Orthogonal Test About Biogas Upgrading by Pressured Water Scrubbing

Biogas is a kind of regenerable energy which is inexpensive and friendly to the environment, but the potential ofbiogas is difficult to develop fully in China, for most biogas have badly qualities and the utilization of it is monotonous. The suitable operation term about biogas upgrading by pressurized water scrubbing was researched through the orthogonal test in this study. Two sorts of scrubber packing included the random multidimensional hollow sphere packing and the structured screen packing were also used, and the effects of experiment factors included packing, water temperature, gas flow speed, water flow speed and washing pressure were studied. The results showed that better effect was got when the screen structured packing was used; all the five test factors affected the processing significantly in the arrange as before and had better and better significant effects.

Biogas upgrading technologies: Energetic analysis and environmental impact assessment

Biogas upgrading for removing CO2 and other trace components from raw biogas is a necessary step before the biogas to be used as a vehicle fuel or supplied to the natural gas grid. In this work, three technologies for biogas upgrading, i.e., pressured water scrubbing(PWS), monoethanolamine aqueous scrubbing(MAS) and ionic liquid scrubbing(ILS), are studied and assessed in terms of their energy consumption and environmental impacts with the process simulation and green degree method. A non-random-two-liquid and Henry's law property method for a CO2 separation system with ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide([bmim][Tf2N]) is established and verified with experimental data. The assessment results indicate that the specific energy consumption of ILS and PWS is almost the same and much less than that of MAS. High purity CO2 product can be obtained by MAS and ILS methods, whereas no pure CO2 is recovered with the PWS. For the environmental aspect, ILS has the highest green degree production value, while MAS and PWS produce serious environmental impacts.

A highly efficient photocatalytic system for environmental applications based on TiO_(2) nanomaterials

Sustainable and efficient water treatment techniques to improve the quality of water for various applications include advanced oxidation processes(AOP),mainly focusing on heterogeneous photocatalysis.Materials science and nanotechnology have contributed to tailoring the properties of photocatalytic materials to significantly enhance their photoactivity and stability.Here we report the development of a well-organized nanoporous TiO_(2)-based photocatalytic reactor for water treatment.Nanoporous TiO_(2) materials were directly grown using a two-step electrochemical anodization process in ethylene glycol+0.3 wt%NH_(4)F+2 wt%H_(2)O.The prepared nanomaterials were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),and energy-dispersive X-ray spectroscopy(EDX).To enhance the photocatalytic activity of the system,water scrubbing was incorporated to boost the presence of oxygen in the water,enhancing the electron uptake at the conduction band thus significantly reducing the electron–hole recombination and increasing the photocatalytic activity.To further enhance the efficiency and reduce the negative environmental impact of the technology,a UVA-LED assembly was used instead of the typical mercury-based UV lamps for photocatalysis.The nanoporous TiO_(2) was tested as a catalyst for the photochemical oxidation of various categories of pollutants;dye(methylene blue),and the removal of microbes such as E.coli.The photoreactor developed in this research work was also successfully applied and tested in real-world applications such as keeping heavily used hot-tub water clean without using harmful chemicals(chlorine,bromine,ozone,etc.)or expensive equipment.The simplicity and efficacy of the new approach described in this study make possible the integration of nanoporous TiO_(2) in the design of high-performance air and water purification technologies.

Fundamentals and developments of compressed biogas in city gas distribution network in India:A review

Biogas is a significant renewable source as well as an alternative energy carrier provided by Anaerobic Digestion(AD)of biodegradable food wastes and other organic materials.This paper describes some major facts about biogas along with the barriers and adaptation of CBG in society,it also narrates the types of feedstocks available for biogas generation and what are the major sources in India.In this study,different stages of anaerobic digestion are discussed such as hydrolysis,acidogenesis,acetogenesis and methanogenesis for biogas production.After its purification,the biogas can be used as a fuel for domestic as well as transportation purposes.A glimpse of biogas like purification techniques like biological desulphurization,iron chloride dosing,pressure swing adsorption,chemical scrubbing and water scrubbing is given,the major additions of national policy of biofuels in 2018 is also highlighted.It has been found that in India,majorly pressure swing adsorption and water scrubbing methods are used for biogas purification,currently,the country has 12 commercial CBG plants with a total CBG output capacity of 18,461.7 tonnes per year,which is just 0.06 percent of the total ability.The details of the plants along with their CBG production capacity are described,and sustainable alternative towards affordable transportation(SATAT)launched by MoPNG is introduced in this study,furthermore,the features and types of models suggested by Ministry of Petroleum and Natural Gas(MoPNG)to introduce compressed biogas(CBG)in city gas distribution(CGD)network are discussed.