Patent Publication Number: US-8968557-B2

Title: Method and apparatus for converting coal to petroleum product

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present Application claims the benefit of U.S. Provisional Application No. 61/490,506, filed May 26, 2011, the contents of which are incorporated herein by reference. 
    
    
     FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     N/A 
     TECHNICAL FIELD 
     The invention relates to processing of coal. More particularly, the present invention relates to a process of converting coal into a liquid synthetic petroleum. 
     BACKGROUND OF THE INVENTION 
     Petroleum products such as oil, gasoline, diesel fuel, and the like, have become very expensive. Their prices will continue to rise as production levels fall. 
     The present invention will provide an apparatus and method for producing synthetic petroleum products from coal. The high quality synthetic petroleum contains little or no asphaltene component, and high levels of mid-range petroleum products commonly used for fuel or solvents. It will also produce gases containing methylcyclobutane and butane. Finally, the present invention will also produce a solid fuel or coke product that has low ash content, low sulfur, mercury, and chlorine content, with a high energy content. Such fuels are desirable in metallurgical production, and particularly in manufacturing silicon wafers, which requires low levels of contaminants. 
     The present invention is also environmentally favorable as it is specifically designed to eliminate or minimize use of fossil fuels and carbon dioxide or nitrous oxide emissions. Gas produced during the process can be used to produce energy to run the process or produce more liquid for engineered fuel products. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method of converting coal to a petroleum product. The method includes the steps of mixing the coal and water to form a mixture, and heating the mixture to approximately 500 degrees Fahrenheit. The method further includes separating the mixture in a first separator into a liquid stream of a water bearing minerals and a solid stream of coal, and transferring the coal from the first separator to a coking reactor wherein the temperature is raised to approximately 1,000 degrees Fahrenheit to drive off lighter fractions of the coal as a gas. The method also includes transferring the gas to a fourth separator to separate water and liquid petroleum product from the gas. 
     The present invention also provides an apparatus for converting coal to a petroleum product. The apparatus includes a mixing tank for mixing water and coal to form a mixture, and a stir tank for receiving and stirring the mixture. The apparatus also includes a heater for receiving and heating the mixture to a temperature of approximately 500 degrees Fahrenheit, and a first separator for receiving and separating the mixture into a liquid stream of a water bearing minerals and a solid stream of coal. The apparatus further includes a coking reactor for receiving the stream of coal and wherein the temperature is raised to approximately 1,000 degrees Fahrenheit to drive off lighter fractions of the coal as a gas, and a fourth separator for receiving the gas and separating water and liquid petroleum product from the gas. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings in which: 
         FIG. 1  is a schematic drawing of a process and apparatus in accord with an embodiment of the present invention; 
         FIG. 2  is a schematic drawing of a water in tank in accord with an embodiment of the present invention; 
         FIG. 3  is a schematic drawing of a mixer and an equalization tank in accord with an embodiment of the present invention; 
         FIG. 4  is a schematic drawing of a heat exchanger in accord with an embodiment of the present invention; 
         FIG. 5  is a schematic drawing of a stir tank in accord with an embodiment of the present invention; 
         FIG. 6  is a schematic drawing of a first separator in accord with an embodiment of the present invention; 
         FIG. 7  is a schematic drawing of a heat exchanger and process heater in accord with an embodiment of the present invention; 
         FIG. 8  is a schematic drawing of a coking reactor in accord with an embodiment of the present invention; 
         FIG. 9  is a schematic drawing of a mineral vitrification system in accord with an embodiment of the present invention; 
         FIG. 10  is a schematic drawing of a third separator in accord with an embodiment of the present invention; and 
         FIG. 11  is a schematic drawing of a condenser and a separator in accord with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated. 
     Referring to  FIG. 1 , a process  10  and apparatus  12  is schematically shown for converting coal into a liquid synthetic petroleum product in accord with an embodiment of the present invention. More detailed FIGS. and descriptions of the process and apparatus are included below. 
     Water in tank  14  and coal  16  are transferred to a mixing tank  18 . In the mixing tank  18 , the water  14  and coal  16  are mixed to form a mixture  19  thereof. The mixture of water  14  and coal  16  is transferred through a first heat exchanger  22  to a second heat exchanger  45 , then through a process heater  84  and into a stir tank  24 . The mixture in the stir tank  24  is heated to approximately 250 degrees Celsius or 500 degrees Fahrenheit. The heated mixture remains in the stir tank  24  for approximately one to two hours. 
     After that time, the heated coal  16  and water  14  mixture  19 , with its entrained minerals is transferred to a first separator  28 . In the first separator  28 , the mixture  19  is separated into a liquid stream  30  of water and minerals, and a solid stream  32  of coal. 
     The liquid stream  30  of water and minerals is sent through the first heat exchanger  22  and gives up its heat to the incoming mixture  19  of water  14  and coal  16  from the mixing tank  18 . The solid coal  32  taken from the bottom of the first separator  28  is transferred to a second separator  33 . In second separator  33 , water is removed as a vapor  36  and the water vapor  36  and other gases then travel through a fifth heat exchanger  35 . The water condensed from the vapor  36  in the fifth heat exchanger  35  is sent to the water  14 . The solid coal  32  is removed from the bottom of the second separator  33  and transferred to a coking reactor  42 . 
     In the coking reactor  42 , the temperature of the solid coal  32  is raised to approximately 1,000 degrees Fahrenheit to drive off the lighter fractions of the coal  32  as gas  43 . Additional water is removed as a vapor with the gas  43  and the water vapor and gas  43  travel to a second heat exchanger  45 . 
     The liquid stream  30 , after traveling through the first heat exchanger  22  is transferred to a third separator  34 . Here, the minerals  37  and water  38  are separated from the liquid stream  30 . The minerals  37  are transferred to a mineral vitrification system  40 . The water  38  from the liquid stream  30  is returned to the water  14  to be remixed with coal  16 . The water  38  may pass through a fourth heat exchanger  39  before being returned to the water  14 . The vitrification system  40  also produces mineral waste  41 . 
     From the coking reactor  42 , the cooked carbon  48  travels through a third heat exchanger  50  and into coke storage. The cooled gases  51  from the second heat exchanger  45  travel to a fourth separator  52 . Water is removed from the bottom of the fourth separator  52  and transferred to the water  14 . Liquid petroleum product is removed using a ware and transferred to a synthetic petroleum storage. Gases  56  are removed from the top of the fourth separator  52  and are transferred to a condenser  58 . The condensed liquid product  60  from the gases  56  are sent to storage. 
     The process and apparatus will now be described in greater detail referring to  FIGS. 2 through 11 . The water from the water in tank  14  is transferred through a first pump  62  to the mixing tank  18  through a first level control valve  64 . The level in the water in tank  14  is maintained by a differential pressure sensor  63 . Waste gas is removed from the water in tank  14  through the top of the tank, and is controlled by a pressure control valve  67  that receives pressure information from a pressure indicator  69 . Mineral sediment accumulating in the water in tank  14  is removed from the bottom thereof and transferred by pump  71  to second separator  33 . 
     The control valve  64 , and other instances in the FIGS. indicated by “To Computer/Control” may all be controlled from a centralized or any suitable control system for the process  10  and apparatus  12 . The mixing tank  18  includes a mixer  65 . From the first level control valve  64 , it flows through a first flow totalizer  66 . The coal  16  is transferred through a second flow control valve  68  and then through a second flow totalizer  70  into the mixing tank  18 . In the mixing tank  18 , the coal  16  and water  14  are thoroughly mixed. The temperature of the mixture  19  is measured using first thermocouple  72 . The pressure in the mixing tank  18  is maintained by a differential pressure sensor  73 . 
     The mixture  19  is transferred from the mixing tank  18  by a second pump  74  through a second thermocouple  76  which measures its temperature. The mixture  19  travels through a first heat exchanger  22  where it picks up waste heat from a first separator  28 . The mixture  19  then travels through a third thermocouple  78  to determine the output temperature of the mixture  19  leaving the first heat exchanger  22 . 
     The pre-heated mixture  19  then travels to a fourth thermocouple  80  where its temperature is determined as it enters second heat exchanger  45 . The mixture  19  material travels through a fourth thermocouple  82  and then into a process heater  84 . The process heater  84  heats the mixture  19  to the reaction temperature of approximately 250 degrees Celsius or 500 degrees Fahrenheit. The heated mixture  19  travels through a fifth thermocouple  86  as it leaves the process heater  84  to a first level control valve  88  that controls the level for the stir tank  24 . In the stir tank  24 , the mixture  19  is mixed by a mixer  90  and cooked for about 1-2 hours at around 250 C/500 F while the temperature in the stir tank  24  is measured using a fifth thermocouple  92 . The level of the stir tank  24  is maintained by a differential pressure sensor  94 . 
     The mixture  19  is transferred through a level control valve  96  to the first separator  28 . The mixture  19  with minerals entrained is separated in the first separator  28  by use of specific gravity and by phase. In the first separator  28 , the water and minerals are separated into a gas vapor stream, a liquid stream of water bearing minerals  30 , and a solid stream of coal  32 . The temperature in the first separator  28  is measured by sixth thermocouple  98  and pressure is maintained by use of a pressure indicator  100  and a pressure control valve  102 . The valve  102  allows the hot gas vapor mostly water and methane to leave the first separator  28  and travel through a seventh thermocouple  104  to the first heat exchanger  22  where it gives up its heat to the incoming mixture  19  of coal and water. 
     The hot liquid stream  30  of water and minerals is separated using a ware with a first level controller  106 . The water travels through a second level control valve  108  and through seventh thermocouple  104  into the first heat exchanger  22 . The water  30  is then transferred to the third separator  34 . The temperature of the water is measured by thermocouple  109 . The solid coal  32  from the bottom of first separator  28  is transferred using a differential pressure separator  112  that controls a third level control valve  114  to a transfer auger  116 . The solid coal material  32  is then transferred into second separator  33  where more water is removed as a vapor. The water vapor then travels through the fifth heat exchanger  35 , and then to level control valve  118 . 
     The solid coal  32  is removed from the bottom of the second separator  33  and transferred into a heater  120  where it is heated in the coking reactor  42 . The temperature of the coking reactor is measured by thermocouple  121 . The mineral water  30  from first separator and then through the first heat exchanger  22  and to the third separator  34  now cooled by the first heat exchanger  22  enters the third separator  34 . The level of the minerals that are separated is controlled using a differential pressure sensor  122  controls a screw auger  124  that transfers the separate minerals to heater  126  that is part of the mineral vitrification system  40 . The cooled water from the fifth heat exchanger  35  is transferred to the water in tank  14 . The cooling water for the first heat exchanger  22  is provided by a radiator cooler  162 . The temperature exiting the radiating cooler is measured by seventeenth thermocouple  196 . Pump  197  transfers the water from the third heat exchanger  50  through thermocouple  198  where the temperature is measured before entering the radiator cooler  162 . A stream of this cooled water is transferred to the fifth heat exchanger  35  to provide cooling for the water vapor leaving second separator  33 . The coal solids  32  are now transferred to heater  120  where the coal is heated to approximately 1,000 degrees Fahrenheit to drive off the lighter fractions of the coal as gas. The temperature is controlled by twelfth thermocouple  166  that sends information to a temperature control module  168 . The heated coal now enters the coking reactor  42  where the gases are removed from the coking reactor  42  a pressure control valve  170  that receives information from a pressure indicator  172 . 
     The temperature of the third separator  34  is measured using an eighth thermocouple  128 . The water level in the third separator  34  is controlled by a ware using a level controller  130  and the water travelling through a third pump  132  through level control valve  118  and into the water in tank  14 . 
     The minerals from the third separator  34  are transferred to high temperature heater  126  that is either gas fired or electric heated. This heater  126  heats the minerals  37  to around 1,000 degrees Fahrenheit. The temperature on the heater  126  is controlled by a temperature control module  136  that receives temperature measurements from a ninth thermocouple  138 . The heated minerals  37  are transferred into a vitrifier  47 , where any gas and water vapor are removed. The removal of the gas or water vapor is controlled by a pressure control valve  140  that receives information from a pressure indicator  142 . The gas temperature is measured by a tenth thermocouple  144 . The gas then travels through the fourth heat exchanger  39 . The temperature of the cooled output water is measured by an eleventh thermocouple  146 , and the cooled water is sent to a vitrification water storage tank  147  for storage and then is sent back to the water in tank  14  by a pump  148 . The level in the storage tank  147  is maintained by differential pressure sensor  149 . 
     The hot minerals are removed from the vitrifier  47  by weight using a differential pressure sensor  150  and a level controller  152 . The hot minerals are transferred through a rotary valve  154  and into a screw conveyor  156  that has a cooling jacket. The cooled minerals are then sent to a mineral storage tank. 
     The hydrocarbon gas that is being formed off of the coking reactor  42  is transferred to the second heat exchanger  45 . The cooled gases travel to the fourth separator  52 . The temperature of the cooled gases is measured by thermocouple  157 . There the water is removed off of the bottom of the fourth separator  52  and transferred to the water in tank  14  by a pump  174 . The liquid petroleum product is removed using a ware and transferred to a synthetic petroleum storage by a pump  178 . Gases are removed off of the top of the fourth separator  52  by a pump  180  that is controlled by pressure control module  182 . Pressure control module  182  receives information from a pressure indicator  184 . The temperature of the fourth separator  52  is measured by thermocouple  185 . Gas is transferred through a thirteenth thermocouple  186  where the temperature is recorded as it enters condenser  58 . The output temperature of condenser  58  is also by a fourteenth thermocouple  188 , and liquid condensed from the gas  60  is sent to storage. 
     The carbon coke  48  being formed in the coking reactor  42  is transferred through a second rotary valve  190  past a fifteenth thermocouple  192  where the temperature of the incoming coke material is measured as it enters the third heat exchanger  50 , which can be an augured cooler. The level in the coking reactor  42  is controlled by the weight of the coal as measured by a level controller  193 . The cooled coke is then transferred past a sixteenth thermocouple  194  where the outgoing coke material temperature is measured and then transferred into storage. The gases coming off of coking reactor  42  are transferred to the second heat exchanger  45  where the heat is given off to the incoming coal and water going to the process heater  84 . 
     While the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying Claims.