Solar energy is converted to the method and the device of fuel chemical energy
Technical field
The present invention relates to solar energy and chemical energy technical field, is a kind of new method and device that solar energy is converted to fuel chemical energy.
Background technology
The energy is the basic assurance of human development existence, along with expanding economy, population growth, the consumption of the energy and day sharp increase, a large amount of exploitations of fossil energy make it and will face exhaustion, meanwhile, the discharging of a large amount of pollutants, seriously pollute environment, worsened the human existence situation, threatened sustainable development from now on.Seek the energy new, reproducible, cleaning and caused the extensive concern of countries in the world scientific and technological circle.Solar energy will occupy important ground with its unique reserves " unlimitedness ", the generality that exists, the spatter property of development and use in the energy resource structure in future.But, discontinuous, shortcoming the restricted development of self such as energy-flux density is low of solar energy.Therefore, seek new energy utilization patterns, particularly the complementation of fossil energy and solar energy utilizes the focus that becomes various countries scientific and technological circle, and cleaning liquid synthetic fuels such as methyl alcohol, dimethyl ether are used widely gradually simultaneously, becomes the following most promising main flow energy that substitutes conventional energy resource.Methyl alcohol is as " the omnipotent intermediate " of chemical industry, can be synthetic from coal, natural gas, living beings equal energy source, be only except that synthetic ammonia can be by coal gasification and the extensive simple chemicals that synthesizes of gas renormalizing.Methyl alcohol and dimethyl ether are as important cleaning synthetic fuel, have the combustion characteristics of similar oil product and advantage easy to carry and transport, in the application that will obtain aspect the energy, the power more and more widely, carry out methyl alcohol and dimethyl ether fuel and efficiently utilize research imperative.Burning on the ordinary meaning is exactly to utilize boiler or cooking stove, and the direct oxidation exothermic reaction-i.e. directly burning of methyl alcohol and oxygen takes place, and this is the main mode of utilizing of present methyl alcohol and dimethyl ether fuel.
Solar energy need convert thereof into the energy of other form usually when utilizing, the conversion regime of at present extensive use is the photo-thermal conversion.The collection of solar energy is general adopts various concentrators, from low temperature heat collectors such as flat, electron tubes types to slot type, dish formula, high temperature heat collector such as tower, solar energy is risen to higher grade be used.General heat-collecting temperature is high more, and corresponding cost is also high more, and efficient is low more.Solving the discontinuous problem of energy, can adopt the means of accumulation of heat, is a difficult problem but how to reduce the regenerative apparatus volume all the time, also has inevitable heat loss, and application is restricted.Therefore therefore the approach of solar energy and conventional energy resource integrated complementary use also is subjected to paying close attention to biglyyer.At present general way is solar energy and fuel (comprising electric power) having complementary functions on isolated footing separately, promptly (cloudy day, night) supplied with by fuel when solar energy does not reach temperature required or do not have solar energy and can use, complementary system on this class simple physical meaning is in solar-heating, refrigeration, and is extensive use of in the solar heat power generation system.This complementary system only is the simple superposition of solar energy and fossil fuel, perhaps only is confined to the cascade utilization of physical energy, can not fundamentally improve the utilization ratio of solar energy.At present solar heat chemistry and reaction unit thereof be mainly in the high-temperature heat-gathering mode, as be used for the system of gas renormalizing, and the heat-collecting temperature that needs has increased the conversion cost of solar energy to chemical energy greatly generally more than 800 ℃.
Summary of the invention
The object of the present invention is to provide a kind of method that solar energy is converted to fuel chemical energy, in this method, solar energy directly is the endothermic chemical reaction heat supply, need not thermal medium, system flow is simple, can reduce the expense that adopts thermal medium to bring, can avoid thermal medium to store, transmit the heat loss that produces simultaneously.
Another purpose of the present invention is to provide a kind of energy conversion device that is used to realize said method, this device is the integrated device that a kind of parabolic slot type solar collector that is different from the high-temperature heat-gathering thermochemical process developed first and substituted liquid fluid fuel decompose catalytic reaction device, has constituted solar heat chemical conversion device as core together with accessory systems such as charging, product separation.
A further object of the present invention is to provide a kind of energy conversion device, can realize the complementation of solar energy and conventional energy resource, utilize solar energy to change liquid fuel into high heating value clean air synthetic fuel, can realize comprising that the cascade utilization of fuel chemical energies such as methyl alcohol or dimethyl ether and low-grade solar thermal energy promote and the chemistry storage to the grade of high-grade fuel chemical energy.
To achieve these goals, technical solution of the present invention provides a kind of method that solar energy is converted to fuel chemical energy, use solar energy heating/reaction integral system, directly collect, be radiated at solar energy on absorption/reactor, solar energy is converted to 150 ℃-300 ℃ heat energy, be the decomposition reaction heat supply of liquid fuel in the reactor, high-grade catabolite chemical energy is changed, saved as to middle low-temperature solar energy, discharge high-grade heat energy by the combustion decomposition product again;
Wherein, liquid fuel is methyl alcohol or dimethyl ether synthetic liquid fuel; Catabolite is for being the synthesis gas of main component with hydrogen and carbon monoxide.
Described method, the catabolite that the decomposition reaction of its described liquid fuel produces, be introduced in the condenser and cool, make the unreacted reactant condensation, gas-liquid mixture enters separator and realizes gas-liquid separation then, the synthesis gas output of hydrogen and carbon monoxide is for using or storing, and unreacted reactant returns blender, delivers in the cooling evaporimeter through feedstock pump to recycle again.
The employed device of a kind of described method, comprise head tank, parabolic slot type solar-energy light collector, cooling evaporimeter, condensate cooler, separator, blender, feedstock pump and pipeline, wherein, parabolic slot type solar-energy light collector is the line style beam condensing unit, cooling evaporimeter and condensate cooler are wall-type heat exchange equipment, and each parts is communicated with by seal for pipe joints routinely; It also comprises an absorption/reactor, absorption/reactor is an elongated tubular equipment, suitable with the length of parabolic slot type solar-energy light collector, be placed on the focal line place of parabolic slot type solar-energy light collector, have the sunshine high-absorbility, the reinforcement selectivity of low-launch-rate and antiradar reflectivity absorbs coated surface, and overcoat reduces the high permeability glass sleeve pipe of convection current and conductive heat loss; Fill the required catalyst of reaction in its elongated tubular equipment; Absorption/reactor inlet connects the cooling evaporimeter by seal for pipe joints, and outlet connects condensate cooler by seal for pipe joints.
Described device, its described absorption/reactor, can satisfy the requirement of parabolic slot type solar-energy light collector collecting efficiency, be the size and the focal spot width coupling of caliber, also can satisfy the requirement of chemical reaction caliber size, be that reaction velocity and bed pressure drop are reasonable, taken into account the double requirements of collecting efficiency and reaction yield.
Described device, its described cooling evaporimeter, its external heat source are 80~120 ℃ of thermals source.The cooling evaporimeter utilizes more low temperature thermal source preheating material, can be energy-conservation, but can be replaced by solar thermal collector for the simplified apparatus purpose.
Described device, its described thermal source is parabolic slot type solar-energy light collector, electron tubes type or flat type solar heat collector, external boiler, or the waste heat of native system product.
Described device, the waste heat of its described native system product, it is the backheat utilization of the overheated gaseous mixture of absorption/reactor outlet product, the overheated gaseous mixture of product is fed the water back of cooling evaporimeter, part of heat energy as raw material preheating, insufficient section is replenished by 80~120 ℃ external heat source, and the reaction product mixture of lowering the temperature after the heat release feeds the further condensation process of condensate cooler again.
Described device, its described catalyst is solid metal oxide catalyst.
Described device, its described elongated tubular equipment is copper pipe; Coated surface is the aluminiferous metals ceramic membrane; Glass bushing is the high-boron-silicon glass pipe.
Energy conversion method of the present invention has following three features:
1. the heat-collecting temperature of solar-energy light collector is integrated with reaction temperature: the temperature levels that solar-energy light collector can provide is consistent with the needed temperature of decomposition reaction, has realized the temperature counterpart, and grade is coordinated, the reasonable utilization of middle low-temperature solar energy;
2. solar collector and reactor apparatus are integrated: placing the integration apparatus on the focal spot of solar-energy light collector is solar collector, it also is reactor, the direct irradiation of sunlight of the high fluence density of assembling is on absorption/reactor, directly be the endothermic chemical reaction heat supply, need not thermal medium;
3. the reacting sucting collector architectural feature is integrated: the caliber width of absorption/reactor and the focal line width of beam condensing unit are coordinated coupling, not only help reducing radiation loss, improve collecting efficiency, and help the carrying out of decomposition reaction, realize the coupling of conducting heat and reacting.
Apparatus of the present invention have following three aspect advantages:
1) integral method has been used in the device design, liquid fuel catalytic decomposition temperature coordination couplings such as solar energy heating temperature and methyl alcohol, dimethyl ether have been realized, reduced the solar thermal collector cost, also reduce the available energy loss of whole system heat utilization process, be better than adopting the thermochemical method of high-temp solar heat collector; Absorber and reactor are integrated; Solar collector and reactor in the system are integrated, have realized the equipment minimizing, need not heat transfer, transfer heat loss that thermal medium can be avoided bringing thus; Not only help reducing radiation loss by absorption/structure of reactor feature is integrated, improve collecting efficiency, and help the carrying out of decomposition reaction, realize conducting heat and the coupling of reaction, obtain good solar energy conversion effect.
2) power conversion and utilize the aspect: the fuel chemical energy that decomposes back methyl alcohol, dimethyl ether is converted to H
2With the fuel chemical energy of CO, solar thermal energy also is converted to H simultaneously
2Chemical energy with CO.System of the present invention is the calorific value that has increased methyl alcohol, dimethyl ether fuel in the effect of first law of thermodynamics aspect, and the part of increase equals the solar thermal energy that decomposition reaction absorbs; Effect on second law of thermodynamics aspect is embodied in the lifting of solar thermal energy grade, by the reaction of fuel decomposition such as methyl alcohol, dimethyl ether, makes low-grade solar thermal energy promote and is high-grade H
2With the chemical energy of CO, increased the acting ability of solar thermal energy.Total effect is that fuel chemical energy has improved efficiency of energy utilization to the loss of heat energy transfer process in the minimizing traditional combustion process.
3) following user had greater advantages: need gaseous fuel and do not have user's (as surrounding city, the area that gas distributing system does not cover, orographic conditions such as mountain area, island are unfavorable for the area of supplying gas) of combustion gas access conditions; Solar irradiation resource good (most of area, the especially west area of China); Methyl alcohol, dimethyl ether fuel consumption possess certain scale (distributed energy station, methyl alcohol, dimethyl ether heat supply or power, electricity generation system), are the user of feedstock production synthesis gas with methyl alcohol, dimethyl ether.
The present invention can be used for multiple use, as the supply of cooling, heating and electrical powers of heat supply, refrigeration, fuel-solar combined power generating, solar energy and fuel complementation and combustion gas production etc., utilizes solar energy that the synthesis gas fuel or the raw material of high-quality are provided for the user.
Description of drawings
Fig. 1 is the fundamental diagram of the inventive method or device;
Fig. 2 is energy grade conversion schematic diagram of the present invention;
Fig. 3 is apparatus of the present invention structure and schematic flow sheet.
The specific embodiment
A kind of method that solar energy is converted to fuel chemical energy provided by the invention, as shown in Figure 1, wherein, the solar light irradiation of the high fluence density of assembling through heat collector is on absorption/reactor, directly the decomposition reaction for fuel provides heat, obtains the catabolite synthesis gas; Thereby solar thermal energy is converted, is stored in the chemical energy of catabolite, and the grade of low-temperature solar energy is promoted, and is converted into high-grade synthesis gas chemical energy, further makes fuel and uses.
In the said process, energy grade is changed as shown in Figure 2: among the figure, abscissa is the process enthalpy change, and ordinate is energy grade A, and it is defined as the process available energy and changes ratio with enthalpy change.Therefore the area that abcda surrounds among the figure as can be known is that methyl alcohol directly burns-lose, and the area that efgde surrounds among the figure is catabolite burning-loss, and the area that cgnmc surrounds among the figure is represented the income of solar thermal energy grade lifting generation in the new mechanism.The fuel decomposition process can be regarded as calorific value in the drawings | ab|, the about A of grade
1=1.02; Methyl alcohol absorbs heat (solar thermal energy) | mn|, the about A of grade
2=0.44; The catabolite fuel value is | ef|, the about A of grade
3=0.95.
Described fuel is methyl alcohol or dimethyl ether liquid;
Described catabolite is with H
2With CO be the synthesis gas of main component.
The invention provides a kind of energy conversion device that is used to realize said method, the fundamental diagram of this device sees also Fig. 1.Apparatus of the present invention be utilize 150 ℃~300 ℃ middle low-temperature solar energy to material benzenemethanol or dimethyl ether endothermic decomposition reaction heat energy, production main component are provided is hydrogen (H
2) and the synthesis gas of carbon monoxide (CO), change middle low-temperature solar energy the chemical energy of synthesis gas into, improved the calorific value of fuel, promoted the grade of solar energy, increased the acting ability of solar energy.
As shown in Figure 3, apparatus of the present invention mainly comprise:
Parabolic slot type solar-energy light collector 5: select to adopt the line focus mode, optically focused is than about 60~150, heat-collecting temperature can reach 200 ℃~400 ℃ parabolic slot type solar-energy light collector 5, be the liquid fuel decomposition reaction heat supply of range of reaction temperature between 150 ℃~300 ℃, integrated with the heat-collecting temperature and the reaction temperature that realize solar-energy light collector;
Absorption/reactor 6: being the tubular type equipment that is placed on the focal line place of parabolic slot type solar-energy light collector 5, is solar collector, is again thermochemical reactor.As absorber, it has the sunshine high-absorbility, and the reinforcement selectivity of low-launch-rate and antiradar reflectivity absorbs coated surface, also has for reducing the glass bushing of the high permeability that convection current and conductive heat loss be provided with; As reactor, fill the required catalyst of reaction in the pipe; Absorption/reactor 6 connects cooling evaporimeter 4 and condensate cooler 7.
Cooling evaporimeter 4 is wall-type heat exchange equipment, connects absorption/reactor 6 and feedstock pump 3 respectively, receives from the raw material in the blender 2, and this raw material is preheated, evaporates, is superheated to gaseous reactant at this; The thermal source of cooling evaporimeter 4 can be to be higher than 80 ℃ thermal source arbitrarily, such as above-mentioned all kinds of concentrating solar devices or electron tubes type solar thermal collector, and other external heat source;
Condensate cooler 7 is wall-type heat exchange equipment, connects absorption/reactor 6 and separator 8, and condensation comes the catabolite of self-absorption/reactor 6.
Separator 8 is gas-liquid separation device, with the mixture that cools down in the condensate cooler 7, carries out gas-liquid separation, connects condensate cooler 7 and blender 2 respectively, and the product of gas phase is as product, and liquid phase component is got back to blender 2.
Blender 2 is accepted and is mixed the unreacted reactant of separating from the fresh feed in the head tank 1 and separator 8, is supplied raw materials for absorption/reactor 6 by the feedstock pump that is attached thereto 3.
The flow process of apparatus of the present invention is: the raw material in the head tank 1 through blender 2, feedstock pump 3 deliver to preheating, evaporation in the cooling evaporimeter 4, overheated after, the unstripped gas that forms enters absorption/reactor 6, in absorption/reactor 6, absorb 150 ℃~300 ℃ solar thermal energies, under catalyst action, carry out simultaneously the endothermic decomposition reaction, reaction output hydrogen (H
2) and the synthesis gas of carbon monoxide (CO) after, be introduced in the cooling evaporimeter 4 and cool, make the unreacted reactant condensation, gas-liquid mixture enters separator 8 and realizes gas-liquid separations, hydrogen (H then
2) and the output of the synthesis gas of carbon monoxide (CO) for using or storing, unreacted reactant returns blender 2, delivers to cool off in the evaporimeter 4 through feedstock pump 3 again to recycle.
In apparatus of the present invention, beam condensing unit 5 is various parabolic groove type solar line style beam condensing units.
In apparatus of the present invention, condensate cooler 7 is connected with recirculated cooling water.
In apparatus of the present invention, head tank 1 downstream connects a chemical metering pump, and head tank 1 is communicated with (not illustrating among the figure) through chemical metering pump with blender 2.
Apparatus of the present invention also comprise the backheat utilization that realizes the overheated gaseous mixture of absorption/reactor 6 outlet product, be about to the overheated gaseous mixture of product and feed the part of heat energy of cooling evaporimeter 4 as raw material preheating, insufficient section is replenished by the external heat source that is higher than 80 ℃ arbitrarily, the mix products of lowering the temperature after the heat release feeds condensate cooler 7 further condensations again.
Please in conjunction with Fig. 3, solar energy decomposes substituted liquid fluid fuel device, is made up of solar-energy light collector 5, integrated absorption/reactor 6 and other auxiliary equipment.
Liquid methanol in the head tank 1 or dimethyl ether raw material are input in the blender 2 through piping 9, again through piping 10, by the flow of feedstock pump 3 by 500~10000ml/h, send into cooling evaporimeter 4 through pipeline 11, through preheating, evaporation, overheated after, superheated feedstock gas enters absorption/reactor 6 through pipeline 12; Under normal pressure, 150~300 ℃ of reaction temperatures and catalyst action, be used to the solar energy of collecting from solar-energy light collector 5, decomposition reaction takes place in absorptions/reactor 6, generation contains H
2, CO and unreacting material and small amounts of by-products mix products, this mix products is introduced into cooling evaporimeter 4 preheating materials through pipeline 13, supplemental heat source is advanced by pipeline 18, pipeline 19 goes out, mix products self temperature descends simultaneously, and partial condensation enters condensate cooler 7 by pipeline 14 subsequently, be cooled to below 25 ℃ and enter separator 8, main component H wherein through pipeline 15
2With CO be well behaved gas synthetic fuel, discharge by pipeline 17, fed downstream is directly utilized or is stored.Unreacted raw material and small amount of liquid accessory substance come out from separator 8, return in the blender 2 by pipeline 16, and continue to use after pipeline 9 enters 2 fresh feed and mixes from head tank 1.The cooling medium of condensate cooler 7 is gone into by pipeline 20, goes out from pipeline 21, and product is cooled off, and cooling medium can be recycling.
Various device in apparatus of the present invention is known technology, as:
The solar-energy light collector 5 that the present invention adopts can be various parabolic slot type beam condensing units.
Cooling evaporimeter 4 of the present invention or condensate cooler 7 can be various dividing wall type heat exchangers.
The catalyst that the present invention adopts can be the known catalyst that is used for methyl alcohol or dimethyl ether decomposition reaction, as solid metal oxide catalyst etc.
Because the emphasis of discussion of the present invention is to change solar energy the chemical energy of fuel product into by the solar heat chemical process, so the above-mentioned concrete equipment that belongs to known technology is not described in detail.
Following embodiment can illustrate effect of the present invention:
With an optically focused ratio is 70, maximum heat outputting power is the parabolic slot type solar-energy light collector 5 of 4kW, the long copper pipe that adopts 35 millimeters of external diameters is as absorption/reactor 6, it is 0.9 that the copper pipe outer surface is coated with absorptivity, emissivity is 0.085 aluminiferous metals ceramic membrane, and the overcoat diameter is 56 millimeters a high-boron-silicon glass pipe; Raw material is the liquid industrial methanol of 99.9% concentration under the normal temperature and pressure, and catalyst is Cu/ZnO/Al
2O
3The series solid metal oxide catalyst.
From the liquid-phase product that separate separator 8 lower ends, mainly be unreacted raw material and small amount of liquid accessory substance, the gaseous products that separate separator 8 upper ends is the H more than 90%
2And CO, add a small amount of flammable raw material and carbon dioxide (CO
2) synthesis gas formed.
The pipeline flow process parameter of present embodiment, as shown in table 1.
In the present embodiment, as solar irradiation 700W/m
2, under 5 liters of/hour conditions of liquid methanol inlet amount, methanol conversion reaches 80%, and the solar thermal energy utilization ratio reaches 77%.
Present embodiment is from the angle of energy grade, and advantage is more obvious.The notion of energy grade equals Carnot's cycle efficiency for its value of heat energy.Under above-mentioned reaction condition, 260 ℃ of solar thermal energies are converted to the chemical energy of catabolite mist through methanol decomposition reaction, energy grade is thus lifted to 0.923 by 0.443, increased its acting ability greatly, can make simultaneously energy utility system in the direct relatively combustion process of fuel combustion link, loss reduces 30.8%.
Table 1 embodiment of the invention pipeline flow process parameter
Pipe number | Pipeline internal medium | Temperature (pressure is normal pressure) |
9 | Fresh feed, liquid | 16℃ |
10 | Blended stock, liquid | 16℃ |
11 | Blended stock, liquid | 18℃ |
12 | Superheated feedstock, gas | 100℃ |
13 | Mixture of reaction products, gas | 200~300℃ |
14 | Mixture of reaction products, gas-liquid mixed | 50℃ |
15 | Mixture of reaction products, gas-liquid mixed | 20℃ |
16 | Product and unreacted reactant, liquid | 20℃ |
17 | Synthesis gas, gas | 20℃ |
18 | External heat source | 120℃ |
19 | External heat source | 80℃ |
20 | Recirculated cooling water | 17℃ |
21 | Recirculated cooling water | 20℃ |