Conversion Of Waste Biomass Research Articles

Using Agricultural Residues as a Biomass Briquetting: An Alternative Source of Energy

Every year millions of tons of agricultural wastes are generated which are either destroyed or burnt inefficiently in loose form causing air pollution. These wastes can be recycled & can provide a renewable source of energy by converting biomass waste into high density - fuel briquettes without addition of any binder. This recycled fuel is beneficial for the environment as it conserves natural resources. For this the biomass briquetting is the main renewable energy resource. In this paper the raw material including rice husk, coffee husk, saw dust, ground nutshell and cotton stalks etc. were densified into briquettes at high temperature and pressure using different technologies. We discuss the various advantages, factors that affecting the biomass briquetting and comparison between coal and biomass briquetting. The details of the study were highlighted in this paper. Keywords- Biomass, Briquetting, Potential, Process, Technologies

Thermal decomposition of guaiacol in sub- and supercritical water and its kinetic analysis

The conversion of biomass waste into resources as a recycling process is receiving increased interest due to the perceived need for a sustainable global carbon cycle and environmental considerations. Several treatment processes are being developed. Hydrothermal treatment is one of the most effective approaches, because water at high temperatures and high pressures behaves as a reaction medium with remarkable properties. In this work, the reaction behavior of guaiacol as a biomass model compound was studied in subcritical water at 483–563 K and in supercritical water at 653–673 K using a batch reactor. Guaiacol can be considered representative of the aromatic ring structures present in lignin, a major component of woody biomass. The chemical species formed in aqueous products were identified by gas chromatography/mass spectrometry and quantified using high-performance liquid chromatography. The effect of pressure and reaction time on the conversion process of guaiacol is discussed. The results obtained indicate that this method has potential for efficient organic waste conversion.

Catalytic conversion of waste biomass by hydrothermal treatment

The purpose of the work presented here is the production of liquid biofuels from wet organic waste matter in a continuous one-step catalytic process under hydrothermal conditions. The catalytic reaction of wet organic matter at near-critical water conditions ( T > 300 °C, p > 22.1 MPa) is used to produce a mixture of combustible organics which can be used as liquid biofuel. In order to achieve a good product quality in a continuous one-step process, two catalysts were applied, a homogeneous potassium carbonate catalyst and a heterogeneous ZrO 2 catalyst. In addition, the reaction mixture was recirculated. The continuous flow of concentrated waste biomass feed at low flow rates and recirculation of the hot reaction mixture were the most challenging obstacles to overcome. The scale of the plant (0.1 l reactor volume) allowed for a variation of the feed, reaction temperature, and recirculation rate in order to optimise the process conditions. Still, the product quantity obtained was sufficient to perform a analytical characterisation. The experimental results confirmed the feasibility of the process. Hydrothermal treatment of waste biomass, after dewatering, resulted in a biocrude oil of high calorific value.

Biomass to dimethyl ether by gasification/synthesis technology-an alternative biofuel production route

Technical and economic analysis was done for the biomass to dimethyl ether (DME) technology to promote the gasification/synthesis route for biofuel production and its application as a fossil fuel substitute. The technology of biomass gasification/synthesis has obvious advantages, including production flexibility, environmental friendliness, economic feasibility, and application versatility. Biomass gasification/synthesis technology integrates bio-DME synthesis, fertilizer production, electricity generation, and waste heat utilization to convert waste biomass residues to DME for use as liquid petroleum gas, transportation fuel substitute, and chemical intermediates, which has been proven to be one of the most effective and clean biomass utilization routes. The 1000 t/a-scale demonstration plant has a bio-DME production rate of 6 to 7tbiomass/tDME, biomass gasification efficiency of ⩾82%, once-through CO conversion of ⩾70%, DME selectivity (DME/DME + other organic products) of ⩾90%, and a total system efficiency of ⩾38%. The demonstration plant also has self-sufficient steam and electricity supply. The 10,000tons/a-scale bio-DME production cost with or without feedstock subsidy is estimated to be 1968 Yuan/t and 2868 Yuan/t, respectively in China. Because of the limitation in biomass feedstock collection cost, massive and disperse commercial plants with a capacity of 10000 t/a bio-DME are more suitable for rural areas.

Exergy and Energy Analysis of Plasma Waste-to-power Generation Model

ABSTRACT This research addresses three major problems currently affecting our globe. These problems are the pending energy crisis, the environmental degradation caused by an ever increasing growth of waste and the environmental degradation resulting from the continuous generation of greenhouse gas emissions. In light of these problems, efforts are geared towards the development of a ‘one-stop’ solution. A preliminary survey of available technical data indicates that the three problems could be solved through the use of an efficient plasma gasification technology. The use of this plasma technology can simultaneously disintegrate waste while electrical power is generated and greenhouse gas emissions eliminated. The other two methods of converting biomass (waste) to heat energy, namely combustion and conventional gasification are also presented with the chemical composition of the three methods analyzed using thermochemical data to determine which of the three has the best optimum option for heat energy conv...

Anaerobic bacterial degradation for the effective utilization of biomass

Biomass is originally photosynthesized from inorgainic compounds such as CO2, minerals, water and solar energy. Recent studies have shown that anaerobic bacteria have the ability to convert recalcitrant biomass such as cellulosic or chitinoic materials to useful compounds. The biomass containing agricultural waste, unutilized wood and other garbage is expected to utilize as feed, food and fuel by microbial degradation and other metabolic functions. In this study we isolated several anaerobic, cellulolytic and chitinolytic bacteria from rumen fluid, compost and soil to study their related enzymes and genes. The anaerobic and cellulolytic bacteria,Clostridium thermocellum, Clostridium stercorarium, andClostridium josui, were isolated from compost and the chitinolyticClostridium paraputrificum from beach soil andRuminococcus albus was isolated from cow rumen. After isolation, novel cellulase and xylanase genes from these anaerobes were cloned and expressed inEscherichia coli. The properties of the cloned enzymes showed that some of them were the components of the enzyme (cellulase) complex,i.e., cellulosome which is known to form complexes by binding cohesin domains on the cellulase integrating protein (Cip: or core protein) and dockerin domains on the enzymes. Several dockerin and cohesin polypeptides were independently produced byE. coli and their binding properties were specified with BIAcore by measuring surface plasmon resonance. Three pairs of cohesin-dockerin with differing binding specificities were selected. Two of their genes encoding their respective cohesin polypeptides were combined to one gene and expressed inE. coli as a chimeric core protein, on which two dockerin-dehydrogenase chimeras, the dockerin-formaldehyde dehydrogenase and the dockerin-NADH dehydrogenase are planning to bind for catalyzing CO2 reduction to formic acid by feeding NADH. This reaction may represent a novel strategy for the reduction of the green house gases. Enzymes from the anaerobes were also expressed in tobacco and rice plants. The activity of a xylanase fromC. stercorarium was detected in leaves, stems, and rice grain under the control of CaMV35S promoter. The digestibility of transgenic rice leaves in goat rumen was slightly accelerated.C. paraputrificum was found to solubilize shrimp shells and chitin to generate hydrogen gas. Hydrogen productivity (1.7 mol H2/mol glucose) of the organism was improved up to 1.8 times by additional expression of the own hydrogenase gene inC. paraputrficum using a modified vector ofClostridium perfringens. The hydrogen producing microflora from soil, garbage and dried pelletted garbage, known as refuse derived fuel (RDF), were also found to be effective in converting biomass waste to hydrogen gas.

Hydrothermal conversion of biomass wastes into resources

Abstract Hydrothermal process is one of the most promising processes for the conversion of biomass waste into useful materials among several biomass conversion processes, because water of high temperature and high pressure has remarkable properties as a reaction medium. This report describes some recent advances in our research involving the production of acetic and lactic acids from biomasses and their some reaction mechanisms, mainly including (1) acetic acid production by controlling pathways of hydrothermal reaction, (2) oxidation pathways for some model compounds of biomass, (3) acid-base behavior of water in the subcritical region, and (4) influence of lignin and/ or phenol derivatives as oxidation retardant on the acetic acid production in WO of lignocellulosic biomass.

Cyanobacterial bioconversion of carbon dioxide for fuel productions

Abstract Laboratory-scale systems for bioconversion of CO 2 to biofuels, H 2 and ethanol, have been developed in an attempt to present data for baseline evaluation of a resource recycling technology utilizing biomass of cyanobacteria. The procedure employs cultivation in the light of photolithotroph Synechococcus leopoliensis , onset, by shift into anaerobic dark, of hydrogenase-mediated H 2 formation reaction, and conversion of biomass waste into ethanol. Cyclic turnover of carbon by harnessing photosynthesis was successfully demonstrated by the experiment, but the research for a large-scale fuel production is still in its preliminary stage.

Conversion of waste biomass (pea-shells) into hydrogen and methane through anaerobic digestion

Conversion of waste biomass (pea-shells) into hydrogen and methane through anaerobic digestion

96/00517 Conversion of waste biomass (pea-shells) into hydrogen and methane through anaerobic digestion

96/00517 Conversion of waste biomass (pea-shells) into hydrogen and methane through anaerobic digestion

Conversion of waste biomass (pea-shells) into hydrogen and methane through anaerobic digestion

Waste pea-shells were digested under batch anaerobic conditions. Digestion of pea-shell slurries (PSS) at 1–5% total solids (TS) concentration, with H 2-producting organisms yielded 99–362l biogas-H/kg organic solids reduced (biogas-H: mixture of H 2, CO 2 and H 2S). Hydrogen constituted 33–46% of the total biogas-H. Methanogenesis of PSS (1–5% TS) was most effective at 1% TS level. During 25 days of incubation, 507 l biogas/kg was generated (biogas: mixture of CH 4, CO 2 and H 2S). Methane accounted for 43% of the total biogas yield. Biogas yield of 1% TS PSS without the fibrous sheath was only 16·5% of that of 1% TS PSS with the fibrous sheath. However, 3% TS PSS without the fibrous sheath showed improved results, which could be employed for continuous-culture digestions.

A decentralized approach for biocoal production in a mud kiln

The thermochemical conversion of waste biomass was studied in a 1-m 3 mud kiln. The yield of biocoal from the kiln ranged between 32 and 33%, depending upon the raw material used for carbonization. The physiochemical properties of the biomass and the biocoal, the composition of the flue gases, and the heating value of the fuel were determined, and a cost benefit analysis performed.