DESC:CATALYTIC CONVERSION OF MICROALGAE INTO METHANE RICH SYNGAS USING REACTIVE FLASH VOLATILIZATION

TECHNICAL FIELD
[0001] The present disclosure relates to production of methane using reactive flash volatilization, and more particularly to a method of production of methane using tri-metallic catalyst for conversion of microalgae into methane rich syngas using reactive flash volatilization.

BACKGROUND
[0002] Currently very small fraction of energy is generated using hydro, wind, solar and geothermal renewable energy resources. Attempts are being made for reducing the world’s dependence on fossil fuels as a source of energy.

[0003] Lignocellulosic biomass and microalgae are two major sources of biofuel. Lignocellulosic biomass being one of the promising resource for renewable energy generation when compared to wind and solar energy. It has also been observed that microalgae exhibit characteristic properties such as; sustainability with respect to its growth, high yield per unit area, high density of produced fuel and, ability to sequester waste carbon making it a suitable candidate for renewable energy production when compared to lignocellulosic biomass. Microalgae has an additional advantage, it avoids food vs fuel debate.

[0004] Biomass gasification technology is a promising solution for energy generation. However, gasification needs extensive downstream processing with respect to tar cleaning. Tar cleaning is a major hurdle in commercialization of gasification technology. Among the current conversion processes, hydrothermal liquefaction (HTL) is limited by harsh operating conditions such as high temperature (400 °C to 600° C) and high pressure (up to 280 bar). A lower efficiency of lipid extraction is the main hurdle for transesterification route. A prior art have noted that biomass gasification technology to produce syngas is a promising solution for the generation of energy. Moreover, gasification has an edge over other biochemical and thermochemical conversion processes such as, HTL because it generates a product without any ringed or double bond structures. However, tar cleaning remains a challenge in the commercialization of the gasification technology.

[0005] Novel approach such as reactive flash volatilization was recently proposed by Salge et al. (2006). Reactive Flash Volatilization is a combination of fast pyrolysis, partial oxidation, water-gas shift reaction along with steam reforming, wherein Salge et al. (2006) first demonstrated the reactive flash volatilization (RFV) for conversion of soy oil and glucose water to hydrogen rich gas. They observed, that RFV was able to convert non-volatile feed into hydrogen rich gas and, therefore assuming that this process is a combination of gasification reactions. Colby et al. (2008a) revisited their work, and compared RFV with pyrolysis and gasification on the basis of two parameters viz. Space velocity and mass flow rate of carbon, wherein size of the reactor is related to carbon space velocity and, amount of catalyst required is related to mass flow rate of carbon. Their analysis clearly showed that, RFV needs lesser volume as well as catalyst, when compared to gasification and pyrolysis. They observed that, maximum 0.9 - 0.8 (mass flow of C. mass of catalyst-1 h-1) of carbon mass velocity can be achieved in conventional gasifier whereas, RFV can be operated at carbon mass velocity of 50-80 (mass flow of C. mass of catalyst-1 h-1).

[0006] Therefore, there is a need to develop a catalytic process for conversion of microalgae in to methane rich syngas using reactive flash volatilization method, without the formation of tar and char.

SUMMARY
[0007] In a main aspect of the present disclosure, a process for producing methane using metal catalyst for conversion of microalgae into methane rich syngas using reactive flash volatilization, wherein single-step conversion of microalgae into methane-rich syngas using reactive flash volatilization in presence of tri-metallic catalyst is carried out, wherein carbon to steam ratio is maintained at 0.12:1, thereby producing 16% (v/v) yield of methane without tar and char formation.

OBJECT OF THE PRESENT INVENTION
[0008] The object of the present disclosure discloses a method of production of methane using catalyst for conversion of microalgae into methane rich syngas using reactive flash volatilization.
[0009] Another object of the invention is to develop a Single-step conversion of microalgae into methane-rich syngas using reactive flash volatilization.
[0010] Yet another object of the invention is to study the catalytic effect of Tri-metallic catalyst on reactive flash volatilization of microalgae.
[0011] Yet another object of the invention is to study the effect of steam and temperature on reactive flash volatilization of microalgae.
[0012] Yet another object of the invention is to resolve the formation of tar and char.
[0013] Yet another object of the invention is to obtain higher yield of methane.
[0014] Yet another object of the invention is to study the effect of ash on the reaction.

BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The detailed description is described with reference to the accompanying figures.
[0016] Figure 1, shows a schematic representation of Processing alternatives for microalgae.
[0017] Figure 2, shows a schematic diagram of custom build instrument for TPR analysis.
[0018] Figure 3, shows a schematic diagram of Reactive Flash Volatilization reactor setup.
[0019] Figure 4, shows a graphical representation of TPR profile of the tri-metallic catalyst.
[0020] Figure 5, shows a graphical representation of TPD profile of the trimetallic catalyst.
[0021] Figure 6, shows a block representation of Comparison of various thermos-chemical conversion processes.
[0022] Figure 7 shows effect of temperature and catalyst promoters on product gas composition.
[0023] Figure 8 shows effect of steam and catalyst promoters on product gas composition.
[0024] Figure 9 shows effect of steam and catalyst promoters on carbon distribution.

DETAILED DESCRIPTION
[0025] The present invention relates to a method of production of methane using catalyst for conversion of microalgae into methane rich syngas using reactive flash volatilization, wherein single-step conversion of microalgae into methane-rich syngas using reactive flash volatilization in presence of tri-metallic catalyst is carried out, wherein the steam to carbon ratio is maintained at 0.12:1, thereby producing 16% (v/v) yield of methane without tar and char formation.

[0026] Reactive flash volatilization (RFV) is a chemical process that rapidly converts non-volatile solids and liquids to volatile compounds by thermal decomposition for integration with catalytic chemistries.

[0027] Figure 1 shows conventional approaches for processing alternatives for biomass. Biomass gasification technology is the promising solution for energy generation. However, gasification needs extensive downstream processing with respect to tar cleaning. Tar cleaning is a major hurdle in commercialization of gasification technology.

[0028] In a conventional method of Reactive flash volatilization (RFV), Rhodium-Cesium (Rh-Ce) catalyst was used to produce H2 and CO, without char formation. Rh-Ce catalysts are expensive, hence activity of nickel catalyst with a promoter metal was analyzed by the present invention. The present invention utilizes nickel catalysts, which are a better alternative for the expensive rhodium-cesium catalyst. In another conventional method of Reactive flash volatilization (RFV), pure crystalline cellulose was reacted in presence of Rh-Ce/Al as catalyst at 600-800°C temperature, wherein space time for reaction was reported to be 24 ms. The present invention performed similar reactions using Ni based catalyst supported on alumina in the temperature range of 700-800°C wherein, higher space time of 50 ms was observed with no char and tar formation. Nickel- Rhodium (Ni- Rh) supported on alumina was reported to show higher selectivity towards gases compared to other catalysts.

[0029] Carbon conversion of 95% was observed in RFV with no accumulation of char and tar due to high surface temperature of catalyst, which rapidly oxidizes the decomposed products to form gases. This exothermic reaction prevents condensation reactions that is responsible for carbon and tar formation. 60% hydrogen selectivity was reported without catalyst whereas, increased selectivity of 95%, was observed towards hydrogen during catalytic RFV.

[0030] Biomass Scenedesmus sp. (henceforth referred as microalgae) is selected, as a biomass feedstock material, wherein the biomass was characterized using European standards 55 (EN); EN14774, EN14775 and EN15148:2009 to determine their moisture, ash and proximate content of the biomass respectively. The microalgae generally comprises of about 11 % ash and about 35% to 42% Carbon, about 4% to 8% Hydrogen, about 4% to 10% Nitrogen, about 0.1% to 2% sulphur and about 40% to 60% of oxygen. The microalgae which is used as the feedstock comprises of 40.29% of Carbon, 7% Hydrogen, 8.1% Nitrogen, 1.22 % Sulphur and 43.39% Oxygen.

[0031] The metal catalyst comprises a plurality of transition metal elements supported on a post transition metal element, wherein the plurality of transition metal elements are at least three of metals selected from Nickel (Ni), Copper (Cu), Palladium (Pd), Platinum (Pt), Rhodium (Rh), Rhenium (Re), Ruthenium (Ru), Iron (Fe) or a combination thereof. The post transition metal element comprises Aluminium (Al) or gamma Alumina. The transition metal element comprises nanoparticles of metal or metal alloy having particle size about 20 nm to about 100 nm. In the current disclosure a tri-metallic catalyst, consisting of the nickel-copper-palladium (Ni-Cu-Pd) respectively was developed, using the wet impregnation method. Gamma Alumina (?-Al2O3) was used as a support and Nickel nitrate hexahydrate (Ni (NO3)2.6H2O), Rhodium chloride (RhCl3), Cupric nitratetrihydrate (CuN2O6.3H2O) all obtained from Sigma Aldrich were used as source for nickel, rhodium and copper respectively. Firstly, nickel nitrate hexahydrate was dissolved in the deionized water, then alumina and the precursors were added into the solution. Final concentration of nickel, copper and palladium in trimetallic catalyst was at a percentage of 20% nickel, 1% copper and 1% palladium. Homogeneity of the mixture was ensured by continuous stirring at 65°C for 5 hours. The solution was dried at 100°C and the precipitate was then calcinated at 600°C for 6 hours. The resultant catalysts were reduced in-situ before analyzing their catalytic activity.

[0032] Characterization of the catalysts was carried out to understand the surface area, active metal sites and reducibility, using nitrogen physisorption, carbon monoxide temperature programmed desorption (CO-TPD) and temperature programmed reduction (TPR) respectively.

[0033] X-Ray fluorescence spectroscopy of the catalyst is also carried out for analysis of ash and elemental composition of catalyst, and the X-Ray fluorescence spectroscopy is measured using Ametek Spectro iQ II XRF.

[0034] Nitrogen physisorption is used to measure specific area, pore volume and distribution of the catalyst. Brunauer, Emmett and Teller (BET) method of analysis is used to measure the specific surface area. Whereas, pore volume is analysed using BJH method. 1 gm of catalyst was degassed at 350°C for 10 hours.

[0035] Figure 2 shows the schematic diagram of custom build instrument for temperature programmed reduction (TPR) analysis), said TPR analysis was performed to understand the temperature required for onset of catalyst reduction and effect of promoters on the reducibility. Custom build instrument for TPR analysis consisted compact vacuum pump, a Systems Residual Gas Analyser (RGA) 300 and a vertical tube furnace. To perform TPR analysis, 1 gm of trimetallic catalyst is loaded into a quartz reactor fitted with a frit. The reactor is then placed into the furnace. Heating profile for the furnace is programmed to reach 800°C with the ramping of 10°C/min. 5% hydrogen in nitrogen is fed to the reactor continuously with the flow rate of 50 ml/min during heating. A small fraction of the gas coming out of the reactor is introduced to the RGA via a capillary tube. Partial pressure of the gas is recorded for further analysis.

[0036] Further, carbon monoxide temperature programmed desorption (CO-TPD) of the catalyst is carried out to understand, the strength and number of metal active sites; CO-TPD analysis was performed with the help of an instrument described in Figure 2. 1 gm of trimetallic catalyst was reduced at 400°C by 5% H2/N2 mixture for 4 hours. The reactor is then purged with argon for 1 hour at 400°C. In the presence of inert atmosphere reactor is allowed to cool down to room temperature. CO doping of the catalyst surface is achieved by flowing 10% CO/Ar gas mixture through the reactor for 15 min. Then, to ensure monolayer adsorption of CO, reactor was purged with Ar gas for 2 hours. Furnace was then programmed to reach 800°C with the ramping of 10°C/min. Gas coming out of the reactor is then analysed using RGA 300.

[0037] Results of Characterization of catalyst obtained from nitrogen physisorption showed that catalytic property of tri metallic catalyst used for the reactive flash volatilization of microalgae depends on two major factors a) surface area and b) pore size of the catalyst. The Surface area and pore volume of the non-impregnated alumina was reported to be 101.32 m2/g and 0.18 cm3/g respectively. In metal impregnated catalyst; the surface metal is responsible for catalysing the gas phase reactions. Whereas, pores of alumina are responsible for the enhancement of the steam reforming reactions. In case of metal impregnated catalyst although pore volume remain the same surface area of tri metallic catalyst is measured to be 81.5 m2/g.

[0038] Similarly, XRF spectroscopy performed to analyse the percentage of the metal loading on the alumina surface is studied. Since, the XRF was not calibrated for the trace elements like Rhodium and Palladium their percentage was calculated by mass difference. In case of a tri-metallic catalyst it was observed that, 21.5% - 0.8% of Nickel, 1.33% - 0.23% of Copper and 1.2% of Palladium was impregnated on the surface of the alumina.

[0039] Ni0 and Ni+2 are the most active and inactive catalytic states of the Ni catalysts respectively and hence, it is important to analyze the reducibility of the catalyst.

[0040] Figure 3 shows schematic diagram of Reactive Flash Volatilization reactor setup, to evaluate the activity of tri-metallic catalysts, catalytic reactive flash
volatilization (RFV) of microalgae was performed in the reactor shown in the figure 3. RFV mainly consists of a 25 mm X 700 mm quartz tube reactor, a K-Tron twin screw powder feeder (K-MV-KT20), an HPLC pump (model 426), three Teledyne Hasting mass flow controllers for nitrogen and oxygen, a vertical split tube furnace, a Series evaporator and a custom-built gas-liquid separator. The biomass feedstock is dropped onto the metal catalyst by a screw feeder and allowed to react in the reactor for about 0.5 sec to 100 sec.

[0041] To perform RFV, reactor was loaded with 1 g of trimetallic catalyst and assembled in the furnace. The trimetallic catalyst was reduced with 5% H2/N2 gas mixture at 400°C for 4 hours. Furnace is then programmed to reach desired operating temperature with the ramping of 10°C/min. Carbon to steam ratio (CSR) was controlled by using the flow rate of the water. Whereas, gas space velocity was controlled using flow rate of nitrogen. 7 g/h of microalgae biomass was fed to the reactor using twin-screw feeder. Product gas was sampled periodically after gas-liquid separator and injected into GC for analysis. Gas chromatograph equipped with a molecular sieve 5A column, Thermal Conductivity Detector (TCD) and a Flame Ionisation Detector (FID) was used for gas analysis. Bubble-O-Meter was used to measure the flow rate of product gas. Trapezoidal rule of integration was used to calculate the gas yield. Carbon content of condensate and slag, produced after RFV was analysed using LECO TruMac CHNS analyser. Depending on the carbon content analysis selectivity was calculated using following formulae.

[0042] Figure 4 shows a graphical representation of TPR profile of the tri-metallic catalyst. Onset temperature for reduction is observed to 300°C . It is known in the literature that reducibility of the Ni catalyst is promoter dependent. Reducibility is governed by the hydrogen spillover effect attributed by the individual promoter. The present invention discloses the effect of the Palladium; on the reducibility of Nickel catalyst supported on alumina is greater than the Rhodium.

[0043] Figure 5 shows a graphical representation of TPD profile of the tri-metallic catalyst. Though CO desorption at elevated temperature is a complex process. The entire mechanism of CO desorption is not always fully understood Desorption is mainly dependent on a) activation energy and b) surface area coverage by CO. The dependence and mutual effect of these factors is reported by the graphical representation of TPD profile of trimetallic catalyst.

[0044] It is stated that the desorption is a pore and position dependent phenomenon.

[0045] Figure 6 illustrates block representation of comparison of various thermos-chemical biomass conversion process. As described above, conventional methods demonstrated reactive flash volatilization (RFV) reaction and also showed that size of the reactor is related to carbon space velocity and amount of catalyst required is related to mass flow rate of carbon. Their analysis clearly showed that, RFV needs lesser volume and catalyst, when compared to gasification and pyrolysis. It is to be noted that all the analysis was performed for the nitrogen deficient feedstocks. However, microalgae is rich in nitrogen mainly due to protein content in it. Microalgae has around 8% of nitrogen on dry weight basis. The blue square in the figure 6 denotes the operating zone for RFV described by conventional methods, whereas, the red square denoted in the figure 6 corresponds to the operating zone for microalgal reactive flash volatilization described in the present invention.

[0046] Experimental analysis was carried out by using conventional methods which demonstrated reactive flash volatilization (RFV) reaction. However, it was observed that the nitrogenous compounds get accumulated in the form of the tar, resulting into the reactor clogging.

[0047] The present invention performed RFV of microalgae at same carbon space velocity with reduced carbon mass velocity, by doing so it is found that the problem of tar formation is resolved. Further analysis of effect of temperature and steam content on the product distribution for the RFV of microalgae is carried out. The results are discussed in the following sections mentioned below.

[0048] Figure 7 illustrates effect of temperature and catalyst promoters on product gas composition. Microalgae mainly consists of cellulose, hemicellulose, lipids and proteins. These, components are comparatively easy to gasify at 600°C. Moreover, one of the objective of the present disclosure is to produce methane rich syngas and methanation being exothermic reaction favoured at lower temperature. Hence, to evaluate the activity and stability of the catalyst RFV is performed at 550°C, 600 °C and 650°C by keeping Carbon to steam ratio at 0.12, wherein reaction condition was maintained with flow rate 7g/h, operating for 3 hours.

[0049] Although, 550°C is favourable for methanation over Ni/Cu/Pd catalyst, selectivity of carbon for gaseous products was lower. Reactor was clogged due to tar accumulation after 3 hours of operation. At 600°C, selectivity of carbon for gaseous products was observed to be 90%. Figure 7 shows that, the methanation was promoted over WGS and reforming reaction. At 650°C, yield of methane was dropped by 50% with the selectivity of carbon to be 91% towards gaseous products. This confirms that, methanation is not favoured at 650°C. By this it can be concluded in the present invention that nickel based catalyst can be used to catalyse low as well as high temperature water gas shift reaction.

[0050] Figure 8 illustrates effect of steam and catalyst promoters on product gas composition. Reactive flash volatilization demonstrated earlier (in the literature) used oxygen as a gasifying agent for char and steam as a reforming agent for tars, formed during devolatilization. It has been noted that, the selectivity of carbon towards CO is higher compared to CH4 in the oxidative environment. To enhance the yield of methane and reform the tars in the present invention, steam is used as gasifying and reforming agent for char and tar respectively. Tri-metallic catalyst is tested for its stability and activity under four different carbon to steam ratios (0.12, 0.2, 0.4 and 0.8) by operating at constant 600°C. The reaction conditions were maintained at flow rate of 7g/h. These ratios are selected based on the prior understanding of reaction stoichiometry and behaviour of nitrogenous compounds under gasification environment. Figure 8 shows the percentage of various components in the produced gas calculated on nitrogen free basis. Figure 8 shows the effect of the trimetallic catalyst.

[0051] Figure 9 illustrates effect of steam and catalyst promoters on carbon distribution. Major concern for using steam as a gasifying agent is methane reformation; resulting into hydrogen and carbon monoxide. To minimize the methane reformation, experiments are carried out in the present invention wherein carbon to steam ratio of 0.8 were maintained, wherein 7% of methane is obtained in the generated gas, and reactor is functional only for 2.5 hours because it is found to be clogged due to accumulation of tars on the frit. Figure 9 is devoid of carbon distribution in tar. However, it was found out that, tar was made up of 62% of carbon and 78% nitrogen. Considering the percentage of carbon in the tar, overall conversion of carbon to gaseous product was very low.

[0052] To reform the tars which is produced during devolatilization of microalgae, steam content of the reaction is increased. With C/S ratio of 0.4, the trimetallic catalysts showed around 95% selectivity towards gaseous products and tar accumulation is reduced. Thereby it was found out that increased steam content promoted the (water gas shift) WGS reaction, resulting in the higher CO2 percentage. With increased steam content, catalysts showed different behaviour in regards to their reaction selectivity. At C/S ratio of 0.12, the trimetallic catalyst showed higher selectivity towards carbon hydrogenation reaction resulting in lower percentage of hydrogen (Figure 8). With carbon to steam ratio of 0.12 and temperature 600°C tar and char free conversion of microalgae into methane rich syngas was achieved.

[0053] Catalytic properties of Ash: Scenedesmus sp. contains 11% ash; enriched with Phosphorus. During RFV of microalgae with operating conditions such as carbon to steam ratio 0.12 and temperature 600°C, 230 mm of porous bed of slag was formed. XRF analysis showed that, slag was mainly composed of phosphorus and some alkali and alkaline earth metals.

[0054] Nitrogenous compounds tend to form oils and heavy tars during pyrolysis and low temperature gasification. Scenedesmus sp. has around 8% nitrogen. Cellular proteins are the major source of the nitrogen in microalgae. Formation of bio-oils from microalgae during pyrolysis and formation of ammonia and formonitrile during catalytic pyrolysis has been reported. The formation of ammonia during RFV was confirmed using mass spectrometry

[0055] The present disclosure demonstrates that the trimetallic catalyst is tested for various carbon to steam ratios and operating temperatures to produce methane rich syngas. The volume percentage (v/v) of molecular methane in the produced methane rich syngas is in the range of 5% to 20% in the present disclosure. 16% (v/v) methane is produced when operated at 600°C and carbon to steam ratio of 0.12, in presence of trimetallic catalyst without significant amount of char and tar formation. The yield of methane obtained and analysed during the RFV of microalgae is highest for single-step tar and char free methane production. Gasification of whole microalgae is a challenge due to presence of nitrogenous compounds, since nitrogenous compound are responsible for tar formation during gasification. The method and components described in the present invention are selected such that nitrogenous compounds gets converted to ammonia. Thereby solving the problem of tar formation and also adds to overall profit. Another advantage of the process described here is that, as the reactive flash volatilization proceeds aluminium phosphate is formed which acts as a catalyst for
steam reforming of tars. This results into better catalytic activity as reaction proceeds. It is rare, that process improves the catalytic activity.

[0056] The above description along with the accompanying drawings is intended to describe the preferred embodiments of the invention in sufficient detail to enable those skilled in the art to practice the invention. The above description is intended to be illustrative and should not be interpreted as limiting the scope of the invention. Those skilled in the art to which the invention relates will appreciate that many variations of the described example implementations and other implementations exist within the scope of the claimed invention.
,CLAIMS:
1. A process of producing methane rich syngas, the process comprising the steps of:
providing a biomass feedstock;
feeding the biomass feedstock into a reactor, wherein the reactor is loaded with a metal catalyst;
providing a gasifying agent into the reactor;
exposing the biomass feedstock in the reactor, on to the metal catalyst in presence of the gasifying agent for Reactive Flash Volatilization (RFV) reaction of the biomass in the reactor; and
extracting methane rich syngas from the reactor, wherein the methane rich syngas comprises hydrogen, carbon monoxide, carbon dioxide and methane.

2. The process as claimed in claim 1, wherein the metal catalyst comprises a plurality of transition metal elements supported on a post transition metal element, maintained at a temperature at about 400° C to about 650° C.

3. The process as claimed in claim 2, wherein the plurality of transition metal elements are at least three of metals selected from Nickel (Ni), Copper (Cu), Palladium (Pd), Platinum (Pt), Rhodium (Rh), Rhenium (Re), Ruthenium (Ru), Iron (Fe) or a combination thereof.

4. The process as claimed in claim 2, wherein post transition metal element comprises Aluminium (Al) or gamma Alumina.

5. The process as claimed in claim 2, wherein each transition metal element comprises nanoparticles of metal or metal alloy having particle size about 20 nm to about 100 nm.

6. The process as claimed in claim 1, wherein the biomass feedstock comprises microalgae in a dried powdered or slurry form, fed at room temperature and pressure.

7. The process as claimed in claim 1, wherein the biomass feedstock is selected from Scenedesmus species.

8. The process as claimed in claim 1, wherein the biomass feedstock comprises about 11 % ash, about 35% to 42% Carbon, about 4% to 8% Hydrogen, about 4% to 10% Nitrogen, about 0.1% to 2% sulphur and about 40% to 60% of oxygen.

9. The process as claimed in claim 1, wherein the biomass feedstock is dropped onto the metal catalyst by a screw feeder and allowed to react in the reactor for about 0.5 sec to 100 sec.

10. The process as claimed in claim 1, wherein the reaction temperature is maintained in the range of 550°C to 600°C.

11. The process as claimed in claim 1, wherein the reactor is heated externally at a temperature about from 550°C to 700°C.

12. The process as claimed in claim 1, wherein the metal catalyst is preheated to 400°C and reduced in presence of H2.

13. The process as claimed in claim 1, wherein the gasifying agent comprises steam having temperature about 150° C to 180° C, provided into the reactor at an atmospheric pressure.

14. The process as claimed in claim 1, wherein the concentration of steam in the reactor is adjusted to maintain a ratio of carbon-to-steam in the reactor in the range of 0.1 to 0.8.

15. The process as claimed in claim 1, wherein the volume percentage (v/v) of molecular methane in the extracted methane rich syngas is about in the range of 5% to 20%.
16. The process as claimed in claim 1, wherein during RFV reaction, 1 gm of metal catalyst is loaded in a furnace of the reactor followed by reduction of metal catalyst with 5% H2/N2 gas mixture at 400°C for 4 hours.

17. The process as claimed in claim 1, wherein during RFV reaction, the biomass feedstock is converted into gaseous phase before contacting the catalyst surface or the biomass feedstock gets pyrolyzed by contacting a bed formed due to transformation of elements into tar and gas and reacts in the metal catalyst bed formed due to the element transformation.

18. The process as claimed in claim 17, wherein catalytic conversion of biomass in to gaseous phase leads to formation of porous bed of slag.

19. The process as claimed in claim 18, wherein the slag contains transition elements, non-metals, post transition elements, metalloids, alkali and alkaline earth metals.

20. The process as claimed in claim 19, wherein the alkali and alkaline metals comprise of Na, K, Mg and Ca non-metals comprise of P, metalloids comprise of Si, metals comprise of Zn, Fe, and post transition elements comprise of Al.