Renewable synthetic methane gas (RSMG) and Ramana Power Cycle (RPC) for Zero emission base load power.

RSMG is an abbreviation for ‘Renewable synthetic methane gas’ and it is a new form of a Carbon negative synthetic fuel to substitute natural gas. It is synthesized using  CO2 extracted from the sea or from power plant using Oxy combustion CO2 power cycle at the site such as CES, Graz cycle or Allam cycle (using supercritical CO2 as working fluid)  and Renewable Hydrogen (RH) by the following reactions using a renewable energy source.

1.    CO2=> CO + ½ O2 (electro-chemical reduction)

2.    CO + 3 H2=> CH4 + H2O (catalytic conversion)

There are other methods too can be applied but our patented process uses a unique method to synthesize RSMG from CO2 and renewable Hydrogen with a heating value (LHV) around 52 Mj/kg.

By using only, the sun and sea water, RSMG is continuously synthesized using continuous renewable energy such as OTE (ocean thermal energy) on 24 x 7 basis. Ocean is the largest reservoir for clean drinking water, Carbon dioxide, Hydrogen and thermal energy and it is imperative that the absorbed CO2 is extracted along with  stored thermal energy in order to restore the warming ocean to pre-industrial state to mitigate climate change. The success of the system depends on the availability of the lowest cost of renewable energy on 24 x7 basis such as Hydro or OTEC. Alternatively, the cost of renewable energy should be less than a $0.05/kwh.

What is RSMG?

RSMG is like natural gas with higher heating value consisting of pure methane and Hydrogen with no other impurities such as sulfur compounds or CO2. It is synthesized using a proprietary technology using CO2 extracted from seawater and renewable hydrogen (RH) using a renewable energy sources such as OTEC or Solar/wind etc. It can be compressed like CNG or liquified like LNG and can be transported or shipped to various destinations. RSMG is a Carbon negative fuel because it uses already absorbed CO2 from the sea and not from burning fossil fuel and it is also renewable because the O2 from CO2 emission is substituted with renewable Hydrogen (RH) constituting synthetic CH4. The purpose of this technology is to recycle Carbon indefinitely at the site of usage and that is why transportation in the form of CNG or LNG is discouraged.

Ramana Power Cycle (RPC)

RPC is a new patent (pending) technology to generate a base load power 24 x7 using a renewable synthetic methane gas (RSMG) with Zero emission. By constantly recycling CO2 in the form of RSMG during Oxy combustion CO2 power cycle we can eliminate usage of fossil fuel completely. Moreover, there will be no need to extract further CO2 from seawater for a specific power plant because Carbon is being recycled constantly. Only further RH will be required to run the base load power plant.

How RPC works?

RPC uses an Oxy combustion power cycle such as CES, Graz cycle or Allam cycle (using super critical CO2 as a working fluid) to generate a base load 24 x7 power. It uses 80% of CO2 generated internally leaving 20% high purity pipeline grade CO2 which is used to synthesize RSMG at site for recycling. That is why RSMG is renewable. Thus, RPC continues to generate a base load power with Zero emission. The electric efficiency of RPC is nearly 70 % and the cost of power is competitive to any other power source. By continuously generating RSMG and recycling CO2 it achieves Zero emission without any requirement of fossil fuel such as natural gas. Thus, the process can decarbonize the fossil fuel industry completely at the fastest time frame. Using 100% renewable hydrogen (RH) in gas turbine is still a long way off to achieve a commercial reality. Currently only up to 30% RH has been tested along natural gas (30:70) and there are several technical problems to be solved with combustor. Moreover, the maximum efficiency in Hydrogen based gas turbine will not exceed 35% at the maximum.

How RPC is different from Allam cycle, for example?

Allam cycle has been selected by IEA (International energy agency) as the most efficient (electric efficiency at 55.4%) Oxy combustion power cycle to generate a base load power using natural gas. It generates 20% pipeline grade CO2 as by-product suitable for CCS applications. It requires natural gas as a fuel. It generates pure Oxygen from air using ASU (air separation unit) by cryogenic process. Air separation is an energy intensive process consuming as much as 15% generated power internally thereby reducing overall electric efficiency of the system. Moreover 20% CO2 discharged from the plant requires long distance piping and sequestration both are expensive thus increasing the cost of power.

RPC uses pure Oxygen generated as by-product of renewable hydrogen (RH) by electrolysis for Oxy combustion of RSMG and to continue to generate a base load power at highest electrical efficiency at competitive rate. Synthesis of RSMG is highly exothermic chemical reaction which generates superheated steam as a by-product which generates additional power using steam turbine thus enhancing the overall electric efficiency of RPC.

RPC is suitable only for large power generation such as 100 Mw and above. The process requires the cheapest and continuous renewable energy source such as OTEC, offshore wind turbines supplemented by PV solar. The main advantage of the system is it does not require large scale energy storage and the base load power can be exported directly to the grid using a substation as it has been done over several decades.

RPC has the potential to decarbonize the fossil economy at the fastest rate than any other methods currently used.

Any power generation technology should be able to meet the following seven criteria in order to be successful.

1.Power availability.

2.Power dispatchability.

3.Zero emissions.

4.Lowest levelized cost of power

5.Potential to decarbonize the fossil economy at the shortest time frame.

6.Potential to Completely eliminate fossil fuel

7. Sustainable and has a potential to achieve circular economy.

RPC can meet all the above seven criteria.

Ocean-the largest source of Clean energy

Water makes up seventy one percent of the planet earth and ninety eight percent of it constitutes the ocean. It is a single source of water for all forms of life on earth and it also plays an important role in climate changes in the atmosphere. Ocean is the biggest heat sink and absorbs sun’s heat and also a carbon sink absorbing excess carbon dioxide from atmosphere. The surface temperature of seawater is warmer than the temperature at the bottom of the ocean. Sun supplies solar energy to the ocean. In fact the water temperature in Deep Ocean is about 15-20C less than the surface temperature, and it is used as a working fluid to cool buildings by evaporative cooling without using any electricity like commercial air-conditioning. OTEC (ocean thermal energy conversion) system is a potential method of generating power using the temperature gradient between ocean’s surface water and ocean’s deep water. A temperature difference, as small as 15 -20C is sufficient to generate power using Kalina cycle, similar to geothermal energy systems. Commercial plants using this technology are already in operation in few countries. The biggest advantage with open cycle ocean thermal energy conversion system is the fresh water (desalinated ocean water) as a by-product. This technology is unique because it can generate not only power but also drinking water from sea without polluting the air with greenhouse gas emissions. In fact this technology should be deployed commercially is many islands around the world, where there is always a demand for power and drinking water. “Water, water, everywhere but not a drop to drink”. It is the situation in many islands and many parts of the world. Islands like Maldives and Mauritius should adopt this technology to generate power and supply drinking water without burning fossil fuels like diesel or setting up desalination plants. Of course, the economy of scale and finance is an issue in many islands. PNG (Papua New Guinea) is one of the biggest islands in Pacific Ocean where there is s severe shortage of power and water. The country is endowed with rich minerals, oil and gas but the basic necessity like power and water are in short supply. OTEC will be an ideal solution for such islands. Fresh water supply is going to be a major issue in parts of the world due to global warming and climate changes. In countries like India, drinking water is in short supply and a number of seawater desalination plants are coming up. Bottled waters are expensive and unaffordable to a common man. This will only increase the power requirements in the country when there is already a massive shortage of power. OTEC is an ideal solution for India with its long coastal line. One of the major issues with current power generation technologies is the pollution. In any combustion process involving fossil fuel the combustion products like carbon dioxide, carbon monoxide and Oxides of Nitrogen (the greenhouse gases) will contribute global warming. What is the level of such emission and how fast the globe is warming is a futile argument. The pollution can be small in term of PPM (parts per million) but the cumulative effects over several decades is a major issue and that cannot be simply dismissed. There are many places where the Arsenic content in drinking water is above certain acceptable levels (only in ppms) but such small excess cause debilitating health conditions. This is the same argument with greenhouse emission and global warming. It can be gradual and insignificant but it will reach a tipping point and dramatic changes can happen all of a sudden. Nature has got its own mechanism to adjust any imbalances and maintain certain equilibrium. But humans cannot take them for granted and pollute the air and water indiscriminately. There will be a price to pay. Ocean is the largest and inexhaustible source of Hydrogen. Currently Caustic soda plants use sodium chloride (salt) brine as the raw material for conversion into Caustic soda; the by-products are Hydrogen and Chlorine. Caustic soda plants are currently using Hydrogen as a fuel or use to manufacture Hydrochloric acid. They can generate onsite power using Hydrogen to offset their energy cost. In both water electrolysis as well as brine electrolysis, Hydrogen is a product and Ocean water is the largest source of such Hydrogen. In fact countries should generate Hydrogen using desalinated water and OTEC power. The stored Hydrogen is a stored energy that can be used as and when required. That is why we believe ‘water and energy are two sides of the same coin’.