ITFI20000150A1 - APPLICATION OF THE ENDOTHERMAL GASIFICATION PROCESS ON LIQUID FUELS THROUGH H2O AND / OR H2O2 FOR THE REALIZATION OF COMBUSTIBLE GAS - Google Patents

Description

Application of the endothermic gasification process on liquid fuels through H20 or H202 for the production of combustible gases suitable for powering combustion engines, gas turbines, aircraft engines, thermal and / or steam generators; its chemical-physical methods of realization and construction of suitable devices and accessories suitable for the purpose.

Object of the invention:

Application of the gasification of liquid organic substances through steam of water and / or hydrogen peroxide and / or water with or without catalysis at a suitable temperature with the aim of generating combustible gases and exploiting the combustion in the gaseous phase to reduce pollution and improve the consumption of heat engines, gas turbines, aircraft engines and steam generators (boilers).

Premise;

It has been known for several years that mixing water with fuels leads to an improvement in general performance if it can be achieved. The main limitation of this technological solution is the sense that water and hydrocarbons are immiscible substances.

A possible chemical solution is to mix the two substances together with a mediator (surfactant) which allows the formation of emulsions. It is known, however, that the emulsion is a delicate system and often involves separations over time and / or with variations in temperature. A more advanced system, using water, had been marked by the Ferrari team in the 80s on turbocharged engines which used a Venturi system emulsifier that allowed to take full advantage of the above performances, the only problem is that this system was linked to the presence of a turbocharger.

A second obstacle to emulsions is the lower evaporability of the emulsified liquid; this is mainly due to the large heat capacity of the water and its high heat of vaporization. To overcome this drawback, high temperatures in the combustion chamber are required (for correct engine operation) which are not always obtainable. The solution to all the problems related to both the combustion of liquids and their mixing with water is therefore the “gasification with water” of the fuel. With this device, in fact, a hydrogen and carbon monoxide gas (water gas) is generated which is highly combustible and produces water and carbon dioxide as the only final combustion products. Furthermore, since combustion is a phenomenon that occurs in the gas phase, a mixture between combustion air and water gas is total and burns perfectly (so there are no unburned products). This fact improves engine performance and drastically reduces pollution. Furthermore, if all or part of the energy required for gasification is recovered from waste (fumes, cooling, current not supplied), an extraordinary increase in performance is obtained, all however compatible with the second principle of thermodynamics.

Process description:

In industrial chemistry, the process used by the idea is known as "Steam Reforming" (reference 1) and has so far been applied to the gasification of DPL and / or LPG and various hydrocarbons for the generation of gas both in the ammonia industry and, in the past, in the generation of city gas. This process can be endothermic or autothermal depending on the number of moles of water vapor involved and / or the presence or absence of oxidants (air / oxygen / hydrogen peroxide). Basically it is a question of manufacturing a water gas starting from a liquid fuel (alcohol, oil, gasoline, petroleum, bitumen, lard etc ...) and high temperature water vapor in the presence or not of a catalyst by carrying out a gasification for reforming. A catalyst that has proved particularly effective for this process is Supported Nickel. It should be emphasized that for applications to engines, turbines and heat generators, the endothermic process (both for the calorific value of the gas generated and for the absence of non-combustible C02-type compounds) is preferable to the autothermal one (although even if the latter is, to a lesser extent, functional for the purpose). In this ideal "endothermic" process, each carbon atom of the fuel is at the end of the reaction combined with a single oxygen atom (such as carbon monoxide "CO") whether the latter comes from water vapor and / or from the fuel itself (case of alcohols, ketones, organic acids). The hydrogen, in turn, passes from the combined state in organic compound or in water to molecular hydrogen ("H2"). Given the endothermic nature of the reaction, an external energy source is required and therefore a heat source coupled to the gasifier (electric, partial combustion of the fuel, plasma, heat recovery from exhaust fumes, external fuel furnace).

The overall overall reaction of the process can be described as:

C, HyOx (x - Z) H20 heat = xCO (y / 2 x - z) H2

The practical process (see attached diagram) first involves a generation of possibly superheated steam, subsequent injection of fuel, possibly in a gaseous state (even if this is not decisive) into the steam flow and finally re-heating in the mixture for final gasification with or without catalysis. This succession of steps in the process has the purpose of avoiding parasitic reactions such as: Pyrolysis of organics, production of carbon black, partial polymerization, aromatization, alkenization and, in any case, competing processes. Moreover, this sequence allows an initial cracking of complex fuels (facilitated both by the temperature and by the presence of steam).

It is also possible to carry out the process in a single stage through the remulsification of water with the fuel with the use of a non-ionic surfactant (the ionics produce harmful and toxic substances), but this does not allow adequate control of the reaction (especially for breaking up the emulsions) and does not even allow the proper use of the catalyst.

Some gasification applications (but of the autothermal type) can already be observed in the automotive sector and in the energy production sector. These processes, however, are oriented towards the maximum production of hydrogen from hydrocarbons (total steam reforming) for the purpose of exploitation in fuel cells.

Example of application of the idea:

Taking a car and its engine as an example, we can consider the strengths and weaknesses of a liquid fuel supply and alternatively a gaseous fuel one.

In the case of a gaseous fuel vehicle there is total and clean combustion, absence of antiknock agents (aromatic or organic lead-based), longer engine life, lower cost of gas, as advantages but, on the other hand, there is the fact of having to accept the presence of a high pressure gas storage tank (about 200 atmospheres) with the possible risk of explosions in the event of an accident, especially if it is a question of detonating gases (hydrogen).

A liquid fuel vehicle, such as petrol, offers greater safety on storage (it is known that combustion always occurs in the gaseous phase) but presents greater pollution as combustion is not perfect, it requires the presence of toxic anti-knocks, it has shorter engine life and further loss of useful power (given the worse combustion often ending outside the cylinders).

The system proposed in the patent allows a combination of the 2 systems to exploit the advantages of both as it allows:

a) to store the fuel in liquid form by exploiting its relative stability (however, a similar system must be provided for the reforming water)

b) to take advantage of the best combustible properties of the gas compared to the aerosol of liquid fuel and combustion air

c) to reduce pollution due to the absence of unburnt, anti-knock, etc.

d) to significantly increase engine efficiency and therefore reduce consumption accordingly (this is due to various factors including energy recycle, and the presence of water to improve combustion (in appropriate doses)).

As regards point b), it should be specified that by completely gasifying the fuel, gaseous hydrogen and carbon monoxide are obtained with a good combustion rate (~ 16 dm / s) against the approximately 3.9 dm / s characteristic of pure benzene (component about one third of unleaded gasolines). This increases the overall performance of the gasification system. It must also be said that gasolines are also disadvantaged by the need for a first phase of evaporation due to the fact that combustion always takes place in the gaseous phase.

With regard to point c) it must be said that a gas composed of only hydrogen and carbon monoxide allows a single chemical evolution in combustion: Carbon dioxide and water, both non-polluting. The formation of other compounds is typical instead of liquid fuels which are mixtures formed by more complex molecules such as benzenes and PAHs that are unable to finish the oxidation process in the short residence times in the combustion chambers. Infect often the combustion completes outside the actual heat engine (on the exhaust catalyst; when it works) causing a loss of useful power and pollution.

In point d) it is appropriate to make a small premise: In an endothermic motor for automotive there is a practical mechanical efficiency of 25% relative to the energy developed by the fuel. The remaining 75% is lost both in the fumes (about 50%) and in cooling and various frictions (the remaining 25%). It is intuitive to understand that a system that recovers part of this energy as heat to gasify introduces a sort of energy recycling while keeping the energy inside the system, consequently reducing waste and increasing the actual efficiency. By obtaining, then, an increase in the combustion temperature, due both to the increase in the flame speed and to the fact that the gases already enter at a high temperature (we are talking about values around 350 ° C), a significant increase in thermal efficiency is achieved and therefore of the thermal machine in general. If knocking phenomena occur, one can simply plan to dilute the gas with part of the exhaust gases in order to get out of the explosive limits of the mixture with air and achieve an even more extreme heat recovery. Tests carried out on an experimental basis and with not entirely suitable means have shown a decrease in fuel consumption (with the same performance) and a clean exhaust without unburnt materials and / or odors. The system is however open to improvements and innovations.

Devices necessary for gasification:

The devices suitable for gasification can be made in different ways but follow the general scheme of the attached scheme. In this scheme the process starts with a generation of water vapor followed by mixing with fuel and its subsequent catalytic or non-catalytic gasification. The process, being / endothermic, requires an external energy input (Q) which can be obtained in various ways (autogenous heat, 'external or recovery heat, plasmas, electro-thermal fomets etc ..). The multiplicity of configurations and variants that can be created is therefore evident. As a clarifying example, the diagram of the apparatus used for the first experiments is shown.

Claims (2)

Patent claims: 1) Application of the thermal and / or catalytic gasification system by means of water, steam, and / or hydrogen peroxide, of liquid organic substances for the generation of combustible gases suitable for powering combustion engines, gas turbines, aeronautical engines, generators thermal and / or steam. 2) Types of energy supply for the gasifier system of point 1): Electrothermal systems with internal or external resistance or resistive piping Heat recovery systems from exhaust gases or other thermal sources Systems with partial fuel combustion both inside and outside the reaction chamber Systems using chemical reactions directly or not directly involved in plasma gasification Other unspecified energy sources 3) Applications of the gasifier system of point 1 in detail: for internal combustion and diesel engines for transport, ship propulsion, railway propulsion, energy production, district heating, generation of motorbikes for various uses, for endothermic engines such as Wankel, Stirling (closed cycle) in any use for power supply and heat recovery in gas turbines, turbojets and turbofans, applied to automotive, jet and turboprop aircraft propulsion, both direct, naval propulsion, generation and cogeneration of thermal and / or electrical energy. for power supply and / or heat recovery in steam generators (boilers) or heat generators. 4) Equipment and accessories designed to implement the application of point 1