212017975-Hydrogen-Production (new).pptx

Hydrogen

1. Hydrogen Production Dr. Snunkhaem Echaroj ดร . สน ัน ตน ์เ ขม อิช โรจน์

2. One Advantage of using hydrogen One advantage is that it stores approximately 2.6 times the energy per unit mass as gasoline, and the disadvantage is that it needs about 4 times the volume for a given amount of energy. A 15 gallon automobile gasoline tank contains 90 pounds of gasoline . The corresponding hydrogen tank would be 60 gallons, but the hydrogen would weigh only 34 pounds.

3. Current global hydrogen production 48% from natural gas 30% from oil 18% from coal 4% from electrolysis of water

4. Primary Uses for Hydrogen Today 1. About half is used to produce ammonia (NH3) fertilizer. 2. The other half of current hydrogen production is used to convert heavy petroleum sources into lighter fractions suitable for use as fuels.

5. Hydrogen Production Processes Steam Methane Reforming Coal Gasification Partial Oxidation of Hydrocarbons Biomass Gasification Biomass Pyrolysis Electrolysis

6. Steam Methane Reforming Most common method of producing commercial bulk hydrogen. Most common method of producing hydrogen used in the industrial synthesis of ammonia. It is the least expensive method. High temperature process (700 – 1100 °C. Nickel based catalyst (Ni)

7. The Steam Methane Reforming Process At 700 – 1100 °C and in the presence of a nickel based catalyst (Ni), steam reacts with methane to yield carbon monoxide and hydrogen. CH 4 + H 2 O → CO + 3 H 2 Additional hydrogen can be recovered by a lower-temperature gas-shift reaction with the carbon monoxide produced. The reaction is summarized by: CO + H 2 O → CO2 + H 2

8. Purification of Hydrogen Carbon dioxide and other impurities are removed from the gas stream, leaving essentially pure hydrogen. Endothermic reaction (Heat must be added to the reactants for the reaction to occur.)

9. Schematic of the SMR Process REMOVAL OF CO AND CO 2 REFOR MER 10% CO 2,000 ppm CO WATER GAS SHIFT REACTOR Water Methane Gasoline Ethanol Methanol <100 ppm CO O 2 H 2 O H 2 FUEL CELL STACK

10. Coal Gasification well-established commercial technology competitive with SMR only where oil and/or natural gas are expensive. coal could replace natural gas and oil as the primary feedstock for hydrogen production, since it is so plentiful in the world.

11. Partial Oxidation Hydrocarbons process can be used to produce hydrogen from heavy hydrocarbons such as diesel fuel and residual oil. Any hydrocarbon feedstock that can be compressed or pumped may be used in this technology.

12. Partial Oxidation Methane and other hydrocarbons in natural gas are reacted with a limited amount of oxygen (typically, from air) that is not enough to completely oxidize the hydrocarbons to carbon dioxide and water. CH 4 + ½O 2 → CO + 2H 2 (+heat) Exothermic reaction (heat is evolved)

13. Schematic of Partial Oxidation Partial Oxidation Plant Diagram

14. Thermochemical Production of Hydrogen When water is heated to above 2500 o C, it separates into oxygen and hydrogen in a process known as thermolysis. However, at such high temperatures, it is difficult to prevent the oxygen and hydrogen from recombining to form water.

15. Thermochemical Production of Hydrogen Thermochemical water-splitting cycles can lower the temperature and help separate oxygen and hydrogen products to produce pure hydrogen gas. These cycles can improve the efficiency of hydrogen production from 30% for conventional electrolysis to around 50% efficiency One of the most promising cycles so far is the sulfur-iodine (S-I) cycle.

16. Sulfur dioxide (SO 2 ) and iodine (I 2 ) are fed into the cycle as chemical catalysts.. A catalyst lowers the activation energy of a reaction without being used up by the reaction.

17. Sulfur-Iodine Thermochemical Cycle In this cycle, sulfur dioxide (SO 2 ) and iodine (I 2 ) are feed into the cycle as a chemical catalyst. A catalyst lowers the temperature at which the reaction will occur without being used up by the reaction.

18. There are three steps in the S-I cycle Step 1: I 2 + SO 2 + 2H 2 O 2HI + H 2 SO 4 The reaction is run at 120 degrees C. The hydrogen iodide and sulfuric acid are separated, usually by distillation.

19. Step 2: Generation of oxygen and regeneration of SO 2 . H 2 SO 4 H 2 O + SO 2 + 1/2 O 2 This reaction is run at 850 degrees C.

20. Step 3: Generation of hydrogen and regeneration of I 2HI H 2 + I 2 This reaction is run at 450 degrees C.

21. Sulfur—Iodine Cycle These reactions can reduce the high temperature demands of the thermolysis of water for the production of hydrogen gas and can provide a mechanism for the separation of oxygen and hydrogen products to prevent recombination. Source: Office of Nuclear Energy, Science and Technology

22. Biomass Production of Hydrogen Hydrogen can be produced numerous ways from biomass. Biomass is defined as a renewable resource made from renewable materials. Examples of biomass sources include: >switchgrass >plant scraps >garbage >human wastes Gasification of biomass could be a way of extracting hydrogen from these organic sources.

23. Biomass Production of Hydrogen The biomass is first converted into a gas through high-temperature gasifying. The hydrogen rich vapor is condensed in pyrolysis oils. These oils can be steam reformed to generate hydrogen. This process has resulted in hydrogen yields of 12% - 17% hydrogen by weight of the dry biomass. When biological waste material is used as a feedstock, this process becomes a completely renewable, sustainable method of hydrogen generation.

24. Hydrogen from Fossil fuels The production of Hydrogen can also take place from fossil fuels, and steam reforming process is used to carryout the process. 95% prefers production of Hydrogen through steam reforming Steam reforming also known as Steam methane reforming, a method to produce Syngas (H2 and CO) by reacting of hydrocarbons with H2O. The reaction proceed as follows: CH4 + H2O ⇌ CO + 3H2

25. Step 1) Furnace - Steam Production The steam reforming will take place in 5 steps.

26. Steps of Steam reforming 2. Reforming: Involves the catalytic reaction of methane with steam(H2O) at very high temperatures of 1400 – 1500 F. The reaction will be: CH4 + H2O ⇌ CO + 3H2 The reaction is endothermic and it takes place through catalyst filled tubes in a furnace. It consist of 25 – 40% Nickel oxide which will be deposited on a low silica refractory base.

27. Steps of Steam reforming 3. Water S-hift Conversion: The CO of the previous process is further reacted with steam to produce Hydrogen which result in the following reaction: CO + H20  CO2 + H2 The excessive heat will be produced and the reaction will be exothermic and carried out at a temperature of 650 deg F in a fixed bed catalytic converter. The catalyst is also used to speed up the reaction which is a mixture of Chromium and iron oxide .

28. Steps of Steam reforming 4. Gas Purification: The carbon dioxide is further removed from the system of gases by absorption in a circulating amine or hot potassium carbonate solution. We will also add treating solutions which will contact the H2 and CO2 in the absorber containing about 24 trays. Carbon dioxide will be absorbed by the solution which will send for regeneration. 5. Methanation: In this step the small amount of that remaining CO and CO2 are converted to methane gas to get back to the initial step for further production of H2. CO + 3H2  CH4 + H2O CO2 + 4H2  CH4 + 2H2O This process also takes place in fixed-bed catalytic reactor at temperature of about 700 to 800 deg F. Both reactions are exothermic .

29. Steam Reforming Process

30. Steam Reforming Process The H2 gas from Steam Reforming may includes small amount of CO, CO2, H2S as impurities and we must have to remove them in order to get pure H2 gas. Two steps can be taken: Feedstock purification: Using this process, we will remove poison, including sulphur, chloride to increase the life of catalyst. Product purification: The CO2 will be removed. The product gases undergoes a methanization step to remove residual traces of carbon oxides. New SMR are using Pressure Swing Absorption (PSA) units which produces 99.9% pure H2 gas

31. Advantages for the process of Steam Reforming The process is highly economical, efficient, environmental friendly and widely used for H2 production. The efficiency of the process is 65 to 75% It is the cheapest of all above discussed processes, since the production depends on the cost of Natural gas(methane) which is readily available. Relatively stable during transition operation

32. Demerits for the process of Steam Reforming Excess amount OF CO2 is produced. The impurities of Chlorides, CO, CO2 and sulphides are also present which may damage the catalyst in the reactor which must be removed. External heat transfer device is required and hence result in system complexity and potential higher cost

33. Hydrogen Production in Germany The current production of H2 gas in Germany is almost 20billion cubic centimeters annually. 5% of H2 is produced from green resources, while 95% is produced from fossil fuel such as Natural gas or coal

34. Possible Hydrogen applications in Germany Rail transport line, hydrogen could be effective for tracks that have no overload contact line. Hydrogen may also be attractive for public road and freight road transport because in comparison with electric vehicles, the charging times and weight of the batteries needed for electric vehicles are not always economically feasible Thyssen -Krupp is aiming to produce climate-neutral steel by 2050 and has begun a project on the use of green hydrogen in blast furnaces Uniper is also focusing to increase the use of hydrogen in electricity production and, in cooperation with Siemens, is examining how gas power plants can become more environmentally friendly. Converting excess green electrical energy into enrich hydrogen and methane that can be stored and then used to power fuel cells.

35. Possible Hydrogen applications in Germany

36. Germany’s future strategy for production of Hydrogen Germany plans to built hydrogen production plant with a total capacity of 5GW, and by 2035 to 2040 it will expand to 10GW. The 5GW of energy will still not be able to meet the demands in 2030, so focus on import of H2 will be emphasized, and it will also be urged. Opportunities for new businesses and cooperation models between operators of electrolysers and TSOs in line with the regulatory unbundling regime will be developed

37. References   1.Kamran Ashraf, (2015), Steam Methane Reforming, https://urlzs.com/tswds 2.Anupam Basu , (Oct, 2009), Hydrogen Production in Refinery, https://tinyurl.com/yafxeegh 3.S. Shiva Kumar, V. Himabindu , (March, 2019), Hydrogen Production by PEM Water Electrolysis, Material Science for Energy Technologies, Vol 2, Issue 3 https://tinyurl.com/y6upx9d3 4.Hydrogen Production:Biomass Gasification, Office of U.S. Department of Energy, https://tinyurl.com/yxfbqtbk 5.Meng Ni, Dennis Y.C. Leung, Michael K.H. Leung, (May 2006), An overview of Hydrogen production from biomass, Fuel Processing Technology, Vol 87, Issue 5, Pages: 461-472 https://tinyurl.com/y8mzhzx3 6.N.Z Muradov , (March 1993), How to produce Hydrogen from fossil fuels without CO2 emission, Vol: 18, Issue 3, pg : 211-215 https://tinyurl.com/ybp6j9qm 7.M. Steinberg, Hydrogen Production from fossil fuels, Energy carriers and conversion system, Vol:1, https://tinyurl.com/y9rcm628 8.L Garcia, (2015), Hydrogen production by steam reforming of natural gas and other nonrenewable feedstocks , Compendium of Hydrogen Energy, pg 83-107 https://tinyurl.com/yan24jk8 9.Isabelle Huber, Germany’s Hydrogen industrial strategy, (Oct 2021), Centre for Strategic & International Studies https://tinyurl.com/ya3b8qq2 Opportunities for Hydrogen Energy Technologies considering the National Energy & Climate Plans https://tinyurl.com/yanyc233

38. Electrolysis Electrolysis is the technical name for using electricity to split water into its constituent elements, hydrogen and oxygen. The splitting of water is accomplished by passing a DC electric current through water. The electricity enters the water at the cathode, a negatively charged terminal, passes through the water and exists via the anode, the positively charged terminal. The hydrogen is collected at the cathode and the oxygen is collected at the anode. Electrolysis produces very pure hydrogen for use in the electronics, pharmaceutical and food industries

39. Electrolysis The hydrogen is collected at the cathode and the oxygen is collected at the anode. Electrolysis produces very pure hydrogen for use in the electronics, pharmaceutical and food industries.

40. Photobiological This method involves using sunlight, a biological component, catalysts and an engineered system. Specific organisms, algae and bacteria, produce hydrogen as a byproduct of their metabolic processes. These organisms generally live in water and therefore are biologically splitting the water into its component elements. Currently, this technology is still in the research and development stage and the theoretical sunlight conversion efficiencies have been estimated up to 24%.