RECIRCULATING BIOREACTOR EXHAUST SYSTEM

1 . A bioreactor exhaust recirculating apparatus comprising:

a. a bioreactor;

b. a condenser capable of removing a gaseous element from an exhaust gas of the bioreactor; and

c. a return line extending from the condenser to the bioreactor capable of returning the remaining exhaust gas to the bioreactor.

2 . The apparatus of claim 1 , wherein the gaseous element to be removed is carbon dioxide.

3 . The apparatus of claim 1 , further comprising a cooling element capable of maintaining the temperature of condenser below the freezing temperature of the gaseous element to be removed.

4 . The apparatus of claim 3 , wherein the cooling element is a refrigeration unit.

5 . The apparatus of claim 3 , wherein the cooling element comprises a liquefied gas in contact with the condenser.

6 . The apparatus of claim 3 , wherein the cooling element is capable of maintaining the temperature of condenser below −75° C.

7 . The apparatus of claim 5 , wherein the liquefied gas is selected from nitrogen and oxygen.

8 . The apparatus of claim 1 , further comprising culture media in the bioreactor, wherein the return line end is placed below the surface of culture media in the bioreactor.

9 . The apparatus of claim 1 , further comprising a heating element capable of heating the exhaust gas return to approximately the temperature of the culture media in the bioreactor.

10 . The apparatus of claim 1 , further comprising a filter capable of sterilizing the exhaust gas.

11 . A bioreactor exhaust recirculating apparatus comprising:

a. a bioreactor;

b. a plurality of condenser elements capable of removing a gaseous element from an exhaust gas of the bioreactor; and

c. a return line from the condenser capable of returning the remaining exhaust gas to the bioreactor.

12 . The apparatus of claim 11 , wherein a plurality of condensers are arranged in parallel or in a series.

13 . The apparatus of claim 12 , wherein the apparatus comprises two condensers in parallel.

14 . The apparatus of claim 11 , further comprising a cooling element capable of maintaining the temperature of condenser below −75° C., wherein the gaseous element is carbon dioxide.

15 . The apparatus of claim 14 , further comprising a carbon dioxide sensor placed in the path of the exhaust gas.

16 . A bioreactor exhaust recirculating apparatus comprising:

a. a bioreactor; and

b. an exhaust recirculating apparatus comprised of three connected portions, wherein a first portion is in fluid connection with a second portion, and the second portion is in fluid connection with a third portion;

i. wherein the first portion comprises: (1) an exhaust tube connected to the bioreactor having a one-way valve inside the exhaust tube directed away from the bioreactor and (2) a valve capable of closing the connection between the first portion and the second portion;

ii. wherein the second portion comprises: (1) a condenser comprising a coiled tube wrapped by a second tube external to the flow of exhaust gas, wherein the second tube is capable of delivering a cooling agent capable of freezing the gaseous element or a warming agent capable of thawing the frozen gaseous element and wherein the condenser is in fluid connection with the first portion and third portion; (2) an inlet port and an outlet port capable of introducing a gas into the condenser wherein each port comprises a valve for opening or closing the port, each port optionally having a filter capable of sterilizing the gas being introduced or exiting the condenser, and (3) a valve for closing the connection between the second portion and the third portion; and

iii. wherein the third portion comprises: (1) a return tube extending from the condenser to the bioreactor capable of returning the remaining exhaust gas to the bioreactor; (2) a heater element, (3) a sensor, and (4) a one-way valve inside the return tube directed toward the bioreactor.

17 . The apparatus of claim 1 or claim 11 or claim 16 , further comprising one or more control elements capable of automated opening and closing of valves and following programmed instructions to direct the flow of exhaust gas.

18 . A method of removing a gaseous element from the exhaust gas of a bioreactor comprising;

a. providing a bioreactor;

b. attaching to the bioreactor a recirculating bioreactor exhaust apparatus comprising:

i. a first portion of a recirculating bioreactor exhaust apparatus comprising: (1) an exhaust tube connected to the bioreactor having a one-way valve inside the tube directed away from the bioreactor and (2) a valve capable of closing the connection between the first portion and a second portion;

ii. a second portion of a recirculating bioreactor exhaust apparatus comprising: (1) a condenser capable of removing a gaseous element from an exhaust gas of the bioreactor; (2) a cooling element external to the condenser capable of maintaining the temperature of condenser below the freezing temperature of the gaseous element to be removed; (3) an inlet port below the condenser and an outlet port above the condenser for removing the frozen gaseous element, each port comprising a valve for opening and closing the port; and (4) a valve for closing the connection between the second portion and a third portion;

iii. a third portion of a recirculating bioreactor exhaust apparatus comprising: (1) a return line from the condenser to the bioreactor capable of returning the remaining exhaust gas to the bioreactor; (2) a heating element; (3) a sensor; and (4) a one-way valve inside the return tube directed toward the bioreactor;

c. adding a culture medium to the bioreactor;

d. adding a cell to the culture medium;

e. operating the bioreactor at a temperature suitable for growth of the cell culture;

f. allowing the exhaust gas to pass through the condenser;

g. cooling the condenser to a temperature capable of freezing the gaseous element to be removed;

h. heating the remaining exhaust gas leaving the condenser to the temperature of the bioreactor;

i. returning the remaining exhaust gas to the bioreactor;

j. monitoring the sensor in the third portion for the presence of the gaseous element being removed by the condenser;

k. when the level of gaseous element being removed by the condenser exceeds a predetermined value, the condenser is cleared to remove the gaseous element from the condenser.

19 . The method of claim 18 , wherein step (k) comprises the steps of:

a. closing the valve between the first portion and the second portion;

b. closing the valve between the second portion and the third portion;

c. attaching a filter to the inlet port of the second portion and opening its valve;

d. optionally attaching a filter to the outlet port of the second portion and opening its valve;

e. introducing a warming agent such as compressed air;

f. optionally measuring the gas leaving the outlet port for the gaseous element;

g. closing the inlet and outlet ports;

h. opening the valve between the first portion and the second portion;

i. opening the valve between the second portion and the third portion;

j. resuming the flow of exhaust gas from the bioreactor through the recirculating bioreactor exhaust apparatus.

20 . The method of claim 18 , wherein a second condenser is added to the recirculating bioreactor exhaust apparatus.

21 . The method of claim 20 , wherein step (k) comprises the steps of:

a. closing the valve between the first portion and the first condenser;

b. closing the valve between the first condenser and the third portion;

c. opening the valve between the first portion and the second condenser;

d. opening the valve between the second condenser and the third portion;

e. attaching a filter to the inlet port of the first condenser and opening its valve;

f. optionally attaching a filter to the outlet port of the first condenser and opening its valve;

g. introducing a warming agent such as compressed air;

h. optionally measuring the gas leaving the outlet port for the gaseous element;

i. closing the inlet and outlet ports of the first condenser;

j. opening the valve between the first portion and the first condenser;

k. opening the valve between the first condenser and the third portion;

l. closing the valve between the first portion and the second condenser;

m. closing the valve between the second condenser and the third portion;

n. attaching a filter to the inlet port of the second condenser and opening its valve;

o. optionally attaching a filter to the outlet port of the second condenser and opening its valve;

p. introducing a warming agent such as compressed air;

q. optionally measuring the gas leaving the outlet port for the gaseous element;

r. closing the inlet and outlet ports to the second condenser; and

s. repeating steps a-r.