Liquid natural gas processing with hydrogen production

Abstract

Devices, systems, and methods for liquefied natural gas production facilities are disclosed herein. A liquefied natural gas (LNG) production facility includes a liquefaction unit that condenses natural gas vapor into liquefied natural gas; an electric-driven compression system for the refrigerant(s) in power to the liquefaction unit; and a sequestration compression unit configured to compress and convey at least one CO2-rich stream towards a sequestration site, thereby reducing the overall emissions from the LNG facility.

The invention is claimed as follows: 
     
         1 . A liquefied natural gas (LNG) facility comprising:
 an acid gas removal unit configured to process a feed natural gas and generate an acid gas stream, a flash gas stream, and a purified natural gas stream, the LNG facility being configured to direct the acid gas stream to a sequestration compression unit;   a liquefaction unit configured to condense a natural gas stream into an LNG; and   the sequestration compression unit configured to compress a CO2-rich stream and convey the compressed CO2-rich stream towards a sequestration site, the CO2-rich stream comprising the acid gas stream.   
     
     
         2 . The LNG facility of  claim 1 , wherein the CO2-rich stream further comprises the flash gas stream. 
     
     
         3 . The LNG facility of  claim 1 , wherein the sequestration compression unit comprises a compressor selected from the group consisting of an electric-driven compressor, and electrically driven refrigerant compressor, and combinations thereof. 
     
     
         4 . The LNG facility of  claim 1 , wherein the sequestration site is selected from the group consisting of
 an underground geological formation comprising an at least partially depleted hydrocarbon reservoir,   a region on top of a seabed and located at a depth greater than about 3.0 kilometers below a sea level,   a region below a seabed, and   combinations thereof.   
     
     
         5 . The LNG facility of  claim 1 , wherein the acid gas removal unit comprises at least one of (i) an amine absorber and a liquid amine absorbent for absorbing CO2 from the feed natural gas or (ii) an ammonia absorbent for absorbing CO2 from the feed natural gas in a chilled ammonia process. 
     
     
         6 . The LNG facility of  claim 1  further comprising a dehydration unit configured to dry the purified natural gas stream from the acid gas removal unit. 
     
     
         7 . The LNG facility of  claim 6  further comprising:
 a heavies removal unit configured to condense the dried purified natural gas stream from the dehydration unit and produce a liquid condensate product and a vapor product; and 
 a condensation storage tank configured to receive the liquid condensate product from the heavies removal unit and vent a first boil off gas (BOG). 
 
     
     
         8 . The LNG facility of  claim 7 , wherein the LNG facility is configured to direct the first BOG to at least one of the sequestration compression unit or the liquefaction unit. 
     
     
         9 . The LNG facility of  claim 1  further comprising an LNG storage tank configured to receive and store the LNG from the liquefaction unit and vent a second BOG. 
     
     
         10 . The LNG facility of  claim 9 , wherein the LNG facility is configured to direct the second BOG to at least one of the sequestration compression unit or the liquefaction unit. 
     
     
         11 . The LNG facility of  claim 10  further comprising an LNG loading facility configured to receive the LNG from the LNG storage tank and transfer the LNG to a marine vessel comprising a marine LNG storage tank, the LNG loading facility further configured to vent a third BOG. 
     
     
         12 . The LNG facility of  claim 11 , wherein the LNG facility is configured to direct the third BOG to at least one of the sequestration compression unit or the liquefaction unit. 
     
     
         13 . A process of producing a liquefied natural gas (LNG) in an LNG facility comprising an acid gas removal unit configured to process a feed natural gas and generate an acid gas stream, a flash gas stream, and a purified natural gas stream, the LNG facility being configured to direct the acid gas stream to a sequestration compression unit; a liquefaction unit configured to condense a natural gas stream into the LNG; and the sequestration compression unit configured to compress a CO2-rich stream and convey the compressed CO2-rich stream towards a sequestration site, the CO2-rich stream comprising the acid gas stream, the process comprising:
 processing the feed natural gas and generating the acid gas stream, the flash gas stream, and the purified natural gas stream by the acid gas removal unit;   condensing the natural gas stream into the LNG by the liquefaction unit; and   compressing the CO2-rich stream and conveying the compressed CO2-rich stream towards the sequestration site by the sequestration compression unit.   
     
     
         14 . The process of  claim 13 , wherein the CO2-rich stream further comprises the flash gas stream. 
     
     
         15 . The process of  claim 13 , wherein the sequestration compression unit comprises a compressor selected from the group consisting of an electric-driven compressor, and electrically driven refrigerant compressor, and combinations thereof. 
     
     
         16 . The process of  claim 13 , wherein the sequestration site is selected from the group consisting of
 an underground geological formation comprising an at least partially depleted hydrocarbon reservoir,   a region on top of a seabed and located at a depth greater than about 3.0 kilometers below a sea level,   a region below a seabed, and   combinations thereof.   
     
     
         17 . The process of  claim 13 , wherein the acid gas removal unit comprises at least one of (i) an amine absorber and a liquid amine absorbent for absorbing CO2 from the feed natural gas or (ii) an ammonia absorbent for absorbing CO2 from the feed natural gas in a chilled ammonia process. 
     
     
         18 . The process of  claim 13 , wherein the LNG facility further comprises a dehydration unit configured to dry the purified natural gas stream from the acid gas removal unit, and the process further comprises drying the purified natural gas stream from the acid gas removal unit by the dehydration unit. 
     
     
         19 . The process of  claim 18 , wherein the LNG facility further comprises
 a heavies removal unit configured to condense the dried purified natural gas stream from the dehydration unit and produce a liquid condensate product and a vapor product, and   a condensation storage tank configured to receive the liquid condensate product from the heavies removal unit and vent a first boil off gas (BOG); and   the process further comprises   condensing the dried purified natural gas stream from the dehydration unit and producing the liquid condensate product and the vapor product by the heavies removal unit, and   receiving the liquid condensate product from the heavies removal unit and venting the first BOG by the condensation storage tank.   
     
     
         20 . The process of  claim 18  further comprising directing the first BOG to at least one of the sequestration compression unit or the liquefaction unit. 
     
     
         21 . The process of  claim 13 , wherein the LNG facility further comprises an LNG storage tank configured to receive and store the LNG from the liquefaction unit and vent a second BOG, and the process further comprises receiving and storing the LNG from the liquefaction unit and venting the second BOG by the LNG storage tank. 
     
     
         22 . The process of  claim 21  further comprising directing the second BOG to at least one of the sequestration compression unit or the liquefaction unit. 
     
     
         23 . The process of  claim 21 , wherein the LNG facility further comprises an LNG loading facility configured to receive the LNG from the LNG storage tank and transfer the LNG to a marine vessel comprising a marine LNG storage tank, the LNG loading facility further configured to vent a third BOG; and
 the process further comprises receiving the LNG from the LNG storage tank, transferring the LNG to the marine vessel, and venting the third BOG, by the LNG loading facility.   
     
     
         24 . The process of  claim 23  further comprising directing the third BOG to at least one of the sequestration compression unit or the liquefaction unit.