1. A process for separating an acidic contaminant and a light hydrocarbon of a feed stream that comprises said acidic contaminant and said light hydrocarbon to provide a high-purity hydrocarbon product and an acid stream product that is highly concentrated in said acidic contaminant, wherein said process comprises:
introducing said feed stream into a distillation fractionator for separating said acidic contaminant and said light hydrocarbon of said feed stream;
yielding from said distillation fractionator an overhead stream that is rich in said light hydrocarbon and a bottoms stream that is rich in said acidic contaminant and suitable as said acid stream product;
introducing said overhead stream into a membrane separator for separating said overhead stream into a permeate acidic contaminant stream that is rich in said acidic contaminant and a retentate hydrocarbon product stream that is rich in said light hydrocarbon and suitable as said high-purity hydrocarbon product;
introducing said permeate acidic contaminant stream into said distillation fractionators;
yielding a vapor overhead from said distillation fractionator;
passing said vapor overhead to an overhead condenser that provides for at least partially condensing said vapor overhead to thereby provide an at least partially condensed overhead;
separating said at least partially condensed overhead into a separated overhead vapor used as said overhead stream and a separated overhead liquid useful as a reflux to said distillation fractionators;
introducing said second permeate acidic contaminant stream to a low pressure inlet of a compressor;
introducing said first permeate acidic contaminant stream to an intermediate pressure inlet of said compressor; and
discharging said permeate acidic contaminant stream from said compressor at an increased pressure above the pressure of said first permeate acidic contaminant stream and said second permeate acidic contaminant stream, wherein said permeate acidic contaminant stream has an acidic contaminant concentration in the range of from 40 vol % to 99 vol %;
wherein said membrane separator comprises a plurality of membrane units arranged in series flow communication,
wherein said plurality of membrane units comprises a first membrane unit and a second membrane unit, which said first membrane unit has a first feed side with a first feed inlet, a first retentate outlet and a first permeate side, and said second membrane unit has a second feed side with a second feed inlet, a second retentate outlet and a second permeate side, wherein said first retentate outlet is operatively connected in fluid flow communication with said second feed inlet, and said retentate hydrocarbon product stream is yielded from said second retentate outlet and a first permeate acidic contaminant stream is yielded from said first permeate side of said first membrane unit and a second permeate acidic contaminant stream is yielded from said second permeate side of said second membrane unit;
further comprising:
introducing a cooled high-pressure feed stream, comprising said acidic contaminant and said light hydrocarbon, to a separator for separating said cooled high-pressure feed stream into a gas fraction and a liquid fraction;
expanding said liquid fraction to a lower pressure so as to provide a low pressure liquid fraction;
expanding said gas fraction to provide a low pressure vapor fraction; and
combining said low pressure liquid fraction and said low pressure vapor fraction to give said feed stream.
2. The process as recited in claim 1, further comprising:
prior to introducing said overhead stream into said membrane separator, heating said overhead stream by indirect heat exchange with said cooled high-pressure feed stream.
3. The process as recited in claim 2, wherein said light hydrocarbon is selected from the group of low molecular weight alkanes consisting of methane and ethane, wherein said feed stream contains from 20 vol % to 85 vol % of said acidic contaminant and from 15 vol % to 80 vol % of said light hydrocarbon, wherein said high-purity hydrocarbon product contains greater than 85 vol % of said light hydrocarbon, wherein said bottoms stream contains greater than 85 vol % of said acidic contaminant, and wherein said distillation fractionator is operated at a pressure in the range of from 200 psia to 900 psia.
4. The process as recited in claim 3, wherein said light hydrocarbon is methane, wherein said high-purity hydrocarbon product contains methane in the range of from 95 vol % to 99.9 vol %, and wherein said bottoms stream contains said acidic contaminant at a concentration in the range of from 90 vol % to 99.9 vol %.
5. The process as recited in claim 1, wherein said bottoms stream contains greater than 85 vol % of acidic contaminant, and wherein said process further comprises: introducing said bottoms stream into a subterranean reservoir for the purpose of enhancing oil recovery or gas production therefrom or to store said bottoms stream.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A media drive that exchanges a command and transfer data with a host by means of serial communications, said media drive comprising:
a temporary storage unit which temporarily stores transfer data read out from a medium;
a serial communication unit which transfers, to the host, the transfer data read out from the temporary storage unit;
a command execution controller which controls the execution of one or more commands so as to generate a transfer unnecessary period during which the command and the transfer data need not be exchanged with the host; and
a communication controller which brings the serial communication unit into a power save mode during the transfer unnecessary period;
wherein said command execution controller controls data transfer timing, at which data is transferred from the temporary storage unit to the host, so as to generate the transfer unnecessary period.
2. A media drive according to claim 1, wherein:
said command execution controller controls the data transfer timing on the basis of a medium transfer rate at which the transfer data is read out from the medium into the temporary storage unit, and a host transfer rate at which the transfer data is transferred from the temporary storage unit to the host.
3. A media drive according to claim 2, wherein:
when transferring transfer data stored in the medium to the host, if the host transfer rate is higher than the medium transfer rate, said command execution controller delays the data transfer timing by a specified period of time relative to the read timing at which the transfer data is read out from the medium into the temporary storage unit.
4. A media drive according to claim 3, wherein:
said specified period of time is a difference between a medium transfer time taken to read out the transfer data from the medium at the medium transfer rate and a host transfer time taken to transfer the transfer data in question to the host at the host transfer rate.
5. A media drive according to claim 2, wherein:
said medium has a plurality of zones; and
said medium has the medium transfer rates that differ from one another on a zone basis.
6. A media drive according to claim 2, wherein:
said medium has a plurality of the host transfer rates.
7. A media drive according to claim 2, wherein:
said medium has a plurality of zones;
said medium has the medium transfer rates that differ from one another on a zone basis; and
on the assumptions that a period of time required to transfer data to the host at the host transfer rate is a host transfer time, and that a period of time required to read out data into the temporary storage unit at a medium transfer rate corresponding to each of the zones is a medium transfer time, said command execution controller is configured to determine the read timing and the data transfer timing on the basis of the host transfer time and the medium transfer time corresponding to each of the zones.
8. A media drive according to claim 7, wherein:
said transfer data is formed of a plurality of sectors; and
said command execution controller calculates the number of read-ahead sectors from a read-ahead ratio, which is calculated on the basis of the host transfer time per sector and the medium transfer time per sector, and from the number of the sectors of the transfer data, and then adopts, as the data transfer timing, timing at which the transfer data, the size of which is equivalent to the number of read-ahead sectors, has been read out from the medium into the temporary storage unit.
9. A media drive according to claim 8, wherein:
said command execution controller refers to a table in which the read-ahead ratio is stored, and thereby calculates the number of read-ahead sectors.
10. A media drive that exchanges a command and transfer data with a host by means of serial communications, said media drive comprising:
a serial communication unit which is configured to receive, from the host, transfer data to be written to the medium;
a temporary storage unit which temporarily stores the transfer data received from the host;
a command execution controller which controls execution of one or more commands so as to generate a transfer unnecessary period during which the command and the transfer data need not be exchanged with the host; and
a communication controller which brings the serial communication unit into a power save mode during the transfer unnecessary period;
wherein said command execution controller controls a data transfer timing, at which the transfer data is transferred from the host, so as to generate the transfer unnecessary period.
11. A media drive according to claim 10, wherein:
said command execution controller controls the data transfer timing on the basis of a medium transfer rate at which data in the temporary storage unit is written to the medium, and a host transfer rate at which the transfer data is transferred from the host to the temporary storage unit.
12. A media drive according to claim 11, wherein:
if an amount of free space of the temporary storage unit is smaller than a size of the transfer data, and the host transfer rate is higher than the medium transfer rate, said command execution controller adopts, as the data transfer timing, timing at which the amount of free space of the temporary storage unit reaches a specified value or more.
13. A media drive according to claim 12, wherein:
said medium has a plurality of zones;
said medium has the medium transfer rates that differ from one another on a zone basis; and
on the assumptions that a period of time required to transfer data from the host at the host transfer rate is a host transfer time, and that a period of time required to write data to the medium at the medium transfer rate is a medium transfer time, said command execution controller determines the data transfer timing on the basis of the host transfer time, the medium transfer time corresponding to each of the zones, and the amount of free space of the temporary storage unit.
14. A media drive according to claim 13, wherein:
said transfer data is formed of a plurality of sectors; and
said command execution controller calculates the number of free sectors required for the temporary storage unit from a write ratio, which is calculated on the basis of the host transfer time per sector and the medium transfer time per sector, and from the number of sectors of the transfer data, and then determines the data transfer timing on the basis of the result of the calculation.
15. A media drive according to claim 14, wherein:
said command execution controller refers to a table in which the write ratio is stored, and thereby calculates the number of free sectors required for the temporary storage unit.
16. A media drive according to claim 13, wherein:
said command execution controller starts writing data of the temporary storage unit to the medium, and then adopts, as the data transfer timing, timing at which the amount of free space of the temporary storage unit reaches a level equivalent to the number of free sectors.
17. A media drive according to claim 11, wherein:
said medium has a plurality of host transfer rates.
18. A power saving method of a media drive that exchanges a command and transfer data with a host by means of serial communications performed by a serial communication circuit, said power saving method comprising:
when transferring, to the host, transfer data that has been read out from a medium into a temporary storage unit according to a read command, andor when receiving, from the host into a temporary storage unit, transfer data to be written to the medium according to a write command, controlling a data transfer timing at which the transfer data is transferred from the temporary storage unit to the host, or a data transfer timing at which the transfer data is transferred from the host to the temporary storage unit, so as to generate a transfer unnecessary period during which the command and the transfer data need not be exchanged through a transmission line; and
bringing the serial communication circuit into a power save mode during the transfer unnecessary period.
19. A power saving method of a media drive according to claim 18, wherein:
when executing a read command that transfers transfer data stored in the medium to the host, a read timing at which the transfer data is read out from the medium into the temporary storage unit, and the data transfer timing, are determined on the basis of the medium transfer time required to read out the transfer data from the medium, and a host transfer time required to transfer the transfer data in question from the temporary storage unit to the host.
20. A power saving method of a media drive according to claim 18, wherein:
when executing the write command, the data transfer timing is determined on the basis of a medium transfer rate at which the transfer data is written from the temporary storage unit to the medium, a host transfer rate at which the transfer data is transferred from the host to the temporary storage unit, and an amount of free space of the temporary storage unit.