A. Introduction
Biogas – a term that has been synonymous to the rural culture, a viable alternate to the rapidly depleting conventional sources, a resource whose production is cheaper, and almost cent percent of the raw materials used to produce it get utilised. Owing to the tremendous rise in the fuel consumption, we need to search for substitutes – one that can replace (the already not-so-left resources), revive (a less polluting option) and replenish (the present state of livelihood).
In this report, I’d discuss about one of the adsorption techniques involved in the removal of hydrogen sulphide – a vital component of biogas which needs to be removed from the source gas (apart from water and carbon dioxide which are in excess proportions and others components found in traces).
B. Anaerobic Digestion
Anaerobic Digestion is a natural process where plant and animal materials (biomass) are broken down by micro-organisms in the absence of air.
The nature of the raw materials and the operational conditions used during anaerobic digestion, determine the chemical composition of the biogas. Raw biogas consists mainly of methane (CH4, 40–75%) and carbon dioxide (CO2, 15–60%). Trace amounts of other components such as water (H2O, 5–10%), hydrogen sulphide (H2S, 0.005–2%), siloxanes (0–0.02%), halogenated hydrocarbons (VOC, < 0.6%), ammonia (NH3, <1%), oxygen (O2, 0–1%), carbon monoxide (CO, <0.6%) and nitrogen (N2, 0–2%) can be present depending upon the type of feedstock being digested.
C. Biomethane
Biomethane is pipeline-quality, high BTU methane derived from biogas. A renewable and readily available low-carbon alternative fuel, Biomethane, can be produced locally from organic waste. After it is processed to required standards of purity...
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...anism of the wet streams with no oxygen:
H2S (gas) → H2S (ads) (i)
H2S (ads) → H2S (ads-liq) (ii)
H2S (ads-liq) → HS- (ads) + H+ (iii)
2HS- (ads) + O* (ads) → 2S (ads) + H2O (iv) where H2S (gas), H2S (ads-liq) and H2S (ads) are concentration of hydrogen sulphide in gas, liquid film and adsorbed phases respectively. First, the H2S (gas) is adsorbed onto the carbon surface, followed by the dissolution of H2S (ads) into the water film, then the dissociation of the H2S (ads-liq) into ions concluding with the surface reaction with oxygen functional group.
Assuming the equilibrium isotherm to behave linearly, I’ve considered the Thomas model (Thomas, 1944), that uses Langmuir isotherm for equilibrium and 2nd order reversible reaction kinetics based on ion exchange theory.
Image courtesy: google/images/activated carbon
The expression for adsorption kinetics is described as
Sulfur is found in the cells of all living organisms and plays a critical role in the oxygenation and detoxification of all cells. It is one of the basic building blocks used throughout the body to make a variety of chemicals such as enzymes, collagen, amino acids, hormones, neurotransmitters, and much more.
Biodiesel is considered an environmentally friendly alternative because it reduces the amount many toxic substances. Plants such as soybeans require carbon dioxide from the air to produce their stems, roots and leaves. During biodiesel production from soybean oil, carbon dioxide is produced and released in the atmosphere. Carbon dioxide is considered a green house gas (GHG). However, this cycle of GHG emission does not neccersarily contribute to the atmospheric carbon dioxide levels. This is because the next soybean crop will reuse the carbon dioxide emitted for its growth. Another important environmental benefit is that biodiesel reduces particulate matter (PM), hydrocarbon (HC) and carbon monoxide (CO) emissions. These benefits occur because biodiesel contains 11% oxygen by weight. Oxygen allows the fuel to burn better, resulting in fewer emissions from unburned fuel. And lastly, biodiesel fuels do not contain any sulfur and does not have an unpleasant smell when it is emitted from vehicles.
mainly composed of methane and carbon dioxide, is the result of the anaerobic decomposition of
Villagers use firewood, which they get, from community forests where each community has its own allocation of wood. Buffalo and cow dung mixed with water and then fed into a reactor is used to provide villagers with biogas.
Carlson, T. R., Vispute, T. P. & Huber, G. W. Green gasoline by catalytic fast pyrolysis of solid biomass derived compounds. ChemSusChem 1, 397–400 (2008).
The human digestive system is a bodily process made up of many systems, organs and substances that break down food both physically and chemically for use by the body. But what exactly is human digestion and what happens to food as it moves through the digestive system? “…[digestion] is a group of organs working together to convert food into energy and basic nutrients to feed the entire body” (Tim Taylor). There are three major bodily mechanisms that contribute to the process of digestion. The first mechanism is the breakdown of food, the second mechanism is the process of extracting nutrients from food, and the third mechanism is excretion, or the body’s natural waste system. Each mechanism uses specific bodily organs and chemical compounds to assist in the digestion process. Organs such as the mouth, tongue, throat, liver, esophagus, gallbladder, pancreas, small and large intestines, rectum and anus are all key to the digestive process. These organs and mechanisms come together to convert the food humans eat into energy and nutrients that the body uses to sustain life, and to get rid of unnecessary waste that could be harmful to the body. Although the removal of waste from the human body can be an awkward subject to discuss it is an important part of the digestive system because if left in the body this waste would eventually poison us. The digestive system is interesting, complex and truly important to our daily lives. Without the digestive system energy and nutrients vital to the body could never reach body cells and a person wouldn't be able to do all the things they like to do, such as study, play sports, and hang out with friends.
Gas grills are ideal for year-round cooking and the perfect option when you crave the smoky flavor of outdoor grilling. A great grill serves as the focal point for well-planned backyard parties and impromptu family barbecues, and the best will last for many years. We have searched near and far to bring you five of the best grills available today - check out all the features and pick the one that you can’t grill without! Char-Broil® Classic 4-Burner Gas Grill 40,000 BTU This Classic Char-Broil® grill has a stainless steel lid and and handle and control panel for stylish good looks and functionality.
...ch is used to replace natural gas. He also stated that, among the equipment used to burn the biofuel, the suspension burner have the ability to exceed 99% efficiency and whole-tree burner can reduce the cost of harvesting and handling woody fuels by about 35% (Brown, 2003). Moreover, the usage of bio-energy in long term is to provide a degree of ecological balance and climate change, avoid acid rain, reduce soil erosion and minimize water pollution (Gevorkian, 2007). Therefore, biomass is environmental friendly like solar energy. Based on the research that has been carried out regarding the synthesis of gas from biomass, the gas gasifies in the internal combustion engine. The relative energy density of synthesis gas is higher than the fossil fuel under certain conditions. In addition, the relative flame speed of synthesis gas can reduce the time for spark ignition.
Results showed that the adsorption efficiency is highly dependent on quanttity of adsorbent added. This was expectedas with increasing conc...
Energy, especially from fossil fuels, is a key ingredient for all sectors of a modern economy and plays a fundamental role in improving the quality of life in less developed economies. In 2007, India is ranked fifth in the world in terms of energy demand; accounting for 3.6% of total energy consumed, and is expected to grow at 4.8% in the future. India imports 70% of the oil it uses, and the country has been hit hard by the increasing price of oil, uncertainty and environmental hazards that are concerned with the consumption of fossil fuels. In such context, bio energy constitutes a suitable alternative source of energy for India, as large amounts of raw material are available to be harnessed.
Microbial decomposition releases nutrients into the environment that are needed by other organisms. Microbes are also involved in the cycling of many other important compounds in — and between — ecosystems, including oxygen, carbon and nitrogen. Many microbes use the energy of sunlight to convert carbon dioxide to oxygen, which we need to breathe. As they do this, they create new organic material — themselves — which are then eaten by other organisms. In this way, the cycling of nutrients and energy
Composting is the process of biodegrading the waste material in which an enormous number of materials like hydrocarbons, nitrogenous compounds, acids, their derivatives and even other organic and inorganic substances can be remediated from the environment (Finstein et al., 1986). Compost pro...
Gasification products can be divided in fuel gases and non-fuel gases. The fuel gas (mixture of Carbon monoxide, Hydrogen and traces of Methane) is called producer gas. In particular, section 2.2 focuses on the non-fuel gases such as Carbon dioxide, Nitrogen, some hydrocarbons and water steam which cannot be utilized for combustion. Table 1 shows that according to the gasifier system and the gasifier agent, the biogas composition
The concept of this essay is to stress that biofuels are a viable and sustainable energy source than fossil fuels, showing its advantages but not ignoring its disadvantages which also enlightens us about the cleaner and renewable natural resources. Biofuels is an alternative source of energy which can end the global dependence on fossil fuels.
Food waste is huge issue these days. It is a huge amount of waste that ends up in landfills and can have lasting effects on the environment. One of major issues of food waste is the greenhouse gases that it produces. Methane gas is the main culprit when it comes to the gases being released. This can absorb infrared radiation and heat up the earth’s atmosphere and cause climate change. Another issue that food waste causes is, water loss due to use for production of fruits and vegetables.