Biogas Purification Process Research Articles

Membrane applications for biogas production and purification processes: an overview on a smart alternative for process intensification

Biogas is the result of a complex conversion process that takes place because of the metabolic activity of various types of bacteria.

Water Scrubbing for Removal of Hydrogen Sulfide (H<sub>2</sub>S) Inbiogas from Hog Farms

Biogas from anaerobic digestion of biological wastes is a renewable energy resource. H2S in biogas may cause corrosion or other damage to engines if it is not removed from the gas before utilization. Because the solubility of H2S in water is higher than methane, water can be used as an adsorbent to remove H2S from biogas. A simple water scrubbing column to reduce the H2S content was designed in this study. The biogas purification process took place in the scrubbing column with water where the gas was continuously fed from the bottom of the column through the diffuser which could produce bubbles. The biogas bubbles and the water can accelerate the reaction inside the column. The water in the column was circulated by means of a pump. H2S content in raw biogas was about 6000 ppm. First, the efficiencies of H2S removal for different biogas flow rate and water level were conducted at 30 and 90 sec. Second, the efficiencies of H2S removal with water recycling system were induced. The results showed that the concentration of H2S in biogas decreased significantly with water level and increased with biogas flow rate through the water scrubbing. It was an effective technique for removing H2S in a short operation time, but absorption capability of water declined rapidly with time. To maintain high absorption rate, water scrubbing after adsorption needed to be replaced or regenerated. The water scrubbing system is a simplest and cheapest method. This work is investigated the feasibility of water scrubbing system and its application to a small hog farm.

Evaluation of Organic and Ionic Liquids for Three-Phase Methanation and Biogas Purification Processes

Three ionic liquids {butyl-trimethyl-ammonium bis(trifluoromethylsulfonyl)imide [N1114][BTA], 1-methyl-1-propyl-piperidinium bis(trifluoromethylsulfonyl)imide [PMPip][BTA], and 1-ethyl-3-methylimid...

Multicomponent adsorption measurements on activated carbon, zeolite molecular sieve and metal–organic framework

Sorptive gas treatment for biogas purification, mainly in pressure swing adsorption processes, currently constitutes the state of the art. Consequently the knowledge of sorption properties of appropriate sorbent materials is of great importance. In this context pure gas isotherms are often used for the evaluation of such materials. To allow a realistic description of sorptive biogas purification processes the multicomponent sorption behavior of corresponding materials is of special interest. For this reason we present measurement data for the selective sorption of quaternary gas mixtures on activated carbon Norit R1 Extra, zeolite molecular sieves 13X and metal–organic framework Basolite C300 with a gas mixture consisting of 60 mol% CH4, 33 mol% CO2, 5 mol% N2 and 2 mol% H2. Measurements were performed with a manometric-gravimetric sorption measurement apparatus, combined with a gas chromatography system. In contrast to the aforementioned multicomponent sorption measurement, measured pure gas sorption data are often used for multicomponent sorption prediction. For this purpose, several prediction models, i.e. the IAST model, are available. In this context, the multicomponent sorption behavior of the materials mentioned above was also predicted using the IAST model. The results of the performed sorption measurements and the comparison to the predicted sorption data will be presented and discussed in this paper.

Design simulations for a biogas purification process using aqueous amine solutions

AbstractUsing the simulation program CHEMCAD, performance characteristics, design optimization, and costs of an absorption/stripping system used to purify 100 kg h−1 of biogas in a biogas power plant were investigated. Potential absorbents used in the chemical absorption process were the following aqueous solutions: pure diglycolamine, diglycolamine/piperazine, and diglycolamine/methyldiethanolamine/piperazine. Mixtures for agricultural biogas purification to below 1 vol. % of CO2 and 4 × 10−4 mass % of H2S were determined via a simulation in the above mentioned program. The chosen mixtures were then entered into an absorption/desorption system and simulations for each unit were provided by CHEMCAD. From the simulation results, the design parameters were calculated and entered into each unit’s “cost estimation” section in the aforementioned program to estimate the purchase costs of the apparatuses. Taking into account the installation, maintenance, as well as other additional costs, the actual machine purchase costs were multiplied by the Lang factor. Costs of additional streams were also calculated by multiplying the ten-year utility losses by their respective cost factors. From these calculations, the absorbent mixture, allowing biogas production at the lowest estimated costs for ten years, was found.

A review of biogas purification processes

AbstractBiogas is a valuable renewable energy carrier. It can be exploited directly as a fuel or as a raw material for the production of synthesis gas and/or hydrogen. Methane (CH4) and carbon dioxide (CO2) are the main constituents, but biogases also contain significant quantities of undesirable compounds (contaminants), such as hydrogen sulfide (H2S), ammonia (NH3) and siloxanes. The existence and quantities of these contaminants depend on the biogas source (i.e., landfills, anaerobic fermentation of manure). Their presence constitutes a major problem because (i) they can be detrimental to any biogas thermal or thermocatalytic conversion device (e.g., corrosion, erosion, fouling); and (ii) they generate harmful environmental emissions. It is therefore important to include biogas purification steps upstream of its final use processes. This review is aimed at presenting the scientific and technical state‐of‐theart in biogas purification processes. Both mature, already‐applied and promising, under‐development technologies are reported and described here. © 2008 Society of Chemical Industry and John Wiley & Sons, Ltd