Production of Light Fraction-Based Pyrolytic Fuel from Spirulina platensis Microalgae Using Various Low-Cost Natural Catalysts and Insertion

The use of catalysts has significantly enhanced the yield and quality of in-situ pyrolysis products.However,there is a lack of understanding regarding pyrolysis approaches that utilize several low-cost natural catalysts(LCC)and their placement within the reactor.Therefore,this study aims to examine the effects of various LCC on the insitu pyrolysis of spirulina platensis microalgae(SPM)and investigate the impact of different types of catalysts.We employed LCCsuch as zeolite,dolomite,kaolin,and activated carbon,with both layered and uniformlymixed LCCSPM placements.Each experiment was conducted at a constant temperature of 500℃for 60 min.The resulting pyrolytic liquids(bio-oil)and syngas were analyzed using a Gas Chromatography Mass Spectrometry(GC-MS)analyzer to determine the distribution of hydrocarbon compounds.The experimental results indicated that the presence of catalysts significantly influenced the mass yield productivity of liquid fuels and syngas.Activated carbon and zeolite were preferred among the four catalysts for producing liquid fuels(22.4 and 18.6 wt%)when layered and uniformly mixed,respectively.Kaolin with a layered mixture with SPM was more suitable for the production of light fractions(C_(5)–C_(12)),achieving approximately 95.7%peak area,while zeolite with a uniform mixture produced the highest light fraction at about 86.3%peak area.All catalysts except kaolin significantly increased the aromatic compounds in the liquid fuels.Although the amount of oxygenated hydrocarbons in the bio-oil remained relatively high,the final hydrocarbon composition was highly comparable to conventional fuels such as gasoline-88,which has a C_(5)–C_(12)hydrocarbon distribution of approximately 88.1%peak area.Regarding the syngas products,all catalysts except activated carbon successfully converted nitromethane compounds into tetranitromethane hydrocarbons,with activated carbon predominantly yielding nitromethane compounds.

Process Optimization of Effective Partition Constant in Progressive Freeze Concentration of Wastewater

Response surface methodology (RSM) was employed to optimize the process parameters for effective partition constant (K) in progressive freeze concentration (PFC) of wastewater. The effects of coolant temperature, circulation flowrate, initial solution concentration and circulation time on the effective partition constant were observed. Results show that the data were adequately fitted into a second-order polynomial model. The linear and quadratic of independent variables, coolant temperature, circulation flowrate, initial solution concentration and circulation time as well as their interactions have significant effects on the effective partition constant. It was predicted that the optimum process parameters within the experimental ranges for the best K would be with coolant temperature of -8.8℃, circulation flowrate of 1051.1 ml/min, initial solution concentration of 6.59 mg/ml and circulation time of 13.9 minutes. Under these conditions, the effective partition constant is predicted to be 0.17.

Lignocellulosic Biocomposite Membranes for Air Filtration and Environmental Protection:A Review

The increasing severity of air pollution necessitates more effective and sustained air filtration technology.Concurrently,the desire for more environmentally friendly,sustainable materials with better filtering performance and less environmental impact drives the move away from conventional synthetic membranes.This review presents lignocellulosic biocomposite(LigBioComp)membranes as an alternative to traditional synthetic membranes.It focuses on their materials,fabrication,and functionalization techniques while exploring challenges and proposing methods for resourceful utilization.Renowned for their abundance and renewable nature,lignocellulosic materials consist of cellulose,hemicellulose,and lignin.Various applications can benefit from their antibacterial properties,large surface area,and remarkable mechanical strength.LigBioComp membranes are fabricated through casting,electrospinning,and freeze-drying,with advancements in fabrication techniques enhancing their performance and applicability.It is suggested to use solvent-free or low-solvent techniques such as Layer-by-Layer assembly to minimize environmental impact.Freeze-drying and electrospinning with green solvents can be used for achieving specific membrane properties,though energy consumption should be considered.Apply dry-wet spinning and solvent casting processes selectively.Functional groups,including carboxyl,hydroxyl,or amino groups,can significantly improve the membrane’s capacity to capture particulate matter.Chemical etching or the precise deposition of nanoparticles can further optimize pore size and distribution.The choice of chemicals and methods is critical in functionalization,with silane coupling agents,polyethyleneimine,and polydopamine.Future research should prioritize refining fabrication methods,advancing functionalization strategies,and conducting performance and recyclability assessments on hybrid and composite materials.This will enhance integrated systems and contribute to the development of smart filters.

Catalytic steam reforming of tar for enhancing hydrogen production from biomass gasification:a review

Presently,the global search for alternative renewable energy sources is rising due to the depletion of fossil fuel and rising greenhouse gas(GHG)emissions.Among alternatives,hydrogen(H2)produced from biomass gasification is considered a green energy sector,due to its environmentally friendly,sustainable,and renewable characteristics.However,tar formation along with syngas is a severe impediment to biomass conversion efficiency,which results in process-related problems.Typically,tar consists of various hydrocarbons(HCs),which are also sources for syngas.Hence,catalytic steam reforming is an effective technique to address tar formation and improve H2 production from biomass gasification.Of the various classes in existence,supported metal catalysts are considered the most promising.This paper focuses on the current researching status,prospects,and challenges of steam reforming of gasified biomass tar.Besides,it includes recent developments in tar compositional analysis,supported metal catalysts,along with the reactions and process conditions for catalytic steam reforming.Moreover,it discusses alternatives such as dry and autothermal reforming of tar.