DE666624C - Process for smoldering and simultaneous cracking of lignite and other bituminous fuels - Google Patents

Description

Process for smoldering and simultaneous cracking of lignite and other bituminous fuels It is known that the smoldering process with application certain methods and devices with a cracking process of the oil vapors formed can be combined in the same smoldering device, so that a common process of smoldering and cracking occurs in one operation, which is called the cracking process of solid bituminous fuels, and by which the Subsequent, generally customary pressure cracking of the oils resulting from the smoldering and tar is unnecessary.

In these known processes are through. more attempts a series of improvements, which are partly the possible applications of the process, sometimes the quality of one of the end products in special cases of the process of low-temperature coke.

The new process works as follows: The oil vapors are extracted from the Smoldering and cracking device passed into the condensation, which is not yet finished here cracked, heavier hydrocarbons from the lighter, ready-cracked ones separated and as return oil in solid, liquid or vaporous phase again returned to the smoldering and cracking process to come into contact with the heated Cracking coke further.

A cycle of heavy oils is formed from the smoldering and Cracking device in the condensation and back as well as a cracking in a row of time stages, the number of which for the different easily cracking components of the Oil is a different one, so the different components are dealt with on their own and a maximum yield is achieved. The return of each stake of the heavy oils takes place so often and so long until the desired degree of cracking is reached, so that all of the resulting oil is also completely converted into light oils, gas' and coke can be broken down. The cracked coke that forms is partially through the steam is gasified, it partially fills the pores of the low-temperature coke and becomes together with the same from the device, if the same works continuously, also carried out continuously.

The process can be carried out in any smoldering device, the yield of light hydrocarbons from the fuel is when used this process is far higher than with separate smoldering of the fuel and afterwards Cracking of the oils contained in the liquid phase, as there is a complete cracking up to dry coke is made possible, which is what happens in the cracking of heavy viscous oils in the liquid phase is not possible, as a number of. Sources of loss through the new procedures are no longer applicable.

Another advantage is that the cracking of the heavier oil fractions separated out in the condensation is returned to the smoldering and cracking process be, owing to the strong catalytic Effect of the smoldering coke at low Temperatures extremely fast in front of you. As a rule, an introduction of liquid return oil on the already formed coke is sufficient to produce a sufficiently strong herbaceous effect; In this case, the low-temperature coke absorbs the oil due to its porosity and evaporates it again due to its stored heat. The cracked coke that forms fills the pores of the smoldering; coke and enriches it with carbon.

Such a smoldering and cracking process of bituminous solid fuels in a single operation can also be used to pull apart from the solid Fuel-derived oils still. in addition to cracking oils, which from other Source for complete cracking to dryness in a cheap device High yield coke and continuous cracking with continuous discharge to achieve the cracked coke with the smoldering coke, which in pressure cracking plants in liquid Phase is not possible.

The additional oil, like the own return oil, can be used in the process vapor, liquid or solid phase are introduced, z. B. in shape of pitch, with the help of which the solid fuel is briquetted. Particularly suitable This process is therefore suitable for cracking in the form of additional oils of heavy viscous Oils and primary tars that leave a very high level of coke residue and their cracking in the liquid phase in the 'generally customary devices not possible or at least not possible is unprofitable and inefficient. The addition of foreign oils naturally has its effects Limit in the absorption capacity of the smoldering coke.

It has finally been shown in further experiments that in use the smoldering cracking on the German lignite by a certain change in the Process not only a complete splitting of the lignite tar down to gasoline, Gas and coke, but also a perfectly solid smoldering and cracking coke and this solves the acute question of the possibility of selling the smoldering coke.

An exemplary embodiment of the method with regard to the use of German lignite is as follows: The lignite is predried to a water content of about 25 to 30 °, briquetted in moldings without the addition of binders and, for example, subjected to smoldering cracking in a ladle tunnel furnace I. The volatile smoldering and cracking products are fed into a condenser in which the over .z000 boiling components are separated out as return oil. The latter is separated into lighter fractions and pitch residue, for example in a continuous distillation arrangement. The volatile components of the return oil return to furnace I in the vaporous phase and are cracked further here. The liquid pitch is continuously withdrawn and used for the renewed briquetting of the non-solid smoldering coke from furnace I.

The smoldering coke briquetted with the pitch residue of the return oil from oven I, for example, in a Pfannentulinelofen II, another one Subjected to heating or coking, the pitch partially evaporating again and the vapors are further split, while the solid residue of the pitch that Cracked coke, which makes the binding agent for the low-temperature coke.

The final temperature of the second coker is a little lower to keep than that of the first furnace for smoldering cracking, so that in the first furnace any volatile constituents still remaining in the low-temperature coke not in the second furnace can be driven out, which tears the briquettes and prevents their strength would. Is z. B. the final temperature of the oven I 50o to 52o0, so may in the oven II do not exceed the coking temperature 450 to 475 '.

Under these conditions, perfectly hard and firm coke briquettes are produced that neither soften nor disintegrate in the fire. By further increasing the final temperature of the smoldering cracking in furnace I can also be a perfect metallurgical coke getting produced.

The volatile products of coking are involved in the condensation of the Furnace.I passed and separated the finished gasoline, while the heavier components continue to participate in the cycle as return oil until they are completely converted into gasoline, gas and Cracked coke are broken down.

Even in the case of these modified procedures, other sources can be used Additional oil for the purpose of simultaneous cracking of the same together with the smoldering of Lignite and cracking of the resulting tars are introduced. Through this the amount of return oil increases and therefore the amount of heavier fractions also increases (Pitch) from the same, so that the necessary for the briquetting of the smoldering coke Amount of pitch can also be obtained if the pitch is from the return oil of the brown coal alone shouldn't be enough. The new procedure is therefore a special, the nature of the German lignite adapted process of a smoldering cracking the same, which in a division of the smoldering cracking in two operations or Processes. In the first, the lignite is subjected to a smoldering process and get a non-solid coke, in the second the one with the. heaviest parts of the return oil, smoldering coke briquetted a further coking and cracking subjected to the heavy proportions of the return oil. The return oil of the two processes or operations are separated into lighter and heavier components, and it the lighter ones, for example, in the first process turn into vapor, the heavier ones in the second process back in solid phase. By introducing the return oil from Additional oil from another source In solid, liquid or vapor phase in one or in both processes this additional oil can be used at atmospheric pressure can also be cracked in a cheap device and cheap cracking method at the same time, as well as the amount of pitch separated from your return oil to the need for binder for the briquetting of the smoldering coke of the brown coal.

The following drawing shows an example of an arrangement for the application of the process and means: 0I ladle tunnel furnace I for carbonization of pressed lignite and cracking of the volatile components of the return oil, OII ladle tunnel furnace II for coking of coke briquettes, which are made from the smoldering coke of furnace I and the liquid, pitch-like constituents of the return oil are produced and simultaneous cracking of the pitch vapors evaporating in the furnace, lt radiators in the two furnaces, a1, a2, a3, a4 entry of the heating gases into the radiators, b1, b2, b3, b4 exit. of the heating gases from the radiators, Circulation fan for circulating the smoldering and crackling vapors through the externally heated pipes of the radiators and the smoldering food in the pans. With a perforated bottom for the reception of the smoldering material, v feed gear wheel for uninterrupted feed of the pans through the furnace, cl, c2 escape of smoldering and crackling vapors from the furnace in a common condensation, KI first tube cooler for condensation, KI, fractionation column for condensation for separation of the heavy return oil from the light oil, KIII water pipe cooler for light oil, KIV gas scrubber, -g outlet for permanent gas, R0 heavy return oil in the sump of the cooler KI and KII, I_0 light oil, WO washing oil, P pump for return, auföl, dl, d2, d3, d4, d, distillation stills of a continuous distillation device for the division of the return oil into vapors (pitch), a, entry of the heating gases for the distillation, b5 exit of the heating gases from the distillation, r entry of the return oil into the distillation, ri, 121 y3, r4, r ,, exit of the vaporous components of the return oil from the distillation. into furnace I, y, exit of the pitch of the return oil3 from the distillation, e1 entry of the pans loaded with lignite pressings into furnace I, f1 exit of the smoldering coke from the presses from furnace I, e2 entry of the smoldering coke briquettes briquetted with the return oil pitch of the distillation into the furnace II, f2 exit of the coked solid coke briquettes from the furnace II.

The process is as follows: With ei step into the furnace I die with Pans filled with pressed lignite, wander through the furnace, are. smoldered and occur at f 1 as. not solid coke off.

The furnace is heated by three burners.

The heating gases for the drying room enter the radiator h at a1 of the drying room on and off at b1. The heating gases for the first half of the smoldering room enter the radiators at a2 and exit at b2. The heating gases for the second Half of the. Smoldering room, in which also. The cracking of smoldering vapors and the vaporous parts of the return oil, the distillation takes place, occur at a3 one and; at b3 off.

The heat transfer from the pipe walls of the radiators to the carbonized food takes place through the water vapor or smoldering vapors, which by means of the circulation fan put into a cycle through the pipes of the radiator and the smoldering food.

The last three chambers are cooled by a circuit of water vapor, which by means of three circulation fans through the Schwelgut and through Water sprinkled scrubber going on. The water vapor forms through transfer the warmth of the smoldering coke to the sprinkling water.

The smoldering and crashing vapors wander through constantly. Circulate the smoldering room in direct current with the smoldering good and exit at cl in the first: tube cooler KI, in which the heaviest oil condenses. The uncondensed vapors escape. the condenser KI into the fractionation column KI, in which the above aoo ° boiling constituents of the. Oil condense and combine in the sump with the heavy oils of the cooler KI and form the return oil, while the components boiling below 20o ° in the condenser KIIi get knocked down.

That. Return oil is pumped by means of the pump P through the continuous distillation dl, d2, d3, d4, d @, and here the lighter constituents are evaporated again, while the pitch residue flows off at r. The vapors return through pipes r1, r2, r3, y4 and r. back into furnace I and carry out this cycle until they are split into light oil, gas or coke.

The pitch flowing off at r, '- is mixed with the smoldering coke from furnace I. mixed and briquetted; the briquettes enter furnace II at e2, wander through same, are heated to about 4500 and leave the same as hard coke briquettes after cooling down in the cooling chambers at f 2.

The furnace II is heated by a furnace; the heating gases enter the radiators at a4 and exit at b4. The heat transfer and cooling takes place as with furnace I by means of a circulation fan.

The pitch contained in the briquettes partially evaporates and is cracked and leaves a coke residue in the briquettes, which acts as a binder of the same serves.

The vapors exit at c2 in the cooler KI, in the coolers KI and KI, the heavier return oil is separated, which together with the return oil of furnace I divided into pitch and vaporous components in the distillation will.

The cycle of pitch from the distillation in the furnace II and out the same in the condensation and distillation is repeated until this too Components of the oil are split into coke, light oil and gas. As end products The process becomes hard and solid coke briquettes, light oil and permanent valuable Get gas.

Claims (2)

PATENT CLAIMS: i. Process for smoldering, especially of lignite and similar bituminous fuels with simultaneous cracking of the here accruing tars and oils by separating the heavy, not fully cracked Shares in the condensation and return of the same to the operation as return oil so that this cycle from the smoldering and cracking process into the condensation and back repeatedly until the desired degree of cracking is reached, characterized in that the smoldering and cracking process is carried out in two steps is divided, in which in the first the brown coal is smoldered and smoldering coke is obtained is, in the second, the smoldering coke briquetted with the heaviest proportions of the return oil heated again to a slightly lower temperature than in the first step and is coked while: the return oil from the common condensation in two Fractions is separated, of which the first lighter in vapor phase into a of the work steps, the second heavier in solid phase in the second work step is returned, the cracked coke of the latter being the binder for the coked Briquettes form, making a solid, durable coke. is obtained. 2. Procedure. according to claim i, characterized in that with your return oil the brown coal also introduced other oils as additional oils into the cracking process and together with the return oil of the lignite can be cracked to the desired degree of Krak-'kungs @, the resulting cracked coke -of the additional oil, the additional binder for the Smoldering coke briquettes forms.