Abstract: An internal combustion engine inducts no air from outside atmosphere and it discharges no gas into outside environment. The engine receives hydrocarbon fuel and oxygen, and its combustion gas consists mostly of carbon dioxide and water vapor. Carbon dioxide is captured, stored and subsequently sequestered by using it with water to create a hydrocarbon fuel that can be supplied back to the engine. In that way, the engine fuel is repeatedly regenerated and reused, and the engine operates in a carbon neutral mode of operation. Some of the combustion gas is used as a diluent gas in the engine. High specific heat and high density of that gas permit operation in high-efficiency overexpanded cycle without an increase in the engine size. Various methods of the engine control and operation are described, including methods to reduce pumping loss. Various modes of in-cylinder diluent gas formation are considered.

Abstract: An internal-combustion engine achieves much higher thermodynamic cycle efficiency than it is possible to achieve in other engines of the same type. It achieves this by operating with a much higher expansion ratio, without an increase in effective compression ratio. The engine geometric compression ratio is considerably larger than it is in conventional engines of the same type. It operates unthrottled most of the time, and the control of the volume of the intake air retained in the cylinder is performed by varying the timing of the intake valve closure. Ignition timing is after the top-dead-center most of the time. Suitable coordination of ignition timing control with intake valve timing control insures that the peak combustion pressure and temperature remain within acceptable limits.

Abstract: An internal-combustion engine receives no air from outside atmosphere and it discharges no gas into outside atmosphere. The engine receives fuel, oxygen and recycled combustion gas and its exhaust consists mostly of carbon dioxide and water vapor. Most of the gas exhausted from the engine is recycled back into the engine intake, and the remaining gas is cooled and condensed into liquid carbon dioxide and water. Discharge of greenhouse gas into environment and emission of other harmful air pollutants are eliminated.

Abstract: A gas-turbine engine receives no air from outside atmosphere. Instead, combustion gas expelled from the engine is cooled and recycled back into the engine. That gas contains no nitrogen and consists mostly of carbon dioxide and water vapor. Oxygen and fuel are added to the recycled gas, and the resulting mixture is used to perform an internal-combustion process. A small amount of the expelled combustion gas is discharged into outside environment, and the rest is recycled. Since no nitrogen is present, no nitrogen oxides are produced. The amount of other harmful exhaust emissions, including particulate matter, is greatly reduced too, since most of them are recycled back into the engine. The engine is inherently supercharged with controllable combustion-gas pressure and, in some cases, can operate without a compressor. Since the combustion gas is heavier than air, the engine can be substantially smaller than a conventional engine of equal power.

Abstract: An internal-combustion engine receives no air from outside atmosphere. Instead, combustion gas expelled from the engine is cooled and recycled back into the engine. That gas contains no nitrogen and consists mostly of carbon dioxide and water vapor. Oxygen and fuel are added to the recycled gas, and the resulting mixture is used to perform an internal-combustion cycle. Cooling that gas condenses its water vapor, and liquid water is separated from the gas. That water is used for injection into the recycled gas at a later time. A small amount of the expelled combustion gas is discharged into outside environment, and the rest is recycled. Water too is recycled back into the engine, and whatever is lost to outside environment is replaced by reclaiming water produced in combustion. No additional supply of water is needed. Since no nitrogen is present, no nitrogen oxides are produced. The amount of other harmful exhaust emissions is greatly reduced too, since most of them are recycled back into the engine.

Abstract: An internal-combustion engine receives no air from outside atmosphere. Instead, combustion gas expelled from the engine is cooled and recycled back into the engine. That gas contains no nitrogen and consists mostly of carbon dioxide and water vapor. Oxygen and fuel are added to the recycled gas, and the resulting mixture is used to perform an internal-combustion cycle. A small amount of the expelled combustion gas is discharged into outside environment, and the rest is recycled. Since no nitrogen is present, no nitrogen oxides are produced. The amount of other harmful exhaust emissions, including particulate matter, is greatly reduced too, since most of them are recycled back into the engine. The engine is inherently supercharged with combustion-gas pressure and, since the combustion gas is heavier than air, the engine can be substantially smaller than a conventional engine of equal power. Direct injection of oxygen leads to further reduction in engine size. A smaller engine has much better fuel economy.

Abstract: A vehicle system includes an engine that can operate as a compressor, as an air motor and an internal-combustion engine. It also includes short-term and long-term air-storage reservoirs filled with compressed air. During braking, the engine slows down the vehicle by pumping compressed air into the short-term storage. That air is later used for vehicle propulsion. The engine uses the recovered braking energy whenever possible, but when the compressed air in the short-term storage is exhausted; it switches to the long-term storage and continues to operate with compressed-air assist. The amount of compressed air in the long-term storage is such that it is sufficient for a typical day of driving. An on-board electrically-driven compressor, using an outside source of electric power, charges the long-term storage during overnight parking. In this way, electric power from an electric grid is indirectly used for vehicle propulsion.

Abstract: High vehicle fuel efficiency is achieved by reducing fuel consumption during driving both in the city and on the highway. During driving in the city, the system accumulates the energy derived from vehicle motion during braking, and uses it to assist in vehicle propulsion at a later time. The energy can be stored either in a compressed-air reservoir or in an electric battery. During cruising on the highway, the engine operates in a two-stage gas-expansion cycle. The engine has primary and secondary cylinders. Only primary cylinders operate in internal-combustion mode. After expansion in primary cylinders, combustion gas is subjected to a second stage of expansion in secondary cylinders. This substantially improves the engine efficiency. Whenever heavy engine load is needed, all cylinders operate in internal-combustion mode.

Abstract: A vehicle engine has a system of valves that permits various cylinders to operate in different modes of operation. During braking, some of the engine cylinders receive air, compress it, and transfer it to an intermediate air container. Other cylinders receive compressed air from the intermediate air container, further compress it, and transfer it to a high-pressure air reservoir for storage. During acceleration, some of the engine cylinders receive compressed air from the high-pressure air reservoir, expand it to a lower level of pressure, and transfer it to the intermediate air container. Other cylinders receive air from the intermediate air container, further expand it, and use it for combustion in an internal-combustion cycle. During short stops, the engine is shut down, for the duration of the stop, and then, it is restarted with compressed air. During cruise, the engine operates as a conventional internal-combustion engine.

Abstract: An air-hybrid engine operates in two operational modes. It employs uniquely designed camshafts with cam lobe activators, and camshaft phase shifters to operate and control the engine valves. It uses a different cam lobe for operating an engine valve during each of the two operational modes, and it uses camshaft phase shifters to vary the valve event timing and duration. The system exploits non-linearity that exists in relationship between the piston motion and the camshaft rotation. Varying the phase relationship between the camshaft and the engine crankshaft in a pre-determined specific way varies the duration of the engine valve opening in the required way, thus varying the volumes of air received into and discharged from the engine.

Abstract: A vehicle engine has a system of valves that permits various engine cylinders to operate in different modes of operation. During braking, some of the engine cylinders receive atmospheric air, compress it, and transfer it to an intermediate air-container. Other cylinders receive compressed air from the intermediate air-container, further compress it, and transfer it to a high-pressure air-reservoir for storage. During acceleration, some of the engine cylinders receive compressed air from the high-pressure air-reservoir, expand it to a lower level of pressure, and transfer it to the intermediate air-container. Other cylinders receive air from the intermediate air-container, further expand it, and use it for combustion in an internal-combustion cycle. During short stops, the engine is shut down, for the duration of the stop, and, then, it is restarted with compressed air. During cruise, the engine operates as a conventional internal-combustion engine.

Abstract: A method of operating an automotive-type engine at part loads by eliminating engine throttling altogether and controlling the intake flow by heating the intake air and utilizing variable late or early intake valve closings.

Abstract: A four stroke, spark ignition, high compression ratio, internal combustion engine including at least one intake valve (30), exhaust valve (32) and charging valve (36) per cylinder (16). Each of the valves is actuable by a variable timing mechanism (50), which is controlled by an on-board computer (82) that varies the timing of valve opening and closing depending upon engine operating conditions. Each charging valve port (34) leads to an auxiliary chamber (40) having geometry to cause a swirling motion of the charge entering the chamber and surrounded by a cooling jacket (42) to cool the charge as it swirls before being released back into the cylinder during the next engine cycle.

Abstract: A method of operating a four stroke, spark ignition, high compression ratio, internal combustion engine including at least one intake valve (30), exhaust valve (32) and charging valve (36) per cylinder (16). Each of the valves is actuable by a variable timing mechanism (50), which is controlled by an on-board computer (82) that varies the timing of valve opening and closing depending upon engine operating conditions. Each charging valve port (34) leads to an auxiliary chamber (40) having geometry to cause a swirling motion of the charge entering the chamber and surrounded by a cooling jacket (42) to cool the charge as it swirls before being released back into the cylinder during the next engine cycle.