Abstract: The present application relates to a process for producing acrylic acid.

Abstract: Provided is a process for producing acrylic acid, wherein the process comprises a first step and a second step in which a first absorbent is added to a reaction product of a bio-material and cooled to separate a first low-boiling-point material including acetaldehyde (ACHO) and a first high-boiling-point material including acrylic acid (AA). The process is capable of producing high-purity acrylic acid at high yield, and acetaldehyde is produced as by-product along with the reaction product of the bio-material. The process includes separating the acetaldehyde produced as by-product into a high-purity product at high yield.

Abstract: Provided is a process for producing acrylic acid, comprising (step 1) separating a first low-boiling-point material including acetaldehyde (ACHO) and a first high-boiling-point material including acrylic acid (AA) by adding a first absorbent to a reaction product of a bio-raw material and cooling the result; (step 2) separating a first incompressible material and a second low-boiling-point material including acetaldehyde (ACHO) by adding a second absorbent to the first low-boiling-point material including acetaldehyde (ACHO) and cooling the result; (step 3) heating the second low-boiling-point material including acetaldehyde (ACHO); (step 4) separating the heated second low-boiling-point material including acetaldehyde (ACHO) to acetaldehyde (ACHO) and the second absorbent and (step 5) producing acrylic acid by purifying the first high-boiling-point material including acrylic acid (AA).

Abstract: Provided is a process for producing acrylic acid, the process comprising: (step 1) preparing a first aqueous lactic acid solution by diluting a lactic acid raw material with water; (step 2) heat exchanging the first aqueous lactic acid solution to form a vaporized second lactic acid vapor and an unvaporized third aqueous lactic acid solution; (step 3) including the unvaporized third aqueous lactic acid solution in the aqueous solution of the step 1; and (step 4) supplying and absorbing an absorption liquid to the vaporized second lactic acid vapor to form an absorbed fourth aqueous lactic acid solution and an unabsorbed fifth lactic acid vapor, wherein the absorption liquid is water or an aqueous lactic acid solution.

Abstract: Provided is a process for producing acrylic acid, the process including supplying a lactic acid raw material to an upper portion of a distillation tower; supplying water to a lower portion of the distillation tower; supplying a first lactic acid vapor vaporized in the distillation tower to a reactor; and supplying a second aqueous lactic acid solution not vaporized in the distillation tower to a middle portion of the distillation tower. The process uses a distillation tower instead of a vaporizer, and is capable of preventing formation of a lactic acid oligomer during vaporization of an aqueous lactic acid solution, and, by introducing a concentrated lactic acid raw material to the distillation tower as it is, is capable of producing acrylic acid without a separate dilution device.

Abstract: Provided is a method for producing acrylic acid, the method including: preparing a reaction product containing acrylic acid by supplying lactic acid to a reactor and performing a dehydration reaction; supplying a reactor discharge stream containing the reaction product to a cooling tower and condensing the result to transfer a lower discharge stream including a condensate to an acrylic acid purification unit and supplying a non-condensate discharged as an upper discharge stream to a distillation tower; and, in the distillation tower, circulating the lower discharge stream containing acrylic acid to the cooling tower, and removing acetaldehyde from the upper discharge stream.

Abstract: Provided are an interworking procedure with an external network in a WLAN, a station supporting the interworking procedure, and a message format for the interworking procedure. In the interworking procedure, a non-AP station transmits a request message which includes an advertisement protocol ID set to a value indicating native query protocol and a native query information ID set to a value indicating emergency call number information. And the non-AP station receives from an access point (AP) a response message including zero or more emergency call numbers in response to the request message.

Abstract: If a hand-held terminal is connected to a single AP, the AP is provided from an administration server information of all the APs controlled by the administration server, transmits the information to the hand-held terminal, updates and stores it, and uses the updated and stored information of the APs to execute handoff. Basic lines and forwarding lines are disposed between all the APs and a private branch exchange, and a communication channel is formed using the basic lines to allow transferring the communication channel to the forwarding lines, thereby enabling to continuously perform a telephone communication session even if there is handoff during the telephone communication session using the hand-held terminal.

Abstract: Provided are an interworking procedure with an external network in a WLAN, a station supporting the interworking procedure, and a message format for the interworking procedure. In the interworking procedure, a non-AP station transmits a request message which includes an advertisement protocol ID set to a value indicating native query protocol and a native query information ID set to a value indicating emergency call number information. And the non-AP station receives from an access point (AP) a response message including zero or more emergency call numbers in response to the request message.

Abstract: If a hand-held terminal is connected to a single AP, the AP is provided from an administration server information of all the APs controlled by the administration server, transmits the information to the hand-held terminal, updates and stores it, and uses the updated and stored information of the APs to execute handoff. Basic lines and forwarding lines are disposed between all the APs and a private branch exchange, and a communication channel is formed using the basic lines to allow transferring the communication channel to the forwarding lines, thereby enabling to continuously perform a telephone communication session even if there is handoff during the telephone communication session using the hand-held terminal.