produce products from biological activity and or alter the material of flow 88.(preferred as methane producing anaerobic bacteria to make methane and or other gas if required, but may also be a yeast or fungi,or combination of one or more of yeast, bacteria or fungi if required processing time thought to be 0-90 days as required, so as to become biologically inert).

81 =flow of biogas/gases collected from BD unit/units/process to BG unit BG=Biogas /gas separation unit, which could be a gas separation membrane/process and/or use a water absorption of non-Methane gases/vapours (preferred as water absorption system).

B2=Carbon dioxide/carbon monoxide flow (from a gas separation membrane process, as BG process choice if used) from BG to C3

Introduction to Drawings continued:

B3=Water/carbonated flow from a water absorption system of carbon dioxide and carbon dioxide gases of flow B1 and water absorption system choice of methane separation in BG if used. Flowing from BO to water flow W1 B4=flow of gaseous methane from BG unit/units to either grid distribution and/or to store.

S9=waste flow from BD to DW DW=De watering of waste flow S9, where water is mechanically /physically separated out.

W1=water flow from DW to WT (and any particles/chemicals from said DW process unavoidably carried within and receiving flow 83 if chosen).

VVT=Water treatment, physical, biological /chemical treatment of flow W1 from DW unit,to process to standards suitable for release to a body of water e.g. a river and /or re use as Fl,F2,F3 and F4 water uses/feeds.

F1=water recycle from unit WT to water use feed Fl.

F2=water recycle from unit WT to water use feed F2 F3=water recycle from unit WT to water use feed F3 F4=water recycle from unit WT to release to a body of water e.g. a river FS= fine solids by products from WT that can pass through the DW process filters or where a flocculent is used WT to bind up micro particles, fine solids and or chemicals,then sent to DGST1.

S10=flow of de watered waste flow from unit DW to DGST1 DGST1=store of biologically inert Digestate /waste flow S10,which can be blended with other inert products as required e.g. treated /processed Inert bio solids/inert sewage sludge and transported in bulk to be used as fuel for combustion or in another process.

Introduction to Drawings continued:

Figure 2: A schematic representation of a sewage waste processing system that can co work with a waste processing system/process to give greater efficiency. Key:

SW=Raw sewage reception /store/size reduction/maceration/grit removal.

SS1=flow of sewage from SW unit to HT unit HT=Heat treatment to allow,oils,fats and waxes to become liquid and separate within the body of the sewage flow/mass.(suggested temperature less than 80oC,but will be as required, receiving some/all heat from the MX unit via the HXHC circuit) SS2=flow of sewage from HT unit to OFWR unit.

OFVVR=unit for removing oils, fats and waxes via either a natural separation due to said oils/fats and waxes having a lower density than water and so rise to the surface and float as layer that can be removed, and/or via application of a blotting substance e.g. dried paper,and or other method of physical fat, oils and waxes removal.

OFVV1=flow of oils and fats and waxes from separation to store and/or as a supply to drawings figure lunit ADM1.

SS3=flow of sewage from OFVVR unit to HHT unit.

HHT=High heat treatment where the flow 6S3 is subjected to a direct steam heat treatment,to both mix and kill any biological life present in flow 883.

S54=Flow of sewage from HHT unit to MX unit.

HX=heat exchanger to extract the heat from sewage flow SS4 and transfer/utilise it to provide heat to the HT unit via a water or other substance as the HXHC circuit and to cool outflow S85 from HX unit.

HXHC=circulatory liquid transfer substance/conduit to remove heat from the MX unit and transfer it to the HT unit.

Introduction to Drawings continued:

Figure 2 continued: A schematic representation of a sewage waste processing system that can co work with a waste processing system/process to give greater efficiency.

8S5=Flow of sewage from FIX unit to BD unit BD=Bio digestion unit receiving the flow SS5 consisting of a Bio digestion process where vessel/vessels (preferred as continuous system but could be batch and where said substance within the vessels is also fed/percolated through with gaseous carbon dioxide and /or carbon monoxide and or other gases or gaseous/chemical mixture) ,with in vessel mixing or size reduction of particles of constituent components of waste stream SS5, to which is added biological organism/organisms via feed BA3 and further useful substrates/chemicals via feed ADM3 such as sugars/carbohydrates,acids/alkali. Said BD process/conditions to facilitate, said biological organism to flourish/multiply and act upon constituent particles of waste flow SS5, so as to produce products from biological activity and or alter the material of flow 855.(preferred as methane producing anaerobic bacteria to make methane and or other gas if required, but may also be a yeast or fungi,or combination of one or more of yeast, bacteria or fungi if required processing time thought to be 0-90 days as required, so as to become biologically inert).

BA34eed of Biological additive/organism to the BD unit either bacteria, yeast or fungi or combination of one or all microorganisms (preferred as methane producing bacteria) ADM3=Feed of additional materials to the BD unit where required for the* process, e.g. sugars/carbohydrates as substrate for the microorganism process or chemicals such as acid and alkali to help breakdown substances found in flow SS5.

BG1= flow of biogas/gases collected from BD unit/units/process to BG unit.

BG=Biogas /gas separation unit, which could be a gas separation membrane/process and/or use a water absorption of non-Methane gases/vapours (preferred as water absorption system).

Introduction to Drawings continued:

B2=Carbon dioxide/carbon monoxide flow (from a gas separation membrane process, as BG process choice if used) from BG to CC1 B3=Water/carbonated water flow from a water absorption system of carbon dioxide and carbon dioxide gases of flow B1 and water absorption system choice of BGS if used. Flowing from BG to water flow VVW1 B4=flow of gaseous methane from BGS unit/units to either grid distribution and/or to store.

8S6=inert waste flow from BD unit to DW unit DW=De watering unit to separate water from solids of flow S56 via mechanical/physical means.

SS7=flow of solids collected from DW (termed sewage sludge or bio solids) to ID unit.

WW1=flow of separated water from DW unit (with chemical and micro fine particles) to WT unit.

VVT=Water treatment unit to treat flow W1 VVT=Water treatment, physical, biological /chemical treatment of flow WWI from DW unit,to process to standards suitable for release to a body of water e.g. a river and /or re use as STW1,STVV2 and STW3 water uses/feeds.

STVV1=water recycle from unit WT to water use feed F1. STW2=water recycle from unit WT to water use feed F2 STW3=water recycle from unit WT to release to a body of water e.g. a river.

ID=Inert digestate store MS= micro solids feed from WT unit to join flow SS7. Introduction to Drawings continued: Figure 2 continued: A schematic representation of a sewage waste processing system that can co work with a waste processing system/process to give greater efficiency.

DIG1=flow from ID which can be mixed with flow DGST from drawings figure 1 to provide a fuel for combustion (preferred use) or other process.

DIG2=flow from ID which can be used as soil for growing plants to make fuel or to feed insects,either in containers or as bed and/or in greenhouse/horticulture methods. Spent soil/bio solids once used to be sent to DIG4.

DIG3=flow from ID which as a sludge could have a further biological treatment/treatments (preferred as fungi) to create an improved fuel for combustion or other use.

DIG4=flow from ID where sludge is made into briquettes or pellets and given a further biological treatment /treatments (preferred as fungi) to create an improved fuel for combustion or other use.

Detailed description:

Drawings figure 1 show a schematic representation of waste processing system, to make fuels such as alcohols and methane by use of biological organisms /chemical processes and give inert residual solids that can be used as fuel for combustion. Drawings Figure 2 shows a schematic representation of a sewage processing and treatment system to make fuel methane by use of biological organisms/chemical processes to give an inert residual solids that can be used as fuel for combustion, but may also have further uses and further biological treatments to either improve its fuel utility and/or to provide a soil type medium for growing plants, which in turn could be used as a fuel, or provide a food stock for insects.

The drawings have some similar features, but it is necessary that a system for processing collected wastes (such as collected in municipal waste collection.e.g. waste paper, food leftovers, suitable packaging waste) ,is separated due to operation, from a sewage collection system that contains human excreta and/or harmful chemicals or microorganisms that are pathogens. It is possible to combine the two systems as one, however in this patent application the differences of the two systems is used to gain overall improvements in water and energy use and an increase in fuels produced compared to conventional systems/processes currently in use.

In both systems shown in the drawings figures 1 and 2 the various components and units can be in multiplicities, and the designs attempt to achieve continuous processing, although particularly for fermentation and bio digestion stages,batch processing may be used. The fermentation and bio digestion stages of both systems can be many days and this outlines a process containing many such fermentation or bio digestion vessels, which as a basic construction would be vessels or tanks to contain (with a sealed lid to contain contents and collect products such as gases) a liquid slurry/material of around 60% water 40% solids with in vessel size reduction/mixing apparatus, a means of introducing transferring and removing said liquid slurry/material in tubes and pipes and of cleaning and of introducing biological organism (yeast, moulds,fungi and bacteria) in any part of the process, and a means of introducing additional materials that may come as single material e.g. sugar to aid any biological process by the microorganisms so introduced,or acid or alkali to give a chemical effect to change materials in the waste flows, or to improve conditions for the microorganisms that are active within the vessels and tanks. All flows of materials in both systems would be initiated/controlled/managed by pumps and valves (not shown in drawings) powered by energy that may be electrical or physical drives or actuators (energy supplies not shown in drawings) and it suggested that these are from renewable sources of power generation where possible. Where carbon dioxide from an outside source is suggested, this may be carbon dioxide collected from another process, e.g. a combustion exhaust It is felt that using nitrogen oxides such as found in air aspirated combustion engines may be unhelpful to the processes so described, but if able to separate out the nitrogen oxides, a useful source of carbon dioxide could be sourced and be used to make a carbon based fuel again.

If the final inert digestate from both systems is to be used for combustion then it is important that it is free from the sorts of materials that may cause problems in a combustion system and the drawings assume that glass and metals even as small particles can and will be removed at suitable points in the processes (not shown in drawings) ,as the waste streams are slurries,then ferrous materials can be removed by magnetic apparatus, however non-ferrous metals would need metal detection and a way of removing fine metal particles. Glass and metals not removed by the sorting process could be removed in the municipal waste system of drawings figure 1 at the cold and hot wash units possibly using a gravitational sorting system, such as grades differing sizes of aggregates with a slurry flowing over a series of baffles, in which the heavier particles become trapped (not shown in drawings).Sewage processing in current technology has well understood maceration and grit removal,of raw sewage and generally metal and glass are not found in modem raw sewage reception units, but none the less any final inert digestate for combustion should be free of metal and glass particles.

Detailed description continued:

The important relationship between the two systems is that Sewage as a material contains a good deal of water already due to the way it is collected, sorted municipal waste does not contain a great deal of water as it is collected in relatively dry form, by using treated water from the sewage process, water for the municipal waste process can be minimised and recycled. The further important relationship is that,where final digestate (as an inert product) is given to making a fuel for combustion,that these two end products from either system can be combined to produce a fuel that improves the energy value, and or gives a more consistent energy density.Sewage sludge is a very low energy fuel compared to e.g. waste paper per kg mass, by combining the streams of inert digestate the low energy value of sewage sludge can be compensated for in some way, and as two sources of inert digestate offer a more regular fuel supply and in good quantity/volume so as to make such a combined fuel of use to large fuel user such as a power station.

1 Taking the municipal waste process of drawings figure 1 first,the process begins with unit "S" which is a waste sorting process for municipal waste that produces a stream of waste shown as "S1" ,that is suitable for biological processing in unit "S" it would be expected that things which cannot be used and/or may be harmful to any biological process will be removed Although there are many items that find their way into municipal waste streams items I suggest removing are, metals, glass,electrical goods, pesticide and herbicide residues/containers, and any material that has a recycling use before it is to be processed by biological means into a fuel to be combusted e.g. certain wood,paper and plastic wastes. Theoretically the waste flow "Sl" should consist ideally of biodegradable wastes including bio degradable plastics, and also food waste (but not slaughter wastes unless approved, as this type of waste has some specific problems,slaughter house waste could however be processed in the sewage process of drawings figure 2 and be placed in flow "SS1" of drawings figure 2) .The waste processing of unit "S" in drawings figure 1 covers a great deal of activity, to remove and sort items that are unsuitable and

Detailed description continued:

are common to such waste streams of general municipal wastes, how well the process unit of V can sort materials will greatly affect the efficiency of the biological processes that are to be used, it is possible that wood or plastics (if prepared by size reduction apparatus not shown in drawing figure 1) could be streamed into flow "Si" if required.

From unit "S" via flow "81" the sorted waste stream that should be macerated, which then passes through a cool/cold water washer "CVV"which washes the materials in the flow becoming "82",loosening and softening some materials and then flows (with its wash water) to heated/hot water washer 1-11VV"which further loosens and softens some materials in the flow, as well as some pre heating of the waste flow (with its heated/hot wash water) shown as flow "83".additional materials can be added to flow "S3" via unit "ADM1" , these being pre-approved e.g. waste oils fats or waxes (noting that the patent application can also use the oils, fats,waxes that are extracted from the sewage process system of drawings figure 2 via this "ADM1" unit), or sugars and carbohydrates or chemicals that alkali or acid. Some additions are substrates/food supply for biological organisms, however it is know that pretreatment with add or alkali can break some long chain molecules into shorter ones that biological processes can more easily utilise and convert into the products desired.

Waste flow "83" then is processed via high temperature heating unit "HTSr,this is to kill/reduce any microorganisms present,it may also physically change some materials to be useful, but primarily it is to give a near sterile waste stream (it is suggested that heating is achieved by direct steam injection into the waste flow "83", but non steam and indirect heating methods could also be used).The waste flow "84" then proceeds onto the "FIX" unit which is a heat exchanger to cool flow "84" (and pre heater water for the heat/hot wash "HTVV" section fed by water flow F2)which upon exiting the heat exchanger becomes flow "85". "85" then flows to the FM unit where fermentation can take place using yeast or other microorganisms (added via the "BA" unit), to convert sugars into alcohols (other processes are outlined in modifications

Detailed description continued:

and variations), producing carbon dioxide gas, which is collected as flow Cl to store "CO2". This process of fermentation could take up to a suggested 30 days, by which time most available sugars will have been converted to alcohols and carbon dioxide gas,materials that are not broken down into sugars remain in the waste stream,additionally dead/living, yeast/microorganism cells will have accumulated in the waste stream.

The "FM" unit may have carbon dioxide gas percolating through its vessels contents, this may help to stir/mix the contents and produce a slight acidification of the water to aid breakdown of some materials within the waste stream contained within the "FM" vessel/vessels. In Fermentation sugars are converted to alcohol producing carbon dioxide as gas, this gas can be collected/filtered to stored "CO2" and piped in the "C3" flow used in the "BD" units to stir/mix the contents and produce a slight acidification which may aid the breakdown of some materials, but primarily will provide free Hydrogen ions to help in the bio chemical processes that enable methanogenesis by the microorganisms used in methane production by bio digestion and enable a greater production of methane (if other conditions are suitable/favourable to microorganism function/reproduction) ,than a system that does not percolate gaseous carbon dioxide through the materials/waste stream so contained/being processed.

Unit "BA" of the "FM" unit is a feed of biological organism, yeast, mould, fungi, bacteria and or combination of them and could be present at any part of the system in the "FM" unit, where fresh seed organisms may be required.

On exiting the "FM" unit the waste stream (now containing added alcohols and yeast cells and some glycerol) as waste flow "S6" enters a heat treatment /distillation process "Hr where flow "S6" is heated (preferred by direct steam injection heating,supply "ST", but non steam or indirect could be used) to kill any live microorganisms present and rupture the cell walls where possible, but primarily to enable the alcohols to be evaporated off (but to retain the glycerol in the waste flow,this could be attained by a vacuum evaporation process not shown in the drawings). The

Detailed description continued:

collected evaporated alcohols, and other volatile substances collected are removed vi flow "Dl" to a fraction distillation device "DSFV' unit, where by fine temperature control any individual chemical substances may be concentrated and removed separately, alcohols to "AL" and other volatiles/products to "OV'. The main component to be distilled out would be the alcohols ethanol and methanol, however some more complex molecules could accumulate by the alcohols behaving as a solvent, such as naphtha could be created shown as the "OV' stream and these may have further uses, as an onsite fuel or for other processes. The outflow from the "HT" section not evaporated becomes waste flow "S7" which passes through a heat exchanger to cool it (and provide heat, for water for steam or other use via unit WF) to become flow "S8" which enters the "BD" or biodegestion unit. In the "BD" unit a biological microorganism (preferred as bacteria capable of methanogenesis but could also be another microorganism or combination of microorganisms see modifications and variations) is added via input "5A2", also additives such as sugar/carbohydrates, acids or alkalis could be added if required via input "ADM2".The "BD" unit is preferred as continuous throughput unit and anaerobic conditions,but could be batch system,suggested retention time is 0-90 days depending upon what is required and the methane or other products wishing to be extracted or formed. Carbon dioxide should be percolated through via feed "C2"to assist in mixing/size reduction and provide an increased methane yield in favourable conditions for microorganism function and reproduction After the required time in the "BD" unit the waste flow "S9" from the 'SD" unit to the "DW' or de watering unit, which is usually mechanical apparatus with filter screens to separate the water from the solids the water then being fed to via the "W1" flow to the "WT" or water treatment unit, where the water is treated via addition of flocculant/fittration and/or flocculent settling tank and fine particles removed and stored in unit "FS" and then added to the inert digestate "DGST1",the water from the "WT" then either being treated for release in water bodies e.g. a river via flow "F4" and/or being treated to be used to supply the "CW' or "BG" unit via flow "F1"or to supply "HTW" unit via flow "F2" or as a supply for steam generation via flow "F3".Flow S10 being the solids from the "OW" unit to "DGST1" which should be biologically inert.

2) The drawings figure 2 shows a process for the processing of sewage which begin with raw sewerage arriving to the unit "SW" where grit may be removed and maceration take place. Waste flow "SS1" then is heated in a heat treatment unit "HT" (using the spent heat of the "HHT' unit via heat exchanger "HX3" transferred by the "HXHC" circuit, or other heating method) to a suggested temperature of 60-80oC and/or as temperature as required, to allow the lower density fats, oils and waxes to rise and be collected in the "OFR" unit via flow "S52", where in the "OFR" a layer of liquid/semi liquid oils,fats and waxes can form and be skimmed or siphoned off from the waste stream "SS2" (or by using a blotting/absorption material such as paper).The separated/extracted fats, oils and waxes then being transferred via flow "OF1" to the "ADM1" section of the waste process of drawings figure 1 to be used in that process. Flow "8S3" then exits the "OFR" unit, also additives such as sugar/carbohydrates, acids or alkalis could be added if required via input "ADM3" and enters the "HHT" unit where it is subjected a high temperature heat treatment (suggested as direct steam injection from steam supply "ST" but could be other forms of direct or indirect heating) to mix/breakdown some materials and to kill any microorganisms present,flow "SS4" then passing through a heat exchanger unit "HX3" to be cooled (the recovered heat then being supplied to the uHr unit to heat the flow "SS1" via the "HXHC" circuit). Flow "S85" then exits the "HX3" unit to enter the "BD" or biodegestion unit. In the "BD" unit a biological microorganism (preferred as bacteria capable of methanogenesis but could also be another microorganism or combination of microorganisms see modifications and variations) is added via input "BA". The BD" unit is preferred as continuous throughput unit and anaerobic conditions, but could be batch system, suggested retention time is

Detailed description continued:

0-90 days depending upon what is required and the methane or other products wishing to be extracted or formed. Carbon dioxide should be percolated through from feed "C2"to assist in mixing/size reduction and provide an increased methane yield in favourable conditions for microorganism function and reproduction After the required time in the "BD" unit the waste flow "SS6" from the "BD" unit to the "OW" or de watering unit, which is usually mechanical apparatus with filter screens to separate the water from the solids,the water then being fed to via the "W1" flow to the "VVT" or water treatment unit, where the water is treated via addition of flocculent/filtration and/or flocculent settling tank and fine particles removed and stored in unit "FS" and then added to the inert digestate "DGST2",the water from the "WT" then either being treated for release in water bodies e.g. a river via flow "F4" and/or being treated to be used to supply waste flow "SS1" or "13G" unit via flow "Fl "or "HHT' unit via flow "F2" or as a supply for steam generation "Sr via flow Tr.

The inert digestate flows via "S87" to the store "DGST2" which has four routes shown in drawings figure 2 these being flow "DIG I" the inert digestate can be combusted and/or mixed with other fuels/digestate to produce a combined fuel for combustion. The flow "DI02" utilises the use of sewage inert digestate as good growing medium for plants and fungi, food for human consumption should not be grown in any "DI02" medium as human pathogens may be present, however it could be used to grow plants that can make a fuel e.g. miscanthus in pots or in a greenhouse, alternatively, plants could be grown that feed insects that could be turned into animal foods, and spent "DIM" medium sent to combustion or to to mix with feed "SS1". The flow "DIGS" offers a route where a microorganism could grow on the inert digestate as an unprocessed material, where it may improve its combustion energy value e.g. fungi that removes the nitrogen but adds mass. The flow "DIG4" offers a route for processing the inert digestate into briquettes or pellets that can be used as fuel or treated via a biological microorganism to improve its combustion energy by e.g. removing the nitrogen or adding mass.

Detailed description continued:

The collected biogas from the BD flows via "BB1" to the gas separation "BO" unit where two forms of separating the methane out are possible,if using a gas membrane system then the separated methane will exit the "BO" unit as 13[34" and go to grid or store,the carbon dioxide/carbon monoxide component of bio gas then becoming stream "BB2" and going to "C3".If using a water separation system then carbon dioxide/carbon monoxide will be absorbed into water,the carbonated water then becoming flow "BB3" to "W1", the separated methane (which is not soluble in water then exiting as flow "8B4"). Flow "C4" to the "CO2" store is an external source of carbon dioxide, from e.g. the exhaust of a combustion unit.

Possible modifications and variations: 1) In drawings figure 1 part of the process uses fermentation unit "FM", to produce alcohols from the substrate waste stream this could be replaced with a processes that converts the waste to another combustable material/fuel e.g. lignin, this would require a treatment of acid or alkali to break down long chain molecules and a microorganism such as a mould or fungi or bacteria. This would act both to reformulate some carbon that could be used in the "BD" unit to make methane, and/or fix carbon into solid fuel that can be combusted. The distillation apparatus would not be required.

2) In drawings figure 2 the separated water from the "OW" unit, may be high in nitrogen and other beneficial chemicals for growing certain types of plants,these chemicals could be extracted and/or the water used to water certain types of plants (for non-human food use or as a fuel).

3) In general for on-site energy needs, it is best to use a renewable form of energy, wind, solar, hydro if available, however in drawings figure 1 the "FM" unit is producing alcohols and other volatiles which could be used as fuel for a combustion engine to make mechanical and/or electrical power, and also some heat for steam generation, the carbon dioxide from the exhaust could be used to percolate through the "FM" and "BD" units and increase the methane production.

4) In drawings figures 1 and 2 the water treatment unit "WT" could use a flocculent agent to enable rapid formation of removable fine debris that can be separated by filtration/mechanical separation as "FS". However the chemical gluconic acid,which is made by a microorganism process and used as flocculent, is cited as increasing the fuel energy, by using gluconic acid as flocculent in water treatment, collected solid debris will have an increased fuel value when combusted.

5) Both systems in drawings figures 1 and 2 could processes wood waste, as chips/flakes or dust and this is preferred as using the process of drawings 1"it may also be tyre and rubber crumb (free from metals) should be processed this way at flow "Sl".

Advantages of the invention: 1) The processes of general waste disposal and sewage treatment are necessarily separate in current technology, by using the inert digestate as fuel for combustion this enables waste end products of the process to not go to landfill or in the case of bio solids be applied to the land, where some of the problems of micro particles becoming persistent in soils have been recognised.

2) General municipal wastes as a collection system in most systems in use,have forms of streaming some materials so that these are collected and processed individually, and it is increasingly evident that some materials as wastes do have further uses, and a general collection and sorting of wastes would increase the amount of recycling of materials that previously have gone to landfill as well as enabling the sorting of wastes that the drawings of figures 1 and 2 can process into a useful fuel for combustion at e.g. a power station.

3) In drawings figure 1 a fermentation unit "FM" is used to produce alcohols via microorganism actions,the alcohols should act as wash/solvent to remove any chemicals in the material that are soluble in them, thereby removing some potentially harmful chemicals prior to the biodegestion section,which may enhance the performance of the "BD" unit in its microorganism actions. Further that the production of alcohols by fermentation produces a by-product called Glycerine which converts to methane very well in biodegestion further enhancing the performance of the "BD" units output of methane.

4) Given the long residence times of waste flows in the "FM" and "BD" units in drawing 1 and of the "BD" unit in drawing 2,this allows maximum extraction of methane, but also enables these units to act as fuel bunkers,which in a larger system of combustion of inert digestate waste would be very useful in enabling fuel to be better distributed as required to various sites of combustion as well as enabling the store to Advantages of the invention continued: facilitate rapid loading of a large quantity of inert digestate to a large load transport such as railway train load.

5) Both the systems of drawings 1 and 2 could be located adjacent to one another, making use of energy and water much better and gaining new overall energy efficiencies.

6) In drawings figure 2 sewage arrives as raw sewerage usually via a pipe collection system from service users however, sewerage and or specific food processing effluents could be transported via/road rail to the site for processing saving on the need for on-site processing for large food process effluent producers.

7) Both processes outlined in drawings 1 and 2 enable a good closed system where wastes that may be toxic or harmful to the environment can be safely sorted and processed into a material that is inert digestate, and methane that can be supplied to gas grid distribution system.

8) By locating such a combined system as shown in drawings figure 1 and 2 in major towns and cities, such sites could provide sufficient methane for heating or energy of core structures, infrastructure and greatly contribute to local energy needs.

9) Methane produced from bio digestion can be said to be carbon neutral, where the feedstock for methanogenesis is not a direct fossil fuel source, whilst many materials in the process of drawings figure 1 and 2 have links to fossil fuels if we move to a system of more bio materials being used in packaging and so being disposed to waste, using these processes would move us to a more carbon neutral energy system.

10) The "FM" unit of drawings figure 1 will produce yeast as by product, which (if heat treated to rupture microorganism cell walls) will give a useful substrate for increased methane production of the subsequent "BD" unit.

Claims

Claims: 1) That the drawings of figures 1 and 2 show a schematic representation of a municipal waste processing system and sewage waste processing system, working in way that has mutual energy, water and transport efficiencies, that could not be attained should these systems be separate and could be a continuous throughput system or batch system.
2) That processes described in drawings 1 show a system of processing general waste to 3 types of fuel,alcohoUalcohols, biomethane and an inert digestate that can be used to generate energy, converting waste into a greater amount of useable energy than a system not using these methods.
3) That the processes described in drawings 2 show a system for processing sewerage waste into 2 direct fuels bio-methane and an inert digestate that can be used to generate energy, converting more waste into a greater amount of useable energy than a system not using these methods.
4) That the said components of drawings figure 1 consist of sorting process to remove non suitable wastes/materials for subsequent biological processes e.g. metals/glass or substances that may act toxically in any biochemical action, and or that may not be combustable in the end inert digestate product, to produce a mixed waste stream that may consist of substrates that can be utilised by the chemical reactions and microorganism actions, and/or may pass through the process being inert in themselves, e.g. fabrics, carpet,tyre rubber crumb.
5) That the components of drawings figure 1 consist (or multiplicities thereof) of sorting, washing, carbon dioxide/carbon monoxide collection and vessel percolation systems, steam generation apparatus, fermentation and distillation vessels, alcohol/vapour distillation, collection/storage of alcohols and other distilled products, water treatment and dewatering systems, bio digestion vessels, methane collection systems, and processing to gas distribution grids, and storage of inert digestion waste for transport by road, water or railway, and associated pipework, conveyors, pumps, size reduction devices e.g. in tank stirrers/chopper pumps Claims continued: and valves and energy used (some of which are not shown on the drawing figure 1 for showing the basic process flows).
6) That the process so outlined in drawings figure 1 can utilise water from the process of drawings figure 2 and or vice versa.
7) That the process outlined in drawings figure 1 consists of using a fermentation process prior to biodegestion processes to produce alcohols mainly ethanol and methanol which are then distilled off by using the convention of the process of distillation and the vapours collected and processed where further substances from the distillation other than the alcohols may be present.
8) Further to claims 7 that a fermentation process will create yeast cells and a by-product called glycerine, both of which may act as as substrate for the subsequent Biodegestion stage, increasing the methane yield per kg of solids processed, than via a system that does not a fermentation system to produce alcohols.
9) That the components of drawings figure 2 consist (or multiplicities thereof) of sorting, washing, fat and oil extraction, carbon dioxide/carbon monoxide collection and vessel percolation systems, steam generation apparatus, water treatment and dewatering systems, bio digestion vessels, methane collection systems, and processing to gas distribution grids, and storage of inert digestion waste for transport by road, water or railway, and associated pipework, conveyors pumps and valves, size reduction devices e.g. in tank stirrers/chopper pumps and energy used (some of which are not shown on the drawing figure 1 for showing the basic process flows).
10) That further to claims 9 that the inert digestate from the treatment process may be used as growing medium to grow a biofuel, or provide insect food, that may further enhance energy production and/or utility.
11) That by percolating carbon dioxide through the waste medium so contained within the fermentation and biodegestion units/vessels of drawings figure 1 that this will increase mixing in the vessel and enable the creation of weak acid in the water/waste material which may aid the breakdown of long chain molecules into materials that Claims continued: any microorganism so used may be able to use better and convert into products better.
12) That further to claims 11 that by percolating carbon dioxide through the waste medium so contained within the biodegestion units/vessels of the drawings of figure 1 and 2 that this will increase mixing in the vessel and enable the creation of weak acid in the water/waste material which may aid the breakdown of long chain molecules into materials that any microorganism so used may be able to use better and convert into products better, by enabling more free hydrogen ion /molecules to be present to be used by methane producing microorganism and enable a greater production of methane from bio digestation (as anaerobic digestation) than would be gained from a system that does not percolate carbon dioxide through its waste medium.
13) That when combining the claims of 4-12 that the two systems so deathbed in drawings 1 and 2 can utilise water better than as individual units, giving an energy and environmental efficiency, and that the greater production of fuels (via conversion of the waste substrate to alcohols and/or methane or utility as an inert fuel for combustion) gives a greater fuel returned from suitable wastes than current technology in use can achieve, and enabling materials that would previously have been put to landfill to be used as a fuel.
14) That in drawings figure 1 and 2 water treatment from the DW or dewatering section may be treated with a flocculating agent to coagulate/conglomerate fine particles that are able to pass through the dewatering process into the separated water. If the said agent is a chemical such as gluconic acid (which is also produced by a microorganism reaction using a sugar/carbohydrate) then this will give the resultant product a greater energy value in combustion, than were it not used. Thereby the flocculent agent helping to increase the low energy value of an inert digestate, when the extracted fine solids that use this type of flocculent are added to it enabling a greater energy output of treating waste and waste processes than would be attained by not using this type of flocculating agent.
Claims continued: 15) That microorganisms so used in the processes of drawings 1 and 2 are to effect biological and biochemical conversion of the waste materials into more useable substances, for further processing or increased efficiency and yields of fuels, that said microorganisms may include yeasts, moulds, fungi and bacteria.
16) That plants may be used to gain energy from the inert digestate of drawings figure 2 which may produce fuels.
17) That the long residence times of waste materials in fermentation and biodegestion, outlined in the processes of drawings 1 and 2 act as both storage and enable maximum extraction of the required products/by products and that this is useful in energy efficiency, where an inert digestate end product is to be used as a combustion fuel.