GB2547696A

GB2547696A - Method of reclaiming and utilizing water and carbon dioxide from the exhaust to create near zero greenhouse gas emission exhaust system

Info

Publication number: GB2547696A
Application number: GB1603414.2A
Authority: GB
Inventors: John Brown Allan
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-02-26
Filing date: 2016-02-26
Publication date: 2017-08-30
Also published as: GB201603414D0

Abstract

A method of producing calcium carbonate from the exhaust 2 of an internal combustion engine 1 comprises; treating 3 the exhaust gas to remove particulate matter, sulphur dioxide (SO2) and carbon monoxide (CO); passing the exhaust gas through a scrubbing device 6 that will separate the gas into a carbon dioxide (CO2) rich stream and an nitrogen/water vapour rich stream; cooling 11 the nitrogen/water vapour rich stream; passing the nitrogen/water vapour rich stream through a membrane condensing device 14 to separate demineralised water from the stream to leave it nitrogen rich; passing the reclaimed water to a reservoir 16; venting 8 the nitrogen rich gas to the atmosphere; passing the carbon dioxide rich gas stream and at least some of the reclaimed water to a catalysed carbon capture device 41; adding amounts of caustic soda/sodium hydroxide (NaOH) 44 and calcium chloride (CaCl2) 45 to the device; and reacting the carbon dioxide, water, caustic soda and calcium chloride at a temperature below 140 degrees centigrade to produce calcium carbonate (CaCO3) and sodium chloride (NaCl).

Description

METHOD OF RECLAIMING AND UTILIZING WATER AND CARBON DIOXIDE FROM THE EXHAUST TO CREATE NEAR ZERO GREENHOUSE GAS EMISSION EXHAUST SYSTEM.

BACKGROUND TO INVENTION

Carbon dioxide (CO2) is released into the atmosphere by the burning of fossil fuels. The preindustrial carbon dioxide level was around 278 ppm and had stayed fairly constant for several centuries. In the 20th century atmospheric carbon dioxide levels have increased from about 315 ppm in 1958 to 378 ppm at the end of 2004. Thus, since the beginning of the industrial revolution the concentration of carbon dioxide in the atmosphere has increased by around 36%. Carbon dioxide is a greenhouse gas, contributing to the increasing of the temperature of the earth. Carbon dioxide from the atmosphere is also absorbed by the oceans where it forms carbonic acid and increases the acidity of the water, impacting on populations of many life forms and threatening delicate ecosystems such as the coral reefs.

One method of reducing the amount of carbon dioxide in the atmosphere is to capture and store it as it is produced rather than release it into the atmosphere.

Of the various approaches to the capture and storage of carbon dioxide, the one that has gained the interest of governments and industries is storage of carbon dioxide in geological forms. The geological storage of carbon dioxide can be achieved in two ways: a) separate the carbon dioxide and pump it into empty or depleted oil wells (both terrestrial and oceanic oil wells can be used); or b) to convert it into calcium carbonate and dispose of it as landfill. One limitation of method a) is that there has to be a continuous monitoring of the oil well for possible leaks (especially for oceanic storage). The conversion to calcium carbonate for use in landfill is considered to provide a more reliable solution to the problem of carbon dioxide storage.

Calcium carbonate is a thermodynamically stable material and is abundantly found on the earth's surface. The calcium carbonate present on the earth is estimated to be a carbon reservoir equivalent to 150,000 x 10 metric tons of carbon dioxide about 4% of the earths crust. It is the main component of shells of marine organisms, snails, pearls, and eggshells and is a completely stable mineral, widely used in the building industry to make cement and other materials and also in hospitals to make plaster casts.

With concerns about global warming caused by C02 emissions, research into zero emission engines has become a priority. With small land-based vehicles, electric engines are the preferred route. However at sea battery power is not an option. The best way forward for the marine industry is carbon capture and utilisation. Captured C02 and water can be used as feed-stocks for a carbon to calcium carbonate reactor. This invention proposes reclaiming C02 and low PH water from a ship's exhaust and processing them into calcium carbonate which can then be disposed of at sea with the environmentally beneficial effect of reversing the acidification of the ocean which is itself caused by the growth of C02 in the atmosphere so this invention will not only remove C02 from the atmosphere it will help to reverse some of the acidification of the sea caused by the man made increase of C02 in the atmosphere. A win- win situation. It is possible to produce calcium carbonate using sea water however this invention proposes using potable water reclaimed from the exhaust. There will clearly be environmental concerns about disposing of anything at sea especially if the water used is taken from polluted busy shipping lanes so this system proposes that to comply with Bio Safety Regulations the water used is potable water reclaimed from the exhaust, this will ensure that the calcium chloride produced will be pure and that an instant alert to any system malfunction will exist as the ships drinking water will also be reclaimed from the exhaust.

Use of reclaimed potable water would also be environmentally better than the use of seawater as seawater is already supersaturated with C02 and it is the C02 from the engines exhaust that we wish to convert to calcium carbonate not the C02 that is already in the sea. With the removal of C02 from the exhaust a near zero greenhouse gas emission system can be achieved.

At present the research into carbon capture and utilisation has concentrated on large industrial plants like power stations and cement works; but with land based system different prime considerations come to the fore. There is a patent (Hsu 2014, Zero emission power plant with C02 waste utilisation) which outlines the nature of the problem and claims a system for a zero emission plant in a land-based situation.

For example, at land-based industrial sites the best thing economically to do with the C02 that can be reclaimed from the flue gas is to store it on-site for future use in manufacturing or for transporting to long term storage, for example in underground worked-out oilfields. Water in a land-based industrial plant is normally available on-site more cheaply than via reclaiming it from the exhaust. The industrial process will be scaled up to make it as economic as possible and there will be no particular incentive to produce any specific carbon based product. They will produce the carbon-based product that is most economically advantageous for them, and that will be the one with the highest resale value. Also given the large scale of the operation a chemical process at high temperature and high energy use is likely to be used for the reactor. (e,g Fisher Trope or Sabatier reactors well known to those skilled in the art.)

Mobile systems have a different set of problems. The low PH water supply would take up valuable space if it were stored in an on-board reservoir, which might require about 300 cubic metres of extra water storage per ship. This makes water reclamation from the exhaust the only viable option. A similar problem would arise with what to do with the carbon-based product that was produced. The logistics of on-board storage and collecting and marketing of the carbon-based product that had been produced, given the relatively small scale of the operation, would not make it economically viable. The resulting carbon-based product, if it is to reduce C02 emissions as economically as possible, must be fed back to the ship's engine as fuel or turned into an environmentally friendly product for disposal at sea. With the current state of technology no low cost low energy method of converting the C02 in the exhaust to fuel (e.g. methanol) exists so conversion of the C02 into calcium carbonate for disposal at sea is the only viable option.

Nitrogen oxides (Nox) act indirectly as greenhouse gasses by producing the tropospheric greenhouse gas ozone via photochemical reactions in the atmosphere. The best possible current technology for Nox reduction in I/C engines is the on board production of emulsified fuel. It is another primary object of this invention to provide a source of low PH water reclaimed from the exhaust for use in an on board fuel/water emulsification device.

DNV Kema had a project that found that on board carbon capture and storage was theoretically possible but that the practicalities involved in on shore handling and selling the C02 produced when the shipped docked and of building the onshore infrastructure involved stopped them pursuing the project beyond the theoretical stage. ( http :/7'www. ship -technology com/feauires/featureonboard-carbon-caoture-dream-or-realitvA

There are already patents for on board sequestration and storage of C02 with a view to subsequent removal and processing of the C02 storage cartridges (Houston 2010 , Hamad 2012 & Zaromb2013)

This invention proposes that the C02 produced can be processed into calcium carbonate that can be disposed of at sea thus avoiding the need for on shore infrastructure or massive storage tanks on board ship or energy intensive conversion of C02 to fuel.

It is the object of this invention to take known technologies and put them together in a viable but unique way to function on a mobile platform. As technologies improve it is probable that the system described could be used on larger scale land based vehicles (e.g.Trains,) To that end the use of reclaimed water for the water injection that cools the hot exhaust stream is particularly relevant as on a ship sea water can be used but on a train or truck the use of reclaimed water would avoid the use of a large reservoir or the need for the end user (the driver) to get involved with topping up the reservoir.

SUMMARY OF THE INVENTION

The object of this invention is to have an exhaust system that reprocesses low PH the water reclaimed from the exhaust and C02 reclaimed from the exhaust into a carbon based product that can safely disposed of at sea. The remaining exhaust consists of nitrogen and oxygen, which are not greenhouse gases. The invention has four parts x the reclamation of potable /demineralised water from the exhaust A the reclamation of C02 from the exhaust. x The conversion of the reclaimed C02 and into an environmentally beneficial carbon based product for disposal at sea.

^ the utilisation of that portion of the reclaimed water that is not used in the C02 to carbon reaction process as drinking water and for returning to the combustion chamber to enhance combustion WATER RECLAMATION

It has been known for many years that water-vapour was a large part of the exhaust gas of an internal combustion engine and from time to time there have been patents for processes that attempt to reclaim this water (e.g. Bradley 2011) but, prior to the introduction of capillary condensing membranes, the water was always contaminated and needed to go through an extensive purification process. However, with the help of modern technology carbon monoxide, sulphur dioxide and particulate matter can be removed and then potable /demineralised low Ph water produced by passing the exhaust stream through a capillary condensing membrane device - but the gas stream still needs to be cooled thermodynamically before passing to the capillary membrane condenser, as these membranes do not work at high temperatures.

It is a primary objective of this invention to supply a source of demineralised water to a C02 to calcium carbonate reactor

Downstream of the dry SOx scrubber and selective catalytic reduction device, the exhaust stream consists of largely C02, nitrogen and water vapour. However, it is typically over 400 degrees Centigrade. The C02 can be removed at high temperature, but a capillary membrane condenser capable of producing potable water can only operate with gas streams of 120 degrees Centigrade or less; it is therefore necessary to reduce the nitrogen/water vapour gas stream temperature to an agreed level before passing it to the condensing membrane. This can be achieved by passing the gas stream through an exhaust gas cooling by water-injection device. There is a comprehensive system for cooling exhaust streams on modem warships marketed by W.R. Davis Engineering Ltd. Its function is to cool the hot engine exhaust of a warship in order to achieve a low infra-red signature; there is also a patent (Lijima 2000) issued to Mitsubishi Heavy industries. These systems are based on the principle of water injection into the exhaust stream but they are cited as non-limiting examples of exhaust gas cooling systems.

The present invention also relates to utilising some of the water reclaimed from the exhaust to enhance combustion, using methods well known to those skilled in the art, specifically fuel-emulsification systems which require clean water, but also water-injection systems (Donahue 2006), humid air motors, steam-injection systems and any other systems like oxy/fuel combustion systems that supply water to the combustion chamber of an engine.

The effects of steam and water on combustion in EC engines have been well known for many years. They are used to lower in-cylinder temperature and burn the air/fuel mixture more efficiently, thus helping to avoid detonation, and results in a power boost and/or fuel saving. They also allow for the use of poorer quality lower-octane fuel, as is common in ships, and have a cleaning (de-carbonising) effect on the engine and head. The more efficient bum also reduces NOX and CO emissions.

In the present invention, the cold water used to cool the exhaust gas stream can be provided from the water reservoir containing water reclaimed from the exhaust. Because this water will be heated by contact with the hot exhaust stream, the heated water will become available as a energy source to power the C02 to calcium carbonate reaction. A ship is currently best suited to spare the space required for this exhaust cooling technology but large land based vehicles ( e.g.Trains) could also,

With this invention the water supply is reclaimed from the exhaust and is potable. The reclaimed water in this invention can also be used to cool the exhaust stream upstream of the condensing membrane although sea water can also do this on board ships. The advantage of using the reclaimed water to cool the exhaust on land based vehicles would be that the need to top up a large reservoir of water by the driver would be avoided as the system would be self -contained.

The potable/demineralised water produced is passed to a reservoir and then to the combustion chamber, The water in the reservoir can also be passed to a device for mixing with fuel by an emulsification process before passing the emulsified fuel to the combustion chamber. Fuel emulsification systems on board ships are well known to those skilled in the art (e.g. Nonox Ltd. Cottel.E 2011 or Donahue et al 2006 or Exomission) but these are cited as non- limiting examples of adding potable/demineralised water to the combustion process

An important prerequisite for the faultless functioning of the emulsion technology is the treatment of the water that is used. The water that is used must be completely desalinated and as free from minerals as possible in order to prevent a negative effect on the injection system.

Because the reclaimed water from the exhaust is potable it can be used to supply the ship's drinking water. The approximate calculations are: if a ship bums 300 tonnes of fuel a day it could produce up to 180 tonnes of water a day from the exhaust. 45 tonnes of that could be used for the fuel emulsification process, about 3.5 tonnes used for human consumption, assuming a crew of about 22. Depending on the technology used, the C02 to calcium carbonate reactor could require about 10% of water to C02 and the ship might produce over 300 tonnes of C02 per day so 30 tonnes of water would be required for the process and 45 +3.5+ 30 = 78.5 comes in at under the 180 tonnes that could be reclaimed from the exhaust. This leaves ample reclaimed water for the cold water spray into the hot exhaust gas or for a water jacket or for the greater amount of water that may be required for oxy/fuel combustion or for the fresh water used in the osmotic power source.

An important prerequisite for the faultless functioning of the emulsion technology is the treatment of the water that is used. It would not be true to say that the water for the emulsification process needs to be potable but the water that is used must be completely desalinated and as free from minerals as possible in order to prevent a negative effect on the injection system so this rules out the use of seawater and water from the exhaust clearly has advantages over on board storage.

It is a principal object of the current invention to provide a source of demineralised/potable water for these systems by reclaiming water from the exhaust downstream of the dry SOx scrubber and selective catalytic reduction unit by injecting cold water into the hot exhaust stream to cool the gas stream to below 100 degrees centigrade and then passing the cooled gas stream through a capillary condensing membrane.

CARBON DIOXIDE RECLAMATION

According to basic chemistry principles it is possible to neutralize increased ocean acidity by adding a base, limestone. To do so it has been proposed * dumping huge quantities of powdered limestone — around 4b tons every year — into the oceans A self-regulating carbonate buffering system normally helps keep the ocean's pH constant at around 8.1 — by maintaining an equilibrium between the four forms of dissolved carbon dioxide: the gas itself, carbonate ions, bicarbonate ions and carbonic acid. This delicate balance allows the oceans to absorb large amounts of carbon dioxide without much variation in seawater chemistry.

However, the rapid build-up in carbon dioxide levels over the last few decades now threatens to overwhelm the system, with some scientists projecting that pH levels could drop 0.5 units by 2100 — wiping out most of the world's coral reefs and adversely affecting the majority of marine organisms.

Adding limestone (or calcium carbonate) would have the dual effect of mitigating the process of ocean acidification and increasing carbon sequestration, though the latter would predominate. The reason is that the limestone, by bolstering the carbonate buffering system, allows the surface waters to take up more carbon dioxide. As more is drawn down, however, the neutralizing effect of the calcium carbonate begins to diminish — resulting in an overall slight decrease in acidity.

This process would take a long time, it could take several decades (and many hundreds of billions of tons of limestone) before the limestone accomplishes its objective -- and that's assuming everything goes according to predictions. Adding the limestone to regions of active upwelling could eventually lead to the sequestration of an additional 0.3b tons of carbon a year.

Carbonate Limestone is not pure CaC03 and contains impurities. The impact of these impurities on the marine system should be considered before adding calcined limestone products to seawater calcium carbonate produced using demineralised water from the exhaust is pure however. * Danny Harvey. University of Toronto 2008 A primary objective of this invention is the utilisation of the carbon dioxide reclaimed from the exhaust of a marine diesel engine to use as feedstock for a C02 to calcium carbonate reactor.

The DNV project envisaged taking an existing onshore carbon capture unit design and adapting it for maritime use this involved a C02 absorber and amine regenerator.

Alternatively approaches being investigated for the capture and separation of carbon dioxide from flue gas streams include solvent, membrane, chemical looping, oxy combustion and biological fixation based approaches.

In the preferred embodiment downstream of the dry SOx scrubber and the selective catalytic reduction device (SCR) the exhaust gas stream is passed through a compressor which increases the pressure for passing the gas stream through a high temperature gas separation membrane (e g. Lackner 2009) to separate the gas stream into a hot C02 rich stream and a water-vapour rich stream. The carbon dioxide stream is then passed to the C02 to carbon reactor. Because of the high temperature of the C02 gas stream, the recoverable heat energy is then available to power the conversion process within the C02 to calcium carbonate reactor, which can be based on a number of technologies well known to those skilled in the art. Some of the reclaimed C02 can also be passed back to the combustion chamber as recycled exhaust gas (EGR), a technology well known to those skilled i

CARBON DIOXIDE TO CARBON BASED PRODUCT REACTORS /BIOREACTORS A bioreactor is any apparatus that uses a biological reaction in its process. They tend therefore to have to operate at lower temperatures and atmospheric pressures then purely chemical based reactions and therefore be less energy intensive. Bioreactors require carefully maintained ph and temperature but low temperature non bio reactors are used in the preferred embodiment..

There are various research reactors/ bioreactors used for the production of calcium carbonate that work at low temperatures in development and some have begun to reach the market: they can be based on the principles of: 1. Use of solid metal catalysts for the hydration of C02 (Bhaduri et al 2015)

The preferred low energy embodiment or 2 Direct biological conversion by microbes (Lovley et.al. 2012) 3 Enzymes in bioreactors (Anctil 2006) 4 Calcium carbonate preparation and carbon dioxide conversion by magnesium phyllosilicate.

And not on the principle of thermal reforming of C02 With regard tol above The preferred embodiment:

In the presence of a Nickel catalyst, C02 can be converted rapidly and cheaply into the harmless, solid mineral, calcium carbonate.

The process involves passing the waste gas directly from the exhaust, through a water column rich in Nickel nano-particles and recovering the solid calcium carbonate from the bottom.

The beauty of a Nickel catalyst is that it carries on working regardless of the pH and because of its magnetic properties it can be re-captured and re-used time and time again. It’s also very cheap - 1,000 times cheaper than enzymes. And the by-product - the carbonate - is useful and not damaging to the environment.

However no other form of C02 to calcium carbonate reactor is excluded

With regards to 2 above : Direct microbial conversion involves the direct selection of micro- organisms to produce liquid and gaseous fuels by biological action it offers the advantage that micro-organisms carry out the conversions at ambient temperatures which results in energy and equipment savings also yields from microbial conversion are often as high as 95% since the microbes utilise only a small fraction of the substrate for energy and growth. Under proper conditions microbial conversions are quite specific generally converting a substrate into a single product with few by products. The advantages are offset by slower reaction rates and reactor considerations of sterility and nutrient provision. An onboard supply of potable/ demineralised water helps mitigate these problems, lowest power consuming type of C02 to Calcium carbonate would be appropriate and these are bioreactors

With regard to 3. above: A naturally occurring bacteria could help fight global warming by converting C02 into calcium carbonate (CaC03) - a common compound found as rock all the world over.lt has been found that when the bacteria, which has been extracted from a number of places including brick kilns in the Indian city of Satna, is used as an enzyme it converts C02 into CaC03. The resulting CaC03 can fetch minerals of economic value, as CaC03 has a variety of uses from being used in the purification of iron from iron ore, neutralizing acidic effects in soil and water, and even as a dietary calcium supplement or antacid . The enzyme can be put to work in any situation, like in a chamber fitted inside a factory chimney through which C02 would pass before being emitted into the atmosphere, and it will convert the greenhouse gas into calcium carbonate Abstract

With regard to 4 above : Careful investigation of Magnesium phyllosilicate (Mg-APTES) surface properties revealed a lamellar structure and the existence of an amine group, which is the expected CO 2 capture site. The prepared magnesium phyllosilicate was found to successfully convert gaseous CO 2 into HCO 3 A (bicarbonate ion), actively forming CaCO 3 (calcium carbonate) when Ca 2+ (calcium ion) was supplied. This study shows that the magnesium phyllosilicate, a new type of carbonation agent and a concept of an artificial mimetic catalyst, can be a good candidate catalyst for CO 2 capture. A ship could have photovoltaic panels and wind turbines on board or thermoelectric generators using heat from the exhaust, which could produce enough energy to power a C02-to Calcium Carbonate reactor.

Given the current state of the technology, it is thought that the production of Calcium Carbonate from C02 in the exhaust should initially be used in large-scale marine engines, as they would not be subject to the physical constraints that small-scale mobile applications would present. Technology of the type is in an advanced stage of development for use with large scale industrial plants but the existence of an on-board potable /demineralised water supply reclaimed from the exhaust makes it practical for marine applications. This technology would offer the possibility of a near zero-greenhouse-gas exhaust emission system.

Land based reactors use sustainable sources like wind or solar to power them in order not to become an energy sink. At sea you cannot depend on wind or solar so the lowest temperature sustainable sources to power the reaction should be used if appropriate. There are other sustainable power sources which may become available which include osmotic power and Hydro electric power ( e g. Gorlov Helical turbine).

The various stages of this exhaust system are either: A available proprietary items ( selective catalytic reduction units, particulate traps, thermoelectric generators, compressors, gas separation membranes, exhaust gas cooling system by water injection, fuel/water emulsification devices) A or are in an advanced state of development and covered by other people's patents (capillary condensing membrane, C02 to calcium carbonate reactors, C02 adsorption /desorption equipment)

The inventive step of this system is that its feed-stocks of C02 and water come from the exhaust and the exhaust gas is cooled to make it a suitable temperature for passing through a capillary membrane condenser using water reclaimed from the exhaust which is not super saturated with C02 thus producing potable/demineralised water suitable for use in a C02 to Calcium Carbonate reactor that can produce a pure product that will not pollute the sea and an on board emulsified fuel device The C02 reactor can where possible be powered by onboard sustainable sources: wind power, solar PV panels, and electricity obtained from waste heat.

There is ultimately no reason why this invention need be restricted to ships. The main restraint currently preventing the invention being used on land-based vehicles is that the temperature of the exhaust entering the membrane condenser needs to be below 100 degrees centigrade. This can be achieved on a ship by passing the exhaust stream through a water jacket and cooling the exhaust stream with cold water injection into the gas stream, but space might make these difficult to achieve in a land-based vehicle. Another consideration is that the C02-Calcium Carbonate reactor also requires an energy input and this should be from a sustainable source, if the conversion process is not to become an energy sink. A ship lends itself to osmotic power or PV panels, wind turbines and thermoelectric generators, which can help with taking heat energy from the exhaust, all of which could be used to power the C02-to- Calcium Carbonate reaction and the compressor. It should be pointed out that the invention would still have value even if it proves to be an energy sink because of the zero-greenhouse-gas emissions potential.

TECHNOLOGIES DEFINED

Solid metal materials for catalysing the hydration of carbon dioxide.

This is the combining of carbon dioxide and water to capture carbon. The solid metal materials may be nickel nanoparticles. This relates to methods and apparatus for the capture or fixation of carbon dioxide and to methods of increasing the rate of hydration of carbon dioxide. The methods use a solid metal to catalyse the hydration of carbon dioxide, the solid metal is selected from Co, Ni, Cu and Zn. Using this catalyst, researchers have demonstrated reaction rate improvements similar to but more robust and cheaper then more well-known enzymatic methods.

Capillary Membrane Condensers A capillary condenser is based on a metal and ceramic tube through which the exhaust gas passes, the walls of the tube being the condensing membrane, so water may be drawn off from the exhaust, passing through without impeding flow. The water is virtually free of contaminates, so as a result the contact between water-soluble gases such as nitrogen dioxide and the condensed water is eliminated. There are proprietary technologies (Roddie et al. 2011 & Biskoff et. al. 2012 ) and DNV Kema (Beerlage 1999) pertaining to capillary condensers but these are cited as a non-limiting examples.

On board Emulsified Fuel

The most common type of type of water in in oil emulsion fuel used today is produced at the oil terminal using chemical emulsification/stabilization and delivered to the user as a fuel usually at cost greater than oil alone. Although effective for Nox reduction and removing other pollutants altering the surface tension of the fuel in order to chemically stabilize the mix inhibits the micro-explosion phenomenon and does not produce as much energy or give any of the fuel saving benefits of the un-stabilized emulsion fuel produced by on board emulsification units. Therefore use of demineralised water reclaimed from the exhaust is an essential part of this inventions claims to be a “ near zero green house gas exhaust system ” Nox gasses are an indirect greenhouse gas and emulsified fuel is the most efficient method of reducing them.

Oxy-fuel Combustion A third and stand-alone use for reclaimed water relates to the possibility of replacing the nitrogen with water and recycled carbon dioxide in an oxygen-enriched combustion engine or oxy-fuel combustion engine. It would involve using a compressor to pass the intake air through an oxygen enrichment membrane system so that the nitrogen is removed and vented to atmosphere. This would allow the intake to the combustion chamber to be oxygen-rich and much reduce NOx emissions. Both C02 and water absorb heat better then nitrogen, which is the most abundant component of air. Therefore the oxygen concentration in the pseudo-air mixture can be higher than in air and still maintain approximately the same temperature and heat characteristics of the air/fuel system.

The engine would produce more power and improve fuel economy. The C02 separation membrane in this embodiment would need to be placed downstream of the exhaust gas cooling by water injection device because the C02 recycled to the combustion chamber would need to be of low temperature in order to help cool the combustion process.

Sox Scrubbers

Particulate matter and sulphur dioxide are removed from the gas stream by scrubbers which, until recently, used water to wash the gas stream and in the process the gas stream is cooled. The wash water was then conditioned before discharge overboard. However, as the exhaust stream is cooled by the wash water it needs to be reheated before it can be passed through a selective catalytic reduction unit (SCR). More recently, dry scrubbing has been introduced: this requires an operating temperature of between 240 and 450 degrees centigrade and uses calcium oxide granules to react with sulphur dioxide to form gypsum. The point about dry scrubbers from the point of view of this invention is that downstream of them the exhaust gas stream is still hot, so ideally suited for use with an SCR system which requires hot exhaust gas to attain operating temperature. The hot exhaust gas downstream of the SCR is then passed through a hot C02 separation membrane such that hot C02 can be passed to the C02-to-calcium carbonate reactor before the remaining gas stream is cooled, prior to passing it to a capillary membrane condenser. Reheating the exhaust downstream of a wet scrubber before passing it to the SCR unit, and then cooling it before passing it to a capillary condensing unit would not represent good use of available heat energy, although it should be pointed out that if wet scrubbers are used, water from the exhaust dosed with sodium hydroxide would result in only half the power consumption of using sea-water as the wash water.

Humid Air Motors (HAM) A Humid Air Motor (HAM) system is a recent technology that uses combustion air almost entirely saturated with water-vapour (humid air) in a marine diesel engine. The charge air is humidified by water-vapour produced in a humidification vessel by evaporating water directly into the charge air, using the heat from the engine or its exhaust gases. It was developed because emulsified fuel and direct water injection use large quantities of fresh water, which until now has been a precious resource on board vessels. This system employs sea-water as the cooling and humidification medium. Given the current invention and its provision of fresh water, HAM is likely to be rendered obsolete, as it is unlikely to prove as cost effective as fuel emulsification. However if future developments prove it to be efficient/cheap enough in its own right, it could use water from the exhaust in the humidification process.

The Fisher-Tropsch process

The Fisher-Tropsch process is a collection of chemical reactions that that converts a mixture of carbon monoxide and hydrogen into liquid hydrocarbons the process is well known to those skilled in the art for producing synthetic fuel. Fisher-Trope operates in the temperature range 150-300 degrees Centigrade but higher temperatures lead to higher conversion rates and faster reactions. Typical pressures during the process range from one to several tens of atmospheres Because of the high temperatures involved it is not thought to be suitable for this invention.

Osmotic Power

Osmotic power or salinity power gradient is the energy available from the difference in salt concentration between seawater and freshwater. Two practical methods for this are reverse electro-dialysis (RED) and pressure retarded osmosis (PRO) Both rely on osmosis with ion specific membranes and the waste product is brackish water. On board a ship with fresh water reclaimed from the exhaust a supply of both sea water and fresh water would be available at all times allowing the C02 to methanol to have a permanently sustainable energy source. However it would only produce about 3kw so is not currently a viable option.

Gorlov Helical Turbine A helical water stream turbine that creates mechanical power irrespective of direction of water flow

As described above, the embodiments in this application utilise chemical principles for energy conversion and power generation. All embodiments eliminate the C02 emissions from the engine exhaust and produce calcium carbonate from this C02 and potable/demineralised water reclaimed from the exhaust. All embodiments also use this reclaimed potable /demineralised water to enhance combustion, cool the gas stream and supply the ship's drinking water.

Since certain changes may be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense.

DESCRIPTION OF THE PREFERRED AND OTHER EMBODIMENTS

The term vehicle is used as a generic term for all mobile platforms (eg. Ships, trains, trucks) that use internal combustion engines.

Figure 1 refers to the preferred embodiment 1 Engine 2 Exhaust manifold 3 Dry SOx scrubber 4 Selective catalytic reduction unit (SCR) 5 Compressor 6 C02 scrubber 7 C02 feed toC02 cooling device 8 Nitrogen exhaust to atmosphere. 9 Nitrogen/water-vapour exhaust gas stream feed to Water cooling of exhaust gas stream device 10 C02 feed EGR (Exhaust gas recycling) pipe to inlet manifold from C02 scrubber 11 Water cooling of exhaust stream device 12 Hot water drain pipe from water cooling of exhaust device (this hot water becomes a source of available energy). 13 Cooled water-vapour/nitrogen feed to condensing membrane. 14 Capillary condensing membrane 15 Water feed pipe from condensing membrane to reservoir 16 Water reservoir 17 Water feed from water reservoir to water cooling device (eg. radiator) 18 Water cooling device (eg. radiator ) 19 Water feed to vehicle’s water supply 20 Water feed from reservoir to NiNP mixer 21 Hydration Tank 22 C02 free gas exhaust to atmosphere 23 Mixing chamber 24 Water feed from radiator to C02 cooling device. 25 C02 cooling device (eg. cold water injection device) 26 Water feed from reservoir to water/fuel emulsification device 27 Water/fuel emulsification device 28 Emulsified fuel feed to engine 29 Fuel tank 30 Fuel supply from fuel tank to emulsification device. 31 Mixing motor and stirrer 32 Non emulsified diesel fuel feed pipe to fuel tank 33 Engine inlet manifold 34 C02 feed pipe to Hydration Tank 35 Bubbler or sparger 36 NiNP return to mixer 37 C03H2 solution feed pipe to mechanical stirrer 38 C03H2 solution plus NiNP feed to magnetic separator 39 Water/NiNP feed pipe to Hydration tank 40 Magnetic separator 41 Settling tank 42 Mechanical Stirrer and motor 43 Excess salt water outlets to sea 44 Caustic Soda input pipe 45 Calcium Chloride input pipe 46 Screw conveyor 47 Screw conveyor motor C02 Reclamation

In this embodiment of the invention, downstream of the dry SOx scrubber (3) and selective catalytic reduction unit (SRC) (4) the exhaust gas stream passes through a compressor (5) which forces the gas stream through a high temperature C02 separation membrane (6). Some of the C02 is past by pipe (10) to the inlet manifold (33) of the engine (1) as exhaust gas recycling (EGR). The resulting hot C02 from high temperature C02 separation membrane (6) can then be passed via pipe (7) through C02 cooling device (eg. cold water injection device) (25) to the Hydration tank (21)

Water Reclamation A pipe (9) passes the nitrogen/water-vapour downstream of the C02 separation membrane (6) to a water cooling of exhaust device (either based on a water jacket or a cold water spray into the exhaust stream) (11). The water supply for this device is provided from a water feed (17) from the reclaimed water reservoir (16) and cooled in a radiator (18). Downstream of the cooling device (11) the exhaust stream is passed to a membrane condensing device (14) where the water and gas stream are separated. The water produced is passed to the water reservoir (16) via water feed pipe (15). Downstream of the condensing membrane (14), the nitrogen is vented to atmosphere via exhaust pipe (8). Water is passed from the water reservoir (16) to the Hydration tank (21) via water pipe (20).

Water/Fuel Emulsification

Downstream of the Hydration tank the non C02 exhaust is vented to air via pipe (22). Fuel from the fuel tank (29) is passed via pipe (30) to the water/fuel emulsification device (27). The water for the water/fuel emulsification device (27) is supplied by pipe (26) from the water reservoir (16). Emulsified fuel from the emulsification device (27) is supplied to the engine (1) via pipe (28). Water for energy utilisation can be recovered from the water cooling of exhaust stream device (11) via drain pipe (12). There is also a separate pipe (24) supplying a separate water injection cooling device (25) for cooling the C02 exhaust in pipes (7) and (34) if required.

The C02 and demineralised water can then be passed to a Carbon capture by metal catalysed hydration of carbon dioxide device as outlined in UK patent GB2502085A 2013

The apparatus comprises a hydration tank 21 and a settling tank 41.The hydration tank comprises a bubbler 35 (which may also be known as a sparger) which allows the gas containing CO2 to be bubbled through the hydration tank 21. The hydration tank also comprises a vent 22 situated towards the top of the hydration tank, through which any CO2 free gas can escape. In use the hydration tank will contain water and nickel nanoparticles and the CO2 gas which is bubbled through the tank will be converted to carbonic acid in solution.

The apparatus also comprises a mixer chamber 23 in which the nickel nanoparticles are suspended in water. The mixer chamber 23 comprises a mechanical stirrer and motor 31, to drive the stirrer .

The carbonic acid solution, with the nickel nanoparticles in suspension is connected to a magnetic separator 40. This separates the ferromagnetic nickel nanoparticles from the carbonic acid solution. The nickel nanoparticlcs arc then transferred back to into the mixer chamber 23 via pipe 36 and reused in the hydration reaction. The carbonic acid solution is transferred to the settling tank 41. A NaOH solution and a CaCl2 solution are added to the settling tank 41 via pipes 44 and 45 solid calcium carbonate is formed, along with NaCl is solution.

The settling tank 41 comprises a mechanical stirrer driven by a motor 42.

The settling tank 41 comprises one or more outlet pipes 43 through which excess liquid, which largely comprises an NaCl solution, flows. The settling tank is connected, towards the bottom, to a screw conveyor 46 which continuously removes the solid CaC03 from the settling tank. The screw conveyor is driven by a motor 47.

Figure 2 refers to an embodiment of the device for use with a discrete C02-to-calcium carbonate reactor..

In this embodiment, two adsorption and desorption devices (26) (e.g. Dvininov 2012) are used in parallel, one in adsorption mode and one in desorption mode in order to supply the Hydration tank (16) on demand . They are placed downstream of the capillary condensing membrane (9).

The Calcium Carbonate production down stream of the Hydration tank is then the same as in Figure 1 1 Engine block 2 Exhaust manifold 3 Dry SOx scrubber 4 Selective Catalytic reduction unit (SCR) 5 Compressor 6 C02 scrubber 7 Nitrogen exhaust to atmosphere. 8 Water cooling of exhaust device 9 Membrane condensing device 10 Hot water drain pipe from water cooling of exhaust device 11 Feed pipe from water reservoir to exhaust stream cooling device. 12 Water feed pipe from condensing membrane to reservoir 13 C02 feed from separation membrane to C02 control valve. 14 Water reservoir

15 Water feed to mixing tank for H20 and NiNP 16 Hydration tank 17 C03H2 & NiNP feed pipe to Magnetic separator . 18 Oxygen exhaust to atmosphere 19 Water feed to vehicle’s water supply 20 Water/fuel emulsification device 21 Emulsified fuel feed to engine 22 Fuel tank 23 Water feed from reservoir to water/fuel emulsification device 24 Engine inlet manifold 25 NiNP return pipe to mixing chamber 26 Adsorption and desorption devices 27 C02 pipes from adsorption and desorption devices 28 C02 control valve to adsorption and desorption devices 29 Air filter. 30 Non emulsified diesel fuel feed pipe to fuel tank.

31 Mixing Tank for H20 and NiNP 32 Mixing motor and stirrer 33 Bubbler or sparger 34 Feed pipe from mixing tank to hydration tank 35 Fuel feed to water/ fuel emulsification device.

Figure 3 refers to an embodiment of the device using oxy-fuel combustion

An oxy-fuel combustion system uses oxygen-rich air in place of ambient air in the combustion process. This is achieved by replacing the nitrogen with reclaimed water and carbon dioxide in the combustion process. In this embodiment, ambient compressed air downstream of the air filter (1) is passed through a nitrogen separation membrane (3) using a compressor (2) before being passed via an oxygen pipe (4) to the inlet manifold (6). The separated nitrogen is then vented to air. The exhaust gas downstream of the engine is passed through a dry SOx scrubber (9) and selective catalytic reduction unit (SRC) (10), and from there through an exhaust stream cooling device (11). The cooled exhaust stream is then passed through a membrane condensing device (13) where the water and gas stream are separated.

Water reclaimed from the exhaust is passed to a reservoir (16) and from there a portion of the water is passed via a water pipe (17) to the water/fuel emulsification device (24), where it is mixed with fuel from the fuel tank (26) before being passed to the inlet manifold (6), where it is mixed with the oxygen-rich air before passing to the combustion chamber. In the combustion chamber the C02 and water are used to replace the nitrogen in the fuel-air mix, serving to cool the combustion temperature. The C02 reclaiming and conversion to calcium carbonate is the same in this embodiment as in Figure 1. 1 Air intake 2 Compressor 3 Separation membrane 4 Oxygen supply pipe 5 Nitrogen exhaust to atmosphere 6 Inlet manifold and injectors 7 Engine block 8 Exhaust manifold 9 Dry SOx scrubber 10 Selective catalytic reduction unit (SCR) 11 Water cooling of exhaust device 12 C02 and water vapour pipe to capillary condensing unit 13 Capillary condensing unit 14 C02 control valve 15 Water pipe to reservoir 16 Water reservoir 17 Water pipe from reservoir to water/fuel emulsification device 18 C02 feed pipe for cooled exhaust gas recycling (EGR) to engine

19 Water feed to from reservoir to mixing tank for H20 and NiNP 20 Hydration tank 21 C03H2 & NiNP feed to Magnetic separator 22 C02 feed to hydration tank 23 NiNP return pipe to mixing tank 24 Water/fuel emulsification device 25 Emulsified fuel feed to engine 26 Fuel tank 27 Fuel feed pipe to water/fuel emulsification device 28 Feed from water reservoir to water cooling of exhaust device 29 Drain pipe for water from exhaust cooling device 30 Water feed to vehicle’s drinking water supply. 31 Non emulsified diesel fuel pipe to fuel tank. 32 C02 free gas to atmosphere pipe

33 Mixing tank for H20 and NiNP 34 Mixing motor and stirrer 35 Bubbler or sparger

Figure 4 is the same as the preferred embodiment but with the possibility of using some of the reclaimed water as feedstock for a hydrogen enhanced combustion device. 1 Engine 2 Exhaust manifold 3 Dry SOx scrubber 4 Selective catalytic reduction unit (SCR) 5 Compressor 6 C02 scrubber 7 C02 feed toC02 cooling device 8 Nitrogen exhaust to atmosphere. 9 Nitrogen/water-vapour exhaust gas stream feed to Water cooling of exhaust gas stream device 10 C02 feed EGR (Exhaust gas recycling) pipe to inlet manifold from C02 scrubber 11 Water cooling of exhaust stream device 12 Hot water drain pipe from water cooling of exhaust device (this hot water becomes a source of available energy). 13 Cooled water-vapour/nitrogen feed to condensing membrane. 14 Condensing membrane 15 Water feed pipe from condensing membrane to reservoir 16 Water reservoir 17 Water feed from water reservoir to water cooling device (eg. radiator) 18 Water cooling device (eg. radiator) 19 Water feed to vehicle’s water supply 20 Water feed from reservoir to NiNP mixer 21 Hydration Tank 22 Co2 free gas exhaust to atmosphere 23 Mixing chamber 24 Water feed from radiator to C02 cooling device. 25 C02 cooling device (eg. cold water injection device) 26 Water feed from reservoir to water/fuel emulsification device 27 Water/fuel emulsification device 28 Emulsified fuel feed to engine 29 Fuel tank 30 Fuel supply from fuel tank to emulsification device. 31 Mixing motor and stirrer 32 Non emulsified diesel fuel feed pipe to fuel tank 33 Engine inlet manifold 34 C02 feed pipe to Hydration Tank 35 Bubbler or sparger 36 NiNP return to mixer 37 C03H2 solution feed pipe to 38 C03H2 solution plus NiNP feed to magnetic separator 39 Water/NiNP feed pipe to Hydration tank 40 Magnetic separator 41 Settling tank 42 Mechanical Stirrer and motor 43 Excess salt water outlets to sea 44 Caustic Soda input pipe 45 Calcium Chloride input pipe 46 Screw conveyor 47 Screw conveyor motor 48 Water pipe to Ion resin exchange filter 49 Ion resin exchange filter 50 Filtered water pipe to Electrolysis tank 51 Electrolysis tank 52 Hydrogen feed to combustion chamber References cited :-

Anctiletal US0128004A1/2006 . Bhaduri et al US0151248A1/2015

Hsu US0165569A1/2014

Lackner et al US 0101008A1/2009

Cotell E US 7934474B2/2011 US 7930998B2/2011 Bradley US 0168128A1/2011

Roddie et.al. US 8511072B2/2011

Bishoff et.al. US 129560A1/2012

Beerlage US 6490862B1/1999

Lovley et. al. US 0288898A1/2012

Donahue et al. US 0225672A1 /2006

Imran et al US 0098314A1/2013

Houston WO 2010/094923A2

Zaromb US 8413420B1/2013

Dvininov et al. WO 2012/035361 Al

Der et.al. US 6648949B1/2001

LijimaM. US 6485547B1/2000

Hamad E WO 2012/100182A1

Claims

CLAIMS 1 A method of producing a carbon-based product from combustion exhaust gas of an internal combustion engine turning it into an environmentally friendly product, which comprises the following steps : a) Treating the exhaust gas to remove particulate matter and sulphur dioxide b) Treating the exhaust gas to remove carbon monoxide. c) Passing the exhaust gas through a C02 scrubbing device that will separate the gas stream into a C02 rich stream and a nitrogen/water vapour rich stream. These scrubbing methods may include utilising adsorbents that attract C02 to their surface, using selective permeable membranes that prevent C02 from passing,using selective permeable membranes that allow only C02 to pass, cooling the C02 to a temperature that forces the C02 to condense out of the solution for separation but no other C02 scrubbing technology is excluded. d) Cooling the nitrogen/water-vapour rich exhaust gas stream to a pre-agreed temperature . e) Passing the cooled nitrogen/water-vapour rich exhaust gas through a membrane condensing device to separate potable/demineralised water from the gas stream, leaving the exhaust gas stream nitrogen rich. f) Passing the potable/demineralised reclaimed water from the exhaust stream to a reservoir container. g) Venting the nitrogen rich gas stream to the atmosphere. h) Passing the carbon dioxide rich gas stream and at least some of the potable/demineralised reclaimed water to a Carbon capture by metal catalysed hydration of carbon dioxide device i) Adding controlled amounts of Caustic soda and Calcium chloride to the Carbon capture by metal catalysed hydration of carbon dioxide device j) Reacting the carbon dioxide and potable/demineralised water together with the . Caustic soda and Calcium chloride at a temperature below 140 degrees centigrade to . produce pure calcium carbonate. k) Passing the calcium carbonate either directly to the sea or to a storage facility 2 A system in accordance with claim 1 where at least some of the potable/demineralised water reclaimed from the exhaust is passed to the combustion chamber using on board fuel emulsification a system well known to those skilled in the art and which specifically requires demineralised water. 3 A system in accordance with claim 1 where at least some of the demineralised water reclaimed from the exhaust is passed to the combustion chamber, in order to enhance combustion by methods well-known to those skilled in the art, which may include direct water injection, steam injection, humid air motors, and replacing nitrogen with H20 and C02 in oxygen-enhanced combustion. 5 A system according to claim 1 where at least some of the potable water reclaimed from the exhaust is used for the vehicles drinking water supply 6 A system according to claim 1 where at least some of the water reclaimed from the exhaust is used to cool the exhaust gas upstream of the membrane condenser. 7 A system according to claim Id) where the pre-agreed temperature is less than 100 degrees centigrade. 8 A system according to claim le). where the membrane condensing device that converts water-vapour to water is a capillary membrane condenser. 9 A system according to claims Id) where the nitrogen/water-vapour rich exhaust stream is cooled by a water injection device supplied by water reclaimed from the exhaust 10 A system according to claims land 2 where the emulsified fuel is passed to the engine's combustion chamber 11 A system according to claim 1 where the energy source for the C02-to-Calcium Carbonate reactor is based on on-board sources, which may include on-board sustainable sources of: a) Wind b) Solar power, c) Waste heat reclaimed from the exhaust d) A carbon-based fuel produced from C02 and water reclaimed from the exhaust e) Hydro-electric power (e g. Gorlov helical turbine) f) Osmotic power 12 An exhaust system in accordance with Claim 1 that produces exhaust that is C02- rich and has conduit means to feed C02 into a C02 adsorption and desorption device (e g. Dvininov 2012), for use if the reactor has a discrete reaction. 13 A system in accordance to claim 1 a),b), c), d), e), & f), 3 and 7c) that utilises waste heat that has been produced by thermal contact between the engine or exhaust manifold and water that has been reclaimed from the exhaust, to drive a turbine or steam piston to produce auxiliary power. 14 A system according to claims Id) where the nitrogen/water-vapour rich exhaust stream is cooled by a water jacket supplied by water reclaimed from the exhaust or by sea water. 15 A system according to claims 1 a), b), d), e), f), h), i) j) and k) where the gas separation membrane that produces a C02 rich gas stream and a nitrogen rich gas stream is downstream of the exhaust gas cooling by water injection device in order to produce cooled C02 for passing back to the combustion chamber as cooled exhaust gas recycling ( EGR). 16 A system according to claim If) where at least some of the water in the reservoir of water that has been reclaimed from the exhaust is used as wash water in a wet scrubber. 17 A system according to claim If) that passes at least some of the water from the reservoir of water that has been reclaimed from the exhaust into a humidification vessel where the water is evaporated directly into the charge air, using heat from the engine or the exhaust gases ( Humid Air Motor). 18 A system according to claims Id), 9c), 18 and 19 where the water reclaimed from the exhaust that is used to cool the exhaust stream is collected and the heat in it used as an energy source. 19 A system according to claim 1 where the hot C02 exhaust stream is cooled to the required temperature before passing to a hydration chamber 20 A system according to claims 1 which uses water reclaimed from the exhaust is dosed with sodium hydroxide for use as wash water in a Sox scrubber. 21 A system according to claims 1 a),b),c).d),e),f).g) i). &j) Where the carbon dioxide . rich gas stream and at least some of the potable/demineralised reclaimed water is . . . passed to a reactor based in the principle direct biological conversion by microbes 22 A system according to claimsla),b),c).d),e),f).g) i).& j) Where the carbon dioxide rich gas stream and at least some of the potable/demineralised reclaimed water is . passed to a reactor based in the principle enzymes in bioreactors 23 A system according to claimsla),b),c).d),e),f).g), i).& j) Where the carbon dioxide . rich gas stream and at least some of the potable/demineralised reclaimed water is . . . passed to a reactor electro chemical synthesis of calcium carbonate 24 A system where at least some of the water reclaimed from the exhaust is passed through an ion exchange resin filter to produce demineralised water. 25 A system that utilises at least some of the water reclaimed from the exhaust and filtered according to claim 24 is used to feed a tank where hydrogen is produced by electrolysis. 26 A system where at least some of the hydrogen produced by electrolysis is passed to the combustion chamber in order to enhance combustion.