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The CORRECT option is (a) Bio products made from SUGARS

To explain: Bio products that can be made from sugars include antifreeze, plastics, glues, ARTIFICIAL SWEETENERS, and gel for toothpaste. Bio products that can be made from carbon monoxide and hydrogen of Syngas include plastics and ACIDS, which can be used to make photographic films, textiles, and synthetic fabrics.

Right CHOICE is (b) Alcohol

The best I can explain: Ethanol is also called as an alcohol. In BIOMASS, it is made by FERMENTING any biomass high in carbohydrates through a PROCESS similar to BEER brewing. Ethanol is also made from starches and sugars.

The correct CHOICE is (a) True

To elaborate: The use of biomass energy has the potential to greatly reduce greenhouse gas emissions. Burning biomass releases about the same amount of carbon dioxide as burning fossil fuels. HOWEVER, fossil fuels release carbon dioxide captured by PHOTOSYNTHESIS millions of years ago an ESSENTIALLY “new” greenhouse gas.

Right option is (d) Sustainable energy

The best I can explain: Biogas is renewable energy source. BIOMASS energy from plants and plant derived materials. Wood is still the largest biomass energy resource today, but other SOURCES of biomass can ALSO be USED.

The correct answer is (c) Co-current gasifier

To elaborate: A SOLUTION to the problem of tar entrainment in the gas STREAM has been found by designing co-current or down DRAUGHT gasifiers, in which primary gasification air is introduced at or above the oxidation zone in the gasifier.

The correct choice is (c) NH3

To elaborate: Excess availability of NITROGEN leads to the formation of NH3, the concentration of which inhibits further growth. AMMONIA toxicity can be REMEDIED by low loading or by dilution. So in PRACTICE it is necessary to maintain the levels of nitrogen.

The correct option is (a) High

For explanation I would SAY: The SIZE of the digester DEPENDS upon the loading, which is determined by the influent solids content, retention time and the digester temperature. Optimum loading rates vary with their DIFFERENT digesters and sites of location. Higher loading rates have been used when the ambient temperature is high.

Right option is (d) 8

The explanation is: The COMPLETE anaerobic digestion of cow manure takes about 8 weeks at normally warm temperatures. ONE third of the total BIOGAS will be produced in the first week, another quarter in the second week and the remainder of the biogas production will be spread over the remaining 6 weeks.

The correct option is (a) 6.8 – 8.0

To explain: ANAEROBIC digestion will occur best within a PH range of 6.8 – 8.0. More acidic or basic MIXTURES will ferment at a lower speed. The INTRODUCTION of RAW material will often lower the PH (make the mixture more acidic).

The CORRECT answer is (c) Calvin – Benson CYCLE

Best explanation: The Calvin cycle (also known as the Calvin–Benson cycle) is the set of CHEMICAL reactions that TAKE place in CHLOROPLASTS during photosynthesis. The cycle is light-independent because it takes place after the energy has been captured from sunlight. This cycle is used for the production of carbohydrate.

Right answer is (b) Cross draught GASIFIER

For explanation: It is ACTUALLY the advantage of this SYSTEM that it is capable of handling very small amounts for operation. Installations below 10 KW can under CERTAIN conditions be ECONOMICALLY feasible. The reason is the very simple gas cleaning train which can be employed when using this type of gasifier.

Right option is (c) Nitrogen

The explanation: Cow DUNG is the undigested residue of PLANT matter which has passed through the animal’s gut. The resultant fecal matter is rich in minerals. Color RANGES from greenish to blackish, often darkening soon after EXPOSURE to air. And it is very rich in nitrogen.

Correct answer is (a) 2

The best I can explain: There are two basic types of organic decomposition that can occur: aerobic decomposition (in the presence of oxygen) and anaerobic decomposition (In the ABSENCE of oxygen).All organic MATERIAL, both ANIMAL and VEGETABLE can be broken down by these processes.

Right choice is (a) CARBON FIXATION

Easy explanation: Carbon fixation or Carbon assimilation is the CONVERSION process of inorganic carbon (carbon dioxide) to organic COMPOUNDS by living organisms. The most prominent example is photosynthesis, although chemosynthesis is another form of carbon fixation that can take place in the absence of sunlight.

Correct ANSWER is (a) 16^oC

For EXPLANATION: Anaerobic breakdown of waste occurs at temperatures LYING between 0^oC and 69^oC, but the ACTION of digesting BACTERIA will decrease sharply below 16°C. Production of gas is most rapid between 29^oC and 41^oC.

Right choice is (a) Methane

Explanation: A second TYPE of bacteria in secondary stage of anaerobic fermentation starts to form methane. These methane producing bacteria are particularly influenced by the AMBIENT conditions, which can SLOW or halt the process COMPLETELY if they do not lie within a fairly narrow band.

Correct choice is (a) Aerobic decomposition

The BEST I can EXPLAIN: Aerobic decomposition (fermentation) PROCESS produces carbon dioxide, AMMONIA and other small amounts of gases, heat in large QUANTITIES and a final product that can be used as a fertilizer. Aerobic decomposition is process of decomposition in presence of oxygen.

Correct answer is (c) Co-firing

Explanation: Co-firing refers to mixing BIOMASS with fossil FUELS in CONVENTIONAL power plants. COAL fired power plants can use co-firing systems to significantly reduce emissions, especially sulfur dioxide emissions.

Right choice is (c) Direct firing

Explanation: Most of the BIO power PLANTS are direct fired systems. They burn bio energy feed stocks directly to produce STEAM. This steam drives a TURBINE, which in TURNS a generator that converts the power into electricity.

Correct option is (a) Gasifies

The explanation: The word Gasification implies converting a solid or liquid into a gaseous fuel without leaving any solid CARBONACEOUS residue. GASIFIER is a equipment which can gasify a variety of biomass such as wood waste, agricultural waste like STALKS, and roots of various crops. The gasifier is essentially a chemical reactor where various complex physical and chemical PROCESSES take place.

Correct option is (a) True

Explanation: The anaerobic digestion process can be INHIBITED by several compounds, AFFECTING one or more of the bacterial groups responsible for the different organic MATTER degradation steps. The DEGREE of the inhibition depends, among other factors, on the CONCENTRATION of the inhibitor in the digester. Potential inhibitors are ammonia, sulfide, light metal ions and some organics.

Right ANSWER is (a) Sodium, POTASSIUM, calcium and magnesium

Easiest explanation: SALTS of sodium, potassium, calcium and magnesium may be stimulatory or toxic in action, both manifestations being ASSOCIATED with the cat-ion rather than the anionic portion of the salt. Pesticides and synthetic detergents may also be troublesome to the process.

Correct option is (a) Non return valve

Easiest explanation: A non return valve is a valuable investment to prevent air being drawn into digester, which would destroy the activity of BACTERIA and provided a potentially explosive mixture INSIDE the drum. Larger PLANTS may NEED counterweights of some SORT to ensure that the explosive mixture inside the drum.

The correct option is (b) Anaerobic fermentation

For explanation: Anaerobic process is ESPECIALLY considered as a SUITABLE treatment option DUE to low-energy requirements and little quantities of sludge production. Therefore, anaerobic process has become increasingly demanding in the treatment of COMPLEX industrial WASTES.

Right OPTION is (c) By pumps and pipes

Easiest explanation: SYSTEMS intended for the digestion of liquid or suspended solid WASTE (cow manure is a TYPICAL example of this variety) are mostly filled or EMPTIED using pumps and pipe work. A simple version is simply to gravity feed the tank allow the digested slurry to overflow the tank.

Correct CHOICE is (a) 32 – 35^oC

Best explanation: A temperature between 32 – 35^oC has proven most efficient for stable and continuous PRODUCTION of methane. Biogas PRODUCED OUTSIDE this range will have a higher percentage of carbon DIOXIDE and other gases than within this range.

Correct answer is (a) 30: 1

To elaborate: The bacteria responsible for anaerobic process REQUIRE both elements, as do all living organisms, but they consume carbon roughly 30 times faster than nitrogen. Assuming all other conditions are favorable for biogas production, a carbon – nitrogen RATIO of about 30: 1 is ideal for the raw MATERIAL fed into a biogas plant.