Patent Application
20230103843
A system as known in the art is presented in
Cold feed air stream 105 is introduced into HP column 201. Cool boosted feed air stream 110 is introduced into first heat exchanger 203, wherein it exchanges heat with liquid oxygen stream 214, thereby producing at least partially condensed cold boosted feed air stream 204. Second heat exchanger 203 vaporizes liquid oxygen stream 214 against at least partially condensing air stream 110 at a pressure provided by first booster air compressor 106. The pressure of liquid oxygen stream 214 vaporized in second heat exchanger 203 is boosted by static head by positioning second heat exchanger 203 at a lower elevation than the liquid oxygen supply sump 217 of LP column 202. Alternatively, the pressure of liquid oxygen stream 214 may be boosted by a liquid oxygen pump. (not shown). For this process the gaseous oxygen product pressure is in the range of 1.1 bara to 3 bara and preferably in the range of 1.2 bara and 2 bara.
Cold boosted feed air stream 204 may be split into two portions, primary cold boosted feed air stream 205 and secondary cold boosted fed air stream 206. Primary cold boosted feed air stream 205 is introduced into HP column 201. Secondary cold boosted fed air stream 206 is introduced into LP column 202.
In one embodiment, as illustrated in
LP column 202 produces at least three output streams, liquid oxygen stream 214, cold waste nitrogen stream 215, and cold gaseous nitrogen stream 216. Liquid oxygen stream 214 passes through first heat exchanger 203, thereby producing gaseous oxygen product stream 115. Gaseous oxygen product stream 115 may have a pressure between 1.1 and 3 bara, preferably between 1.2 and 2 bara. Cold waste nitrogen stream 215 passes through second heat exchanger 207, thereby producing waste nitrogen stream 113. Cold gaseous nitrogen stream 216 passes through second heat exchanger 207, thereby producing gaseous nitrogen product stream 111.
Gaseous nitrogen product stream 111 is introduced into main heat exchanger 104, thereby producing warmed gaseous nitrogen product 112. Waste nitrogen product stream 113 is introduced into main heat exchanger 104, thereby producing warmed waste nitrogen product 114. Gaseous oxygen product stream 115 is introduced into main heat exchanger 104, thereby producing warmed gaseous oxygen product 116.
HP gaseous nitrogen stream 117 is introduced into main heat exchanger 104, thereby producing warmed HP gaseous nitrogen stream 118. Warmed HP gaseous nitrogen stream 118 is then introduced into turboexpander 119, thereby producing LP gaseous nitrogen stream 120. Turboexpander 119 may have an inlet pressure of between 4 and 10 bara, and an outlet pressure of between atmospheric pressure and 2 bara. Turboexpander 119 may have a loading or braking device to act as a sink for the expander's energy. As a brake, turboexpander 119 may utilize a booster, a generator or oil (not shown). Typically, a booster brake is preferred to put as much energy back into the system as possible, with less overall losses and equipment cost. LP gaseous nitrogen stream 120 is then introduced into main heat exchanger 104 thereby producing warmed LP gaseous nitrogen stream 121.
In another embodiment, as illustrated in
LP column 202 produces at least two output streams, liquid oxygen stream 214, cold waste nitrogen stream 215, Liquid oxygen stream 214 passes through first heat exchanger 203, thereby producing gaseous oxygen product stream 115. Gaseous oxygen product stream 115 may have a pressure between 1.1 and 3 bara, preferably between 1.2 and 2 bara. Cold waste nitrogen stream 215 passes through second heat exchanger 207, thereby producing waste nitrogen stream 113. Waste nitrogen product stream 113 is introduced into main heat exchanger 104, thereby producing warmed waste nitrogen product 114. Gaseous oxygen product stream 115 is introduced into main heat exchanger 104, thereby producing warmed gaseous oxygen product 116.
HP gaseous nitrogen stream 117 is introduced into main heat exchanger 104, thereby producing warmed HP gaseous nitrogen stream 118. Warmed HP gaseous nitrogen stream 118 is then introduced into turboexpander 119, thereby producing LP gaseous nitrogen stream 120. Turboexpander 119 may have an inlet pressure of between 4 and 10 bara, and an outlet pressure of between atmospheric pressure and 2 bara, Turboexpander 119 may have a loading or braking device to act as a sink for the expander's energy. As a brake, turboexpander 119 may utilize a booster, a generator or oil (not shown). Typically, a booster brake is preferred to put as much energy back into the system as possible, with less overall losses and equipment cost. LP gaseous nitrogen stream 120 is then introduced into main heat exchanger 104 thereby producing warmed LP gaseous nitrogen stream 121.
An air separation process having a first booster air compressor comprising a first outlet stream and a second booster air compressor comprising a second outlet stream, Wherein the first booster air compressor and the second booster air compressor are in parallel, and the second booster air compressor is driven by a nitrogen turboexpander. The first outlet stream and/or the second outlet stream may be at least partially condensed by heat exchange with a vaporizing low pressure oxygen stream, and the low-pressure gaseous oxygen pressure is in the range of 1.1 bara to 3.1 bara.
For a further understanding of the nature and objects for the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements are given the same or analogous reference numbers and wherein;
101=feed air stream
102=main feed air stream (first portion)
103=secondary feed air stream (second portion)
104=main heat exchanger
105=cold feed air stream
106=first booster air compressor
107=boosted air feed stream
108=aftercooler
109=cooled compressed air feed stream
110=cool boosted feed air stream
111=gaseous nitrogen product
112=warmed gaseous nitrogen product
113=waste nitrogen
114=warmed waste nitrogen
115=gaseous oxygen product
116=warmed gaseous oxygen product
117=HP gaseous nitrogen
118=warmed HP gaseous nitrogen
119=turboexpander
120=LP gaseous nitrogen
121=warmed LP gaseous nitrogen
201=HP column
202=LP column
203=first heat exchanger
204=cold boosted feed air stream
205=primary cold boosted feed air stream (first portion)
206=secondary cold boosted feed air stream (second portion)
207=second heat exchanger
208=rich liquid (rich in oxygen)
209=cold rich liquid
210=first (nitrogen) reflux stream
211=cold first reflux stream
212=second (nitrogen) reflux stream
213=cold second reflux stream
214=gaseous oxygen stream
215=cold waste nitrogen stream
216=cold gaseous nitrogen
301=tertiary feed air stream (third portion)
302=second booster air compressor
303=drive connection (between turboexpander and secondary feed air compressor)
304=compressed tertiary feed air stream
305=combined boosted feed air stream
Illustrative embodiments of the invention are described below. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims,
It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another, Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
Turning to
Boosted air feed stream 107 is combined with compressed tertiary feed air stream 304, thereby producing combined boosted feed air stream 305. Thus, first booster air compressor 106 and second booster air compressor 302 are in parallel, having the same, or approximately the same, inlet pressures and outlet pressures. The term “the same, or approximately the same” means as close to the same as is reasonable given the conditions. As used herein, the term “the same, or approximately the same” is defined as being within 5 bara, preferably within 1 bara of each other.
First booster air compressor 106, may control this common discharge pressure, in order to fully vaporize the oxygen stream. The load on turboexpander 119 will determine the relative flowrates between first booster air compressor 106 and second booster air compressor 302. Combined boosted feed air stream 305 is introduced into aftercooler 108, thereby producing cooled compressed air feed stream 109. Cooled compressed air feed stream 109 is then introduced into main heat exchanger 104 wherein it is cooled, thereby producing cool boosted feed air stream 110.
Cold feed air stream 105 is introduced into HP column 201. Cool boosted feed air stream 110 is introduced into first heat exchanger 203, wherein it exchanges heat with liquid oxygen stream 214, thereby producing at least partially condensed cold boosted feed air stream 204. Cold boosted feed air stream 204 is split into two portions, primary cold boosted feed air stream 205 and secondary cold boosted fed air stream 206. Primary cold boosted feed air stream 205 is introduced into HP column 201. Secondary cold boosted fed air stream 206 is introduced into LP column 202.
In one embodiment, as illustrated in
LP column 202 produces at least three output streams, liquid oxygen stream 214, cold waste nitrogen stream 215, and cold gaseous nitrogen stream 216. Liquid oxygen stream 214 passes through first heat exchanger 203, thereby producing gaseous oxygen product stream 115. Gaseous oxygen product stream 115 may have a pressure between 1.1 and 3 bara, preferably between 1.2 and 2 bara. Cold waste nitrogen stream 215 passes through second heat exchanger 207, thereby producing waste nitrogen stream 113. Cold gaseous nitrogen stream 216 passes through second heat exchanger 207, thereby producing gaseous nitrogen product stream 111.
Gaseous nitrogen product stream 111 is introduced into main heat exchanger 104, thereby producing warmed gaseous nitrogen product 112. Waste nitrogen product stream 113 is introduced into main heat exchanger 104, thereby producing warmed waste nitrogen product 114. Gaseous oxygen product stream 115 is introduced into main heat exchanger 104, thereby producing warmed gaseous oxygen product 116.
HP gaseous nitrogen stream 117 is introduced into main heat exchanger 104, thereby producing warmed HP gaseous nitrogen stream 118. Warmed HP gaseous nitrogen stream 118 is then introduced into turboexpander 119, thereby producing LP gaseous nitrogen stream 120. LP gaseous nitrogen stream 120 is then introduced into main heat exchanger 104 thereby producing warmed LP gaseous nitrogen stream 121. Second booster air compressor 302 and turboexpander 119 may be connected with a common drive 303.
In another embodiment, as illustrated in
LP column 202 produces at least two output streams, liquid oxygen stream 214, cold waste nitrogen stream 215, Liquid oxygen stream 214 passes through first heat exchanger 203, thereby producing gaseous oxygen product stream 115. Gaseous oxygen product stream 115 may have a pressure between 1.1 and 3 bara, preferably between 1.2 and 2 bara. Cold waste nitrogen stream 215 passes through second heat exchanger 207, thereby producing waste nitrogen stream 113. Waste nitrogen product stream 113 is introduced into main heat exchanger 104, thereby producing warmed waste nitrogen product 114. Gaseous oxygen product stream 115 is introduced into main heat exchanger 104, thereby producing warmed gaseous oxygen product 116.
HP gaseous nitrogen stream 117 is introduced into main heat exchanger 104, thereby producing warmed HP gaseous nitrogen stream 118. Warmed HP gaseous nitrogen stream 118 is then introduced into turboexpander 119, thereby producing LP gaseous nitrogen stream 120. Turboexpander 119 may have an inlet pressure of between 4 and 10 bara, and an outlet pressure of between atmospheric pressure and 2 bara. Turboexpander 119 may have a loading or braking device to act as a sink for the expander's energy. As a brake, turboexpander 119 may utilize a booster, a generator or oil (not shown). Typically, a booster brake is preferred to put as much energy back into the system as possible, with less overall losses and equipment cost. LP gaseous nitrogen stream 120 is then introduced into main heat exchanger 104 thereby producing warmed LP gaseous nitrogen stream 121. Second booster air compressor 302 and turboexpander 119 may be connected with a common drive 303.
It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims, Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above.
