RO128151A1 - Installation and process for burning the mixture of hydrogen and carbon dioxide for thermal stations and thermal power stations used in domestic and industrial fields - Google Patents

Abstract

The invention relates to an installation and a process for burning the mixture of hydrogen and carbon dioxide for thermal stations and thermal power stations. According to the invention, the process carries out, in a first stage, the burning of hydrogen from the H-COmixture, in the presence of magnesium as a catalyst, in an enclosure with orifices for the removal of gases and carbon atoms, while forming MgO, and, in a second stage in the same enclosure, in which the burning of hydrogen took place, according to the first stage, the introduced excess hydrogen permits the magnesium to regenerate, according to the stage reactions: H+ CO+ Mg ---> MgO + C + HO MgO + H---> Mg + HO + Q and to the general balance reaction : 2H+ CO--->C + 2HO + Q, the cycle being continuous. According to the invention, the installation for applying the process comprises a stainless steel housing () consisting of a stainless steel pipe on which there is fixed a cover () connected to a hydrogen supply piping () inside which there are placed : a chamber () for the uniform distribution of hydrogen, a chamber () for the uniform distribution of carbon dioxide, a chamber () for the homogenization of the H-COmixture, a catalyst chamber () in which there is located a magnesium catalyst () both as chips and powder, some copper and stainless steel pipes (), respectively, which ensure the conveyance and uniform distribution of Hand COgases on a quartz layer surface () and also on the surface of the catalyst (), a deflector () for homogenizing the gaseous mixture, ensuring a swirling motion of Hand CO, while on the outer side of the housing () there are provided some pipings () for replenishing a catalyst (), for supplying with H, for supplying with COand a piping for discharging C, the catalyst chamber () being fastened with a nut (), a packing () and a resilient member ().

Description

Installation and process of combustion of the hydrogen mixture with carbon dioxide for thermal or thermoelectric power stations used in the domestic or industrial field

The invention relates to a process of combustion of the H2-CO2 mixture on the basis of a catalyst but also of the very high reactivity of hydrogen, especially with the oxygen and spontaneous release of the carbon atom, obtaining a well controlled thermal energy based on a simple, reliable installation. , efficient and high safety that can contribute to the substantial reduction of excess carbon dioxide in nature, with domestic and industrial applications.

Global warming caused by increasing concentrations of greenhouse gases in the atmosphere is a major concern related to air quality. Carbon dioxide is the most abundant greenhouse gas emitted by burning fossil fuels used for heating, electricity production and transportation, being responsible for most of climate change. Reducing CO ₂ emissions requires measures such as reducing energy consumption, increasing energy efficiency or using alternative, renewable energy.

One of the major alternatives to fossil fuel energy is hydrogen energy. The object of high specific uses in the chemical, electronic and space industries, hydrogen has attracted the interest of public authorities and research organizations, as well as of business people, for more than three decades, and in quality. of clean fuel for the means of transport or as a source for generating electricity. Wide multidisciplinary research and development activities have been initiated and carried out with priority throughout the world, pursuing the development of efficient technologies for generating, separating, purifying, storing, transporting and using in safe conditions of hydrogen.

Hydrogen is the cleanest fuel from the environmental point of view (through its combustion resulting only water) and. at the same time, the most efficient energy carrier, having an energy content per unit of weight 2.1 times higher than for natural gas. Hydrogen is also the most versatile renewable energy resource, which can be used anywhere in the world, independent of traditional energy resources, as a fuel for engines of all types of vehicles, as well as for thermal installations that serve a very wide range of uses (housing, buildings). , localities, etc.). as well as for supplying fuel cells that produce polluting electricity, having a wide variety of applications, including in electronics, telecommunications, computing technique.

An important technical problem to be solved for the use of hydrogen as a fuel is that of the burner. The combustion rate of pure hydrogen is very high, being in the range 265-325 cm / s, compared to 37-45 cm / s in the case of methane. For this reason. Under normal conditions, hydrogen cannot support a flame. It is necessary that the rate of combustion of hydrogen be reduced at the same time as the danger of explosion is reduced.

The temperature of the flame and its propagation speed are dependent on the composition of the combustion mixture, which increases the size of the flame and decreases its speed. Depending on the concrete requirements imposed by a particular use, the composition of the combustion mixture must be carefully optimized. Burning of hydrogen usually involves more frequent maintenance work of the burners, since rapid combustion often makes possible the contact of the flame with the burner components, leading to their rapid degradation.

At the global level, solutions have been conceived and implemented regarding the adaptation of thermoelectric power stations operating on fossil fuels to hydrogen operation. since 1993. as part of a demonstration project carried out in Germany by SWB, the operation of boilers with a thermal capacity of 20 KW has been tested using modified burners for the combustion of hydrogen,

<X-2 0 1 - Ο Ο 33 1 - 2 3 -08- 2011 of natural gas or of some mixtures of these gases (International Journ.tl oj Hydrogen Energy. Vol. 19. no. 10,1994). In Japan, new Rankine cycles have been developed for power plants that use hydrogen as fuel (International Journcd ofE;: ergy. vol. 1. no. I. p. 29-46. 2004).

Improperly designed hydrogen burners vibrate and make noise. More important, however, is the fact that in such burners improperly designed the flame can be very unstable and can be detached from the burner. Some burner manufacturers limit the hydrogen concentration to 90-95%. the difference being methane. Remarkable results worldwide recognized by the American company C'oen in California. The design and commissioning of some 250,000 Ib / h (113.5 t / h) boilers using 95% hydrogen fuel with Coen burners has been reported. as well as the fact that this company can produce burners that burn 100% hydrogen in steam boilers like Rentech or Babcock & Wilcox.

Taiwanese company De Fu Technology currently produces hydrogen-oxygen burners with a maximum thermal capacity of 250,000 kcal / h for boilers. furnaces for heat treatment and other applications (w \ w .dfb.com.tw).

To safely burn hydrogen, it is essential to maintain a minimum combustion rate at the level of hydrogen injectors, so that conventional flow and pressure control devices are not sufficient. The American company CB NATCOM has designed (for the Olin Chior Cheniicals chemical plant) a burner that uses multiple hydrogen injection zones (surplus product of the plant available at a pressure of 0.48 bar) that opens and closes so as to open. maintains the pressure within optimum limits (intended for aquatubular boilers with a capacity of 34 t / h and operating at pressures of the order of 10 bar). A system with 6 such zones provides a 20: 1 adjustment ratio. The developed control system allows the safe and efficient operation in five modes of combustion: only natural gas, only fuel, only hydrogen, hydrogen with natural gas and hydrogen with fuel. To reduce the formation of nitrogen oxides, the immediate contact of the fuel with the air is avoided by steam injection at the periphery of the hydrogen injectors. Also to avoid the formation of nitrogen oxides, the operating temperature should be kept below 650 ^u C \ At the mentioned chemical plant the project of installing two steam boilers using surplus hydrogen and in case of need (availability of hydrogen as surplus product is not constant) gas natural or itchy, it took 14 months to complete. Benefits. rising year on year due to rising fuel prices, they were estimated at $ 2.5 million annually.

In August 2008, a similar system for using surplus hydrogen for the fuel supply of some steam boilers was put into operation in the plant in Runcorn (north-west of England) of INEOS Chior, a global leader in the production of chlorinated derivatives. . (httpr'w w w .chcinicalprocessino.com / articlcs / 2010 / 132.html).

in PC patent application no. WO 2009/068424 Al (applicant for Alstom Technology Ltd. clin Switzerland), which is an improved variant of the PCT patent application ni '. WO 2006/058843 Al, there is presented a transition sector coupled upstream with the vortex generator and a mixing sector, coupled upstream with the transition sector and downstream with the combustion chamber.

In the PCT patent application no. WO 2007/021053 Al (applicant for Daum Energy Co. Ltd. of South Korea), a gas hydrogen burner and a heat supply system using this burner are presented. Hydrogen is generated in situ in an electrolytic cell by electrolysis of an aqueous solution and filtered before use. The possibility of temporarily storing electrolyte hydrogen in a metal alloy is also provided. for later use in the burner. An efficient heat dissipation is ensured, preventing the overheating of the hydrogen feed nozzle. The burner according to this invention can be used in a domestic cooking installation.

Ο-z S 7 Τ -! J »? 5 1 - 2 3 -or- 2iiii in PCT patent application no. WO 2006/136316 Al (applicant company Giacomini SpA in Italy) is presented with a burner; o. · Catalytic hydrogen, operating under safe conditions at low temperatures (around 300 ° C). without the flame. A catalyst for starting the oxidation of hydrogen in the air flow at ambient temperature! it is hated by other catalysts located downstream in the combustion chamber to further support oxidation. ^D n order to prevent clogging of the pores of the catalyst, the air used is purified and UI provided by the compressor. The burner is designed to provide a source of heat for the hot water supply systems and / or heating systems.

in PCT patent application no. WO 2006/058843 Al (applicant for the company Alstom Technology Ltd. in Switzerland) presents a method and device for combustion of a gas fuel containing hydrogen or consisting of hydrogen. 4 'the damper is provided with a whirlpool generator, the gas fuel being introduced axially and / or coaxially into it. The combustion air flow is introduced tangentially and is rotating.

in PCT patent application no. WO 2005/024301 Al (applicant company Giacomini SpA of Italy, according to the invention, hydrogen is chewed with air and burned in a combustion chamber on a catalyst (eg palladium, platinum), at a temperature: cold (200450 ° C) Hydrogen is supplied at a low pressure, preferably 20 millibars. The combustion chamber is surrounded by a heat exchanger through the flue gases, the heat due to the combustion being taken over by a cooling water circuit. The heated water can be stored. in a tank and used as needed Hydrogen can be produced in-situ by electrolysis or taken from storage cylinders after pressure reduction The patented burner is designed to equip some hot water supply systems with some When hot water is not needed, hydrogen can be accumulated in metal hydrides and stored.

Brief presentation of the invention

The process according to the invention, for burning the H2-CO2 mixture eliminates the aforementioned disadvantages, in that in the first phase the combustion of hydrogen in the mixture (H2-CO2) is carried out in the presence of magnesium in a chamber with gas outlet and gas. atomylc: carbon, as a catalyst, with MgO formation, and in the second phase in the same chamber where the hydrogen combustion took place according to the first phase, the addition of hydrogen introduced allows the regeneration of the mileage. All this taking place according to the following phase reactions:

1T ₂ + CO2 + Mg - * MgO + C + H ₂ O

MgO H ₂ - Mg - H ₂ O + Q and general reaction, balance sheet:

catalyst (Mg)

2H ₂ + CO ₂ -------- ► C + 2H ₂ O + Q. The cycle is continuous.

The installation for combustion of the H2-CO2 mixture which is the subject of the present invention eliminates the disadvantages of the previously presented inventions by the fact that it is formed of a housing of ir ox. (stainless steel pipe) on which a lid connected to a hydrogen supply pipe is fixed, inside the housing being:

• a uniform hydrogen distribution chamber delimited by two caps, both of stainless steel sheet;

• a uniform distribution chamber of carbon dioxide bounded by two caps of stainless steel:

• an H2-CO2 mixing chamber delimited by a stainless steel lid and containing quartz sand or quartz in the form of hexagonal crystals;

• a chamber for the catalyst inside which is a catalyst of m.gnesium, both in the form of chips and in the form of powder:

^ - 2 0 1 1-00831--

3 -08- 2011 • some copper pipes that ensure the uniform transport and distribution of H. and CO gases? on the surface of the quartz and the catalyst:

• a deflector of homogenization gas mixture, which ensures a turbulence of the H2-CO2 mixture. before entering the quartz layer. on the outside of the housing being provided:

• a pipeline to complete the catalyst;

• a H2 supply pipeline, and a CCR supply pipeline • hot air directing plant for industrial applications.

The installation and process of combustion of the H2-CO2 mixture for thermal and thermoelectric power stations in the domestic or industrial field, according to the invention, has the following advantages:

o promotes, raises awareness and takes responsibility for the new generation regarding the role and importance of energy in the domestic and industrial applications of hydrogen, the transition to a new era based on hydrogen energy, an inexhaustible source;

o the system allows the burning of H2 and CO2 at both low and medium pressure;

o reducing the pollution effect of the environment by recovering carbon atoms;

o obtaining high-purity carbon that can be used in various fields:

o controlling the burning rate of hydrogen as well as the desired temperature, with numerous applications in the industrial field;

o ensuring a well-controlled combustion atmosphere that allows its use in industrial thermal treatments;

o Higher capitalization of the hydrogen surplus of the chemical compounds and the units of profile for the purpose of obtaining caloric energy or electricity:

o the use of a relatively inexpensive catalyst (Mg) which ensures an O transfer? from the CO? to H2 based on simple reactions using 2 moles of H ₂ at most one mole of CO2.

o relatively simple construction:

o operational safety;

high reliability;

o The process allows the monitoring of the combustion temperature and the atmosphere by regulating the combustion rate of hydrogen.

The invention is further described below. and in relation to Figures 1-6 which represent:

FIG. 1. the combustion plant of the H2-CO2 mixture:

FIG. 2. the cross-section of the combustion plant of the HȘ-CO mixture:

FIG. 3. detail 13, catalyst chamber attachment;

FIG. 4. Detail C. Deflector mounting;

FIG. 5. deflector shape;

the flg. 6, variants for directing air heat provided by a fan for industrial applications.

The process according to the invention, for burning the H2-CO2- mixture in a first phase, is the burning of hydrogen from the H2-CO2 mixture in the presence of magnesium in an enclosure with holes for the exhaust of gases and carbon atoms, as catalyst, with formation of MgO. and in the second phase in the same enclosure the added hydrogen dc regenerates magnesium. according to the phase reactions:

H2 + CO2 + Mg - * MgO + C + H2O

MgO + H-2 -> Mg + H2O + Q and the general, balance reaction:

catalyst (Mg)

2H2 + CO2 -------- ► C + 2H2O + Q. The cycle is continuous.

From the chemical balance of the reaction it can be observed that two moles of hydrogen are used for one mole of carbon dioxide. Quantitatively, the reaction is approx. 2400 Nnr'EB / hour and 1200 Nm ³ CO2 / hour. that is, 2 moles ID / maxlmol CO2. for which the volume of the cylindrical chamber with Mg was D300x30 (about 5.7 kg Mg).

C <- 2 O Π - O O 8 3 1 - - “08 · 2011 V

The combustion takes place on the surface of the chips magnesium layer, the place where the combination of hydrogen with oxygen is produced and the carbon atom is released. Magnesium has a tendency to oxidize but it is regenerated by hydrogen by yielding oxygen to the hydrogen atom 1. Both the magnesium oxidation reaction and the hydrogen oxidation are highly exothermic reactions that lead to a higher energy balance in relation to the required energy loss. decomposition of carbon dioxide. The catalyst and the COt flow rate ensure the reduction of the combustion rate of H2. and the quartz layer ensures homogenization of the H2-CO2 mixture and interrupts the flame when the hydrogen supply is stopped (it does not allow it to propagate in the IL · supply circuit).

The process of combustion of the H2-CO2-domestic mixture is carried out sequentially as follows:

• the valve of the pipe with H2 is opened at minimum flow:

• a piezoelectric system ignites the hydrogen;

• the hydrogen flow is increased;

• open the pipe with CO2 until the optimum molar ratio is assured.

At the stop, the operations are the opposite of the ones from the start.

The process of combustion of the H2-CO2 - industrial mixture is carried out sequentially as follows:

• with a piezoelectric installation a methane flame is ignited, brought through a supply line, the wake flame being directed perpendicular to the axis of the hydrogen burner:

• the hydrogen supply tap is progressively opened to the maximum flow rate.

• the CO2 supply valve is progressively opened until the molar ratio H2 / CO2 is equal to 2 / max.

The operation of stopping the installation is the reverse of the starting operation, namely: stopping CO2. stop H2. stop flame wake with methane. The industrial installations will also be provided with two optical sensors for the wake-up flame and for the flame of the CO2 mixture with COt which enters into a special automation scheme but which is not subject to the present invention.

The air blown by a fan is directed into a room that allows the installation to cool down, figure 1. then the heated air is swirled through a trunk space inside the boiler furnace. The casing for directing the hot air into the boiler is provided with a circuit containing copper pipe filling which ensures the transfer of heat to the ventilated air.

The installation, for both the variant used in the domestic and industrial fields, according to the invention, solves the problem of burning the H2-CO2 mixture with the help of a catalyst from the chips and magnesium powder that allows to obtain carbon atoms, contributing to the elimination of the excess of carbon in nature. maximum safety conditions, according to the claimed process, in that it has a stainless steel housing (1). figure 1. from a stainless steel pipe on which a lid (3) is connected connected to a hydrogen supply pipe (2). inside the housing (1) comprising:

• a uniform hydrogen distribution chamber (Ml) bounded by a lid (3) and a lid (5). both of stainless steel sheet;

• a uniform distribution chamber of carbon dioxide (M2) bounded by the lid (5) and a lid (6) also made of stainless steel;

• a chamber (M3) for mixing H2-CO2 mixture bounded by a lid (9) of stainless steel sheet and inner screen (14). homogenization by means of a deflector (16) made of stainless steel as well as quartz sand or quartz crystals with granulation 0.82 mm:

• a chamber for catalyst (14) stainless steel sieve with perforations of 50 June, inside which is a magnesium catalyst (13), both in the form of chips and in the form of powder;

• copper or stainless steel pipes (7) and (8) respectively, which ensure the uniform transport and distribution of H ₂ and CO2 gases on the catalyst surface (13);

• a deflector (16). which ensures a H2 and CO2 swirl through the quartz start (18).

Pc the outside of the housing (1) are provided:

^ -2 0 1 1 - 0 0 β 3 1 - 2 3 -08- 2011 • ο the catalyst filler pipe. (17);

• an EL supply line. (2);

• a supply pipe with COj. (4).

The arrangement of pipes (7) and (8) inside the housing (1) can be seen from figure 2.

The fixation of the chamber for the catalyst (14) with the element Mg that acts as a catalyst, can be seen in figure 3, this being accomplished with a nut (1.1). a gasket (12) and an elastic member (15).

At the bottom of the catalyst chamber, a 15 * 'inclination is technologically executed on its height so that the carbon remaining in the catalyst can be recovered through a pipe (10).

The fixing and the shape of the dctlcctor (16) is shown in figure 4. respectively figure 5. The stainless steel bolt (19) has a tightening adjustment for fixing in the CO2 distribution pipe and is provided with some holes to allow the entry of CO2Î11 mixing chamber. .

The Mg catalyst is in the form of chips and inside the enclosure with Mg powder. The ratio of Mg shavings / powder Mg = 5/1 ... 4/1

From the chamber (Ml), the hydrogen is evenly distributed through the pipes (7) beaded or welded on the covers (5). (6) and (9) to make a seal of the chambers.

Through the pipe (8) it is evenly distributed and CCfl. It is fastened to the covers (6) and (9) by mandrel or welding. depending on the material used (copper or stainless steel). As a result of the combustion process, the catalyst (13) that provides the transfer of oxygen from carbon dioxide (CO2) to hydrogen (H ₂ ) may also have some losses that require periodic completion of the room where it is destined, which is achieved through the pipeline. (17).

l.a industrial applications also require the control of the flame and the heat by means of the blown air from outside the combustion plant, according to figure 6.

The air blown by a fan is directed into a room that allows the system to cool (described in the figure), then the heated air is swirled through a truncated space on which fins of the sheet (27) are welded inside the boiler outbreak (20). The housing (22) is provided with a circuit containing 12 pipes (23) in number of 12 pieces, filling of copper pipe ΦΙΟχΙχΙΟ mm (26) which provides the heat transfer to the ventilated air. Also in industrial applications, a wake-up flame must be provided through a supply line (25), a piezoelectric system (21) to ignite the flame.

Carbon resulting from the decomposition process of COt. due to the reactivity of hydrogen with oxygen from CO2. it is recovered by the pipe (10). and another part is sprayed at the base of the furnace of the boiler, where the installation is located, which is periodically recovered. It is very important to note that the creation of a larger amount of atomic carbon in the outbreak is not allowed as there would be a risk of its ignition which would lead to the outbreak of the outbreak.

Embodiment examples

Example 1

We use an installation with an external diameter of 300 mm. length 300 mm. Mg layer thickness of 30 mm chips, 5 mm powder Mg layer thickness and 20 mm quartz layer thickness.

At this size of the plant, burns of 900 m7h and 3000 nr / h and carbon dioxide proportional to at most half of the hydrogen used can be burned (at 2 moles of EL at most 1 mole of CO2).

For situations where we do not have carbon dioxide with high concentrations of 98-99%, a gas mixture such as:

nitrogen 40-60%;

or oxygen 2-4%, or CO2 36-48%. gas obtained from existing chemical processes.

^ 2011-00851-2 3 -08- 2011 9 in all situations, is the need for O taken into account? both in free and in combination with COt so as to ensure complete combustion of hydrogen.

Example 2

Industrially, in addition to the installation described in example 1, a casing with a diameter of 1200 mm and a fan are used which ensures both the cooling of the previously presented installation and the management of the flame obtained. A pipeline is also used for the methane gas supply in order to make the wake fire and the ignition is carried out with a piezoelectric installation. The operating cycle is as follows: at start-up - boiler ventilation, ventilation switch-off, flame wake-up ignition, progressive hydrogen valve opening, progressive CO2 valve opening, hot air introduction for flame and heat management, and at stop - ventilation stop, COo stop . EE stop, flame wake stop.

Claims (5)

1. Burning process of the II2-CO2 mixture, characterized in that, in the first phase, the hydrogen is burned from the H2-CO2 mixture in the presence of magnesium as a catalyst in a chamber with holes for the exhaust of gases and carbon atoms, with MgO formation, and in the second phase in the same enclosure in which the hydrogen combustion took place according to the first phase, the addition of hydrogen allowing the magnesium to regenerate. according to the phase reactions: H ₂ + CO2 + Mg MgO + C + H ₂ O MgO + H ₂ Mg + H ₂ O + Q and the general balance sheet reaction: catalyst (Mal 2H ₂ + CO ₂ ----- ► C + 2H ₂ O + Q using two moles of hydrogen for at most one mole of carbon dioxide. 2. The combustion plant of the H ₂ -CO ₂ mixture, for applying the process according to claim 1. characterized in that it has a stainless steel housing (1), formed of a stainless steel pipe on which sc fixes a lid (3). ) connected to a hydrogen supply line (2), inside which are included: • a uniform hydrogen distribution chamber (Ml) bounded by the lid (3) and a lid (5), both made of stainless steel; • a uniform distribution chamber of carbon dioxide (M2) bounded by the lid (5) and a lid (6) also made of stainless steel; • a chamber (M3) for mixing H2-CO ₂ mixture bounded by a lid (9) of stainless steel: • a chamber for the catalyst (14) inside which is a magnesium catalyst (13) both in the form of chips and in the form of powder; • copper or stainless steel pipes (7) and 8 (respectively) that ensure the uniform transport and distribution of H ₂ and CO ₂ gases on the surface of the catalyst and quartz; • a deflector (16) for mixing gas mixture, which ensures a turbulence of H ₂ and CO ₂ through the quartz layer. and on the outside of the housing are provided: • a pipeline for filling the catalyst (17); • a carbon recovery pipe (10); • a CO ₂ supply pipe (4); • a supply pipe with H ₂ (2). 3. Industrial process for combustion of the H ₂ -CO ₂ mixture - industrial, according to claims 1 and 2. characterized in that the flame and the heat released by combustion of H ₂ and Mg are directed with hot air after the air goes through a special circuit with the filling of the copper pipe based on a well-established operating cycle, namely: starting - ventilation boiler, ventilation stop, flame wake ignition, progressive hydrogen valve opening, progressive CO ₂ valve opening. introduction of hot air to direct flame and heat, and at stop - ventilation stop, CO ₂ stop. stop H ₂ . stop flame wake. 4. Combination plant H ₂ -CO ₂ - industrial process application according to claim 3. characterized in that it further comprises: • a housing (22); • several pipes (23) for filling the air in the filling (26): • a methane supply pipe for flame retention (25): • group of holes Φ5 arranged on the maximum diameter of the housing in the truncated part (24), which ensures the exit of the hot acre from the burner. 5. Installation as in point 2 for the domestic version and as in point 4 for the industrial variant characterized in that Mg is replaced with a quartz layer required for average pressures of the gas supply. H ₂ and CO ₂ .