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The correct CHOICE is (a) BIODIESEL

The best I can explain: Biodiesel is MADE by combining alcohol with vegetable oil, animal FAT or recycled cooking grease. It can be used as an additive to reduce vehicle emissions or in its pure form as a renewable alternative fuel for diesel engines.

Correct ANSWER is (b) Petrol engine

Explanation: Petrol engine can run on biogas, but it is required to be STARTED with petrol in the beginning. Petrol engine can be modified for OPERATION on biogas including provision for entry of biogas, throttling of intake air and advancing IGNITION timing.

The correct choice is (c) SUGAR

Explanation: GLUCOSE is a simple sugar with the molecular formula C6H12O6, which means that it is a MOLECULE that is made of six carbon atoms, twelve hydrogen atoms, and six OXYGEN atoms. Plants form sugar (glucose) on photosynthesis.

Correct choice is (a) Feedstock

For explanation I WOULD say: The most important initial issue when considering the application of anaerobic digestion SYSTEMS is the feedstock to the process. Almost any ORGANIC material can be PROCESSED with anaerobic digestion; however, if biogas production is the aim, the LEVEL of digestion is the key factor in its successful application.

Correct option is (a) 1:1

For explanation I would say: Experience has shown the raw material (domestic and poultry WASTES and MANURE) ratio to water should be 1:1, i.e., 100KG of excrete to 100 kg of water. In the slurry, this CORRESPONDS to a total solids CONCENTRATION of 8-11 per cent by weight.

The correct choice is (b) Digester

The best I can explain: The central part of an anaerobic plant in an ENCLOSED tank is known as digester. This is an airtight FILLED with the organic waste, and which can be EMPTIED of digested slurry with some means of catching the produced gas.

The correct OPTION is (b) 10

The explanation: The STORAGE of RAW materials in a damp, confined space for over ten days INITIATES anaerobic bacterial action that, though causing some gas loss, reduces the time for the digester to BECOME operational.

Correct choice is (b) CROSS draught gasifier

The best I can explain: A disadvantage of cross draught gasifiers is their minimal TAR converting capacity and the consequent needs for the high quality charcoal. It is because of the UNCERTAINTY of charcoal quality that a number of charcoal gasifiers EMPLOY down draught principle, in order to maintain at least a minimal tar CRACKING capability.

Right answer is (a) GLYCERALDEHYDES’ 3-PHOSPHATE

For explanation I would say: Glyceraldehydes’ 3-phosphate, also known as trio-phosphate and abbreviated as G3P, GALP or PGAL, is a chemical compound that occurs as an intermediate in several central metabolic pathways of all organisms. It is a phosphate ester of the 3-carbon sugar glyceraldehydes and has chemical FORMULA C3H7O6P.

Correct choice is (b) Vehicle Refueling Appliances

To EXPLAIN: Vehicle refueling appliance is abbreviated as VRAs. Certified natural gas compressors for refueling the VEHICLES are COMMERCIALLY available. These allow refueling at home and WORK. After upgrading with the above-mentioned technologies, the biogas (transformed into biomethane) can be used as vehicle fuel in adapted vehicles.

Correct answer is (a) By dilution

To explain: WASTES and BIODEGRADABLE residue are OFTEN accompanied by a variety of pollutants that could inhibit anaerobic DIGESTION. Potential toxicity can be corrected by remedying the C/N RATIO of manure by dilution.

Right answer is (a) Vegetable matter

For EXPLANATION: Vegetable matter PRODUCES about 8 TIMES more gas, so the quantity required is much smaller in batch production for the same gas production from any other wastes. A mixture of dung and vegetable matter is hence ideal in most ways, with a MAJORITY of vegetable matter to provide the biogas and the VALUABLE methane contained in it.

The correct answer is (b) False

To explain I would say: Energy plantation means GROWING select species of trees and shrubs which are harvestable in a comparably shorter time and are specifically meant for fuel. The fuel wood may be used either directly in wood burning STOVES and boilers or processed into METHANOL, ETHANOL and producer GAS.

The correct choice is (a) Diesel engine

To explain I would say: Diesel engine can run on dual fuel with LITTLE engine modifications. Advancing the INJECTION timing and entry of BIOGAS with INTAKE AIR, it can be achieved by providing a mixing chamber below the air cleaner which facilitates mixing of biogas with air before entering into the cylinder.

Right option is (a) BATCH plants

The best I can explain: Batch plants are filled and then emptied completely after a fixed retention time. Each DESIGN and each FERMENTATION material is SUITABLE for batch filling, but batch plants require high labor input.

Correct choice is (B) Reduction in FERTILITY of mixture

Explanation: Too much nitrogen will cause this to be left over at the end of digestion and reduce the quality of the fertilizer PRODUCED by biogas plant. The correct ratio of carbon to nitrogen will prevent loss of either fertilizer quality or METHANE content.

Correct choice is (c) In INVERTED drum

Explanation: The biogas in an anaerobic DIGESTER is COLLECTED in an inverted drum. The walls of the drum extended down into the slurry to provide a seal. The drum is free to move to accommodate more or less GAS NEEDED.

Correct option is (c) Digestate

The BEST EXPLANATION: Digestate is the solid remnants of the original input material to the DIGESTERS that the microbes cannot USE. It also consists of the mineralized remains of the dead bacteria from within the digesters. Digestate can come in THREE forms: fibrous, liquor, or a sludge-based combination of the two fractions.

The CORRECT choice is (a) 30 – 40^oC

To elaborate: With a mesophilic flora, DIGESTION precedes best at 30 – 40^oC; with thermophiles, the optimum RANGE is 50 – 60^oC. The choice of the temperature to be used is influenced by climatic considerations.

Correct choice is (a) Heat content

To elaborate: The British thermal UNIT (Btu or BTU) is a traditional unit of heat; it is defined as the amount of heat required to RAISE the TEMPERATURE of one pound of water by one degree Fahrenheit. Its counterpart in the METRIC system is the calorie, which is defined as the amount of heat required to raise the temperature of one gram of water by one degree Celsius.

The correct choice is (c) Substrate composition

The best I can explain: Substrate composition is a major factor in determining the methane yield and methane production rates from the digestion of BIOMASS. Techniques to determine the compositional characteristics of the feedstock are available, while parameters such as SOLIDS, ELEMENTAL, and ORGANIC analyses are important for digester design and operation.

The correct answer is (c) Co-current gasifier

Best explanation: Down draught gasifier or co-current GASIFIERS EQUIPMENT lies in its inability to OPERATE on a number of unprocessed fuels. In particular, fluffy, low density materials GIVE rise to flow problems and excessive pressure drop and the solid fuel MUST be pelletized before use.

Right answer is (c) 4

Easiest EXPLANATION: There are four types of gasifiers namely:

i. Up draught or counter CURRENT gasifier.

ii. Down draught or co-current gasifier.

iii. CROSS draught gasifier.

iv. Fluidized BED gasifier.

Correct option is (b) Compressed NATURAL gas

To explain I would say: Compressed natural gas (CNG) (methane stored at high pressure) is a fuel which can be used in place of gasoline (petrol), Diesel fuel and propane/LPG. CNG combustion produces fewer undesirable GASES than the fuels mentioned above.

The correct CHOICE is (d) 85%

To explain: Petrol engine can be OPERATED on BIOGAS after initially STARTING with petrol. Petrol replacement of 1005 is possible and petrol engines can develop about 85% of RATED power where as diesel engine can develop full power.

Right OPTION is (b) Chloroplast

The best I can explain: The MAIN ROLE of chloroplasts is to CONDUCT PHOTOSYNTHESIS, where the photosynthetic pigment chlorophyll captures the energy from sunlight and converts it and stores it in the energy-storage molecules ATP and NADPH while freeing oxygen from water.

The correct CHOICE is (c) Autotrophs

Explanation: An autotrophor producer, is an organism that PRODUCES complex organic compounds (such as carbohydrates, FATS, and proteins) from simple SUBSTANCES present in its surroundings, generally using energy from light or inorganic CHEMICAL reactions.

The correct OPTION is (C) Lumen

To explain: The lumen is the region within the thylakoid MEMBRANE where water is split to obtain OXYGEN. The oxygen diffuses out of the cell, while the protons remain inside to build positive ELECTRICAL charge inside the thylakoid.

The CORRECT answer is (C) [CH2O]n

To elaborate: [CH2O]n is the correct form for representing carbohydrates. Green PLANTS MAKE food in the form of carbohydrates by combining carbon dioxide and water using energy from sunlight. The simplest useful form of carbohydrate produced by photosynthesis is glucose sugar. Glucose may be used as an energy SOURCE.

Right choice is (b) Particle size DISTRIBUTION

Easy explanation: The particle-size distribution (PSD) of a powder, GRANULAR material, or PARTICLES dispersed in fluid is a list of values or a MATHEMATICAL function that defines the relative amount, typically by mass, of particles present according to size.

The correct choice is (C) CHLOROPHYLL

The BEST explanation: The conversion of usable sunlight energy into usable chemical energy is ASSOCIATED with the actions of the green pigment chlorophyll. Most of the time, photosynthetic process use WATER and releases the oxygen that we absolutely must have to stay alive.

Right option is (b) 2 – 4 week

To explain: Depending on the waste material and operating temperature, a batch DIGESTER will start producing BIOGAS after 2 – 4 weeks, slowly INCREASE in production then drop off after three or 4 months. Batch digesters are therefore best OPERATED in GROUPS.

The correct option is (d) 50 – 100 cm

Easiest explanation: In hot regions it is relatively EASY to simply SHADE the digester to keep it in the IDEAL range of temperature, but COLD climates present more of a challenge. The first action is, naturally, to insulate the digester with straw or wood shavings. A layer about 50 – 100 cm thick, coated with a waterproof covering is a GOOD start.

The correct CHOICE is (a) Vegetable MATTER

Explanation: Most vegetable matte has a much higher carbon – nitrogen RATIO than dung has, so some nitrogen producers (preferably organic) must generally be added to vegetable matter, ESPECIALLY when batch digestion is used.

Correct CHOICE is (c) Adenosine pyrophosphate

Explanation: Adenosine di-phosphate (ADP), ALSO known as adenosine pyrophosphate (APP), is an important organic compound in metabolism and is essential to the flow of ENERGY in LIVING cells. ADP consists of three important structural components: a sugar backbone attached to adenine and two phosphate groups bonded to the 5 CARBON atom of ribose.

Right option is (a) 8%

To explain: Anaerobic digestion of organics will proceed BEST if the input material CONSISTS of roughly 8% SOLIDS. In the case of fresh COW manure, this is the equivalent of dilution with roughly an equal quantity of water.

Right answer is (b) 2

Explanation: Photosynthesis is a two stage process. The first process is LIGHT DEPENDENT process which requires the DIRECT energy of light to make energy carrier MOLECULES that are used in the SECOND process. And the second stage is termed as Dark reaction.

The CORRECT choice is (c) Photosynthesis

The best EXPLANATION: Photosynthesis is the process, by which plants, some bacteria and some protistans use the ENERGY from sunlight to produce sugar, which cellular respiration converts into ATP, the fuel used by all living THINGS.

Correct choice is (a) ACETOGENESIS

The best I can explain: The THIRD stage of anaerobic digestion is acetogenesis. Here, simple molecules CREATED through the acidogenesis phase are further DIGESTED by acetogens to produce largely ACETIC acid, as well as carbon dioxide and hydrogen.

Right choice is (a) Counter current GASIFIER

Explanation: The OLDEST and simplest type of gasifier is the counter current or up draught gasifier. The major advantage of this type of gasifier are its simplicity, high charcoal BURNOUT and internal heat EXCHANGE leading to low gas EXIT temperatures and high equipment efficiency.

Correct answer is (a) Their output is not steady

The best explanation: Batch biogas plants are loaded with substrate completely and after some determined digestion TIME are FULLY unloaded. For this LOADING METHOD any DESIGN of biogas plant and any design of biogas plant any substrate can be used, but such plants are distinguished by unstable biogas production. The major disadvantage of batch plant is the output is not steady.

Correct option is (b) ANAEROBIC DECOMPOSITION

Explanation: Anaerobic decomposition will produce methane, carbon DIOXIDE, some hydrogen and other gases in trace, very little heat and a final product with a higher NITROGEN content than is produced by anaerobic fermentation process.