DESC:CATALYTIC CONVERSION OF MICROALGAE INTO HYDROGEN RICH SYNGAS USING REACTIVE FLASH VOLATILZATION

TECHNICAL FIELD
[0001] The present disclosure relates to a process of production of hydrogen using reactive flash volatilization, and more particularly to a process of production of hydrogen by catalytic conversion of microalgae into hydrogen rich syngas using reactive flash volatilization.

BACKGROUND
[0002] Microalgae is one of the leading alternative biomass feedstock because, compared to lignocellulose, it provides a) higher CO2 fixation efficiency, b) higher growth rate, c) higher photosynthetic efficiency, d) higher energy density (J/m3), and e) ability to grow in brackish water. However, most of the research on the utilization of microalgae have focused on the conversion of lipids into biodiesel. The utilization of entire cell has received 10 little attention.
[0003] Biomass gasification is a technology pathway that uses a controlled process involving heat, steam, and oxygen to convert biomass to hydrogen and other products, without combustion. Biomass, is a renewable organic resource, which includes agriculture crop residues (such as corn stover or wheat straw), forest residues, special crops grown specifically for energy use (such as switchgrass or willow trees), organic municipal solid waste, and animal wastes. This renewable resource can be used to produce hydrogen, along with other byproducts, by gasification.
[0004] Gasification is a process that converts organic or fossil-based carbonaceous materials at high temperatures, without combustion, with a controlled amount of oxygen and/or steam into carbon monoxide, hydrogen, and carbon dioxide. The carbon monoxide then reacts with water to form carbon dioxide and more hydrogen via a water-gas shift reaction. After which adsorbers or special membranes can separate the hydrogen from this gas stream.
[0005] 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.
[0006] Pyrolysis is the gasification of biomass in the absence of oxygen. In general, biomass does not gasify as easily as coal, and it produces other hydrocarbon compounds in the gas mixture exiting the gasifier; this is especially true when no oxygen is used. As a result, typically an extra step must be taken to reform these hydrocarbons with a catalyst to yield a clean syngas mixture of hydrogen, carbon monoxide, and carbon dioxide. Then, just as in the gasification process for hydrogen production, a shift reaction step (with steam) converts the carbon monoxide to carbon dioxide. The hydrogen produced is then separated and purified.
[0007] Dry microalgae gasification reports are limited in the published literature. One of the prior arts performed batch experiments on microalgae gasification and observed that a holding time of 20 minutes resulted in gas, char and tar yields of 75.8%, 11.6% and 12.6%, respectively. Another prior art showed chemical looping gasification of microalgae can be performed in the presence of the Fe2O3/CaO catalyst. However, the average conversion efficiency of the process was only 77%. Yet another prior art reported only 70% tar conversion into gas in a microreactor gasification of microalgae in the presence of the Fe2O3/CeO2 catalyst.
[0008] Reactive flash volatilization (RFV) is one of the gasification process, wherein RFV can be defines as a combination of fast pyrolysis, partial oxidation, water-gas shift reaction along with steam reformation.
Another prior art reported reactive ash volatilization of non-volatile feedstock in the presence of the Rh-Ce/_Al2O3 catalyst at 800°C resulting in tar and char-free syngas. It was also possible to tune the ratio of H2-to-CO in the syngas by changing the feed ratio. However, only model components such as oil and cellulose were reported in their study. One of the earlier works reported RFV of lignocellulosic biomass in the presence of the Ni-Rh/Al2O3 catalyst, at 800° C, with a carbon-to-steam ratio (CSR) of 2.35 and a carbon conversion efficiency of 99%.
[0009] RFV conversion of biomass, without significant pre-processing, to a single clean stream of syngas would provide significant economic and environmental benefits. Syngas can easily be converted into diesel fuel, allowing high efficiency end use in modern diesel engines without significant changes in the current transportation infrastructure. However, currently there exist lack in effective catalytic conversion of biomass methodology that are easily scalable and sufficiently simple for coupling to standard reforming practices.
[0010] Accordingly, there is a need to develop a catalytic process for conversion of microalgae in to hydrogen rich syngas using reactive flash volatilization process, without negligible formation of tar and char.

SUMMARY
[0011] An aspect of the present disclosure, relates to a process of production of hydrogen by catalytic conversion of microalgae into hydrogen rich syngas using reactive flash volatilization, wherein single-step conversion of microalgae into hydrogen-rich syngas using reactive flash volatilization at a temperature of 650°C in presence of bimetallic catalyst is carried out, wherein the steam to carbon ration is maintained at 9:1, thereby producing 65% (v/v) yield of hydrogen without tar and char formation.

OBJECT OF THE PRESENT INVENTION
[0012] The object of the present invention is to develop a process of production of hydrogen by catalytic conversion of microalgae into hydrogen rich syngas using reactive flash volatilization.
[0013] Another object of the invention is to develop a Single-step conversion of microalgae into hydrogen-rich syngas using reactive flash volatilization.
[0014] Yet another object of the invention is to study the catalytic effect of bimetallic catalyst on reactive flash volatilization of microalgae.
[0015] Yet another object of the invention is to study the effect of steam and temperature on reactive flash volatilization of microalgae.
[0016] Yet another object of the invention is to resolve the nitrogenous tar formation by converting nitrogenous compounds into ammonia.
[0017] Yet another object of the invention is to obtain higher yield of hydrogen syngas as a source of biofuel.

BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The detailed description is described with reference to the accompanying figures.

[0019] Figure 1 is a schematic diagram of custom build instrument for TPR analysis (TRP).
[0020] Figure 2 is a schematic diagram of Reactive Flash Volatilization reactor setup.
[0021] Figure 3 illustrates effect of temperature and catalyst promoters on product gas composition.
[0022] Figure 4 illustrates effect of steam and catalyst promoters on product gas composition.
[0023] Figure 5, is a block representation of Comparison of various thermos-chemical conversion processes
[0024] Figure 6, illustrates effect of steam and catalyst promoters on carbon distribution.

DETAILED DESCRIPTION
[0025] The present disclosure relates to a process of production of hydrogen by catalytic conversion of microalgae into hydrogen rich syngas using reactive flash volatilization, wherein single-step conversion of microalgae into hydrogen-rich syngas using reactive flash volatilization in presence of bimetallic catalyst is carried out, wherein the steam to carbon ration is maintained at 9:1, thereby producing 65% (v/v) yield of hydrogen without tar and char formation.

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

[0027] Biomass Scenedesmus sp. (henceforth referred as microalgae) is selected, from South Australia Research and Development Institute (SARDI), South Australia. Scenedesmus sp. selected is characterized using European standards (EN) EN14774, EN14775 and EN15148:2009 for its chemical properties, wherein Scenedesmus sp. Used as a biomass is characterized to determine the moisture, ash and proximate content of the biomass. 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.
[0028] 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 bimetallic catalyst, may be consisting of nickel-rhodium (Ni-Rh/?-Al2O3)is developed, using the wet impregnation method. Gamma Alumina (?-Al2O3) is used as a support and Nickel nitrate hexahydrate (Ni (NO3)2.6H2O), Rhodium chloride (RhCl3) all obtained from Sigma Aldrich can be used as source for nickel and rhodium. Firstly, nickel nitrate hexahydrate is dissolved in the deionized water to obtain a solution, then alumina and the precursors are added into the solution. Final concentration of nickel and rhodium in the bimetallic catalyst is 10% (w/w) and 1% (w/w) respectively. Homogeneity of the mixture is ensured by continuous stirring at 65°C for 5 hours. The solution was then dried at 100°C and the precipitate is then calcinated at 600°C for 6 hours. The resultant catalysts were reduced in-situ before analyzing their catalytic activity.

[0029] Characterization of the catalysts is 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.
[0030] Nitrogen physisorption is used to measure specific area, pore volume and distribution of the catalyst.Brunauer, Emmett and Teller (BET) process of analysis is used to measure the specific surface area. Whereas, pore volume is analysed using BJH process. 1 gm of catalyst is degassed at 350°C for 10 hours.
[0031] Results of Characterization of catalyst obtained from nitrogen physisorption showed that catalytic property of bi 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 catalyzing 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 bi metallic catalyst is measured to be 86.6 m2/g.
[0032] X-Ray fluorescence spectroscopy is carried out for analysis of ash and elemental composition of catalyst and is measured using Ametek Spectro iQ II XRF.
[0033] XRF spectroscopy performed to analyze 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 bi-metallic catalyst it was observed, that 11.97% - 0.8% of Nickel was impregnated on the surface and 0.92% of Rhodium
[0034] Figure 1 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 bimetallic 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.Carbon monoxide temperature programmed desorption (CO TPD)To investigate, the strength and number of metal active sites; CO-TPD analysis was performed with the help of an instrument described in Figure 1. 1 gm of bimetallic catalyst was reduced at 400°C by 5% H2/N2 mixture for 4 hours. The reactor was then purged with argon for 1 hour at 400°C. In the presence of inert atmosphere reactor was allowed to cool down to room temperature. CO doping of the bi metallic catalyst surface was 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 was then analysed using RGA 300.
[0035] Figure 2 shows schematic diagram of Reactive Flash Volatilization reactor setup, to evaluate the activity of bimetallic catalysts, catalytic reactive flash volatilization (RFV) of microalgae was performed in the reactor shown in the figure 2. 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.
To perform RFV, reactor is loaded with 1 g of bimetallic catalyst and assembled in the furnace. The bimetallic 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 is controlled by using the flow rate of the water. Whereas, gas space velocity is controlled using flow rate of nitrogen. 7 g/h of microalgae biomass is fed to the reactor using twin-screw feeder. 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. 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) is 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.
[0036]

[0037] 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.

[0038] It has been reported that onset temperature for reduction of the bi-metallic catalyst is observed to be 362°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.

[0039] Carbon monoxide temperature programmed desorption (CO-TPD): 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 bimetallic catalyst.

[0040] It is stated that the desorption is a pore and position dependent phenomenon.

[0041] Fig. 4 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 5 denotes the operating zone for RFV described by conventional methods .Whereas, the red square denoted in the figure 5 corresponds to the operating zone for microalgal reactive flash volatilization described in the present invention.

[0042] Experimental analysis was carried out using reactive flash volatilization (RFV) reaction earlier on various sources of biomass. However, it was observed that the nitrogenous compounds gets accumulated in the form of the tar, resulting into the reactor clogging. The present invention performed RFV of microalgae at same carbon space velocity with reduced carbon mass velocity as demonstrated earlier by using bimetal as a catalytic source and maintain the temperature at 650°C, 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.

[0043] Figure 3 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, the present disclosure to produce hydrogen rich syngas and hydrogenation being exothermic reaction favored 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 ration at 0.12, wherein reaction condition was maintained with flow rate 7g/h, operating for 3 hours.

[0044] Figure 3 shows that, the water gas shift (WGS) and steam reforming of methane were promoted over methanation in presence of Ni/Rh catalyst and that the selectivity of hydrogen can be enhanced in gaseous products at 650°C over Ni/Rh catalyst.

[0045] Figure 4 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 hydrogen and reform the tars in the present invention, steam is used as gasifying and reforming agent for char and tar respectively. Bi-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 650°C. Wherein reaction condition was maintained at flow rate of 7g/h. These ratios are selected based on the prior understanding of reaction stoichiometry and behavior of nitrogenous compounds under gasification environment. Figure 4 shows the percentage of various components in the produced gas calculated on nitrogen free basis. Figure 4 shows the effect of the bimetallic catalyst.

[0046] Figure 6 illustrates effect of steam and catalyst promoters on carbon distribution. Major obstacle for using steam as a gasifying agent is hydrogen reformation; resulting into hydrogen and carbon monoxide. To minimize the hydrogen reformation, experiments are carried out in the present invention wherein carbon to steam ratio of 0.8 were maintained, wherein 7% of hydrogen is obtained in the generated gas, and reactor is functional only for 2.5 hours. It is found to be clogged due to accumulation of tars on the frit. Figure 4 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.

[0047] To reform the tars which is produced during devolatilization of microalgae, steam content of the reaction in the present invention is increased. With C/S ratio of 0.4, the bimetallic catalyst 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, catalyst showed different behavior in regard to their reaction selectivity. At C/S ratio of 0.12, the bimetallic catalyst showed higher selectivity towards hydrogen by promoting WGS reaction. With carbon to steam ratio of 0.12 and temperature 650°C tar and char free conversion of microalgae into hydrogen rich syngas was achieved.

[0048] 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 650°C, 230 mm of porous bed of slag was formed. However, the transformation of Phosphorous rich ash is not extensively reported in the literature. XRF analysis showed that, slag was mainly composed of phosphorus and some alkali and alkaline earth metals. Catalytic properties of alkali and alkaline earth metals present in the ash have been extensively reported in the literature. On the other hand, phosphorus reacted with alumina to form aluminium phosphate (AlPO4). AlPO4 mimics the structural properties of zeolite and hence shows the catalytic activity. It has been reported the catalytic activity of zeolites for microalgae pyrolysis resulting in ammonia and aromatic compounds. This proved the catalytic nature of the porous bed formed of slag.

[0049] 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 is confirmed using mass spectrometry.

[0050] In conclusion, the present invention demonstrates that the bimetallic catalyst is tested for various carbon to steam ratios and operating temperatures to produce hydrogen rich syngas. The volume percentage (v/v) of molecular hydrogen in the produced hydrogen rich syngas is in the range of 25% to 70% in the present disclosure 65% hydrogen is produced when operated at 650°C and carbon to steam ratio of 0.12, in presence of bimetallic catalyst without significant amount of char and tar formation. The yield of hydrogen obtained and analysed during the RFV of microalgae is reported to be the highest. Gasification of whole microalgae is a challenging process due to the presence of nitrogenous compounds, since nitrogenous compound are responsible for tar formation during gasification. The process 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 aluminum 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.

[0051] 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 hydrogen 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 hydrogen rich syngas from the reactor, wherein the hydrogen 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 two 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 650°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 hydrogen in the extracted hydrogen rich syngas is about in the range of 25% to 70%.

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.